import MusicAssistantCore
import XCTest

final class SongProjectGenerationDirectorTests: XCTestCase {
    func testGenerateCompleteProjectBuildsGenerationRequestFromTrimmedIdea() async throws {
        let aiService = RecordingGenerationAIService(
            generationResult: SongProjectGenerationResult(
                project: SongProject(
                    title: "Generated Song",
                    idea: "Hopeful cinematic pop",
                    genres: [GenreStyle(id: "cinematic-pop", name: "Cinematic Pop")]
                ),
                notes: ["Completed from idea."]
            )
        )
        let director = SongProjectGenerationDirector(aiService: aiService)
        let conversation = [
            AIConversationMessage(role: .user, content: "Use piano.")
        ]

        let result = try await director.generateCompleteProject(
            fromIdea: "  Hopeful cinematic pop  ",
            discussionMode: .discuss,
            conversation: conversation,
            localeIdentifier: "en_US",
            generatedAt: Date(timeIntervalSince1970: 200)
        )
        let recordedRequest = await aiService.recordedGenerationRequests.first

        XCTAssertEqual(recordedRequest?.context.userInstruction, "Hopeful cinematic pop")
        XCTAssertEqual(recordedRequest?.context.conversation, conversation)
        XCTAssertEqual(recordedRequest?.context.localeIdentifier, "en_US")
        XCTAssertEqual(recordedRequest?.discussionMode, .discuss)
        XCTAssertNil(recordedRequest?.seedProject)
        XCTAssertEqual(result.project.conversationMode, .discuss)
        XCTAssertEqual(result.project.updatedAt, Date(timeIntervalSince1970: 200))
        XCTAssertEqual(result.notes, ["Completed from idea."])
    }

    func testGenerateCompleteProjectPreservesSeedProjectIdentityAndVersions() async throws {
        let createdAt = Date(timeIntervalSince1970: 10)
        let generatedAt = Date(timeIntervalSince1970: 300)
        var seedProject = SongProject(
            id: "seed-project",
            title: "Draft",
            idea: "Original idea",
            createdAt: createdAt,
            updatedAt: createdAt
        )
        let version = seedProject.createVersion(
            id: "seed-version",
            label: "Before generation",
            createdAt: createdAt
        )
        let aiService = RecordingGenerationAIService(
            generationResult: SongProjectGenerationResult(
                project: SongProject(
                    id: "generated-id",
                    title: "Generated Complete Project",
                    idea: "",
                    sections: [
                        SongSection(id: "verse", type: .verse, title: "Verse", order: 0)
                    ],
                    lyrics: Lyrics(text: "Generated lyrics")
                )
            )
        )
        let director = SongProjectGenerationDirector(aiService: aiService)

        let result = try await director.generateCompleteProject(
            fromIdea: "Build from this idea",
            seedProject: seedProject,
            generatedAt: generatedAt
        )
        let recordedRequest = await aiService.recordedGenerationRequests.first

        XCTAssertEqual(recordedRequest?.seedProject, seedProject)
        XCTAssertEqual(result.project.id, "seed-project")
        XCTAssertEqual(result.project.createdAt, createdAt)
        XCTAssertEqual(result.project.updatedAt, generatedAt)
        XCTAssertEqual(result.project.versions, [version])
        XCTAssertEqual(result.project.title, "Generated Complete Project")
        XCTAssertEqual(result.project.idea, "Build from this idea")
        XCTAssertEqual(result.project.sections.first?.id, "verse")
        XCTAssertEqual(result.project.lyrics.text, "Generated lyrics")
    }

    func testGenerateCompleteProjectRejectsBlankIdeaBeforeCallingAI() async {
        let aiService = RecordingGenerationAIService(
            generationResult: SongProjectGenerationResult(
                project: SongProject(title: "Unused", idea: "Unused")
            )
        )
        let director = SongProjectGenerationDirector(aiService: aiService)

        do {
            _ = try await director.generateCompleteProject(fromIdea: " \n ")
            XCTFail("Expected blank idea to throw.")
        } catch let error as SongProjectGenerationDirectorError {
            XCTAssertEqual(error, .emptyIdea)
        } catch {
            XCTFail("Expected SongProjectGenerationDirectorError.")
        }

        let requestCount = await aiService.recordedGenerationRequests.count
        XCTAssertEqual(requestCount, 0)
    }
}

private actor RecordingGenerationAIService: AIService {
    private(set) var recordedGenerationRequests: [SongProjectGenerationRequest] = []
    private let generationResult: SongProjectGenerationResult

    init(generationResult: SongProjectGenerationResult) {
        self.generationResult = generationResult
    }

    func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult {
        recordedGenerationRequests.append(request)
        return generationResult
    }

    func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
        LyricsRevisionResult(lyrics: request.sourceLyrics)
    }

    func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult {
        SongProjectUpdateResult(project: request.project)
    }
}