feat: add to favorites

src/modules/decks/use-cases/remove-deck-from-favorites.use-case.ts

@@ -0,0 +1,36 @@
+import { BadRequestException, NotFoundException } from '@nestjs/common'
+import { CommandHandler, ICommandHandler } from '@nestjs/cqrs'
+
+import { DecksRepository } from '../infrastructure/decks.repository'
+
+export class RemoveDeckFromFavoritesCommand {
+  constructor(
+    public readonly userId: string,
+    public readonly deckId: string
+  ) {}
+}
+
+@CommandHandler(RemoveDeckFromFavoritesCommand)
+export class RemoveDeckFromFavoritesHandler
+  implements ICommandHandler<RemoveDeckFromFavoritesCommand>
+{
+  constructor(private readonly decksRepository: DecksRepository) {}
+
+  async execute(command: RemoveDeckFromFavoritesCommand): Promise<void> {
+    const deck = await this.decksRepository.findDeckById(command.deckId)
+
+    if (!deck) {
+      throw new NotFoundException(`Deck with id ${command.deckId} not found`)
+    }
+    const favorites = await this.decksRepository.findFavoritesByUserId(
+      command.userId,
+      command.deckId
+    )
+
+    if (!favorites?.includes(command.deckId)) {
+      throw new BadRequestException(`Deck with id ${command.deckId} is not a favorite`)
+    }
+
+    return await this.decksRepository.removeDeckFromFavorites(command.userId, command.deckId)
+  }
+}