src/main/kotlin/com/project/movienight/MovieNightApplication.kt

@@ -3,8 +3,10 @@ package com.project.movienight
 import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.context.properties.ConfigurationPropertiesScan
 import org.springframework.boot.runApplication
+import org.springframework.scheduling.annotation.EnableScheduling
 
 @SpringBootApplication
+@EnableScheduling
 @ConfigurationPropertiesScan("com.project.movienight.config")
 class MovieNightApplication
 

src/main/kotlin/com/project/movienight/adapters/web/FilmController.kt

@@ -25,6 +25,12 @@ import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.bind.annotation.RestController
 import java.util.UUID
 
+private fun String.toContentTypeOrFilm(): com.project.movienight.domain.model.ContentType =
+    runCatching {
+        com.project.movienight.domain.model.ContentType
+            .valueOf(this)
+    }.getOrDefault(com.project.movienight.domain.model.ContentType.FILM)
+
 @RestController
 @RequestMapping("/api/films")
 class FilmController(
@@ -45,6 +51,16 @@ class FilmController(
                 CreateFilmCommand(
                     title = request.title,
                     description = request.description,
+                    contentType = request.contentType.toContentTypeOrFilm(),
+                    releaseYear = request.releaseYear,
+                    genres = request.genres,
+                    cast = request.cast,
+                    directors = request.directors,
+                    imdbRating = request.imdbRating,
+                    platformRating = request.platformRating,
+                    externalUrl = request.externalUrl,
+                    jellyfinItemId = request.jellyfinItemId,
+                    jellyfinLibraryId = request.jellyfinLibraryId,
                 ),
             ),
         )
@@ -61,6 +77,16 @@ class FilmController(
                     EditFilmCommand(
                         title = request.title,
                         description = request.description,
+                        contentType = request.contentType.toContentTypeOrFilm(),
+                        releaseYear = request.releaseYear,
+                        genres = request.genres,
+                        cast = request.cast,
+                        directors = request.directors,
+                        imdbRating = request.imdbRating,
+                        platformRating = request.platformRating,
+                        externalUrl = request.externalUrl,
+                        jellyfinItemId = request.jellyfinItemId,
+                        jellyfinLibraryId = request.jellyfinLibraryId,
                     ),
             ),
         )

src/main/kotlin/com/project/movienight/adapters/web/FilmLibraryController.kt

@@ -11,6 +11,9 @@ import com.project.movienight.application.ports.input.GetAllFilmsUseCase
 import com.project.movienight.application.ports.input.GetFilmByIdUseCase
 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.domain.exception.EntityNotFoundException
@@ -30,10 +33,10 @@ import java.util.UUID
 class FilmLibraryController(
     private val createFilmLibraryUseCase: CreateFilmLibraryUseCase,
     private val addFilmToLibraryUseCase: AddFilmToLibraryUseCase,
+    private val markFilmViewedUseCase: MarkFilmViewedUseCase,
     private val removeFilmFromLibraryUseCase: RemoveFilmFromLibraryUseCase,
     private val getFilmLibraryUseCase: GetFilmLibraryUseCase,
-    private val getFilmByIdUseCase: GetFilmByIdUseCase,
-    private val getAllFilmsUseCase: GetAllFilmsUseCase,
+    private val listFilmLibraryEntriesUseCase: ListFilmLibraryEntriesUseCase,
 ) {
     @PostMapping
     @ResponseStatus(HttpStatus.CREATED)
@@ -60,18 +63,10 @@ class FilmLibraryController(
             ),
         )
 
-    @GetMapping("/films")
-    fun getAllFilmsInLibrary(
+    @GetMapping("/entries")
+    fun list(
         @PathVariable userId: UUID,
-    ): List<FilmResponse> {
-        val library =
-            getFilmLibraryUseCase.getLibrary(
-                GetFilmLibraryQuery(userId = userId),
-            )
-
-        val film = getFilmByIdUseCase.getById(library.filmId)
-        return listOf(FilmResponse.fromDomain(film))
-    }
+    ): List<FilmLibraryResponse> = listFilmLibraryEntriesUseCase.list(userId).map { FilmLibraryResponse.fromDomain(it) }
 
