import 'dart:convert';

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:relationship_saver/core/config/app_config.dart';
import 'package:relationship_saver/features/local/chat_preference_extractor.dart';
import 'package:relationship_saver/features/local/local_models.dart';
import 'package:relationship_saver/features/local/storage/local_data_store.dart';
import 'package:relationship_saver/features/local/storage/local_data_store_hive.dart';
import 'package:relationship_saver/features/local/storage/local_data_store_provider.dart';
import 'package:relationship_saver/features/local/storage/local_data_store_shared_prefs.dart';
import 'package:relationship_saver/features/reminders/scheduling/reminder_scheduler_provider.dart';
import 'package:relationship_saver/features/sync/sync_queue_repository.dart';
import 'package:relationship_saver/integrations/backend/models/backend_models.dart';
import 'package:uuid/uuid.dart';

/// Input payload for shared-message ingest flow (e.g. WhatsApp share intent).
class SharedMessageIngestInput {
  const SharedMessageIngestInput({
    required this.sourceApp,
    required this.messageText,
    this.sourceDisplayName,
    this.sourceUserId,
    this.sourceThreadId,
    this.sharedAt,
  });

  final String sourceApp;
  final String messageText;
  final String? sourceDisplayName;
  final String? sourceUserId;
  final String? sourceThreadId;
  final DateTime? sharedAt;
}

/// Result of shared-message ingest with profile resolution metadata.
enum SharedMessageIngestStatus { imported, queuedForResolution }

class SharedMessageIngestResult {
  const SharedMessageIngestResult({
    required this.status,
    required this.createdProfile,
    required this.createdSourceLink,
    this.profileId,
    this.profileName,
    this.momentId,
    this.inboxEntryId,
  });

  const SharedMessageIngestResult.imported({
    required this.profileId,
    required this.profileName,
    required this.createdProfile,
    required this.createdSourceLink,
    required this.momentId,
  }) : status = SharedMessageIngestStatus.imported,
       inboxEntryId = null;

  const SharedMessageIngestResult.queuedForResolution({
    required this.inboxEntryId,
  }) : status = SharedMessageIngestStatus.queuedForResolution,
       createdProfile = false,
       createdSourceLink = false,
       profileId = null,
       profileName = null,
       momentId = null;

  final SharedMessageIngestStatus status;
  final String? profileId;
  final String? profileName;
  final bool createdProfile;
  final bool createdSourceLink;
  final String? momentId;
  final String? inboxEntryId;

  bool get isQueuedForResolution =>
      status == SharedMessageIngestStatus.queuedForResolution;
}

/// Persisted local data source for offline-first product state.
class LocalRepository extends AsyncNotifier<LocalDataState> {
  static const int _schemaVersion = 3;
  static const int _syncSchemaVersion = 1;

  static const Uuid _uuid = Uuid();
  static const ChatPreferenceExtractor _chatPreferenceExtractor =
      ChatPreferenceExtractor();

  @override
  Future<LocalDataState> build() async {
    final LocalDataStore store = ref.read(localDataStoreProvider);
    LocalDataRecord? record = await store.read();

    if ((record == null || record.rawState.isEmpty) &&
        AppConfig.useHiveLocalDb &&
        store is HiveLocalDataStore) {
      final SharedPrefsLocalDataStore legacyStore = SharedPrefsLocalDataStore();
      final LocalDataRecord? legacy = await legacyStore.read();
      if (legacy != null && legacy.rawState.isNotEmpty) {
        await store.write(
          rawState: legacy.rawState,
          schemaVersion: legacy.schemaVersion,
        );
        await legacyStore.clear();
        record = await store.read();
      }
    }

    if (record == null || record.rawState.isEmpty) {
      final LocalDataState seeded = LocalDataState.seed();
      await _persist(seeded);
      await _reconcileReminderSchedule(seeded);
      return seeded;
    }

    final LocalDataRecord migrated = await _migrateIfNeeded(record);
    try {
      final Map<String, dynamic> json =
          jsonDecode(migrated.rawState) as Map<String, dynamic>;
      final LocalDataState loaded = LocalDataState.fromJson(json);
      await _reconcileReminderSchedule(loaded);
      return loaded;
    } on FormatException {
      final LocalDataState fallback = LocalDataState.seed();
      await _persist(fallback);
      await _reconcileReminderSchedule(fallback);
      return fallback;
    }
  }

  Future<void> addPerson({
    required String name,
    required String relationship,
    required String notes,
    required List<String> tags,
    DateTime? nextMoment,
    String? location,
  }) async {
    final String normalizedName = name.trim();
    final String normalizedRelationship = relationship.trim();
    if (normalizedName.isEmpty || normalizedRelationship.isEmpty) {
      throw ArgumentError('Name and relationship are required');
    }

    final LocalDataState current = _requireState();
    final PersonProfile person = PersonProfile(
      id: 'p-${_uuid.v4()}',
      name: normalizedName,
      relationship: normalizedRelationship,
      affinityScore: 75,
      nextMoment: nextMoment ?? DateTime.now().add(const Duration(days: 3)),
      tags: tags,
      notes: notes.trim(),
      location: location?.trim().isEmpty == true ? null : location?.trim(),
    );

    final List<PersonProfile> people = <PersonProfile>[
      person,
      ...current.people,
    ];
    await _setState(current.copyWith(people: people));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'person',
        entityId: person.id,
        op: ChangeOperation.upsert,
        payload: _personPayload(person),
      ),
    );
  }

  Future<SharedMessageIngestResult> ingestSharedMessage(
    SharedMessageIngestInput input,
  ) async {
    final String trimmedMessage = input.messageText.trim();
    if (trimmedMessage.isEmpty) {
      throw ArgumentError('Shared message text cannot be empty');
    }

    final LocalDataState current = _requireState();
    final DateTime now = DateTime.now();
    final DateTime sharedAt = input.sharedAt ?? now;
    final String sourceApp = input.sourceApp.trim().toLowerCase();
    final String? sourceDisplayName = _trimToNull(input.sourceDisplayName);
    final String normalizedDisplayName = _normalizeDisplayName(
      sourceDisplayName,
    );
    final String? sourceUserId = _trimToNull(input.sourceUserId);
    final String? sourceThreadId = _trimToNull(input.sourceThreadId);
    final String? sourceFingerprint = _buildStableSourceFingerprint(
      sourceApp: sourceApp,
      sourceUserId: sourceUserId,
      sourceThreadId: sourceThreadId,
    );

    final SourceProfileLink? matchedLink = _findExistingSourceLink(
      links: current.sourceLinks,
      sourceApp: sourceApp,
      sourceFingerprint: sourceFingerprint,
      sourceUserId: sourceUserId,
      sourceThreadId: sourceThreadId,
      normalizedDisplayName: normalizedDisplayName,
    );

    PersonProfile? resolvedPerson;
    if (matchedLink != null) {
      resolvedPerson = _findPersonById(current.people, matchedLink.profileId);
    }

    final List<PersonProfile> matchingPeople = normalizedDisplayName.isEmpty
        ? const <PersonProfile>[]
        : _findPeopleByNormalizedName(current.people, normalizedDisplayName);

    if (resolvedPerson == null && matchingPeople.length == 1) {
      resolvedPerson = matchingPeople.first;
    }

    if (resolvedPerson == null && matchingPeople.length > 1) {
      return _queueSharedInbox(
        current: current,
        sourceApp: sourceApp,
        messageText: trimmedMessage,
        sharedAt: sharedAt,
        receivedAt: now,
        sourceDisplayName: sourceDisplayName,
        sourceUserId: sourceUserId,
        sourceThreadId: sourceThreadId,
        sourceFingerprint: sourceFingerprint,
        normalizedDisplayName: normalizedDisplayName,
        reason: SharedInboxReason.ambiguousProfileMatch,
        candidateProfileIds: matchingPeople
            .map((PersonProfile person) => person.id)
            .toList(growable: false),
      );
    }

