import XCTest
@testable import MixBoard

/// Tests for DownloadService helper methods and export pipeline integration.
final class DownloadServiceTests: XCTestCase {

    // MARK: - File Extension Extraction

    func testFileExtensionFromCloudStreamPath() {
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/Artist/Album/track.flac", contentType: nil),
            "flac"
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/Artist/Album/song.mp3", contentType: nil),
            "mp3"
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/Various/Compilation/01 Intro.wav", contentType: nil),
            "wav"
        )
    }

    func testFileExtensionFallsBackToContentType() {
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/noext", contentType: "audio/flac"),
            "flac"
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: nil, contentType: "audio/mpeg"),
            "mp3"
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: nil, contentType: "audio/wav"),
            "wav"
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: nil, contentType: "audio/ogg"),
            "ogg"
        )
    }

    func testFileExtensionPathTakesPrecedence() {
        // Path extension should win over Content-Type
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/track.flac", contentType: "audio/mpeg"),
            "flac"
        )
    }

    func testFileExtensionEmptyWhenNothingAvailable() {
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: nil, contentType: nil),
            ""
        )
        XCTAssertEqual(
            DownloadService.fileExtension(fromPath: "/music/noext", contentType: "application/octet-stream"),
            ""
        )
    }

    // MARK: - Safe File Name

    func testSafeFileNameWithArtist() {
        let track = Track(title: "My Song", artist: "The Artist", filePath: "")
        XCTAssertEqual(DownloadService.safeFileName(for: track), "The Artist - My Song")
    }

    func testSafeFileNameWithoutArtist() {
        let track = Track(title: "Untitled", filePath: "")
        XCTAssertEqual(DownloadService.safeFileName(for: track), "Untitled")
    }

    func testSafeFileNameSanitizesUnsafeChars() {
        let track = Track(title: "AC/DC: Live\\\"Loud\"", artist: "Various", filePath: "")
        let name = DownloadService.safeFileName(for: track)
        XCTAssertFalse(name.contains("/"))
        XCTAssertFalse(name.contains(":"))
        XCTAssertFalse(name.contains("\\"))
        XCTAssertFalse(name.contains("\""))
    }

    // MARK: - ExportOptions effectiveFileURL

    func testEffectiveFileURLForLocalTrack() {
        let track = Track(title: "Local", filePath: "/tmp/local.mp3")
        let options = ExportOptions.default
        let url = options.effectiveFileURL(for: track)
        XCTAssertEqual(url?.path, "/tmp/local.mp3")
    }

    func testEffectiveFileURLForCloudTrackWithDownload() {
        let track = Track(title: "Cloud", filePath: "")
        track.isCloud = true
        track.cloudStreamPath = "/music/Artist/Album/track.flac"

        var options = ExportOptions.default
        let downloadedURL = URL(fileURLWithPath: "/tmp/downloads/Artist - Cloud.flac")
        options.downloadedFiles = [track.id: downloadedURL]

        let url = options.effectiveFileURL(for: track)
        XCTAssertEqual(url, downloadedURL)
    }

    func testEffectiveFileURLForCloudTrackWithoutDownload() {
        let track = Track(title: "Cloud", filePath: "")
        track.isCloud = true
        let options = ExportOptions.default
        XCTAssertNil(options.effectiveFileURL(for: track))
    }

    func testEffectiveFileURLDownloadOverridesLocalPath() {
        let track = Track(title: "Overridden", filePath: "/tmp/original.mp3")
        var options = ExportOptions.default
        let downloadedURL = URL(fileURLWithPath: "/tmp/downloads/new.mp3")
        options.downloadedFiles = [track.id: downloadedURL]

        let url = options.effectiveFileURL(for: track)
        XCTAssertEqual(url, downloadedURL)
    }
}