     @PostMapping("/films/{filmId}")
     @ResponseStatus(HttpStatus.CREATED)
@@ -88,6 +83,20 @@ class FilmLibraryController(
             ),
         )
 
+    @PostMapping("/films/{filmId}/viewed")
+    fun markViewed(
+        @PathVariable userId: UUID,
+        @PathVariable filmId: UUID,
+    ): FilmLibraryResponse =
+        FilmLibraryResponse.fromDomain(
+            markFilmViewedUseCase.markViewed(
+                MarkFilmViewedCommand(
+                    userId = userId,
+                    filmId = filmId,
+                ),
+            ),
+        )
+
     @DeleteMapping("/films/{filmId}")
     @ResponseStatus(HttpStatus.NO_CONTENT)
     fun removeFilm(

src/main/kotlin/com/project/movienight/adapters/web/UserController.kt

@@ -64,6 +64,7 @@ class UserController(
                 command =
                     EditUserCommand(
                         name = request.name,
+                        jellyfinUserId = request.jellyfinUserId,
                     ),
             ),
         )

src/main/kotlin/com/project/movienight/adapters/web/dto/request/CreateFilmRequest.kt

@@ -3,4 +3,14 @@ package com.project.movienight.adapters.web.dto.request
 data class CreateFilmRequest(
     val title: String,
     val description: String,
+    val contentType: String = "FILM",
+    val releaseYear: Int? = null,
+    val genres: List<String> = emptyList(),
+    val cast: List<String> = emptyList(),
+    val directors: List<String> = emptyList(),
+    val imdbRating: Double? = null,
+    val platformRating: Double? = null,
+    val externalUrl: String? = null,
+    val jellyfinItemId: String? = null,
+    val jellyfinLibraryId: String? = null,
 )

src/main/kotlin/com/project/movienight/adapters/web/dto/request/EditFilmRequest.kt

@@ -3,4 +3,14 @@ package com.project.movienight.adapters.web.dto.request
 data class EditFilmRequest(
     val title: String,
     val description: String,
+    val contentType: String = "FILM",
+    val releaseYear: Int? = null,
+    val genres: List<String> = emptyList(),
+    val cast: List<String> = emptyList(),
+    val directors: List<String> = emptyList(),
+    val imdbRating: Double? = null,
+    val platformRating: Double? = null,
+    val externalUrl: String? = null,
+    val jellyfinItemId: String? = null,
+    val jellyfinLibraryId: String? = null,
 )

src/main/kotlin/com/project/movienight/adapters/web/dto/request/EditUserRequest.kt

@@ -2,4 +2,5 @@ package com.project.movienight.adapters.web.dto.request
 
 data class EditUserRequest(
     val name: String,
+    val jellyfinUserId: String? = null,
 )

src/main/kotlin/com/project/movienight/adapters/web/dto/response/FilmLibraryResponse.kt

@@ -9,6 +9,7 @@ data class FilmLibraryResponse(
     val filmId: UUID,
     val comment: String?,
     val isViewed: Boolean,
+    val watchedAt: java.time.LocalDateTime?,
 ) {
     companion object {
         fun fromDomain(filmLibrary: FilmLibrary): FilmLibraryResponse =
@@ -18,6 +19,7 @@ data class FilmLibraryResponse(
                 filmId = filmLibrary.filmId,
                 comment = filmLibrary.comment,
                 isViewed = filmLibrary.isViewed,
+                watchedAt = filmLibrary.watchedAt,
             )
     }
 }

src/main/kotlin/com/project/movienight/adapters/web/dto/response/FilmResponse.kt

@@ -1,5 +1,6 @@
 package com.project.movienight.adapters.web.dto.response
 
+import com.project.movienight.domain.model.ContentType
 import com.project.movienight.domain.model.Film
 import java.util.UUID
 