    final List<PersonProfile> nearMatchPeople = resolvedPerson == null
        ? _findNearMatchPeople(
            current.people,
            normalizedDisplayName: normalizedDisplayName,
          )
        : const <PersonProfile>[];
    if (resolvedPerson == null && nearMatchPeople.isNotEmpty) {
      return _queueSharedInbox(
        current: current,
        sourceApp: sourceApp,
        messageText: trimmedMessage,
        sharedAt: sharedAt,
        receivedAt: now,
        sourceDisplayName: sourceDisplayName,
        sourceUserId: sourceUserId,
        sourceThreadId: sourceThreadId,
        sourceFingerprint: sourceFingerprint,
        normalizedDisplayName: normalizedDisplayName,
        reason: SharedInboxReason.nearProfileConflict,
        candidateProfileIds: nearMatchPeople
            .map((PersonProfile person) => person.id)
            .toList(growable: false),
      );
    }

    bool createdProfile = false;
    final List<PersonProfile> nextPeople = current.people.toList(
      growable: true,
    );
    if (resolvedPerson == null) {
      final String? inferredName = _deriveAutoProfileName(
        sourceDisplayName: sourceDisplayName,
        sourceUserId: sourceUserId,
        sourceThreadId: sourceThreadId,
      );
      if (inferredName == null) {
        return _queueSharedInbox(
          current: current,
          sourceApp: sourceApp,
          messageText: trimmedMessage,
          sharedAt: sharedAt,
          receivedAt: now,
          sourceDisplayName: sourceDisplayName,
          sourceUserId: sourceUserId,
          sourceThreadId: sourceThreadId,
          sourceFingerprint: sourceFingerprint,
          normalizedDisplayName: normalizedDisplayName,
          reason: SharedInboxReason.missingIdentity,
          candidateProfileIds: const <String>[],
        );
      }
      createdProfile = true;
      resolvedPerson = PersonProfile(
        id: 'p-${_uuid.v4()}',
        name: inferredName,
        relationship: 'WhatsApp Contact',
        affinityScore: 70,
        nextMoment: DateTime.now().add(const Duration(days: 2)),
        tags: const <String>['whatsapp'],
        notes: 'Auto-created from shared message.',
      );
      nextPeople.insert(0, resolvedPerson);
    }

    return _ingestIntoResolvedProfile(
      current: current,
      sourceApp: sourceApp,
      messageText: trimmedMessage,
      sharedAt: sharedAt,
      importedAt: now,
      sourceDisplayName: sourceDisplayName,
      sourceUserId: sourceUserId,
      sourceThreadId: sourceThreadId,
      sourceFingerprint: sourceFingerprint,
      normalizedDisplayName: normalizedDisplayName,
      resolvedPerson: resolvedPerson,
      matchedLink: matchedLink,
      createdProfile: createdProfile,
      people: nextPeople,
      resolvedAutomatically: true,
    );
  }

  Future<SharedMessageIngestResult> resolveSharedInboxToExistingProfile({
    required String inboxEntryId,
    required String profileId,
  }) async {
    final LocalDataState current = _requireState();
    final SharedInboxEntry entry = _requireSharedInboxEntry(
      current,
      inboxEntryId,
    );
    final PersonProfile? resolvedPerson = _findPersonById(
      current.people,
      profileId,
    );
    if (resolvedPerson == null) {
      throw ArgumentError('Profile not found for inbox entry');
    }

    final SourceProfileLink? matchedLink = _findExistingSourceLink(
      links: current.sourceLinks,
      sourceApp: entry.sourceApp,
      sourceFingerprint: entry.sourceFingerprint,
      sourceUserId: entry.sourceUserId,
      sourceThreadId: entry.sourceThreadId,
      normalizedDisplayName: entry.normalizedDisplayName,
    );

    return _ingestIntoResolvedProfile(
      current: current,
      sourceApp: entry.sourceApp,
      messageText: entry.messageText,
      sharedAt: entry.sharedAt,
      importedAt: DateTime.now(),
      sourceDisplayName: entry.sourceDisplayName,
      sourceUserId: entry.sourceUserId,
      sourceThreadId: entry.sourceThreadId,
      sourceFingerprint: entry.sourceFingerprint,
      normalizedDisplayName: entry.normalizedDisplayName,
      resolvedPerson: resolvedPerson,
      matchedLink: matchedLink,
      createdProfile: false,
      people: current.people,
      resolvedAutomatically: false,
      consumedInboxEntryId: entry.id,
    );
  }

  Future<SharedMessageIngestResult> resolveSharedInboxByCreatingProfile({
    required String inboxEntryId,
    String? name,
    String relationship = 'WhatsApp Contact',
    String? location,
  }) async {
    final LocalDataState current = _requireState();
    final SharedInboxEntry entry = _requireSharedInboxEntry(
      current,
      inboxEntryId,
    );
    final String profileName =
        _trimToNull(name) ??
        _deriveAutoProfileName(
          sourceDisplayName: entry.sourceDisplayName,
          sourceUserId: entry.sourceUserId,
          sourceThreadId: entry.sourceThreadId,
        ) ??
        'WhatsApp Contact';
    final String normalizedRelationship = relationship.trim().isEmpty
        ? 'WhatsApp Contact'
        : relationship.trim();
    final PersonProfile createdPerson = PersonProfile(
      id: 'p-${_uuid.v4()}',
      name: profileName,
      relationship: normalizedRelationship,
      affinityScore: 70,
      nextMoment: DateTime.now().add(const Duration(days: 2)),
      tags: const <String>['whatsapp'],
      notes: 'Created from Share Inbox resolution.',
      location: _trimToNull(location),
    );

    final SourceProfileLink? matchedLink = _findExistingSourceLink(
      links: current.sourceLinks,
      sourceApp: entry.sourceApp,
      sourceFingerprint: entry.sourceFingerprint,
      sourceUserId: entry.sourceUserId,
      sourceThreadId: entry.sourceThreadId,
      normalizedDisplayName: entry.normalizedDisplayName,
    );

    final List<PersonProfile> nextPeople = <PersonProfile>[
      createdPerson,
      ...current.people,
    ];

    return _ingestIntoResolvedProfile(
      current: current,
      sourceApp: entry.sourceApp,
      messageText: entry.messageText,
      sharedAt: entry.sharedAt,
      importedAt: DateTime.now(),
      sourceDisplayName: entry.sourceDisplayName,
      sourceUserId: entry.sourceUserId,
      sourceThreadId: entry.sourceThreadId,
      sourceFingerprint: entry.sourceFingerprint,
      normalizedDisplayName: entry.normalizedDisplayName,
      resolvedPerson: createdPerson,
      matchedLink: matchedLink,
      createdProfile: true,
      people: nextPeople,
      resolvedAutomatically: false,
      consumedInboxEntryId: entry.id,
    );
  }

  Future<void> dismissSharedInboxEntry(String inboxEntryId) async {
    final LocalDataState current = _requireState();
    final List<SharedInboxEntry> nextInbox = current.sharedInbox
        .where((SharedInboxEntry entry) => entry.id != inboxEntryId)
        .toList(growable: false);
    if (nextInbox.length == current.sharedInbox.length) {
      return;
    }
    await _setState(current.copyWith(sharedInbox: nextInbox));
  }

  Future<void> updatePerson(PersonProfile person) async {
    if (person.name.trim().isEmpty || person.relationship.trim().isEmpty) {
      throw ArgumentError('Name and relationship are required');
    }

    final LocalDataState current = _requireState();
    final List<PersonProfile> updated = current.people
        .map((PersonProfile item) => item.id == person.id ? person : item)
        .toList(growable: false);
    await _setState(current.copyWith(people: updated));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'person',
        entityId: person.id,
        op: ChangeOperation.upsert,
        payload: _personPayload(person),
      ),
    );
  }

