<type>(scope): <description>

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src/main/kotlin/com/project/movienight/application/services/FilmLibraryService.kt

@@ -1,11 +1,15 @@
 package com.project.movienight.application.services
 
+import com.project.movienight.adapters.metrics.BusinessMetricsService
 import com.project.movienight.application.ports.input.AddFilmToLibraryCommand
 import com.project.movienight.application.ports.input.AddFilmToLibraryUseCase
 import com.project.movienight.application.ports.input.CreateFilmLibraryCommand
 import com.project.movienight.application.ports.input.CreateFilmLibraryUseCase
 import com.project.movienight.application.ports.input.GetFilmLibraryQuery
 import com.project.movienight.application.ports.input.GetFilmLibraryUseCase
+import com.project.movienight.application.ports.input.ListFilmLibraryEntriesUseCase
+import com.project.movienight.application.ports.input.MarkFilmViewedCommand
+import com.project.movienight.application.ports.input.MarkFilmViewedUseCase
 import com.project.movienight.application.ports.input.RemoveFilmFromLibraryCommand
 import com.project.movienight.application.ports.input.RemoveFilmFromLibraryUseCase
 import com.project.movienight.application.ports.output.FilmLibraryRepositoryPort
@@ -20,70 +24,119 @@ import java.util.UUID
 class FilmLibraryService(
     private val filmLibraryRepository: FilmLibraryRepositoryPort,
     private val idGenerator: IdGenerator,
+    private val businessMetricsService: BusinessMetricsService,
 ) : CreateFilmLibraryUseCase,
     AddFilmToLibraryUseCase,
+    MarkFilmViewedUseCase,
     RemoveFilmFromLibraryUseCase,
-    GetFilmLibraryUseCase {
+    GetFilmLibraryUseCase,
+    ListFilmLibraryEntriesUseCase {
     override fun create(command: CreateFilmLibraryCommand): FilmLibrary {
-        val existingLibrary = findByUserId(command.userId)
-        if (existingLibrary != null) {
-            return existingLibrary
-        }
+        findByUserId(command.userId)?.let { return it }
 
-        return filmLibraryRepository.save(
-            FilmLibrary(
-                id = idGenerator.generateId(),
-                userId = command.userId,
-                filmId = idGenerator.generateId(),
-                comment = command.name,
-                isViewed = false,
-            ),
-        )
+        val libraryId = idGenerator.generateId()
+        val saved =
+            filmLibraryRepository.save(
+                FilmLibrary(
+                    id = libraryId,
+                    userId = command.userId,
+                    filmId = libraryId,
+                    comment = command.name,
+                    isViewed = false,
+                    watchedAt = null,
+                ),
+            )
+        businessMetricsService.recordLibraryEvent()
+        return saved
     }
 
     override fun addFilm(command: AddFilmToLibraryCommand): FilmLibrary {
-        val existingLibrary = findByUserId(command.userId)
-        if (existingLibrary == null) {
-            return filmLibraryRepository.save(
+        val existingEntry = findByUserAndFilmId(command.userId, command.filmId)
+        if (existingEntry != null) {
+            val saved =
+                filmLibraryRepository.save(
+                    existingEntry.copy(
+                        isViewed = false,
+                        watchedAt = null,
+                    ),
+                )
+            businessMetricsService.recordLibraryEvent()
+            return saved
+        }
+
+        val saved =
+            filmLibraryRepository.save(
                 FilmLibrary(
                     id = idGenerator.generateId(),
                     userId = command.userId,
                     filmId = command.filmId,
                     comment = null,
                     isViewed = false,
+                    watchedAt = null,
                 ),
             )
-        }
-
-        return filmLibraryRepository.save(
-            existingLibrary.copy(
-                filmId = command.filmId,
-                isViewed = false,
-            ),
-        )
+        businessMetricsService.recordLibraryEvent()
+        return saved
     }
 
     override fun removeFilm(command: RemoveFilmFromLibraryCommand): FilmLibrary {
         val existingLibrary =
-            findByUserId(command.userId)
-                ?: throw EntityNotFoundException(entity = "Film library", id = command.userId.toString())
+            if (command.libraryId != null) {
+                filmLibraryRepository.findById(command.libraryId)
+                    ?: throw EntityNotFoundException(entity = "Film library", id = command.libraryId.toString())
+            } else {
+                findByUserAndFilmId(command.userId, command.filmId)
+                    ?: throw EntityNotFoundException(entity = "Film library", id = command.filmId.toString())
+            }
 
-        if (command.libraryId != null && command.libraryId != existingLibrary.id) {
-            throw EntityNotFoundException(entity = "Film library", id = command.libraryId.toString())
-        }
-
-        if (existingLibrary.filmId != command.filmId) {
+        if (existingLibrary.userId != command.userId || existingLibrary.filmId != command.filmId) {
             throw DomainException("Film with id ${command.filmId} not found in user's library")
         }
 
         filmLibraryRepository.deleteById(existingLibrary.id)
+        businessMetricsService.recordLibraryEvent()
         return existingLibrary
     }
 
+    override fun markViewed(command: MarkFilmViewedCommand): FilmLibrary {
+        val existingEntry = findByUserAndFilmId(command.userId, command.filmId)
+        val watchedAt = command.watchedAt ?: java.time.LocalDateTime.now()
+
+        val saved =
+            if (existingEntry == null) {
+                filmLibraryRepository.save(
+                    FilmLibrary(
+                        id = idGenerator.generateId(),
+                        userId = command.userId,
+                        filmId = command.filmId,
+                        comment = null,
+                        isViewed = true,
+                        watchedAt = watchedAt,
+                    ),
+                )
+            } else {
+                filmLibraryRepository.save(
+                    existingEntry.copy(
+                        isViewed = true,
+                        watchedAt = watchedAt,
+                    ),
+                )
+            }
+        businessMetricsService.recordLibraryEvent()
+        return saved
+    }
+
     override fun getLibrary(query: GetFilmLibraryQuery): FilmLibrary =
         findByUserId(query.userId)
             ?: throw EntityNotFoundException(entity = "Film library", id = query.userId.toString())
 
+    override fun list(userId: UUID): List<FilmLibrary> = filmLibraryRepository.findAll().filter { it.userId == userId }
+
     private fun findByUserId(userId: UUID): FilmLibrary? =
         filmLibraryRepository.findAll().firstOrNull { it.userId == userId }
+
+    private fun findByUserAndFilmId(
+        userId: UUID,
+        filmId: UUID,
+    ): FilmLibrary? = filmLibraryRepository.findAll().firstOrNull { it.userId == userId && it.filmId == filmId }
 }