// ignore_for_file: invalid_annotation_target

import 'package:freezed_annotation/freezed_annotation.dart';

part 'backend_models.freezed.dart';
part 'backend_models.g.dart';

/// Supported authentication methods.
@JsonEnum(fieldRename: FieldRename.snake)
enum SignInMethod {
  /// Email link based sign-in.
  emailMagicLink,

  /// Email/password sign-in.
  password,

  /// OIDC token based sign-in.
  oidc,
}

/// Allowed change operation types.
@JsonEnum(alwaysCreate: true)
enum ChangeOperation {
  /// Create or update entity state.
  @JsonValue('upsert')
  upsert,

  /// Remove entity state.
  @JsonValue('delete')
  delete,
}

/// Action taken by user against a signal item.
@JsonEnum(alwaysCreate: true)
enum SignalAction {
  /// Item was viewed.
  viewed,

  /// Item was dismissed.
  dismissed,

  /// Item was saved.
  saved,

  /// Item resulted in purchase.
  purchased,
}

/// Upload category.
@JsonEnum(alwaysCreate: true)
enum UploadPurpose {
  /// Avatar upload.
  @JsonValue('avatar')
  avatar,

  /// Generic attachment upload.
  @JsonValue('attachment')
  attachment,
}

/// Request body for sign-in.
@freezed
abstract class SignInRequest with _$SignInRequest {
  const factory SignInRequest({
    required SignInMethod method,
    String? email,
    String? password,
    String? idToken,
  }) = _SignInRequest;

  factory SignInRequest.fromJson(Map<String, dynamic> json) =>
      _$SignInRequestFromJson(json);
}

/// User profile returned by backend.
@freezed
abstract class UserProfile with _$UserProfile {
  const factory UserProfile({
    required String id,
    String? email,
    String? displayName,
    String? avatarFileId,
  }) = _UserProfile;

  factory UserProfile.fromJson(Map<String, dynamic> json) =>
      _$UserProfileFromJson(json);
}

/// Auth session bundle used by gateway and token storage.
@freezed
abstract class AuthSession with _$AuthSession {
  @JsonSerializable(explicitToJson: true)
  const factory AuthSession({
    required String accessToken,
    required String refreshToken,
    required DateTime expiresAt,
    required UserProfile user,
  }) = _AuthSession;

  factory AuthSession.fromJson(Map<String, dynamic> json) =>
      _$AuthSessionFromJson(json);
}

/// Refresh token request body.
@freezed
abstract class AuthRefreshRequest with _$AuthRefreshRequest {
  const factory AuthRefreshRequest({required String refreshToken}) =
      _AuthRefreshRequest;

  factory AuthRefreshRequest.fromJson(Map<String, dynamic> json) =>
      _$AuthRefreshRequestFromJson(json);
}

/// Refresh token response body.
@freezed
abstract class AuthRefreshResponse with _$AuthRefreshResponse {
  const factory AuthRefreshResponse({
    required String accessToken,
    String? refreshToken,
    required DateTime expiresAt,
  }) = _AuthRefreshResponse;

  factory AuthRefreshResponse.fromJson(Map<String, dynamic> json) =>
      _$AuthRefreshResponseFromJson(json);
}

/// Generic envelope for offline-first change operations.
@freezed
abstract class ChangeEnvelope with _$ChangeEnvelope {
  const factory ChangeEnvelope({
    required int schemaVersion,
    required String entityType,
    required String entityId,
    required ChangeOperation op,
    required DateTime modifiedAt,
    required String clientMutationId,
    Map<String, dynamic>? payload,
  }) = _ChangeEnvelope;

  factory ChangeEnvelope.fromJson(Map<String, dynamic> json) =>
      _$ChangeEnvelopeFromJson(json);
}

/// Push request for batched local changes.
@freezed
abstract class SyncPushRequest with _$SyncPushRequest {
  @JsonSerializable(explicitToJson: true)
  const factory SyncPushRequest({
    required String deviceId,
    String? cursor,
    required List<ChangeEnvelope> changes,
    required String idempotencyKey,
  }) = _SyncPushRequest;

  factory SyncPushRequest.fromJson(Map<String, dynamic> json) =>
      _$SyncPushRequestFromJson(json);
}