  Future<void> deletePerson(String personId) async {
    final LocalDataState current = _requireState();
    final List<RelationshipMoment> removedMoments = current.moments
        .where((RelationshipMoment moment) => moment.personId == personId)
        .toList(growable: false);
    final List<RelationshipIdea> removedIdeas = current.ideas
        .where((RelationshipIdea idea) => idea.personId == personId)
        .toList(growable: false);
    final List<ReminderRule> removedReminders = current.reminders
        .where((ReminderRule reminder) => reminder.personId == personId)
        .toList(growable: false);

    final List<PersonProfile> people = current.people
        .where((PersonProfile person) => person.id != personId)
        .toList(growable: false);
    final List<RelationshipMoment> moments = current.moments
        .where((RelationshipMoment moment) => moment.personId != personId)
        .toList(growable: false);
    final List<RelationshipIdea> ideas = current.ideas
        .where((RelationshipIdea idea) => idea.personId != personId)
        .toList(growable: false);
    final List<ReminderRule> reminders = current.reminders
        .where((ReminderRule reminder) => reminder.personId != personId)
        .toList(growable: false);
    final List<PersonPreferenceSignal> preferenceSignals = current
        .preferenceSignals
        .where((PersonPreferenceSignal signal) => signal.personId != personId)
        .toList(growable: false);

    await _setState(
      current.copyWith(
        people: people,
        moments: moments,
        ideas: ideas,
        reminders: reminders,
        preferenceSignals: preferenceSignals,
      ),
    );

    await _enqueueChanges(<ChangeEnvelope>[
      _buildEnvelope(
        entityType: 'person',
        entityId: personId,
        op: ChangeOperation.delete,
      ),
      ...removedMoments.map(
        (RelationshipMoment moment) => _buildEnvelope(
          entityType: 'capture',
          entityId: moment.id,
          op: ChangeOperation.delete,
        ),
      ),
      ...removedIdeas.map(
        (RelationshipIdea idea) => _buildEnvelope(
          entityType: _ideaEntityType(idea.type),
          entityId: idea.id,
          op: ChangeOperation.delete,
        ),
      ),
      ...removedReminders.map(
        (ReminderRule reminder) => _buildEnvelope(
          entityType: 'reminderRule',
          entityId: reminder.id,
          op: ChangeOperation.delete,
        ),
      ),
    ]);
  }

  /// Merge one person profile into another and rebind related records.
  Future<void> mergePersonProfiles({
    required String sourcePersonId,
    required String targetPersonId,
  }) async {
    if (sourcePersonId == targetPersonId) {
      throw ArgumentError('Source and target profile must be different');
    }

    final LocalDataState current = _requireState();
    final PersonProfile? source = _findPersonById(
      current.people,
      sourcePersonId,
    );
    final PersonProfile? target = _findPersonById(
      current.people,
      targetPersonId,
    );
    if (source == null || target == null) {
      throw ArgumentError('Both source and target profiles must exist');
    }

    final PersonProfile mergedTarget = target.copyWith(
      affinityScore: target.affinityScore > source.affinityScore
          ? target.affinityScore
          : source.affinityScore,
      nextMoment: source.nextMoment.isBefore(target.nextMoment)
          ? source.nextMoment
          : target.nextMoment,
      tags: _mergeTags(target.tags, source.tags),
      notes: _mergeNotes(
        targetNotes: target.notes,
        sourceName: source.name,
        sourceNotes: source.notes,
      ),
      location: _effectiveLocation(target.location, source.location),
    );

    final List<PersonProfile> nextPeople = current.people
        .where((PersonProfile person) => person.id != sourcePersonId)
        .map(
          (PersonProfile person) =>
              person.id == targetPersonId ? mergedTarget : person,
        )
        .toList(growable: false);

    final List<RelationshipMoment> updatedMoments = <RelationshipMoment>[];
    final List<RelationshipMoment> nextMoments = current.moments
        .map((RelationshipMoment moment) {
          if (moment.personId != sourcePersonId) {
            return moment;
          }
          final RelationshipMoment merged = moment.copyWith(
            personId: targetPersonId,
          );
          updatedMoments.add(merged);
          return merged;
        })
        .toList(growable: false);

    final List<RelationshipIdea> updatedIdeas = <RelationshipIdea>[];
    final List<RelationshipIdea> nextIdeas = current.ideas
        .map((RelationshipIdea idea) {
          if (idea.personId != sourcePersonId) {
            return idea;
          }
          final RelationshipIdea merged = idea.copyWith(
            personId: targetPersonId,
          );
          updatedIdeas.add(merged);
          return merged;
        })
        .toList(growable: false);

    final List<ReminderRule> updatedReminders = <ReminderRule>[];
    final List<ReminderRule> nextReminders = current.reminders
        .map((ReminderRule reminder) {
          if (reminder.personId != sourcePersonId) {
            return reminder;
          }
          final ReminderRule merged = reminder.copyWith(
            personId: targetPersonId,
          );
          updatedReminders.add(merged);
          return merged;
        })
        .toList(growable: false);

    final List<SourceProfileLink> nextLinks = current.sourceLinks
        .map((SourceProfileLink link) {
          if (link.profileId != sourcePersonId) {
            return link;
          }
          return link.copyWith(profileId: targetPersonId);
        })
        .toList(growable: false);

    final List<SharedMessageEntry> nextMessages = current.sharedMessages
        .map((SharedMessageEntry entry) {
          if (entry.profileId != sourcePersonId) {
            return entry;
          }
          return entry.copyWith(profileId: targetPersonId);
        })
        .toList(growable: false);

    final List<SharedInboxEntry> nextInbox = current.sharedInbox
        .map((SharedInboxEntry entry) {
          if (!entry.candidateProfileIds.contains(sourcePersonId)) {
            return entry;
          }
          final List<String> candidates = entry.candidateProfileIds
              .map(
                (String profileId) =>
                    profileId == sourcePersonId ? targetPersonId : profileId,
              )
              .toSet()
              .toList(growable: false);
          return entry.copyWith(candidateProfileIds: candidates);
        })
        .toList(growable: false);
    final List<PersonPreferenceSignal> nextPreferenceSignals = current
        .preferenceSignals
        .map((PersonPreferenceSignal signal) {
          if (signal.personId != sourcePersonId) {
            return signal;
          }
          return signal.copyWith(personId: targetPersonId);
        })
        .toList(growable: false);

    await _setState(
      current.copyWith(
        people: nextPeople,
        moments: nextMoments,
        ideas: nextIdeas,
        reminders: nextReminders,
        sourceLinks: nextLinks,
        sharedMessages: nextMessages,
        sharedInbox: nextInbox,
        preferenceSignals: nextPreferenceSignals,
      ),
    );

    await _enqueueChanges(<ChangeEnvelope>[
      _buildEnvelope(
        entityType: 'person',
        entityId: mergedTarget.id,
        op: ChangeOperation.upsert,
        payload: _personPayload(mergedTarget),
      ),
      _buildEnvelope(
        entityType: 'person',
        entityId: sourcePersonId,
        op: ChangeOperation.delete,
      ),
      ...updatedMoments.map(
        (RelationshipMoment moment) => _buildEnvelope(
          entityType: 'capture',
          entityId: moment.id,
          op: ChangeOperation.upsert,
          payload: _momentPayload(moment),
        ),
      ),
      ...updatedIdeas.map(
        (RelationshipIdea idea) => _buildEnvelope(
          entityType: _ideaEntityType(idea.type),
          entityId: idea.id,
          op: ChangeOperation.upsert,
          payload: _ideaPayload(idea),
        ),
      ),
      ...updatedReminders.map(
        (ReminderRule reminder) => _buildEnvelope(
          entityType: 'reminderRule',
          entityId: reminder.id,
          op: ChangeOperation.upsert,
          payload: _reminderPayload(reminder),
        ),
      ),
    ]);
  }

  Future<void> addMoment({
    required String personId,
    required String summary,
    String type = 'capture',
  }) async {
    final LocalDataState current = _requireState();
    final String normalized = summary.trim();
    if (normalized.isEmpty) {
      throw ArgumentError('Capture summary cannot be empty');
    }

    final String payload = normalized.length > 280
        ? normalized.substring(0, 280)
        : normalized;
    final String title = _titleFromSummary(payload);
    final RelationshipMoment moment = RelationshipMoment(
      id: 'm-${_uuid.v4()}',
      personId: personId,
      title: title,
      summary: payload,
      at: DateTime.now(),
      type: type,
    );

    final List<RelationshipMoment> moments = <RelationshipMoment>[
      moment,
      ...current.moments,
    ];
    await _setState(current.copyWith(moments: moments));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'capture',
        entityId: moment.id,
        op: ChangeOperation.upsert,
        payload: _momentPayload(moment),
      ),
    );
  }

  Future<void> updateMoment(RelationshipMoment moment) async {
    if (moment.summary.trim().isEmpty) {
      throw ArgumentError('Capture summary cannot be empty');
    }

    final LocalDataState current = _requireState();
    final List<RelationshipMoment> updated = current.moments
        .map((RelationshipMoment item) => item.id == moment.id ? moment : item)
        .toList(growable: false);
    await _setState(current.copyWith(moments: updated));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'capture',
        entityId: moment.id,
        op: ChangeOperation.upsert,
        payload: _momentPayload(moment),
      ),
    );
  }

