import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:relationship_saver/core/config/app_theme.dart';
import 'package:relationship_saver/features/local/local_models.dart';
import 'package:relationship_saver/features/local/local_repository.dart';
import 'package:relationship_saver/features/shared/frosted_card.dart';

class SelectedPersonIdNotifier extends Notifier<String?> {
  @override
  String? build() => null;

  void select(String id) {
    state = id;
  }

  void clear() {
    state = null;
  }
}

final NotifierProvider<SelectedPersonIdNotifier, String?>
selectedPersonIdProvider = NotifierProvider<SelectedPersonIdNotifier, String?>(
  SelectedPersonIdNotifier.new,
);

class PeopleView extends ConsumerWidget {
  const PeopleView({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final AsyncValue<LocalDataState> localData = ref.watch(
      localRepositoryProvider,
    );

    return localData.when(
      data: (LocalDataState data) {
        final List<PersonProfile> people = data.people;
        if (people.isEmpty) {
          return _EmptyPeopleView(onAdd: () => _handleAddPerson(context, ref));
        }

        final String selectedId =
            ref.watch(selectedPersonIdProvider) ?? people.first.id;
        final PersonProfile selected = people.firstWhere(
          (PersonProfile person) => person.id == selectedId,
          orElse: () => people.first,
        );

        return LayoutBuilder(
          builder: (BuildContext context, BoxConstraints constraints) {
            final bool isCompact = constraints.maxWidth < 860;
            if (isCompact) {
              return _buildCompactLayout(context, ref, people, selected);
            }
            return _buildWideLayout(context, ref, people, selected);
          },
        );
      },
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (Object error, StackTrace stackTrace) {
        return const Center(child: Text('Unable to load people'));
      },
    );
  }

  Future<void> _handleAddPerson(BuildContext context, WidgetRef ref) async {
    final _PersonDraft? draft = await showDialog<_PersonDraft>(
      context: context,
      builder: (BuildContext context) =>
          const _PersonEditorDialog(title: 'Add Person'),
    );

    if (draft == null) {
      return;
    }

    await ref
        .read(localRepositoryProvider.notifier)
        .addPerson(
          name: draft.name,
          relationship: draft.relationship,
          notes: draft.notes,
          tags: draft.tags,
        );
  }

  Future<void> _handleEditPerson(
    BuildContext context,
    WidgetRef ref,
    PersonProfile person,
  ) async {
    final _PersonDraft? draft = await showDialog<_PersonDraft>(
      context: context,
      builder: (BuildContext context) => _PersonEditorDialog(
        title: 'Edit Person',
        initial: _PersonDraft(
          name: person.name,
          relationship: person.relationship,
          notes: person.notes,
          tags: person.tags,
        ),
      ),
    );

    if (draft == null) {
      return;
    }

    await ref
        .read(localRepositoryProvider.notifier)
        .updatePerson(
          person.copyWith(
            name: draft.name,
            relationship: draft.relationship,
            notes: draft.notes,
            tags: draft.tags,
          ),
        );
  }

  Future<void> _handleDeletePerson(
    BuildContext context,
    WidgetRef ref,
    String personId,
  ) async {
    final bool? confirmed = await showDialog<bool>(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: const Text('Delete person?'),
          content: const Text(
            'This will remove the person and related moments from local storage.',
          ),
          actions: <Widget>[
            TextButton(
              onPressed: () => Navigator.of(context).pop(false),
              child: const Text('Cancel'),
            ),
            FilledButton(
              onPressed: () => Navigator.of(context).pop(true),
              child: const Text('Delete'),
            ),
          ],
        );
      },
    );

    if (confirmed != true) {
      return;
    }

    await ref.read(localRepositoryProvider.notifier).deletePerson(personId);
    ref.read(selectedPersonIdProvider.notifier).clear();
  }