/// Acknowledgement for an accepted mutation.
@freezed
abstract class MutationAck with _$MutationAck {
  const factory MutationAck({
    required String clientMutationId,
    String? serverMutationId,
    DateTime? acceptedAt,
  }) = _MutationAck;

  factory MutationAck.fromJson(Map<String, dynamic> json) =>
      _$MutationAckFromJson(json);
}

/// Rejection detail for a mutation.
@freezed
abstract class MutationRejection with _$MutationRejection {
  const factory MutationRejection({
    required String clientMutationId,
    required String code,
    required String message,
  }) = _MutationRejection;

  factory MutationRejection.fromJson(Map<String, dynamic> json) =>
      _$MutationRejectionFromJson(json);
}

/// Result body returned by sync push.
@freezed
abstract class SyncPushResult with _$SyncPushResult {
  @JsonSerializable(explicitToJson: true)
  const factory SyncPushResult({
    required String cursor,
    @Default(<MutationAck>[]) List<MutationAck> accepted,
    @Default(<MutationRejection>[]) List<MutationRejection> rejected,
  }) = _SyncPushResult;

  factory SyncPushResult.fromJson(Map<String, dynamic> json) =>
      _$SyncPushResultFromJson(json);
}

/// Result body returned by sync pull.
@freezed
abstract class SyncPullResult with _$SyncPullResult {
  @JsonSerializable(explicitToJson: true)
  const factory SyncPullResult({
    required String cursor,
    @Default(<ChangeEnvelope>[]) List<ChangeEnvelope> changes,
  }) = _SyncPullResult;

  factory SyncPullResult.fromJson(Map<String, dynamic> json) =>
      _$SyncPullResultFromJson(json);
}

/// Signals feed item.
@freezed
abstract class SignalItem with _$SignalItem {
  const factory SignalItem({
    required String id,
    required String type,
    required String title,
    String? description,
    String? personId,
    required DateTime createdAt,
    Map<String, dynamic>? metadata,
  }) = _SignalItem;

  factory SignalItem.fromJson(Map<String, dynamic> json) =>
      _$SignalItemFromJson(json);
}

/// Cursor-based signals response.
@freezed
abstract class SignalsFeed with _$SignalsFeed {
  @JsonSerializable(explicitToJson: true)
  const factory SignalsFeed({
    String? cursor,
    @Default(<SignalItem>[]) List<SignalItem> items,
  }) = _SignalsFeed;

  factory SignalsFeed.fromJson(Map<String, dynamic> json) =>
      _$SignalsFeedFromJson(json);
}

/// Signal acknowledgement request body.
@freezed
abstract class SignalAckRequest with _$SignalAckRequest {
  const factory SignalAckRequest({
    required SignalAction action,
    required DateTime at,
  }) = _SignalAckRequest;

  factory SignalAckRequest.fromJson(Map<String, dynamic> json) =>
      _$SignalAckRequestFromJson(json);
}

/// Upload init request.
@freezed
abstract class UploadInitRequest with _$UploadInitRequest {
  const factory UploadInitRequest({
    required UploadPurpose purpose,
    required String contentType,
    required int sizeBytes,
  }) = _UploadInitRequest;

  factory UploadInitRequest.fromJson(Map<String, dynamic> json) =>
      _$UploadInitRequestFromJson(json);
}

/// Upload init response.
@freezed
abstract class UploadInitResult with _$UploadInitResult {
  const factory UploadInitResult({
    required String uploadUrl,
    required String fileId,
    required DateTime expiresAt,
  }) = _UploadInitResult;

  factory UploadInitResult.fromJson(Map<String, dynamic> json) =>
      _$UploadInitResultFromJson(json);
}

/// Download URL response.
@freezed
abstract class DownloadUrl with _$DownloadUrl {
  const factory DownloadUrl({
    required String downloadUrl,
    required DateTime expiresAt,
  }) = _DownloadUrl;

  factory DownloadUrl.fromJson(Map<String, dynamic> json) =>
      _$DownloadUrlFromJson(json);
}