import TheMovieDb from '@server/api/themoviedb';
import { MediaType } from '@server/constants/media';
import { getRepository } from '@server/datasource';
import Media from '@server/entity/Media';
import { User } from '@server/entity/User';
import type { WatchlistItem } from '@server/interfaces/api/discoverInterfaces';
import logger from '@server/logger';
import { DbAwareColumn } from '@server/utils/DbColumnHelper';
import {
  Column,
  Entity,
  Index,
  ManyToOne,
  PrimaryGeneratedColumn,
  Unique,
} from 'typeorm';
import type { ZodNumber, ZodOptional, ZodString } from 'zod';

export class DuplicateWatchlistRequestError extends Error {}
export class NotFoundError extends Error {
  constructor(message = 'Not found') {
    super(message);
    this.name = 'NotFoundError';
  }
}

@Entity()
@Unique('UNIQUE_USER_DB', ['tmdbId', 'requestedBy'])
@Unique('UNIQUE_USER_FOREIGN', ['mbId', 'requestedBy'])
export class Watchlist implements WatchlistItem {
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ type: 'varchar' })
  public ratingKey = '';

  @Column({ type: 'varchar' })
  public mediaType: MediaType;

  @Column({ type: 'varchar' })
  title = '';

  @Column({ nullable: true })
  @Index()
  public tmdbId?: number;

  @Column({ nullable: true })
  @Index()
  public mbId?: string;

  @ManyToOne(() => User, (user) => user.watchlists, {
    eager: true,
    onDelete: 'CASCADE',
  })
  public requestedBy: User;

  @ManyToOne(() => Media, (media) => media.watchlists, {
    eager: true,
    onDelete: 'CASCADE',
    nullable: false,
  })
  public media: Media;

  @DbAwareColumn({ type: 'datetime', default: () => 'CURRENT_TIMESTAMP' })
  public createdAt: Date;

  @DbAwareColumn({
    type: 'datetime',
    default: () => 'CURRENT_TIMESTAMP',
    onUpdate: 'CURRENT_TIMESTAMP',
  })
  public updatedAt: Date;

  constructor(init?: Partial<Watchlist>) {
    Object.assign(this, init);
  }

  public static async createWatchlist({
    watchlistRequest,
    user,
  }: {
    watchlistRequest: {
      mediaType: MediaType;
      ratingKey?: ZodOptional<ZodString>['_output'];
      title?: ZodOptional<ZodString>['_output'];
      tmdbId?: ZodNumber['_output'];
      mbId?: ZodOptional<ZodString>['_output'];
    };
    user: User;
  }): Promise<Watchlist> {
    const watchlistRepository = getRepository(this);
    const mediaRepository = getRepository(Media);
    const tmdb = new TheMovieDb();

    let media: Media | null;

    if (watchlistRequest.mediaType === MediaType.MUSIC) {
      if (!watchlistRequest.mbId) {
        throw new Error('MusicBrainz ID is required for music media type');
      }

      const existing = await watchlistRepository
        .createQueryBuilder('watchlist')
        .leftJoinAndSelect('watchlist.requestedBy', 'user')
        .where('user.id = :userId', { userId: user.id })
        .andWhere('watchlist.mbId = :mbId', { mbId: watchlistRequest.mbId })
        .andWhere('watchlist.mediaType = :mediaType', {
          mediaType: watchlistRequest.mediaType,
        })
        .getMany();

      if (existing && existing.length > 0) {
        logger.warn('Duplicate request for watchlist blocked', {
          mbId: watchlistRequest.mbId,
          mediaType: watchlistRequest.mediaType,
          label: 'Watchlist',
        });
        throw new DuplicateWatchlistRequestError();
      }

      media = await mediaRepository.findOne({
        where: { mbId: watchlistRequest.mbId, mediaType: MediaType.MUSIC },
      });

      if (!media) {
        media = new Media({
          mbId: watchlistRequest.mbId,
          mediaType: MediaType.MUSIC,
        });
      }
    } else {
      // For movies/TV, validate tmdbId exists
      if (!watchlistRequest.tmdbId) {
        throw new Error('TMDB ID is required for movie/TV media types');
      }

      const tmdbMedia =
        watchlistRequest.mediaType === MediaType.MOVIE
          ? await tmdb.getMovie({ movieId: watchlistRequest.tmdbId })
          : await tmdb.getTvShow({ tvId: watchlistRequest.tmdbId });

      const existing = await watchlistRepository
        .createQueryBuilder('watchlist')
        .leftJoinAndSelect('watchlist.requestedBy', 'user')
        .where('user.id = :userId', { userId: user.id })
        .andWhere('watchlist.tmdbId = :tmdbId', {
          tmdbId: watchlistRequest.tmdbId,
        })
        .andWhere('watchlist.mediaType = :mediaType', {
          mediaType: watchlistRequest.mediaType,
        })
        .getMany();

      if (existing && existing.length > 0) {
        logger.warn('Duplicate request for watchlist blocked', {
          tmdbId: watchlistRequest.tmdbId,
          mediaType: watchlistRequest.mediaType,
          label: 'Watchlist',
        });
        throw new DuplicateWatchlistRequestError();
      }

      media = await mediaRepository.findOne({
        where: {
          tmdbId: watchlistRequest.tmdbId,
          mediaType: watchlistRequest.mediaType,
        },
      });

      if (!media) {
        media = new Media({
          tmdbId: tmdbMedia.id,
          tvdbId: tmdbMedia.external_ids.tvdb_id,
          mediaType: watchlistRequest.mediaType,
        });
      }
    }

    const watchlist = new this({
      ...watchlistRequest,
      requestedBy: user,
      media,
    });

    await mediaRepository.save(media);
    await watchlistRepository.save(watchlist);
    return watchlist;
  }

  public static async deleteWatchlist(
    id: Watchlist['tmdbId'] | Watchlist['mbId'],
    user: User
  ): Promise<Watchlist | null> {
    const watchlistRepository = getRepository(this);

    // Check if the ID is a number (TMDB) or string (MusicBrainz)
    const whereClause =
      typeof id === 'number'
        ? { tmdbId: id, requestedBy: { id: user.id } }
        : { mbId: id, requestedBy: { id: user.id } };

    const watchlist = await watchlistRepository.findOneBy(whereClause);

    if (!watchlist) {
      throw new NotFoundError('not Found');
    }

    if (watchlist) {
      await watchlistRepository.delete(watchlist.id);
    }

    return watchlist;
  }
}