  Widget _buildWideLayout(
    BuildContext context,
    WidgetRef ref,
    List<PersonProfile> people,
    PersonProfile selected,
  ) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(28, 24, 28, 28),
      child: Row(
        children: <Widget>[
          Expanded(
            flex: 5,
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: <Widget>[
                _PeopleHeader(
                  onAdd: () => _handleAddPerson(context, ref),
                  compact: false,
                ),
                const SizedBox(height: 20),
                Expanded(
                  child: ListView.separated(
                    itemCount: people.length,
                    separatorBuilder: (_, _) => const SizedBox(height: 12),
                    itemBuilder: (BuildContext context, int index) {
                      final PersonProfile person = people[index];
                      return _PersonListItem(
                        person: person,
                        selectedId: selected.id,
                        onSelect: () {
                          ref
                              .read(selectedPersonIdProvider.notifier)
                              .select(person.id);
                        },
                      );
                    },
                  ),
                ),
              ],
            ),
          ),
          const SizedBox(width: 18),
          Expanded(
            flex: 6,
            child: FrostedCard(
              child: _PersonDetail(
                person: selected,
                onEdit: () => _handleEditPerson(context, ref, selected),
                onDelete: () => _handleDeletePerson(context, ref, selected.id),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildCompactLayout(
    BuildContext context,
    WidgetRef ref,
    List<PersonProfile> people,
    PersonProfile selected,
  ) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(18, 16, 18, 20),
      child: ListView(
        children: <Widget>[
          _PeopleHeader(
            onAdd: () => _handleAddPerson(context, ref),
            compact: true,
          ),
          const SizedBox(height: 14),
          ...people.map(
            (PersonProfile person) => Padding(
              padding: const EdgeInsets.only(bottom: 10),
              child: _PersonListItem(
                person: person,
                selectedId: selected.id,
                onSelect: () {
                  ref.read(selectedPersonIdProvider.notifier).select(person.id);
                },
              ),
            ),
          ),
          const SizedBox(height: 8),
          FrostedCard(
            child: _PersonDetail(
              person: selected,
              compact: true,
              onEdit: () => _handleEditPerson(context, ref, selected),
              onDelete: () => _handleDeletePerson(context, ref, selected.id),
            ),
          ),
        ],
      ),
    );
  }
}

class _EmptyPeopleView extends StatelessWidget {
  const _EmptyPeopleView({required this.onAdd});

  final VoidCallback onAdd;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: FrostedCard(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Text(
              'No people yet',
              style: Theme.of(context).textTheme.titleLarge,
            ),
            const SizedBox(height: 8),
            Text(
              'Add the first relationship profile to start tracking moments.',
              style: Theme.of(
                context,
              ).textTheme.bodyLarge?.copyWith(color: AppTheme.textSecondary),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 12),
            FilledButton.icon(
              onPressed: onAdd,
              icon: const Icon(Icons.person_add_alt_1_rounded),
              label: const Text('Add Person'),
            ),
          ],
        ),
      ),
    );
  }
}

class _PersonDetail extends StatelessWidget {
  const _PersonDetail({
    required this.person,
    required this.onEdit,
    required this.onDelete,
    this.compact = false,
  });

  final PersonProfile person;
  final VoidCallback onEdit;
  final VoidCallback onDelete;
  final bool compact;