  Future<void> deleteMoment(String momentId) async {
    final LocalDataState current = _requireState();
    final List<RelationshipMoment> moments = current.moments
        .where((RelationshipMoment moment) => moment.id != momentId)
        .toList(growable: false);
    await _setState(current.copyWith(moments: moments));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'capture',
        entityId: momentId,
        op: ChangeOperation.delete,
      ),
    );
  }

  Future<void> addIdea({
    required IdeaType type,
    required String title,
    required String details,
    String? personId,
  }) async {
    final String normalizedTitle = title.trim();
    if (normalizedTitle.isEmpty) {
      throw ArgumentError('Idea title is required');
    }

    final LocalDataState current = _requireState();
    final RelationshipIdea idea = RelationshipIdea(
      id: 'i-${_uuid.v4()}',
      personId: personId,
      type: type,
      title: normalizedTitle,
      details: details.trim(),
      createdAt: DateTime.now(),
    );

    final List<RelationshipIdea> ideas = <RelationshipIdea>[
      idea,
      ...current.ideas,
    ];
    await _setState(current.copyWith(ideas: ideas));
    await _enqueueChange(
      _buildEnvelope(
        entityType: _ideaEntityType(idea.type),
        entityId: idea.id,
        op: ChangeOperation.upsert,
        payload: _ideaPayload(idea),
      ),
    );
  }

  Future<void> updateIdea(RelationshipIdea idea) async {
    if (idea.title.trim().isEmpty) {
      throw ArgumentError('Idea title is required');
    }

    final LocalDataState current = _requireState();
    final List<RelationshipIdea> ideas = current.ideas
        .map((RelationshipIdea item) => item.id == idea.id ? idea : item)
        .toList(growable: false);
    await _setState(current.copyWith(ideas: ideas));
    await _enqueueChange(
      _buildEnvelope(
        entityType: _ideaEntityType(idea.type),
        entityId: idea.id,
        op: ChangeOperation.upsert,
        payload: _ideaPayload(idea),
      ),
    );
  }

  Future<void> toggleIdeaArchived(String ideaId) async {
    final LocalDataState current = _requireState();
    RelationshipIdea? updatedIdea;
    final List<RelationshipIdea> ideas = current.ideas
        .map((RelationshipIdea item) {
          if (item.id != ideaId) {
            return item;
          }
          final RelationshipIdea toggled = item.copyWith(
            isArchived: !item.isArchived,
          );
          updatedIdea = toggled;
          return toggled;
        })
        .toList(growable: false);
    await _setState(current.copyWith(ideas: ideas));
    if (updatedIdea != null) {
      await _enqueueChange(
        _buildEnvelope(
          entityType: _ideaEntityType(updatedIdea!.type),
          entityId: updatedIdea!.id,
          op: ChangeOperation.upsert,
          payload: _ideaPayload(updatedIdea!),
        ),
      );
    }
  }

  Future<void> deleteIdea(String ideaId) async {
    final LocalDataState current = _requireState();
    final List<RelationshipIdea> ideas = current.ideas
        .where((RelationshipIdea idea) => idea.id != ideaId)
        .toList(growable: false);
    await _setState(current.copyWith(ideas: ideas));
    await _enqueueChange(
      _buildEnvelope(
        entityType: _ideaEntityTypeFromId(current.ideas, ideaId),
        entityId: ideaId,
        op: ChangeOperation.delete,
      ),
    );
  }

  Future<void> addReminder({
    required String title,
    required ReminderCadence cadence,
    required DateTime nextAt,
    String? personId,
  }) async {
    final String normalizedTitle = title.trim();
    if (normalizedTitle.isEmpty) {
      throw ArgumentError('Reminder title is required');
    }

    final LocalDataState current = _requireState();
    final ReminderRule reminder = ReminderRule(
      id: 'r-${_uuid.v4()}',
      personId: personId,
      title: normalizedTitle,
      cadence: cadence,
      nextAt: nextAt,
      enabled: true,
    );

    final List<ReminderRule> reminders = <ReminderRule>[
      reminder,
      ...current.reminders,
    ];
    await _setState(current.copyWith(reminders: reminders));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'reminderRule',
        entityId: reminder.id,
        op: ChangeOperation.upsert,
        payload: _reminderPayload(reminder),
      ),
    );
  }

  Future<void> updateReminder(ReminderRule reminder) async {
    if (reminder.title.trim().isEmpty) {
      throw ArgumentError('Reminder title is required');
    }

    final LocalDataState current = _requireState();
    final List<ReminderRule> reminders = current.reminders
        .map((ReminderRule item) => item.id == reminder.id ? reminder : item)
        .toList(growable: false);
    await _setState(current.copyWith(reminders: reminders));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'reminderRule',
        entityId: reminder.id,
        op: ChangeOperation.upsert,
        payload: _reminderPayload(reminder),
      ),
    );
  }

  Future<void> toggleReminderEnabled(String reminderId) async {
    final LocalDataState current = _requireState();
    ReminderRule? updatedReminder;
    final List<ReminderRule> reminders = current.reminders
        .map((ReminderRule item) {
          if (item.id != reminderId) {
            return item;
          }
          final ReminderRule toggled = item.copyWith(enabled: !item.enabled);
          updatedReminder = toggled;
          return toggled;
        })
        .toList(growable: false);
    await _setState(current.copyWith(reminders: reminders));
    if (updatedReminder != null) {
      await _enqueueChange(
        _buildEnvelope(
          entityType: 'reminderRule',
          entityId: updatedReminder!.id,
          op: ChangeOperation.upsert,
          payload: _reminderPayload(updatedReminder!),
        ),
      );
    }
  }

  Future<void> deleteReminder(String reminderId) async {
    final LocalDataState current = _requireState();
    final List<ReminderRule> reminders = current.reminders
        .where((ReminderRule reminder) => reminder.id != reminderId)
        .toList(growable: false);
    await _setState(current.copyWith(reminders: reminders));
    await _enqueueChange(
      _buildEnvelope(
        entityType: 'reminderRule',
        entityId: reminderId,
        op: ChangeOperation.delete,
      ),
    );
  }

  /// Upserts a profile preference signal observation inferred from chat context.
  ///
  /// This is intentionally local-only for now. We keep inferred signals separate
  /// from manual tags until the user confirms them.
  Future<PersonPreferenceSignal> upsertInferredPreferenceSignalObservation({
    required String personId,
    required String key,
    required String label,
    required String category,
    required PreferenceSignalPolarity polarity,
    required double confidence,
    String? sourceApp,
    String? evidenceMessageId,
    String? evidenceSnippet,
    DateTime? observedAt,
  }) async {
    final LocalDataState current = _requireState();
    final DateTime observed = observedAt ?? DateTime.now();
    final String normalizedKey = _normalizePreferenceKey(key);
    if (normalizedKey.isEmpty) {
      throw ArgumentError('Preference signal key cannot be empty');
    }
    if (!_personExists(current.people, personId)) {
      throw ArgumentError('Profile does not exist for preference signal');
    }

    final int existingIndex = current.preferenceSignals.indexWhere(
      (PersonPreferenceSignal signal) =>
          signal.personId == personId &&
          signal.key == normalizedKey &&
          signal.polarity == polarity,
    );

    final double normalizedConfidence = _clampUnit(confidence);
    final String normalizedLabel = label.trim().isEmpty
        ? normalizedKey
        : label.trim();
    final String normalizedCategory = category.trim().isEmpty
        ? 'general'
        : category.trim().toLowerCase();
    final String? snippet = _trimToNull(evidenceSnippet);
    final String? messageId = _trimToNull(evidenceMessageId);
    final String? source = _trimToNull(sourceApp)?.toLowerCase();

    late final PersonPreferenceSignal nextSignal;
    final List<PersonPreferenceSignal> nextSignals = current.preferenceSignals
        .toList(growable: true);

