import Testing
import Foundation
import MusicShared
@testable import Music

@MainActor
struct StreamingIntegrationTests {
    static let testAPIKey = "integration-test-key"

    // Full flow: start server, authenticate, download DB, verify track is present.
    // Steps:
    // 1. Create an in-memory DB and insert a test track
    // 2. Start StreamingServer on a random port
    // 3. Authenticate via GET /auth
    // 4. Download DB via GET /db
    // 5. Save downloaded DB to disk and verify the track is present
    @Test(.timeLimit(.minutes(1)))
    func fullConnectionFlow() async throws {
        let db = try DatabaseService(inMemory: true)
        var track = Track.fixture(id: nil, fileURL: "/tmp/test.mp3", title: "Test Song")
        try db.insert(&track)

        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"

        // 3. Authenticate
        var authReq = URLRequest(url: URL(string: "\(baseURL)/auth")!)
        authReq.setValue("Bearer \(Self.testAPIKey)", forHTTPHeaderField: "Authorization")
        let (authData, authResp) = try await URLSession.shared.data(for: authReq)
        let authHTTP = try #require(authResp as? HTTPURLResponse)
        #expect(authHTTP.statusCode == 200)
        let authResponse = try JSONDecoder().decode(AuthResponse.self, from: authData)
        #expect(authResponse.protocolVersion == StreamingConstants.protocolVersion)

        // 4. Download DB
        var dbReq = URLRequest(url: URL(string: "\(baseURL)/db")!)
        dbReq.setValue("Bearer \(Self.testAPIKey)", forHTTPHeaderField: "Authorization")
        let (dbData, dbResp) = try await URLSession.shared.data(for: dbReq)
        let dbHTTP = try #require(dbResp as? HTTPURLResponse)
        #expect(dbHTTP.statusCode == 200)
        #expect(dbData.count > 0)

        // 5. Verify downloaded DB contains the track
        let tempPath = FileManager.default.temporaryDirectory
            .appendingPathComponent("integration_test_\(UUID().uuidString).sqlite").path
        defer { try? FileManager.default.removeItem(atPath: tempPath) }
        try dbData.write(to: URL(fileURLWithPath: tempPath))
        let downloadedDb = try DatabaseService(path: tempPath)
        let tracks = try downloadedDb.fetchTracks(search: "", sortColumn: "title", ascending: true)
        #expect(tracks.count == 1)
        #expect(tracks[0].title == "Test Song")
    }

    // Verifies that requests without auth get 401.
    @Test(.timeLimit(.minutes(1)))
    func unauthenticatedRequestsRejected() async throws {
        let db = try DatabaseService(inMemory: true)
        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)

        let request = URLRequest(url: URL(string: "http://127.0.0.1:\(port)/auth")!)
        let (_, response) = try await URLSession.shared.data(for: request)
        let httpResponse = try #require(response as? HTTPURLResponse)
        #expect(httpResponse.statusCode == 401)
    }

    // Verifies the /tracks/:trackId/file endpoint serves audio data.
    @Test(.timeLimit(.minutes(1)))
    func fileEndpointServesTrack() async throws {
        // 1. Create DB with a test track pointing to a real audio file
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.path, title: "Stream Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        // 2. Start server
        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"

        // 3. Request via Bearer auth
        var bearerReq = URLRequest(url: URL(string: "\(baseURL)/file?id=\(trackId)")!)
        bearerReq.setValue("Bearer \(Self.testAPIKey)", forHTTPHeaderField: "Authorization")
        let (bearerData, bearerResp) = try await URLSession.shared.data(for: bearerReq)
        let bearerHTTP = try #require(bearerResp as? HTTPURLResponse)
        #expect(bearerHTTP.statusCode == 200)
        #expect(bearerData.count > 0)

        // 4. Request via token query param
        let tokenURL = URL(string: "\(baseURL)/file?id=\(trackId)&token=\(Self.testAPIKey)")!
        let (tokenData, tokenResp) = try await URLSession.shared.data(for: URLRequest(url: tokenURL))
        let tokenHTTP = try #require(tokenResp as? HTTPURLResponse)
        #expect(tokenHTTP.statusCode == 200)
        #expect(tokenData.count == bearerData.count)

        // 5. Unauthenticated request should be 401
        let noAuthURL = URL(string: "\(baseURL)/file?id=\(trackId)")!
        let (_, noAuthResp) = try await URLSession.shared.data(for: URLRequest(url: noAuthURL))
        let noAuthHTTP = try #require(noAuthResp as? HTTPURLResponse)
        #expect(noAuthHTTP.statusCode == 401)
    }