  @override
  Widget build(BuildContext context) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        if (compact)
          Column(
            children: <Widget>[
              Row(
                children: <Widget>[
                  _AvatarSeed(name: person.name, size: 56),
                  const SizedBox(width: 14),
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Text(
                          person.name,
                          style: Theme.of(context).textTheme.titleLarge,
                          maxLines: 1,
                          overflow: TextOverflow.ellipsis,
                        ),
                        const SizedBox(height: 4),
                        Text(
                          person.relationship,
                          style: Theme.of(context).textTheme.bodyLarge
                              ?.copyWith(color: AppTheme.textSecondary),
                          maxLines: 1,
                          overflow: TextOverflow.ellipsis,
                        ),
                      ],
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 8),
              Row(
                mainAxisAlignment: MainAxisAlignment.end,
                children: <Widget>[
                  IconButton(
                    onPressed: onEdit,
                    icon: const Icon(Icons.edit_rounded),
                    tooltip: 'Edit person',
                  ),
                  IconButton(
                    onPressed: onDelete,
                    icon: const Icon(Icons.delete_outline_rounded),
                    tooltip: 'Delete person',
                  ),
                ],
              ),
            ],
          )
        else
          Row(
            children: <Widget>[
              _AvatarSeed(name: person.name, size: 64),
              const SizedBox(width: 16),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: <Widget>[
                    Text(
                      person.name,
                      style: Theme.of(context).textTheme.titleLarge,
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                    const SizedBox(height: 4),
                    Text(
                      person.relationship,
                      style: Theme.of(context).textTheme.bodyLarge?.copyWith(
                        color: AppTheme.textSecondary,
                      ),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ],
                ),
              ),
              IconButton(
                onPressed: onEdit,
                icon: const Icon(Icons.edit_rounded),
                tooltip: 'Edit person',
              ),
              IconButton(
                onPressed: onDelete,
                icon: const Icon(Icons.delete_outline_rounded),
                tooltip: 'Delete person',
              ),
            ],
          ),
        SizedBox(height: compact ? 14 : 22),
        Text('Next moment', style: Theme.of(context).textTheme.titleMedium),
        const SizedBox(height: 8),
        _DetailTag(
          label:
              '${person.nextMoment.year}-${person.nextMoment.month.toString().padLeft(2, '0')}-${person.nextMoment.day.toString().padLeft(2, '0')} ${person.nextMoment.hour.toString().padLeft(2, '0')}:${person.nextMoment.minute.toString().padLeft(2, '0')}',
        ),
        const SizedBox(height: 18),
        Text('Preferences', style: Theme.of(context).textTheme.titleMedium),
        const SizedBox(height: 8),
        Wrap(
          spacing: 8,
          runSpacing: 8,
          children: person.tags
              .map((String tag) => _DetailTag(label: tag))
              .toList(growable: false),
        ),
        const SizedBox(height: 18),
        Text('Notes', style: Theme.of(context).textTheme.titleMedium),
        const SizedBox(height: 8),
        Text(
          person.notes,
          style: Theme.of(
            context,
          ).textTheme.bodyLarge?.copyWith(color: AppTheme.textSecondary),
        ),
      ],
    );
  }
}

class _PeopleHeader extends StatelessWidget {
  const _PeopleHeader({required this.onAdd, required this.compact});

  final VoidCallback onAdd;
  final bool compact;

  @override
  Widget build(BuildContext context) {
    final TextTheme textTheme = Theme.of(context).textTheme;
    if (compact) {
      return Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          Text('People', style: textTheme.headlineMedium),
          const SizedBox(height: 6),
          Text(
            'Track what matters to each relationship and follow through.',
            style: textTheme.bodyLarge?.copyWith(color: AppTheme.textSecondary),
            maxLines: 2,
            overflow: TextOverflow.ellipsis,
          ),
          const SizedBox(height: 12),
          FilledButton.icon(
            onPressed: onAdd,
            icon: const Icon(Icons.person_add_alt_1_rounded),
            label: const Text('Add person'),
          ),
        ],
      );
    }

    return Row(
      children: <Widget>[
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Text('People', style: textTheme.headlineMedium),
              const SizedBox(height: 6),
              Text(
                'Track what matters to each relationship and follow through.',
                style: textTheme.bodyLarge?.copyWith(
                  color: AppTheme.textSecondary,
                ),
              ),
            ],
          ),
        ),
        FilledButton.icon(
          onPressed: onAdd,
          icon: const Icon(Icons.person_add_alt_1_rounded),
          label: const Text('Add'),
        ),
      ],
    );
  }
}

class _PersonListItem extends StatelessWidget {
  const _PersonListItem({
    required this.person,
    required this.selectedId,
    required this.onSelect,
  });

  final PersonProfile person;
  final String selectedId;
  final VoidCallback onSelect;

  @override
  Widget build(BuildContext context) {
    final bool isSelected = person.id == selectedId;
    return InkWell(
      onTap: onSelect,
      borderRadius: BorderRadius.circular(20),
      child: FrostedCard(
        padding: const EdgeInsets.all(16),
        child: Row(
          children: <Widget>[
            _AvatarSeed(name: person.name),
            const SizedBox(width: 14),
            Expanded(
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: <Widget>[
                  Text(
                    person.name,
                    style: Theme.of(context).textTheme.titleMedium,
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                  const SizedBox(height: 4),
                  Text(
                    person.relationship,
                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                      color: AppTheme.textSecondary,
                    ),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                ],
              ),
            ),
            const SizedBox(width: 8),
            _ScorePill(score: person.affinityScore),
            if (isSelected)
              const Padding(
                padding: EdgeInsets.only(left: 10),
                child: Icon(Icons.check_circle, color: Color(0xFF1AB6C8)),
              ),
          ],
        ),
      ),
    );
  }
}

class _PersonEditorDialog extends StatefulWidget {
  const _PersonEditorDialog({required this.title, this.initial});

  final String title;
  final _PersonDraft? initial;