    if (existingIndex < 0) {
      nextSignal = PersonPreferenceSignal(
        id: 'ps-${_uuid.v4()}',
        personId: personId,
        key: normalizedKey,
        label: normalizedLabel,
        category: normalizedCategory,
        polarity: polarity,
        confidence: normalizedConfidence,
        status: PreferenceSignalStatus.inferred,
        firstSeenAt: observed,
        lastSeenAt: observed,
        occurrenceCount: 1,
        sourceApps: source == null ? const <String>[] : <String>[source],
        evidenceMessageIds: messageId == null
            ? const <String>[]
            : <String>[messageId],
        evidenceSnippets: snippet == null
            ? const <String>[]
            : <String>[snippet],
      );
      nextSignals.insert(0, nextSignal);
    } else {
      final PersonPreferenceSignal existing = nextSignals[existingIndex];
      final int currentCount = existing.occurrenceCount < 1
          ? 1
          : existing.occurrenceCount;
      final int nextCount = currentCount + 1;
      final double mergedConfidence =
          ((existing.confidence * currentCount) + normalizedConfidence) /
          nextCount;
      nextSignal = existing.copyWith(
        label: normalizedLabel,
        category: normalizedCategory,
        confidence: _clampUnit(mergedConfidence),
        lastSeenAt: observed,
        occurrenceCount: nextCount,
        sourceApps: _mergeUniqueStrings(existing.sourceApps, source),
        evidenceMessageIds: _mergeUniqueStrings(
          existing.evidenceMessageIds,
          messageId,
          maxItems: 8,
        ),
        evidenceSnippets: _mergeUniqueStrings(
          existing.evidenceSnippets,
          snippet == null ? null : _truncate(snippet, 220),
          maxItems: 6,
        ),
      );
      nextSignals[existingIndex] = nextSignal;
    }

    await _setState(current.copyWith(preferenceSignals: nextSignals));
    return nextSignal;
  }

  Future<void> upsertPreferenceSignal(PersonPreferenceSignal signal) async {
    final LocalDataState current = _requireState();
    if (!_personExists(current.people, signal.personId)) {
      throw ArgumentError('Profile does not exist for preference signal');
    }
    final List<PersonPreferenceSignal> nextSignals = _upsertItem(
      items: current.preferenceSignals,
      item: signal,
      idOf: (PersonPreferenceSignal value) => value.id,
    );
    await _setState(current.copyWith(preferenceSignals: nextSignals));
  }

  Future<void> setPreferenceSignalStatus({
    required String signalId,
    required PreferenceSignalStatus status,
  }) async {
    final LocalDataState current = _requireState();
    final List<PersonPreferenceSignal> nextSignals = current.preferenceSignals
        .map((PersonPreferenceSignal signal) {
          if (signal.id != signalId) {
            return signal;
          }
          return signal.copyWith(status: status);
        })
        .toList(growable: false);
    await _setState(current.copyWith(preferenceSignals: nextSignals));
  }

  Future<void> confirmPreferenceSignal(String signalId) {
    return setPreferenceSignalStatus(
      signalId: signalId,
      status: PreferenceSignalStatus.confirmed,
    );
  }

  Future<void> dismissPreferenceSignal(String signalId) {
    return setPreferenceSignalStatus(
      signalId: signalId,
      status: PreferenceSignalStatus.dismissed,
    );
  }

  Future<void> toggleTaskDone(String taskId) async {
    final LocalDataState current = _requireState();
    final List<DashboardTask> tasks = current.tasks
        .map(
          (DashboardTask task) =>
              task.id == taskId ? task.copyWith(done: !task.done) : task,
        )
        .toList(growable: false);

    await _setState(current.copyWith(tasks: tasks));
  }

  Future<void> applyRemoteChanges(List<ChangeEnvelope> changes) async {
    if (changes.isEmpty) {
      return;
    }

    LocalDataState next = _requireState();
    for (final ChangeEnvelope change in changes) {
      next = _applyRemoteChange(next, change);
    }
    await _setState(next);
  }

  LocalDataState _applyRemoteChange(
    LocalDataState current,
    ChangeEnvelope change,
  ) {
    switch (change.entityType) {
      case 'person':
        return _applyPersonChange(current, change);
      case 'capture':
        return _applyMomentChange(current, change);
      case 'giftIdea':
      case 'eventIdea':
        return _applyIdeaChange(current, change);
      case 'reminderRule':
        return _applyReminderChange(current, change);
      default:
        return current;
    }
  }

  LocalDataState _applyPersonChange(
    LocalDataState current,
    ChangeEnvelope change,
  ) {
    if (change.op == ChangeOperation.delete) {
      final String personId = change.entityId;
      return current.copyWith(
        people: current.people
            .where((PersonProfile person) => person.id != personId)
            .toList(growable: false),
        moments: current.moments
            .where((RelationshipMoment moment) => moment.personId != personId)
            .toList(growable: false),
        ideas: current.ideas
            .where((RelationshipIdea idea) => idea.personId != personId)
            .toList(growable: false),
        reminders: current.reminders
            .where((ReminderRule reminder) => reminder.personId != personId)
            .toList(growable: false),
        preferenceSignals: current.preferenceSignals
            .where(
              (PersonPreferenceSignal signal) => signal.personId != personId,
            )
            .toList(growable: false),
      );
    }

    final int existingIndex = current.people.indexWhere(
      (PersonProfile person) => person.id == change.entityId,
    );
    final PersonProfile? existing = existingIndex >= 0
        ? current.people[existingIndex]
        : null;
    final Map<String, dynamic> payload = change.payload ?? <String, dynamic>{};
    final PersonProfile next = PersonProfile(
      id: change.entityId,
      name: _stringField(payload, 'name', existing?.name ?? 'Unknown'),
      relationship: _stringField(
        payload,
        'relationship',
        existing?.relationship ?? 'Relationship',
      ),
      affinityScore: _intField(
        payload,
        'affinityScore',
        existing?.affinityScore ?? 70,
      ),
      nextMoment: _dateField(
        payload,
        'nextMoment',
        existing?.nextMoment ?? DateTime.now().add(const Duration(days: 3)),
      ),
      tags: _stringListField(payload, 'tags', existing?.tags ?? <String>[]),
      notes: _stringField(payload, 'notes', existing?.notes ?? ''),
      location: _stringOrNullField(payload, 'location', existing?.location),
    );
    final List<PersonProfile> people = _upsertItem(
      items: current.people,
      item: next,
      idOf: (PersonProfile person) => person.id,
    );
    return current.copyWith(people: people);
  }

  LocalDataState _applyMomentChange(
    LocalDataState current,
    ChangeEnvelope change,
  ) {
    if (change.op == ChangeOperation.delete) {
      return current.copyWith(
        moments: current.moments
            .where((RelationshipMoment moment) => moment.id != change.entityId)
            .toList(growable: false),
      );
    }

    final int existingIndex = current.moments.indexWhere(
      (RelationshipMoment moment) => moment.id == change.entityId,
    );
    final RelationshipMoment? existing = existingIndex >= 0
        ? current.moments[existingIndex]
        : null;
    final Map<String, dynamic> payload = change.payload ?? <String, dynamic>{};
    final String summary = _stringField(
      payload,
      'summary',
      existing?.summary ?? '',
    );
    final RelationshipMoment next = RelationshipMoment(
      id: change.entityId,
      personId: _stringField(
        payload,
        'personId',
        existing?.personId ??
            (current.people.isEmpty
                ? 'person-unknown'
                : current.people.first.id),
      ),
      title: _stringField(
        payload,
        'title',
        existing?.title ?? _titleFromSummary(summary),
      ),
      summary: summary,
      at: _dateField(payload, 'at', existing?.at ?? DateTime.now()),
      type: _stringField(payload, 'type', existing?.type ?? 'capture'),
    );
    final List<RelationshipMoment> moments = _upsertItem(
      items: current.moments,
      item: next,
      idOf: (RelationshipMoment moment) => moment.id,
    );
    return current.copyWith(moments: moments);
  }