    // Verifies that wrong API key gets 401.
    @Test(.timeLimit(.minutes(1)))
    func wrongApiKeyRejected() async throws {
        let db = try DatabaseService(inMemory: true)
        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)

        var request = URLRequest(url: URL(string: "http://127.0.0.1:\(port)/auth")!)
        request.setValue("Bearer wrong-key", forHTTPHeaderField: "Authorization")
        let (_, response) = try await URLSession.shared.data(for: request)
        let httpResponse = try #require(response as? HTTPURLResponse)
        #expect(httpResponse.statusCode == 401)
    }

    // Reproduces the real-world "File not found on disk" (HTTP 404) bug.
    //
    // The production scanner (ScannerService) stores `fileURL` as
    // `url.absoluteString` — e.g. "file:///Users/.../song.m4a" — WITH the
    // "file://" scheme and percent-encoding. StreamingServer reconstructed it
    // with `URL(fileURLWithPath:)`, which treats that whole string as a raw
    // (relative) path, prepends the CWD, and skips percent-decoding, so the file
    // is never found on disk. The earlier `fileEndpointServesTrack` test masked
    // this because it stored `fixtureURL.path` (a bare path) instead.
    //
    // Steps:
    // 1. Create a DB with a track whose fileURL is stored EXACTLY as the scanner
    //    stores it: `fixtureURL.absoluteString` (not `.path`).
    // 2. Start the streaming server.
    // 3. Request GET /file?id=<trackId> with a valid token.
    // 4. Expect HTTP 200 with the file's bytes. Before the fix this returns 404
    //    with body {"error":{"message":"File not found on disk"}}.
    @Test(.timeLimit(.minutes(1)))
    func fileEndpointServesTrackStoredAsAbsoluteString() async throws {
        // 1. Insert a track using the production storage format (absoluteString).
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.absoluteString, title: "Abs Stream Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        // 2. Start the server.
        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"

        // 3. Request the file via the token query parameter.
        let url = URL(string: "\(baseURL)/file?id=\(trackId)&token=\(Self.testAPIKey)")!
        let (data, resp) = try await URLSession.shared.data(for: URLRequest(url: url))
        let http = try #require(resp as? HTTPURLResponse)

        // 4. Must serve the bytes, not 404.
        #expect(http.statusCode == 200)
        #expect(data.count > 0)
    }

    // Same root cause as above, exercised through the HLS path (SegmenterCache
    // also used URL(fileURLWithPath:) on the stored fileURL).
    //
    // Steps:
    // 1. Insert a track whose fileURL is stored as `absoluteString`.
    // 2. Start the server.
    // 3. Request GET /tracks/<id>/segments/0.mp3 with a valid token.
    // 4. Expect HTTP 200 with segment bytes (before the fix the segmenter cannot
    //    open the file, so this returns a 404/error).
    @Test(.timeLimit(.minutes(1)))
    func segmentEndpointServesTrackStoredAsAbsoluteString() async throws {
        // 1. Insert a track using the production storage format (absoluteString).
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.absoluteString, title: "Abs HLS Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        // 2. Start the server.
        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"

        // 3. Request the first HLS segment via the token query parameter.
        let url = URL(string: "\(baseURL)/tracks/\(trackId)/segments/0.mp3?token=\(Self.testAPIKey)")!
        let (data, resp) = try await URLSession.shared.data(for: URLRequest(url: url))
        let http = try #require(resp as? HTTPURLResponse)

        // 4. Must serve segment bytes, not 404.
        #expect(http.statusCode == 200)
        #expect(data.count > 0)
    }

    // Reproduces the "seeking does not work in streaming mode" bug.
    //
    // The client plays the /file endpoint through a plain AVURLAsset/AVPlayer
    // with no custom resource loader, so AVPlayer relies on the OS's default
    // HTTP transport. AVPlayer only treats a progressive HTTP asset as
    // *seekable* when the server honors HTTP byte-range requests: a `Range`
    // request must be answered with `206 Partial Content`, a matching
    // `Content-Range`, `Accept-Ranges: bytes`, a `Content-Length` equal to the
    // slice length, and a body containing ONLY the requested slice. The /file
    // endpoint currently ignores the Range header and always returns the whole
    // file with `200 OK`, so AVPlayer concludes the stream has no random access
    // and silently refuses to seek.
    //
    // Steps:
    // 1. Insert a track pointing at a real audio fixture and start the server.
    // 2. Download the full file once to learn its total byte length and exact
    //    bytes (the ground truth we slice against).
    // 3. Request a middle byte range (Range: bytes=10-19) from /file.
    // 4. Expect 206 Partial Content, Content-Range: bytes 10-19/<total>,
    //    Accept-Ranges: bytes, Content-Length: 10, and a body byte-for-byte
    //    equal to fullBytes[10...19].
    @Test(.timeLimit(.minutes(1)))
    func fileEndpointHonorsRangeRequests() async throws {
        // 1. Insert a track + start the server.
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.absoluteString, title: "Range Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"
        let fileURL = URL(string: "\(baseURL)/file?id=\(trackId)&token=\(Self.testAPIKey)")!