  @override
  State<_PersonEditorDialog> createState() => _PersonEditorDialogState();
}

class _PersonEditorDialogState extends State<_PersonEditorDialog> {
  late final TextEditingController _nameController;
  late final TextEditingController _relationshipController;
  late final TextEditingController _tagsController;
  late final TextEditingController _notesController;

  @override
  void initState() {
    super.initState();
    _nameController = TextEditingController(text: widget.initial?.name ?? '');
    _relationshipController = TextEditingController(
      text: widget.initial?.relationship ?? '',
    );
    _tagsController = TextEditingController(
      text: widget.initial?.tags.join(', ') ?? '',
    );
    _notesController = TextEditingController(text: widget.initial?.notes ?? '');
  }

  @override
  void dispose() {
    _nameController.dispose();
    _relationshipController.dispose();
    _tagsController.dispose();
    _notesController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text(widget.title),
      content: SingleChildScrollView(
        child: SizedBox(
          width: 420,
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: <Widget>[
              TextField(
                controller: _nameController,
                decoration: const InputDecoration(labelText: 'Name'),
              ),
              TextField(
                controller: _relationshipController,
                decoration: const InputDecoration(labelText: 'Relationship'),
              ),
              TextField(
                controller: _tagsController,
                decoration: const InputDecoration(
                  labelText: 'Tags (comma separated)',
                ),
              ),
              TextField(
                controller: _notesController,
                maxLines: 3,
                decoration: const InputDecoration(labelText: 'Notes'),
              ),
            ],
          ),
        ),
      ),
      actions: <Widget>[
        TextButton(
          onPressed: () => Navigator.of(context).pop(),
          child: const Text('Cancel'),
        ),
        FilledButton(
          onPressed: () {
            final String name = _nameController.text.trim();
            final String relationship = _relationshipController.text.trim();
            if (name.isEmpty || relationship.isEmpty) {
              return;
            }

            final _PersonDraft draft = _PersonDraft(
              name: name,
              relationship: relationship,
              notes: _notesController.text.trim(),
              tags: _tagsController.text
                  .split(',')
                  .map((String tag) => tag.trim())
                  .where((String tag) => tag.isNotEmpty)
                  .toList(growable: false),
            );
            Navigator.of(context).pop(draft);
          },
          child: const Text('Save'),
        ),
      ],
    );
  }
}

class _PersonDraft {
  const _PersonDraft({
    required this.name,
    required this.relationship,
    required this.notes,
    required this.tags,
  });

  final String name;
  final String relationship;
  final String notes;
  final List<String> tags;
}

class _DetailTag extends StatelessWidget {
  const _DetailTag({required this.label});

  final String label;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      decoration: BoxDecoration(
        color: const Color(0xFFF2F8FA),
        borderRadius: BorderRadius.circular(99),
      ),
      child: Text(label, style: Theme.of(context).textTheme.bodyMedium),
    );
  }
}

class _AvatarSeed extends StatelessWidget {
  const _AvatarSeed({required this.name, this.size = 48});

  final String name;
  final double size;

  @override
  Widget build(BuildContext context) {
    final String initials = name
        .split(' ')
        .where((String part) => part.isNotEmpty)
        .take(2)
        .map((String part) => part[0].toUpperCase())
        .join();

    return Container(
      width: size,
      height: size,
      decoration: BoxDecoration(
        borderRadius: BorderRadius.circular(size / 2),
        gradient: const LinearGradient(
          colors: <Color>[Color(0xFF1AB6C8), Color(0xFF2274E0)],
        ),
      ),
      alignment: Alignment.center,
      child: Text(
        initials,
        style: Theme.of(context).textTheme.titleMedium?.copyWith(
          color: Colors.white,
          fontWeight: FontWeight.w700,
        ),
      ),
    );
  }
}

class _ScorePill extends StatelessWidget {
  const _ScorePill({required this.score});

  final int score;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      decoration: BoxDecoration(
        color: const Color(0xFFEEF7F3),
        borderRadius: BorderRadius.circular(99),
      ),
      child: Text(
        '$score%',
        style: Theme.of(context).textTheme.labelLarge?.copyWith(
          color: const Color(0xFF1D9C66),
          fontWeight: FontWeight.w700,
        ),
      ),
    );
  }
}