import AppKit

@main
@MainActor
struct ResolvedPlaybackCheck {
    static func require(_ condition: @autoclosure () -> Bool, _ message: String) {
        if !condition() { fatalError("FAIL: " + message) }
    }
    static func until(_ message: String, model: PlayerModel, _ predicate: () -> Bool) {
        let deadline = ContinuousClock.now.advanced(by: .seconds(45))
        while !predicate(), ContinuousClock.now < deadline {
            if model.state.status == PLAYER_ERROR || model.commandError != nil {
                fatalError("FAIL: " + (model.errorText ?? "Playback failed"))
            }
            RunLoop.main.run(until: Date(timeIntervalSinceNow: 0.01))
        }
        require(predicate(), message)
    }
    static func main() async {
        do { try await run() }
        catch { fatalError("FAIL: " + error.localizedDescription) }
    }

    static func run() async throws {
        _ = NSApplication.shared
        NSApp.setActivationPolicy(.prohibited)
        let file = URL(fileURLWithPath: CommandLine.arguments[1])
        let source = try ResolvedSource.load(from: file)
        let suite = "terebi.resolved-check." + UUID().uuidString
        let defaults = UserDefaults(suiteName: suite)!
        defer { defaults.removePersistentDomain(forName: suite) }
        let model = PlayerModel(defaults: defaults, progressFile: CommandLine.arguments.count > 2 ? CommandLine.arguments[2] : nil)
        defer { model.shutdown() }
        model.openResolvedSource(file)
        until("video/audio decode and advancing playback", model: model) {
            model.state.status == PLAYER_PLAYING && model.state.has_video && model.state.has_audio && model.state.position > 0.2
        }
        print("PASS: resolved HLS decodes video/audio and advances")
        fflush(stdout)
        require(model.setPlayback(playing: false), "pause accepted")
        until("pause acknowledged", model: model) { model.state.status == PLAYER_PAUSED }
        require(model.state.can_seek && model.state.duration > 0, "seekable measured duration")
        guard let index = source.subtitles.firstIndex(where: \.isDefault) else {
            fatalError("FAIL: smoke requires a default subtitle")
        }
        let track = source.subtitles[index]
        let document = try await WebVTTDocument.load(url: track.url, headers: track.headers)
        let playableCues = document.cues.filter { !$0.text.isEmpty && $0.start + 0.1 < model.state.duration }
        require(playableCues.count >= 2, "smoke requires two visible subtitle cues")
        let target = playableCues[1].start + min(0.1, (playableCues[1].end - playableCues[1].start) / 2)
        require(!document.text(at: target).isEmpty, "forward seek targets a visible English cue")
        require(model.seekRelative(target - model.state.position), "seek accepted")
        until("seek acknowledged and subtitle synchronized", model: model) {
            !model.state.seek_pending && abs(model.state.position - target) < 0.2 &&
                model.subtitleText == document.text(at: model.state.position) && model.subtitleError == nil
        }
        require(model.selectedSubtitle == index && model.subtitleTracks[index].label == track.label, "default selection and label retained")
        let backward = playableCues[0].start + min(0.1, (playableCues[0].end - playableCues[0].start) / 2)
        require(model.seekRelative(backward - model.state.position), "backward seek accepted")
        until("backward seek subtitle synchronized", model: model) {
            !model.state.seek_pending && abs(model.state.position - backward) < 0.2 &&
                model.subtitleText == document.text(at: model.state.position)
        }
        print("PASS: default VTT selected, forward/backward seek and acknowledged cue timing")
    }
}