import AppIntents

// Siri and Shortcuts (#427). Each is an App Intent, and IPXShortcuts below gives the common ones
// phrases that work with nothing set up: "Resume iPX", "Pause iPX", "How many unread in iPX".
// The playback ones are AudioPlaybackIntents, which iOS runs in the app and lets start audio
// from the background, so they work with the phone locked and the app closed.

struct ResumeIntent: AudioPlaybackIntent {
    static let title: LocalizedStringResource = "Resume Listening"
    static let description = IntentDescription(
        "Carries on with what iPX was playing, or the last episode, from where you left off.")

    @MainActor
    func perform() async throws -> some IntentResult {
        guard Playback.shared.resumeLast() else { throw NothingToResume() }
        return .result()
    }
}

/// What Siri says when there is no episode to carry on with.
struct NothingToResume: Error, CustomLocalizedStringResourceConvertible {
    var localizedStringResource: LocalizedStringResource {
        "There is nothing to resume. Play an episode in iPX first."
    }
}

struct PauseIntent: AudioPlaybackIntent {
    static let title: LocalizedStringResource = "Pause"
    static let description = IntentDescription("Pauses what iPX is playing.")

    @MainActor
    func perform() async throws -> some IntentResult {
        Playback.shared.pause()
        return .result()
    }
}

struct SkipForwardIntent: AudioPlaybackIntent {
    static let title: LocalizedStringResource = "Skip Forward"
    static let description = IntentDescription("Skips 30 seconds ahead, as the player's button does.")

    @MainActor
    func perform() async throws -> some IntentResult {
        Playback.shared.seek(to: Playback.shared.currentTime + 30)
        return .result()
    }
}

struct SkipBackIntent: AudioPlaybackIntent {
    static let title: LocalizedStringResource = "Skip Back"
    static let description = IntentDescription("Goes back 15 seconds, as the player's button does.")

    @MainActor
    func perform() async throws -> some IntentResult {
        Playback.shared.seek(to: Playback.shared.currentTime - 15)
        return .result()
    }
}

struct SleepTimerIntent: AudioPlaybackIntent {
    static let title: LocalizedStringResource = "Set Sleep Timer"
    static let description = IntentDescription(
        "Pauses iPX after a number of minutes, fading out over the last ten seconds. Zero turns it off.")

    @Parameter(title: "Minutes", default: 30, inclusiveRange: (0, 600),
               requestValueDialog: "For how many minutes?")
    var minutes: Int

    @MainActor
    func perform() async throws -> some IntentResult & ProvidesDialog {
        Playback.shared.sleep(after: Double(minutes) * 60)
        return .result(dialog: minutes == 0 ? "The sleep timer is off." : "iPX will pause in \(minutes) minutes.")
    }
}

struct UnreadIntent: AppIntent {
    static let title: LocalizedStringResource = "Unread Count"
    static let description = IntentDescription("How many items are unread in All Subscriptions.")

    func perform() async throws -> some IntentResult & ReturnsValue<Int> & ProvidesDialog {
        guard let n = await Badge.fetch() else {
            return .result(value: 0, dialog: "iPX could not reach your server.")
        }
        await MainActor.run { Badge.set(n) }
        return .result(value: n, dialog: n == 0 ? "Nothing is unread." : "\(n) unread in All Subscriptions.")
    }
}

struct IPXShortcuts: AppShortcutsProvider {
    static var appShortcuts: [AppShortcut] {
        AppShortcut(intent: ResumeIntent(),
                    phrases: ["Resume \(.applicationName)", "Play \(.applicationName)",
                              "Carry on listening in \(.applicationName)"],
                    shortTitle: "Resume", systemImageName: "play.fill")
        AppShortcut(intent: PauseIntent(), phrases: ["Pause \(.applicationName)"],
                    shortTitle: "Pause", systemImageName: "pause.fill")
        AppShortcut(intent: SkipForwardIntent(),
                    phrases: ["Skip forward in \(.applicationName)", "Skip ahead in \(.applicationName)"],
                    shortTitle: "Skip Forward", systemImageName: "goforward.30")
        AppShortcut(intent: SkipBackIntent(), phrases: ["Skip back in \(.applicationName)"],
                    shortTitle: "Skip Back", systemImageName: "gobackward.15")
        AppShortcut(intent: SleepTimerIntent(),
                    phrases: ["Set a sleep timer in \(.applicationName)", "\(.applicationName) sleep timer"],
                    shortTitle: "Sleep Timer", systemImageName: "moon.zzz")
        AppShortcut(intent: UnreadIntent(),
                    phrases: ["How many unread in \(.applicationName)", "What's new in \(.applicationName)"],
                    shortTitle: "Unread", systemImageName: "tray.full")
    }
}