  LocalDataState _applyIdeaChange(
    LocalDataState current,
    ChangeEnvelope change,
  ) {
    if (change.op == ChangeOperation.delete) {
      return current.copyWith(
        ideas: current.ideas
            .where((RelationshipIdea idea) => idea.id != change.entityId)
            .toList(growable: false),
      );
    }

    final int existingIndex = current.ideas.indexWhere(
      (RelationshipIdea idea) => idea.id == change.entityId,
    );
    final RelationshipIdea? existing = existingIndex >= 0
        ? current.ideas[existingIndex]
        : null;
    final Map<String, dynamic> payload = change.payload ?? <String, dynamic>{};
    final IdeaType fallbackType = _ideaTypeFromEntityType(
      change.entityType,
      fallback: existing?.type ?? IdeaType.gift,
    );
    final IdeaType type = _ideaTypeFromRaw(
      payload['type'],
      fallback: fallbackType,
    );
    final RelationshipIdea next = RelationshipIdea(
      id: change.entityId,
      personId: payload['personId'] as String? ?? existing?.personId,
      type: type,
      title: _stringField(payload, 'title', existing?.title ?? 'Untitled idea'),
      details: _stringField(payload, 'details', existing?.details ?? ''),
      createdAt: _dateField(
        payload,
        'createdAt',
        existing?.createdAt ?? DateTime.now(),
      ),
      isArchived: _boolField(
        payload,
        'isArchived',
        existing?.isArchived ?? false,
      ),
    );
    final List<RelationshipIdea> ideas = _upsertItem(
      items: current.ideas,
      item: next,
      idOf: (RelationshipIdea idea) => idea.id,
    );
    return current.copyWith(ideas: ideas);
  }

  LocalDataState _applyReminderChange(
    LocalDataState current,
    ChangeEnvelope change,
  ) {
    if (change.op == ChangeOperation.delete) {
      return current.copyWith(
        reminders: current.reminders
            .where((ReminderRule reminder) => reminder.id != change.entityId)
            .toList(growable: false),
      );
    }

    final int existingIndex = current.reminders.indexWhere(
      (ReminderRule reminder) => reminder.id == change.entityId,
    );
    final ReminderRule? existing = existingIndex >= 0
        ? current.reminders[existingIndex]
        : null;
    final Map<String, dynamic> payload = change.payload ?? <String, dynamic>{};
    final ReminderRule next = ReminderRule(
      id: change.entityId,
      personId: payload['personId'] as String? ?? existing?.personId,
      title: _stringField(payload, 'title', existing?.title ?? 'Reminder'),
      cadence: _cadenceFromRaw(
        payload['cadence'],
        fallback: existing?.cadence ?? ReminderCadence.weekly,
      ),
      nextAt: _dateField(payload, 'nextAt', existing?.nextAt ?? DateTime.now()),
      enabled: _boolField(payload, 'enabled', existing?.enabled ?? true),
    );
    final List<ReminderRule> reminders = _upsertItem(
      items: current.reminders,
      item: next,
      idOf: (ReminderRule reminder) => reminder.id,
    );
    return current.copyWith(reminders: reminders);
  }

  Future<void> _enqueueChange(ChangeEnvelope change) async {
    await ref.read(syncQueueRepositoryProvider.notifier).enqueue(change);
  }

  Future<void> _enqueueChanges(List<ChangeEnvelope> changes) async {
    await ref.read(syncQueueRepositoryProvider.notifier).enqueueAll(changes);
  }

  ChangeEnvelope _buildEnvelope({
    required String entityType,
    required String entityId,
    required ChangeOperation op,
    Map<String, dynamic>? payload,
  }) {
    return ChangeEnvelope(
      schemaVersion: _syncSchemaVersion,
      entityType: entityType,
      entityId: entityId,
      op: op,
      modifiedAt: DateTime.now().toUtc(),
      clientMutationId: _uuid.v4(),
      payload: payload,
    );
  }

  Map<String, dynamic> _personPayload(PersonProfile person) {
    return <String, dynamic>{
      'name': person.name,
      'relationship': person.relationship,
      'affinityScore': person.affinityScore,
      'nextMoment': person.nextMoment.toUtc().toIso8601String(),
      'tags': person.tags,
      'notes': person.notes,
      'location': person.location,
    };
  }

  Map<String, dynamic> _momentPayload(RelationshipMoment moment) {
    return <String, dynamic>{
      'personId': moment.personId,
      'title': moment.title,
      'summary': moment.summary,
      'at': moment.at.toUtc().toIso8601String(),
      'type': moment.type,
    };
  }

  Map<String, dynamic> _ideaPayload(RelationshipIdea idea) {
    return <String, dynamic>{
      'personId': idea.personId,
      'type': idea.type.name,
      'title': idea.title,
      'details': idea.details,
      'createdAt': idea.createdAt.toUtc().toIso8601String(),
      'isArchived': idea.isArchived,
    };
  }

  Map<String, dynamic> _reminderPayload(ReminderRule reminder) {
    return <String, dynamic>{
      'personId': reminder.personId,
      'title': reminder.title,
      'cadence': reminder.cadence.name,
      'nextAt': reminder.nextAt.toUtc().toIso8601String(),
      'enabled': reminder.enabled,
    };
  }

  String _ideaEntityType(IdeaType type) {
    return type == IdeaType.event ? 'eventIdea' : 'giftIdea';
  }

  String _ideaEntityTypeFromId(List<RelationshipIdea> ideas, String ideaId) {
    final int index = ideas.indexWhere(
      (RelationshipIdea idea) => idea.id == ideaId,
    );
    final RelationshipIdea? existing = index >= 0 ? ideas[index] : null;
    if (existing == null) {
      return 'giftIdea';
    }
    return _ideaEntityType(existing.type);
  }

  IdeaType _ideaTypeFromEntityType(
    String entityType, {
    required IdeaType fallback,
  }) {
    switch (entityType) {
      case 'eventIdea':
        return IdeaType.event;
      case 'giftIdea':
        return IdeaType.gift;
      default:
        return fallback;
    }
  }

  IdeaType _ideaTypeFromRaw(dynamic value, {required IdeaType fallback}) {
    if (value is! String || value.isEmpty) {
      return fallback;
    }

    return IdeaType.values.firstWhere(
      (IdeaType type) => type.name == value,
      orElse: () => fallback,
    );
  }

  ReminderCadence _cadenceFromRaw(
    dynamic value, {
    required ReminderCadence fallback,
  }) {
    if (value is! String || value.isEmpty) {
      return fallback;
    }

    return ReminderCadence.values.firstWhere(
      (ReminderCadence cadence) => cadence.name == value,
      orElse: () => fallback,
    );
  }

  List<T> _upsertItem<T>({
    required List<T> items,
    required T item,
    required String Function(T value) idOf,
  }) {
    final int index = items.indexWhere((T value) => idOf(value) == idOf(item));
    if (index < 0) {
      return <T>[item, ...items];
    }

    final List<T> copy = items.toList();
    copy[index] = item;
    return copy;
  }

  String _stringField(
    Map<String, dynamic> payload,
    String key,
    String fallback,
  ) {
    final dynamic value = payload[key];
    if (value is String && value.trim().isNotEmpty) {
      return value.trim();
    }
    return fallback;
  }

  String? _stringOrNullField(
    Map<String, dynamic> payload,
    String key,
    String? fallback,
  ) {
    final dynamic value = payload[key];
    if (value is String) {
      final String trimmed = value.trim();
      if (trimmed.isNotEmpty) {
        return trimmed;
      }
      return null;
    }
    return fallback;
  }

  int _intField(Map<String, dynamic> payload, String key, int fallback) {
    final dynamic value = payload[key];
    if (value is int) {
      return value;
    }
    if (value is num) {
      return value.toInt();
    }
    return fallback;
  }

  bool _boolField(Map<String, dynamic> payload, String key, bool fallback) {
    final dynamic value = payload[key];
    if (value is bool) {
      return value;
    }
    return fallback;
  }

  List<String> _stringListField(
    Map<String, dynamic> payload,
    String key,
    List<String> fallback,
  ) {
    final dynamic value = payload[key];
    if (value is! List<dynamic>) {
      return fallback;
    }

    return value.map((dynamic item) => '$item').toList(growable: false);
  }

  DateTime _dateField(
    Map<String, dynamic> payload,
    String key,
    DateTime fallback,
  ) {
    final dynamic value = payload[key];
    if (value is String) {
      final DateTime? parsed = DateTime.tryParse(value);
      if (parsed != null) {
        return parsed.toLocal();
      }
    }
    return fallback;
  }

  bool _personExists(List<PersonProfile> people, String personId) {
    return people.any((PersonProfile person) => person.id == personId);
  }

  String _normalizePreferenceKey(String value) {
    return value
        .trim()
        .toLowerCase()
        .replaceAll(RegExp(r'[^a-z0-9:_ -]+'), '')
        .replaceAll(RegExp(r'\s+'), ' ');
  }

  double _clampUnit(double value) {
    if (value.isNaN) {
      return 0;
    }
    return value.clamp(0.0, 1.0).toDouble();
  }