@@ -7,6 +8,16 @@ data class FilmResponse(
     val id: UUID,
     val title: String,
     val description: String,
+    val contentType: ContentType,
+    val releaseYear: Int?,
+    val genres: List<String>,
+    val cast: List<String>,
+    val directors: List<String>,
+    val imdbRating: Double?,
+    val platformRating: Double?,
+    val externalUrl: String?,
+    val jellyfinItemId: String?,
+    val jellyfinLibraryId: String?,
 ) {
     companion object {
         fun fromDomain(film: Film): FilmResponse =
@@ -14,6 +25,16 @@ data class FilmResponse(
                 id = film.id,
                 title = film.title,
                 description = film.description,
+                contentType = film.contentType,
+                releaseYear = film.releaseYear,
+                genres = film.genres,
+                cast = film.cast,
+                directors = film.directors,
+                imdbRating = film.imdbRating,
+                platformRating = film.platformRating,
+                externalUrl = film.externalUrl,
+                jellyfinItemId = film.jellyfinItemId,
+                jellyfinLibraryId = film.jellyfinLibraryId,
             )
     }
 }

src/main/kotlin/com/project/movienight/adapters/web/dto/response/UserResponse.kt

@@ -7,6 +7,7 @@ data class UserResponse(
     val id: UUID,
     val name: String,
     val email: String,
+    val jellyfinUserId: String?,
 ) {
     companion object {
         fun fromDomain(user: User): UserResponse =
@@ -14,6 +15,7 @@ data class UserResponse(
                 id = user.id,
                 name = user.name,
                 email = user.email,
+                jellyfinUserId = user.jellyfinUserId,
             )
     }
 }

src/main/kotlin/com/project/movienight/application/ports/input/FilmLibraryUseCase.kt

@@ -1,6 +1,7 @@
 package com.project.movienight.application.ports.input
 
 import com.project.movienight.domain.model.FilmLibrary
+import java.time.LocalDateTime
 import java.util.UUID
 
 interface CreateFilmLibraryUseCase {
@@ -21,6 +22,16 @@ data class AddFilmToLibraryCommand(
     val filmId: UUID,
 )
 
+interface MarkFilmViewedUseCase {
+    fun markViewed(command: MarkFilmViewedCommand): FilmLibrary
+}
+
+data class MarkFilmViewedCommand(
+    val userId: UUID,
+    val filmId: UUID,
+    val watchedAt: LocalDateTime? = null,
+)
+
 interface RemoveFilmFromLibraryUseCase {
     fun removeFilm(command: RemoveFilmFromLibraryCommand): FilmLibrary
 }
@@ -38,3 +49,7 @@ interface GetFilmLibraryUseCase {
 data class GetFilmLibraryQuery(
     val userId: UUID,
 )
+
+interface ListFilmLibraryEntriesUseCase {
+    fun list(userId: UUID): List<FilmLibrary>
+}

src/main/kotlin/com/project/movienight/application/ports/input/FilmUseCase.kt

@@ -1,5 +1,6 @@
 package com.project.movienight.application.ports.input
 
+import com.project.movienight.domain.model.ContentType
 import com.project.movienight.domain.model.Film
 import java.util.UUID
 
@@ -10,6 +11,16 @@ interface CreateFilmUseCase {
 data class CreateFilmCommand(
     val title: String,
     val description: String,
+    val contentType: ContentType = ContentType.FILM,
+    val releaseYear: Int? = null,
+    val genres: List<String> = emptyList(),
+    val cast: List<String> = emptyList(),
+    val directors: List<String> = emptyList(),
+    val imdbRating: Double? = null,
+    val platformRating: Double? = null,
+    val externalUrl: String? = null,
+    val jellyfinItemId: String? = null,
+    val jellyfinLibraryId: String? = null,
 )
 
 interface EditFilmUseCase {
@@ -22,6 +33,16 @@ interface EditFilmUseCase {
 data class EditFilmCommand(
     val title: String,
     val description: String,
+    val contentType: ContentType = ContentType.FILM,
+    val releaseYear: Int? = null,
+    val genres: List<String> = emptyList(),
+    val cast: List<String> = emptyList(),
+    val directors: List<String> = emptyList(),
+    val imdbRating: Double? = null,
+    val platformRating: Double? = null,
+    val externalUrl: String? = null,
+    val jellyfinItemId: String? = null,
+    val jellyfinLibraryId: String? = null,
 )
 
 interface DeleteFilmUseCase {

src/main/kotlin/com/project/movienight/application/ports/input/UserUseCase.kt

@@ -21,6 +21,7 @@ interface EditUserUseCase {
 
 data class EditUserCommand(
     val name: String,
+    val jellyfinUserId: String? = null,
 )
 
 interface DeleteUserUseCase {

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 }
 }

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

@@ -56,21 +56,23 @@ class FilmService(
                 throw BlockedValueException(target = "Film", field = "description")
             }
 