        // 2. Download the full file to establish ground-truth length + bytes.
        let (fullData, fullResp) = try await URLSession.shared.data(for: URLRequest(url: fileURL))
        let fullHTTP = try #require(fullResp as? HTTPURLResponse)
        #expect(fullHTTP.statusCode == 200)
        let total = fullData.count
        #expect(total > 20) // fixture must be large enough to slice a middle range

        // 3. Request bytes 10-19 (10 bytes, inclusive range).
        var rangeReq = URLRequest(url: fileURL)
        rangeReq.setValue("bytes=10-19", forHTTPHeaderField: "Range")
        let (rangeData, rangeResp) = try await URLSession.shared.data(for: rangeReq)
        let rangeHTTP = try #require(rangeResp as? HTTPURLResponse)

        // 4. Assert proper Partial Content semantics.
        #expect(rangeHTTP.statusCode == 206)
        #expect(rangeHTTP.value(forHTTPHeaderField: "Accept-Ranges") == "bytes")
        #expect(rangeHTTP.value(forHTTPHeaderField: "Content-Range") == "bytes 10-19/\(total)")
        #expect(rangeHTTP.value(forHTTPHeaderField: "Content-Length") == "10")
        #expect(rangeData.count == 10)
        #expect(rangeData == fullData.subdata(in: 10..<20))
    }

    // A plain GET with no Range header must still succeed AND advertise
    // `Accept-Ranges: bytes` up front, so AVPlayer knows before scrubbing that
    // the stream supports random access. Without this header AVPlayer never
    // enables seeking even if it would have gotten 206s.
    //
    // Steps:
    // 1. Insert a track + start the server.
    // 2. GET /file with no Range header.
    // 3. Expect 200 OK, Accept-Ranges: bytes, and the full body.
    @Test(.timeLimit(.minutes(1)))
    func fileEndpointAdvertisesByteRangesWithoutRangeHeader() async throws {
        // 1. Insert a track + start the server.
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.absoluteString, title: "Accept-Ranges Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"

        // 2. Plain GET, no Range header.
        let fileURL = URL(string: "\(baseURL)/file?id=\(trackId)&token=\(Self.testAPIKey)")!
        let (data, resp) = try await URLSession.shared.data(for: URLRequest(url: fileURL))
        let http = try #require(resp as? HTTPURLResponse)

        // 3. Full body returned, but server advertises range support.
        #expect(http.statusCode == 200)
        #expect(http.value(forHTTPHeaderField: "Accept-Ranges") == "bytes")
        #expect(data.count > 0)
    }

    // An open-ended range (Range: bytes=N-) means "from byte N to the end" —
    // the form AVPlayer most commonly issues while streaming forward. The
    // server must return 206 with the tail of the file and a Content-Range
    // whose end is total-1.
    //
    // Steps:
    // 1. Insert a track + start the server.
    // 2. Download the full file for ground-truth length + bytes.
    // 3. Request Range: bytes=10- (byte 10 through EOF).
    // 4. Expect 206, Content-Range: bytes 10-<total-1>/<total>, and a body
    //    equal to fullBytes[10...].
    @Test(.timeLimit(.minutes(1)))
    func fileEndpointHonorsOpenEndedRange() async throws {
        // 1. Insert a track + start the server.
        let db = try DatabaseService(inMemory: true)
        let fixtureURL = try TestFixtures.shortMP3URL()
        var track = Track.fixture(id: nil, fileURL: fixtureURL.absoluteString, title: "Open Range Test")
        try db.insert(&track)
        let trackId = try #require(track.id)

        let server = StreamingServer(db: db, apiKey: Self.testAPIKey, port: 0)
        try await server.start()
        defer { server.stop() }
        let port = try #require(server.actualPort)
        let baseURL = "http://127.0.0.1:\(port)"
        let fileURL = URL(string: "\(baseURL)/file?id=\(trackId)&token=\(Self.testAPIKey)")!

        // 2. Ground-truth full file.
        let (fullData, _) = try await URLSession.shared.data(for: URLRequest(url: fileURL))
        let total = fullData.count
        #expect(total > 10)

        // 3. Open-ended range from byte 10.
        var rangeReq = URLRequest(url: fileURL)
        rangeReq.setValue("bytes=10-", forHTTPHeaderField: "Range")
        let (rangeData, rangeResp) = try await URLSession.shared.data(for: rangeReq)
        let rangeHTTP = try #require(rangeResp as? HTTPURLResponse)

        // 4. Tail of the file, correctly described.
        #expect(rangeHTTP.statusCode == 206)
        #expect(rangeHTTP.value(forHTTPHeaderField: "Content-Range") == "bytes 10-\(total - 1)/\(total)")
        #expect(rangeData.count == total - 10)
        #expect(rangeData == fullData.subdata(in: 10..<total))
    }
}