  List<String> _mergeUniqueStrings(
    List<String> existing,
    String? incoming, {
    int maxItems = 12,
  }) {
    final List<String> values = <String>[];
    final Set<String> seen = <String>{};

    for (final String raw in existing) {
      final String value = raw.trim();
      if (value.isEmpty) {
        continue;
      }
      final String key = value.toLowerCase();
      if (seen.add(key)) {
        values.add(value);
      }
    }

    final String? newValue = _trimToNull(incoming);
    if (newValue != null) {
      final String key = newValue.toLowerCase();
      if (!seen.contains(key)) {
        values.insert(0, newValue);
      }
    }

    if (values.length <= maxItems) {
      return values;
    }
    return values.take(maxItems).toList(growable: false);
  }

  String _truncate(String value, int maxChars) {
    if (value.length <= maxChars) {
      return value;
    }
    return value.substring(0, maxChars);
  }

  Future<void> _setState(LocalDataState next) async {
    state = AsyncData<LocalDataState>(next);
    await _persist(next);
    await _reconcileReminderSchedule(next);
  }

  LocalDataState _requireState() {
    final LocalDataState? value = state.asData?.value;
    if (value == null) {
      throw StateError('Local data state is not ready yet');
    }
    return value;
  }

  Future<void> _persist(LocalDataState state) async {
    await ref
        .read(localDataStoreProvider)
        .write(
          rawState: jsonEncode(state.toJson()),
          schemaVersion: _schemaVersion,
        );
  }

  Future<void> _reconcileReminderSchedule(LocalDataState state) async {
    try {
      await ref.read(reminderSchedulerProvider).reconcile(state.reminders);
    } catch (_) {
      // Scheduling failures must not block local-first data updates.
    }
  }

  Future<LocalDataRecord> _migrateIfNeeded(LocalDataRecord record) async {
    final int currentVersion = record.schemaVersion;
    if (currentVersion == _schemaVersion) {
      return record;
    }

    final LocalDataStore store = ref.read(localDataStoreProvider);
    if (currentVersion <= 0) {
      final LocalDataState seeded = LocalDataState.seed();
      await store.clear();
      await _persist(seeded);
      return LocalDataRecord(
        rawState: jsonEncode(seeded.toJson()),
        schemaVersion: _schemaVersion,
      );
    }

    // Migration placeholder for future schema versions.
    await store.write(rawState: record.rawState, schemaVersion: _schemaVersion);
    return LocalDataRecord(
      rawState: record.rawState,
      schemaVersion: _schemaVersion,
    );
  }

  List<String> _mergeTags(List<String> primary, List<String> secondary) {
    final List<String> merged = <String>[];
    final Set<String> seen = <String>{};
    for (final String raw in <String>[...primary, ...secondary]) {
      final String tag = raw.trim();
      if (tag.isEmpty) {
        continue;
      }
      final String normalized = tag.toLowerCase();
      if (seen.add(normalized)) {
        merged.add(tag);
      }
    }
    return merged;
  }

  String _mergeNotes({
    required String targetNotes,
    required String sourceName,
    required String sourceNotes,
  }) {
    final String target = targetNotes.trim();
    final String source = sourceNotes.trim();
    if (target.isEmpty) {
      return source;
    }
    if (source.isEmpty) {
      return target;
    }
    if (target == source) {
      return target;
    }
    return '$target\n\nMerged from $sourceName:\n$source';
  }

  String? _effectiveLocation(String? target, String? source) {
    final String? targetValue = _trimToNull(target);
    if (targetValue != null) {
      return targetValue;
    }
    return _trimToNull(source);
  }

  Future<SharedMessageIngestResult> _queueSharedInbox({
    required LocalDataState current,
    required String sourceApp,
    required String messageText,
    required DateTime sharedAt,
    required DateTime receivedAt,
    required SharedInboxReason reason,
    required List<String> candidateProfileIds,
    required String normalizedDisplayName,
    String? sourceFingerprint,
    String? sourceDisplayName,
    String? sourceUserId,
    String? sourceThreadId,
  }) async {
    final String summary = messageText.length > 1800
        ? messageText.substring(0, 1800)
        : messageText;
    final SharedInboxEntry entry = SharedInboxEntry(
      id: 'si-${_uuid.v4()}',
      sourceApp: sourceApp,
      messageText: summary,
      sharedAt: sharedAt,
      receivedAt: receivedAt,
      reason: reason,
      candidateProfileIds: candidateProfileIds,
      normalizedDisplayName: normalizedDisplayName,
      sourceFingerprint: sourceFingerprint,
      sourceDisplayName: sourceDisplayName,
      sourceUserId: sourceUserId,
      sourceThreadId: sourceThreadId,
    );
    final List<SharedInboxEntry> nextInbox = <SharedInboxEntry>[
      entry,
      ...current.sharedInbox,
    ];
    await _setState(current.copyWith(sharedInbox: nextInbox));
    return SharedMessageIngestResult.queuedForResolution(
      inboxEntryId: entry.id,
    );
  }

  Future<SharedMessageIngestResult> _ingestIntoResolvedProfile({
    required LocalDataState current,
    required String sourceApp,
    required String messageText,
    required DateTime sharedAt,
    required DateTime importedAt,
    required String normalizedDisplayName,
    required String? sourceFingerprint,
    required PersonProfile resolvedPerson,
    required bool createdProfile,
    required List<PersonProfile> people,
    required bool resolvedAutomatically,
    SourceProfileLink? matchedLink,
    String? sourceDisplayName,
    String? sourceUserId,
    String? sourceThreadId,
    String? consumedInboxEntryId,
  }) async {
    final bool createdSourceLink = matchedLink == null;
    final List<SourceProfileLink> nextLinks = current.sourceLinks.toList(
      growable: true,
    );
    if (matchedLink == null) {
      nextLinks.insert(
        0,
        SourceProfileLink(
          id: 'sl-${_uuid.v4()}',
          sourceApp: sourceApp,
          sourceUserId: sourceUserId,
          sourceThreadId: sourceThreadId,
          sourceFingerprint: sourceFingerprint,
          normalizedDisplayName: normalizedDisplayName,
          profileId: resolvedPerson.id,
          firstSeenAt: sharedAt,
          lastSeenAt: sharedAt,
        ),
      );
    } else {
      final int index = nextLinks.indexWhere(
        (SourceProfileLink link) => link.id == matchedLink.id,
      );
      if (index >= 0) {
        nextLinks[index] = matchedLink.copyWith(
          sourceUserId: sourceUserId ?? matchedLink.sourceUserId,
          sourceThreadId: sourceThreadId ?? matchedLink.sourceThreadId,
          sourceFingerprint: sourceFingerprint ?? matchedLink.sourceFingerprint,
          normalizedDisplayName: normalizedDisplayName.isEmpty
              ? matchedLink.normalizedDisplayName
              : normalizedDisplayName,
          profileId: resolvedPerson.id,
          lastSeenAt: sharedAt,
        );
      }
    }

    final String summary = messageText.length > 1800
        ? messageText.substring(0, 1800)
        : messageText;
    final RelationshipMoment moment = RelationshipMoment(
      id: 'm-${_uuid.v4()}',
      personId: resolvedPerson.id,
      title: _titleFromSummary(summary),
      summary: summary,
      at: sharedAt,
      type: sourceApp == 'whatsapp' ? 'whatsapp' : 'shared',
    );

    final List<RelationshipMoment> nextMoments = <RelationshipMoment>[
      moment,
      ...current.moments,
    ];
    final SharedMessageEntry sharedEntry = SharedMessageEntry(
      id: 'sm-${_uuid.v4()}',
      sourceApp: sourceApp,
      profileId: resolvedPerson.id,
      messageText: summary,
      sharedAt: sharedAt,
      importedAt: importedAt,
      resolvedAutomatically: resolvedAutomatically,
      sourceDisplayName: sourceDisplayName,
      sourceUserId: sourceUserId,
      sourceThreadId: sourceThreadId,
    );
    final List<SharedMessageEntry> nextMessages = <SharedMessageEntry>[
      sharedEntry,
      ...current.sharedMessages,
    ];
    final List<SharedInboxEntry> nextInbox = consumedInboxEntryId == null
        ? current.sharedInbox
        : current.sharedInbox
              .where(
                (SharedInboxEntry entry) => entry.id != consumedInboxEntryId,
              )
              .toList(growable: false);