-            val film =
-                Film(
-                    id = idGenerator.generateId(),
-                    title = command.title,
-                    description = command.description,
-                )
-            val saved = filmRepository.save(film)
-
-            filmCreatedCounter.increment()
-
-            log.info("Film created: id='{}', title='{}'", saved.id, saved.title)
-            return saved
-        } finally {
-            sample.stop(createFilmTimer)
-        }
+        val film =
+            Film(
+                id = idGenerator.generateId(),
+                title = command.title,
+                description = command.description,
+                contentType = command.contentType,
+                releaseYear = command.releaseYear,
+                genres = command.genres,
+                cast = command.cast,
+                directors = command.directors,
+                imdbRating = command.imdbRating,
+                platformRating = command.platformRating,
+                externalUrl = command.externalUrl,
+                jellyfinItemId = command.jellyfinItemId,
+                jellyfinLibraryId = command.jellyfinLibraryId,
+            )
+        return filmRepository.save(film)
     }
 
     override fun edit(
@@ -100,20 +102,23 @@ class FilmService(
                 throw EntityNotFoundException(entity = "Film", id = id.toString())
             }
 
-            val updatedFilm =
-                film.copy(
-                    title = command.title,
-                    description = command.description,
-                )
-            val saved = filmRepository.save(updatedFilm)
+        film =
+            film.copy(
+                title = command.title,
+                description = command.description,
+                contentType = command.contentType,
+                releaseYear = command.releaseYear,
+                genres = command.genres,
+                cast = command.cast,
+                directors = command.directors,
+                imdbRating = command.imdbRating,
+                platformRating = command.platformRating,
+                externalUrl = command.externalUrl,
+                jellyfinItemId = command.jellyfinItemId,
+                jellyfinLibraryId = command.jellyfinLibraryId,
+            )
 
-            filmEditedCounter.increment()
-
-            log.info("Film edited: id='{}'", saved.id)
-            return saved
-        } finally {
-            sample.stop(editFilmTimer)
-        }
+        return filmRepository.save(film)
     }
 
     override fun delete(id: UUID) {

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

@@ -37,6 +37,7 @@ class UserService(
                 name = command.name,
                 email = command.email,
                 library = null,
+                jellyfinUserId = null,
             )
         return userRepository.save(user)
     }
@@ -50,7 +51,13 @@ class UserService(
         }
 
         var user = userRepository.findById(id) ?: throw EntityNotFoundException(entity = "User", id = id.toString())
-        user = user.copy(name = command.name)
+
+        user =
+            user.copy(
+                name = command.name,
+                jellyfinUserId = command.jellyfinUserId ?: user.jellyfinUserId,
+            )
+
         return userRepository.save(user)
     }
 

src/main/resources/application.yaml

@@ -95,6 +95,14 @@ info:
     description: MovieNight backend service
     version: ${project.version:unknown}
 
+integrations:
+  jellyfin:
+    enabled: ${JELLYFIN_SYNC_ENABLED:false}
+    base-url: ${JELLYFIN_BASE_URL:}
+    api-key: ${JELLYFIN_API_KEY:}
+    sync-interval-ms: ${JELLYFIN_SYNC_INTERVAL_MS:1800000}
+    request-timeout-ms: ${JELLYFIN_REQUEST_TIMEOUT_MS:20000}
+
 services:
   user:
     blocked-names:

src/test/kotlin/com/project/movienight/application/services/FilmLibraryServiceTest.kt

@@ -1,5 +1,6 @@
 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.CreateFilmLibraryCommand
 import com.project.movienight.application.ports.input.GetFilmLibraryQuery
@@ -23,32 +24,33 @@ import java.util.UUID
 class FilmLibraryServiceTest {
     private lateinit var filmLibraryRepository: FilmLibraryRepositoryPort
     private lateinit var idGenerator: IdGenerator
+    private lateinit var businessMetricsService: BusinessMetricsService
     private lateinit var filmLibraryService: FilmLibraryService
 
