import ExtensionFoundation
import NowPlaying
import Observation
import Foundation

@main
struct MusicBridgeRemote: RemoteMediaSessionExtension {
    var configuration: RemoteMediaSessionExtensionConfiguration<Self> {
        RemoteMediaSessionExtensionConfiguration(extension: self)
    }
    func session(_ attributes: SystemPlayerAttributes) async throws -> PCMediaSession {
        _ = try SystemPlayerCredentials.load(attributes.id)
        return PCMediaSession(attributes)
    }
}

@MainActor @Observable
final class PCMediaSession: RemoteMediaSessionRepresentable {
    let id: String
    var attributes: SystemPlayerAttributes
    private let transport = SystemPlayerTransport()
    init(_ attributes: SystemPlayerAttributes) { id = attributes.id; self.attributes = attributes }

    func update(_ attributes: SystemPlayerAttributes) { self.attributes = attributes }

    var content: (any MediaContentRepresentable)? {
        guard attributes.hasSession else { return nil }
        let artwork = attributes.artworkID.map { artworkID in
            Artwork(id: artworkID) { _ in
                let saved = try SystemPlayerCredentials.load(self.id)
                let client = BridgeClient(saved, timeout: 5)
                defer { client.close() }
                return try ArtworkRepresentation(data: await client.artwork(artworkID))
            }
        }
        return MusicContent(id: attributes.source + "/" + attributes.title + "/" + attributes.artist,
                            songTitle: attributes.title.isEmpty ? "Без названия" : attributes.title,
                            artistName: attributes.artist, albumName: "", type: .audio,
                            duration: attributes.duration > 0 ? .finite(attributes.duration) : nil, artwork: artwork)
    }

    var playbackSnapshot: MediaPlaybackSnapshot? {
        MediaPlaybackSnapshot(state: attributes.playing ? .playing(rate: Float(attributes.rate)) : .paused,
                              elapsedTime: attributes.position, timestamp: attributes.timestamp)
    }

    var commands: [MediaCommand] {
        [
            .play { try await self.send(.play) }.enabled(attributes.capabilities.play),
            .pause { try await self.send(.pause) }.enabled(attributes.capabilities.pause),
            .next { try await self.send(.next) }.enabled(attributes.capabilities.next),
            .previous { try await self.send(.previous) }.enabled(attributes.capabilities.previous),
            .seekToPosition { try await self.send(.seek, value: $0) }.enabled(attributes.capabilities.seek)
        ]
    }

    var devices: [MediaDevice] {
        let capabilities: [MediaDevice.Capability] = attributes.volume.map { volume in
            [.absoluteVolume(Float(volume)) { try await self.send(.volume, value: Double($0)) }]
        } ?? []
        return [MediaDevice(id: id, name: "MusicBridge · ПК", type: .speaker, capabilities: capabilities)]
    }

    private func send(_ action: SystemPlayerAction, value: Double? = nil) async throws {
        let state = try await transport.send(action, value: value, sessionID: id)
        attributes = SystemPlayerAttributes(id: id, state: state)
    }
}