    await _setState(
      current.copyWith(
        people: people,
        moments: nextMoments,
        sourceLinks: nextLinks,
        sharedMessages: nextMessages,
        sharedInbox: nextInbox,
      ),
    );

    final List<ChangeEnvelope> outbound = <ChangeEnvelope>[
      if (createdProfile)
        _buildEnvelope(
          entityType: 'person',
          entityId: resolvedPerson.id,
          op: ChangeOperation.upsert,
          payload: _personPayload(resolvedPerson),
        ),
      _buildEnvelope(
        entityType: 'capture',
        entityId: moment.id,
        op: ChangeOperation.upsert,
        payload: _momentPayload(moment),
      ),
    ];
    await _enqueueChanges(outbound);

    final List<ExtractedPreferenceSignalCandidate> extractedSignals =
        _chatPreferenceExtractor.extract(summary);
    for (final ExtractedPreferenceSignalCandidate candidate
        in extractedSignals) {
      await upsertInferredPreferenceSignalObservation(
        personId: resolvedPerson.id,
        key: candidate.key,
        label: candidate.label,
        category: candidate.category,
        polarity: candidate.polarity,
        confidence: candidate.confidence,
        sourceApp: sourceApp,
        evidenceMessageId: sharedEntry.id,
        evidenceSnippet: candidate.evidenceSnippet,
        observedAt: sharedAt,
      );
    }

    return SharedMessageIngestResult.imported(
      profileId: resolvedPerson.id,
      profileName: resolvedPerson.name,
      createdProfile: createdProfile,
      createdSourceLink: createdSourceLink,
      momentId: moment.id,
    );
  }

  String _titleFromSummary(String summary) {
    final List<String> words = summary.split(RegExp(r'\s+'));
    final int take = words.length < 5 ? words.length : 5;
    return words.take(take).join(' ');
  }

  SourceProfileLink? _findExistingSourceLink({
    required List<SourceProfileLink> links,
    required String sourceApp,
    required String? sourceFingerprint,
    required String? sourceUserId,
    required String? sourceThreadId,
    required String normalizedDisplayName,
  }) {
    if (sourceFingerprint != null && sourceFingerprint.isNotEmpty) {
      for (final SourceProfileLink link in links) {
        final String? linkFingerprint =
            link.sourceFingerprint ??
            _buildStableSourceFingerprint(
              sourceApp: link.sourceApp,
              sourceUserId: link.sourceUserId,
              sourceThreadId: link.sourceThreadId,
            );
        if (link.sourceApp == sourceApp &&
            linkFingerprint == sourceFingerprint) {
          return link;
        }
      }
    }

    if (sourceUserId != null && sourceUserId.isNotEmpty) {
      for (final SourceProfileLink link in links) {
        if (link.sourceApp == sourceApp && link.sourceUserId == sourceUserId) {
          return link;
        }
      }
    }

    if (sourceThreadId != null && sourceThreadId.isNotEmpty) {
      for (final SourceProfileLink link in links) {
        if (link.sourceApp == sourceApp &&
            link.sourceThreadId == sourceThreadId) {
          return link;
        }
      }
    }

    if (normalizedDisplayName.isNotEmpty) {
      for (final SourceProfileLink link in links) {
        if (link.sourceApp == sourceApp &&
            link.normalizedDisplayName == normalizedDisplayName) {
          return link;
        }
      }
    }

    return null;
  }

  PersonProfile? _findPersonById(List<PersonProfile> people, String id) {
    for (final PersonProfile person in people) {
      if (person.id == id) {
        return person;
      }
    }
    return null;
  }

  List<PersonProfile> _findPeopleByNormalizedName(
    List<PersonProfile> people,
    String normalizedDisplayName,
  ) {
    return people
        .where(
          (PersonProfile person) =>
              _normalizeDisplayName(person.name) == normalizedDisplayName,
        )
        .toList(growable: false);
  }

  List<PersonProfile> _findNearMatchPeople(
    List<PersonProfile> people, {
    required String normalizedDisplayName,
  }) {
    if (normalizedDisplayName.isEmpty) {
      return const <PersonProfile>[];
    }

    final Map<String, int> distanceById = <String, int>{};
    final List<PersonProfile> candidates = <PersonProfile>[];
    for (final PersonProfile person in people) {
      final String personName = _normalizeDisplayName(person.name);
      if (personName.isEmpty || personName == normalizedDisplayName) {
        continue;
      }
      final int distance = _levenshteinDistance(
        normalizedDisplayName,
        personName,
      );
      if (_isNearDisplayName(
        normalizedDisplayName,
        personName,
        distance: distance,
      )) {
        distanceById[person.id] = distance;
        candidates.add(person);
      }
    }

    candidates.sort((PersonProfile a, PersonProfile b) {
      final int left = distanceById[a.id] ?? 999;
      final int right = distanceById[b.id] ?? 999;
      if (left != right) {
        return left.compareTo(right);
      }
      return a.name.length.compareTo(b.name.length);
    });
    if (candidates.length <= 5) {
      return candidates;
    }
    return candidates.take(5).toList(growable: false);
  }

  bool _isNearDisplayName(String left, String right, {required int distance}) {
    final int maxLength = left.length > right.length
        ? left.length
        : right.length;
    final int minLength = left.length < right.length
        ? left.length
        : right.length;
    if (minLength >= 4 && (left.contains(right) || right.contains(left))) {
      return true;
    }
    final int threshold = maxLength >= 14 ? 3 : 2;
    if (distance <= threshold) {
      return true;
    }
    return maxLength >= 8 && (distance / maxLength) <= 0.22;
  }

  int _levenshteinDistance(String left, String right) {
    if (left == right) {
      return 0;
    }
    if (left.isEmpty) {
      return right.length;
    }
    if (right.isEmpty) {
      return left.length;
    }

    List<int> previous = List<int>.generate(
      right.length + 1,
      (int index) => index,
      growable: false,
    );
    for (int i = 1; i <= left.length; i += 1) {
      final List<int> current = List<int>.filled(right.length + 1, 0);
      current[0] = i;
      for (int j = 1; j <= right.length; j += 1) {
        final int substitutionCost = left[i - 1] == right[j - 1] ? 0 : 1;
        final int deletion = previous[j] + 1;
        final int insertion = current[j - 1] + 1;
        final int substitution = previous[j - 1] + substitutionCost;
        final int value = deletion < insertion ? deletion : insertion;
        current[j] = value < substitution ? value : substitution;
      }
      previous = current;
    }
    return previous[right.length];
  }

  SharedInboxEntry _requireSharedInboxEntry(
    LocalDataState current,
    String inboxEntryId,
  ) {
    for (final SharedInboxEntry entry in current.sharedInbox) {
      if (entry.id == inboxEntryId) {
        return entry;
      }
    }
    throw ArgumentError('Shared inbox entry not found');
  }

  String? _deriveAutoProfileName({
    required String? sourceDisplayName,
    required String? sourceUserId,
    required String? sourceThreadId,
  }) {
    return _trimToNull(sourceDisplayName) ??
        _trimToNull(sourceUserId) ??
        _trimToNull(sourceThreadId);
  }

  String? _buildStableSourceFingerprint({
    required String sourceApp,
    required String? sourceUserId,
    required String? sourceThreadId,
  }) {
    final String? userId = _trimToNull(sourceUserId);
    final String? threadId = _trimToNull(sourceThreadId);
    if (userId == null && threadId == null) {
      return null;
    }

    final List<String> parts = <String>[
      sourceApp.trim().toLowerCase(),
      if (userId != null) 'u:${userId.toLowerCase()}',
      if (threadId != null) 't:${threadId.toLowerCase()}',
    ];
    return parts.join('|');
  }

  String _normalizeDisplayName(String? raw) {
    if (raw == null) {
      return '';
    }
    final String compact = raw
        .toLowerCase()
        .replaceAll(RegExp(r'[^a-z0-9]+'), ' ')
        .trim();
    return compact.replaceAll(RegExp(r'\s+'), ' ');
  }

  String? _trimToNull(String? value) {
    if (value == null) {
      return null;
    }
    final String trimmed = value.trim();
    return trimmed.isEmpty ? null : trimmed;
  }
}

final AsyncNotifierProvider<LocalRepository, LocalDataState>
localRepositoryProvider =
    AsyncNotifierProvider<LocalRepository, LocalDataState>(LocalRepository.new);