     @BeforeEach
     fun setup() {
         filmLibraryRepository = mockk()
         idGenerator = mockk()
-        filmLibraryService = FilmLibraryService(filmLibraryRepository, idGenerator)
+        businessMetricsService = mockk(relaxed = true)
+        filmLibraryService = FilmLibraryService(filmLibraryRepository, idGenerator, businessMetricsService)
     }
 
     @Test
     fun `should create new film library when user has no library`() {
         val userId = UUID.randomUUID()
         val libraryId = UUID.randomUUID()
-        val filmId = UUID.randomUUID()
         val command = CreateFilmLibraryCommand(userId = userId, name = "My Films")
         val expectedLibrary =
             FilmLibrary(
                 id = libraryId,
                 userId = userId,
-                filmId = filmId,
+                filmId = libraryId,
                 comment = "My Films",
                 isViewed = false,
             )
 
         every { filmLibraryRepository.findAll() } returns emptyList()
-        every { idGenerator.generateId() } returnsMany listOf(libraryId, filmId)
+        every { idGenerator.generateId() } returns libraryId
         every {
             filmLibraryRepository.save(
                 match {
@@ -62,11 +64,11 @@ class FilmLibraryServiceTest {
         assertNotNull(result)
         assertEquals(libraryId, result.id)
         assertEquals(userId, result.userId)
-        assertEquals(filmId, result.filmId)
+        assertEquals(libraryId, result.filmId)
         assertEquals("My Films", result.comment)
 
         verify(exactly = 1) { filmLibraryRepository.findAll() }
-        verify(exactly = 2) { idGenerator.generateId() }
+        verify(exactly = 1) { idGenerator.generateId() }
         verify(exactly = 1) { filmLibraryRepository.save(any()) }
     }
 
@@ -131,7 +133,7 @@ class FilmLibraryServiceTest {
     }
 
     @Test
-    fun `should add film to existing library`() {
+    fun `should add film as a new library entry when another film already exists`() {
         val userId = UUID.randomUUID()
         val oldFilmId = UUID.randomUUID()
         val newFilmId = UUID.randomUUID()
@@ -144,16 +146,24 @@ class FilmLibraryServiceTest {
                 isViewed = true,
             )
         val command = AddFilmToLibraryCommand(userId = userId, filmId = newFilmId)
-        val updatedLibrary = existingLibrary.copy(filmId = newFilmId, isViewed = false)
+        val createdLibrary =
+            FilmLibrary(
+                id = UUID.randomUUID(),
+                userId = userId,
+                filmId = newFilmId,
+                comment = null,
+                isViewed = false,
+            )
 
         every { filmLibraryRepository.findAll() } returns listOf(existingLibrary)
+        every { idGenerator.generateId() } returns createdLibrary.id
         every {
             filmLibraryRepository.save(
                 match {
-                    it.filmId == newFilmId && it.isViewed == false
+                    it.id == createdLibrary.id && it.userId == userId && it.filmId == newFilmId && it.isViewed == false
                 },
             )
-        } returns updatedLibrary
+        } returns createdLibrary
 
         val result = filmLibraryService.addFilm(command)
 
@@ -161,7 +171,7 @@ class FilmLibraryServiceTest {
         assertEquals(false, result.isViewed)
 
         verify(exactly = 1) { filmLibraryRepository.findAll() }
-        verify(exactly = 0) { idGenerator.generateId() }
+        verify(exactly = 1) { idGenerator.generateId() }
         verify(exactly = 1) { filmLibraryRepository.save(any()) }
     }
 
@@ -253,13 +263,13 @@ class FilmLibraryServiceTest {
                 libraryId = wrongLibraryId,
             )
 
-        every { filmLibraryRepository.findAll() } returns listOf(existingLibrary)
+        every { filmLibraryRepository.findById(wrongLibraryId) } returns null
 
         assertThrows<EntityNotFoundException> {
             filmLibraryService.removeFilm(command)
         }
 
-        verify(exactly = 1) { filmLibraryRepository.findAll() }
+        verify(exactly = 1) { filmLibraryRepository.findById(wrongLibraryId) }
         verify(exactly = 0) { filmLibraryRepository.deleteById(any()) }
     }