import Foundation
import MusicAssistantCore
import XCTest

final class LocalSongProjectStoreTests: XCTestCase {
    private var temporaryDirectoryURL: URL!

    override func setUpWithError() throws {
        temporaryDirectoryURL = FileManager.default.temporaryDirectory
            .appendingPathComponent("music-assistant-store-tests")
            .appendingPathComponent(UUID().uuidString)
    }

    override func tearDownWithError() throws {
        if let temporaryDirectoryURL {
            try? FileManager.default.removeItem(at: temporaryDirectoryURL)
        }
        temporaryDirectoryURL = nil
    }

    func testCreatesOpensSavesAndListsSongProjectsLocally() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        let createdAt = Date(timeIntervalSince1970: 100)
        let updatedAt = Date(timeIntervalSince1970: 200)
        var project = SongProject(
            id: "local-project",
            title: "Local Project",
            idea: "Persist this song locally",
            genres: [GenreStyle(id: "pop", name: "Pop")],
            createdAt: createdAt,
            updatedAt: updatedAt
        )

        try await store.create(project)

        let createdProjectIDs = try await store.loadProjectIDs()
        let openedProject = try await store.open(id: project.id)

        XCTAssertEqual(createdProjectIDs, ["local-project"])
        XCTAssertEqual(openedProject, project)

        project.title = "Updated Local Project"
        project.setBPMManually(100)
        try await store.save(project)

        let updatedProject = try await store.open(id: project.id)

        XCTAssertEqual(updatedProject, project)
    }

    func testPersistsSelectedInstrumentsOnSongProject() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        var project = SongProject(
            id: "instrument-selection-project",
            title: "Instrument Selection",
            idea: "Persist selected catalog instruments"
        )

        project.setInstrumentSelected(id: "oud", isSelected: true, variant: "Oud")
        project.setInstrumentSelected(id: "violin", isSelected: true, variant: "Violin")
        project.setInstrumentSelected(id: "oud", isSelected: false)

        try await store.create(project)

        var openedProject = try await store.open(id: project.id)
        XCTAssertFalse(openedProject.isInstrumentSelected(id: "oud"))
        XCTAssertTrue(openedProject.isInstrumentSelected(id: "violin"))
        XCTAssertEqual(openedProject.instrumentTrack(for: "oud")?.variant, "Oud")
        XCTAssertEqual(openedProject.selectedInstrumentIDs, ["violin"])

        openedProject.setInstrumentSelected(id: "oud", isSelected: true, variant: "Oud")
        try await store.save(openedProject)

        let savedProject = try await store.open(id: project.id)
        XCTAssertTrue(savedProject.isInstrumentSelected(id: "oud"))
        XCTAssertTrue(savedProject.isInstrumentSelected(id: "violin"))
        XCTAssertEqual(savedProject.selectedInstrumentIDs, ["oud", "violin"])
    }

    func testRestoresPersistedProjectVersionAndKeepsVersionHistory() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        let restoredAt = Date(timeIntervalSince1970: 900)
        var project = SongProject(
            id: "version-recovery-project",
            title: "Original Direction",
            idea: "Start with acoustic instruments",
            genres: [GenreStyle(id: "folk", name: "Folk")],
            lyrics: Lyrics(text: "Original lyrics"),
            createdAt: Date(timeIntervalSince1970: 100),
            updatedAt: Date(timeIntervalSince1970: 200)
        )

        _ = project.createVersion(
            id: "original-version",
            label: "Original direction",
            createdAt: Date(timeIntervalSince1970: 300)
        )
        project.title = "Later Direction"
        project.idea = "Add electronic elements"
        project.selectInstrument(InstrumentTrack(instrumentId: "oud"))
        project.lyrics = Lyrics(text: "Later lyrics")
        _ = project.createVersion(
            id: "later-version",
            label: "Later direction",
            createdAt: Date(timeIntervalSince1970: 400)
        )
        project.title = "Unsaved direction"

        try await store.create(project)

        var recoveredProject = try await store.open(id: project.id)
        XCTAssertTrue(recoveredProject.restoreVersion(id: "original-version", restoredAt: restoredAt))
        try await store.save(recoveredProject)

        let restoredProject = try await store.open(id: project.id)

        XCTAssertEqual(restoredProject.title, "Original Direction")
        XCTAssertEqual(restoredProject.idea, "Start with acoustic instruments")
        XCTAssertEqual(restoredProject.genres, [GenreStyle(id: "folk", name: "Folk")])
        XCTAssertTrue(restoredProject.instruments.isEmpty)
        XCTAssertEqual(restoredProject.lyrics, Lyrics(text: "Original lyrics"))
        XCTAssertEqual(restoredProject.updatedAt, restoredAt)
        XCTAssertEqual(restoredProject.versions.map(\.id), ["original-version", "later-version"])
        XCTAssertEqual(restoredProject.version(id: "later-version")?.snapshot.title, "Later Direction")
    }

    func testLoadsProjectListSortedByMostRecentUpdate() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        let older = SongProject(
            id: "older-project",
            title: "Older",
            idea: "Created first",
            createdAt: Date(timeIntervalSince1970: 100),
            updatedAt: Date(timeIntervalSince1970: 150)
        )
        let newer = SongProject(
            id: "newer-project",
            title: "Newer",
            idea: "Updated later",
            createdAt: Date(timeIntervalSince1970: 200),
            updatedAt: Date(timeIntervalSince1970: 300)
        )

        try await store.create(older)
        try await store.create(newer)

        let projectList = try await store.loadProjectList()
        let projectIDs = try await store.loadProjectIDs()

        XCTAssertEqual(
            projectList,
            [
                SongProjectListItem(project: newer),
                SongProjectListItem(project: older)
            ]
        )
        XCTAssertEqual(projectIDs, ["newer-project", "older-project"])
    }

    func testCreateDoesNotOverwriteExistingProject() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        let project = SongProject(
            id: "duplicate-project",
            title: "Duplicate",
            idea: "Do not overwrite"
        )

        try await store.create(project)

        do {
            try await store.create(project)
            XCTFail("Expected duplicate project creation to fail.")
        } catch let error as LocalSongProjectStoreError {
            XCTAssertEqual(error, .projectAlreadyExists(project.id))
        }
    }

    func testDeletesSongProjectAndRemovesItFromTheProjectList() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)
        let project = SongProject(
            id: "deletable-project",
            title: "Delete Me",
            idea: "Remove this local project"
        )

        try await store.create(project)
        try await store.delete(id: project.id)

        let remainingProjects = try await store.loadProjectList()
        XCTAssertTrue(remainingProjects.isEmpty)

        do {
            _ = try await store.open(id: project.id)
            XCTFail("Expected deleted project open to fail.")
        } catch let error as LocalSongProjectStoreError {
            XCTAssertEqual(error, .projectNotFound(project.id))
        }
    }

    func testOpenMissingProjectThrowsNotFound() async throws {
        let store = LocalSongProjectStore(directoryURL: temporaryDirectoryURL)

        do {
            _ = try await store.open(id: "missing")
            XCTFail("Expected missing project open to fail.")
        } catch let error as LocalSongProjectStoreError {
            XCTAssertEqual(error, .projectNotFound("missing"))
        }
    }
}