//
//  PlayerQueueView.swift
//  Mobile Music Assistant
//
//  Created by Sven Hanold on 06.04.26.
//

import SwiftUI

struct PlayerQueueView: View {
    @Environment(MAService.self) private var service
    let playerId: String

    @State private var isLoading = false
    @State private var showClearConfirm = false

    private var queueItems: [MAQueueItem] {
        service.playerManager.queues[playerId] ?? []
    }

    private var currentIndex: Int? {
        service.playerManager.playerQueues[playerId]?.currentIndex
    }

    private var currentItemId: String? {
        service.playerManager.playerQueues[playerId]?.currentItem?.queueItemId
    }

    private var shuffleEnabled: Bool {
        service.playerManager.playerQueues[playerId]?.shuffleEnabled ?? false
    }

    private var repeatMode: RepeatMode {
        service.playerManager.playerQueues[playerId]?.repeatMode ?? .off
    }

    var body: some View {
        VStack(spacing: 0) {
            // Control buttons
            controlBar
                .padding(.horizontal, 16)
                .padding(.vertical, 10)

            Divider()

            // Queue list
            if isLoading && queueItems.isEmpty {
                Spacer()
                ProgressView()
                Spacer()
            } else if queueItems.isEmpty {
                Spacer()
                Text("Queue is empty")
                    .font(.subheadline)
                    .foregroundStyle(.secondary)
                Spacer()
            } else {
                queueList
            }
        }
        .task {
            isLoading = true
            try? await service.playerManager.loadQueue(playerId: playerId)
            isLoading = false
        }
        .confirmationDialog("Clear the entire queue?", isPresented: $showClearConfirm, titleVisibility: .visible) {
            Button("Clear Queue", role: .destructive) {
                Task { try? await service.playerManager.clearQueue(playerId: playerId) }
            }
            Button("Cancel", role: .cancel) { }
        }
    }

    // MARK: - Control Bar

    @ViewBuilder
    private var controlBar: some View {
        HStack(spacing: 0) {
            // Shuffle
            Button {
                Task { try? await service.playerManager.setShuffle(playerId: playerId, enabled: !shuffleEnabled) }
            } label: {
                VStack(spacing: 3) {
                    Image(systemName: "shuffle")
                        .font(.system(size: 20))
                        .foregroundStyle(shuffleEnabled ? Color.accentColor : .secondary)
                    Text("Shuffle")
                        .font(.caption2)
                        .foregroundStyle(shuffleEnabled ? Color.accentColor : .secondary)
                }
                .frame(maxWidth: .infinity)
            }
            .buttonStyle(.plain)

            // Repeat
            Button {
                let next: RepeatMode
                switch repeatMode {
                case .off: next = .all
                case .all: next = .one
                case .one: next = .off
                }
                Task { try? await service.playerManager.setRepeatMode(playerId: playerId, mode: next) }
            } label: {
                VStack(spacing: 3) {
                    Image(systemName: repeatMode == .one ? "repeat.1" : "repeat")
                        .font(.system(size: 20))
                        .foregroundStyle(repeatMode == .off ? .secondary : Color.accentColor)
                    Text(repeatMode == .off ? "Repeat" : (repeatMode == .one ? "Repeat 1" : "Repeat All"))
                        .font(.caption2)
                        .foregroundStyle(repeatMode == .off ? .secondary : Color.accentColor)
                }
                .frame(maxWidth: .infinity)
            }
            .buttonStyle(.plain)

            // Clear queue
            Button {
                showClearConfirm = true
            } label: {
                VStack(spacing: 3) {
                    Image(systemName: "xmark.bin")
                        .font(.system(size: 20))
                        .foregroundStyle(.secondary)
                    Text("Clear")
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                }
                .frame(maxWidth: .infinity)
            }
            .buttonStyle(.plain)
            .disabled(queueItems.isEmpty)
            .opacity(queueItems.isEmpty ? 0.4 : 1.0)
        }
    }

    // MARK: - Queue List

    @ViewBuilder
    private var queueList: some View {
        ScrollViewReader { proxy in
            List {
                ForEach(Array(queueItems.enumerated()), id: \.element.id) { index, item in
                    let isCurrent = currentIndex == index || item.queueItemId == currentItemId
                    QueueItemRow(item: item, isCurrent: isCurrent)
                        .id(item.queueItemId)
                        .listRowInsets(EdgeInsets())
                        .listRowSeparator(.hidden)
                        .contentShape(Rectangle())
                        .onTapGesture {
                            Task {
                                try? await service.playerManager.playIndex(
                                    playerId: playerId,
                                    index: index
                                )
                            }
                        }
                }
                .onMove { source, destination in
                    guard let from = source.first else { return }
                    let posShift = destination > from ? destination - from - 1 : destination - from
                    guard posShift != 0 else { return }
                    let itemId = queueItems[from].queueItemId
                    Task {
                        try? await service.playerManager.moveQueueItem(
                            playerId: playerId,
                            queueItemId: itemId,
                            posShift: posShift
                        )
                    }
                }
            }
            .listStyle(.plain)
            .environment(\.editMode, .constant(.active))
            .onAppear {
                if let id = currentItemId {
                    proxy.scrollTo(id, anchor: .center)
                }
            }
            .onChange(of: currentItemId) { _, newId in
                if let newId {
                    withAnimation {
                        proxy.scrollTo(newId, anchor: .center)
                    }
                }
            }
        }
    }
}

// MARK: - Queue Item Row

private struct QueueItemRow: View {
    @Environment(MAService.self) private var service
    let item: MAQueueItem
    let isCurrent: Bool

    var body: some View {
        HStack(spacing: 12) {
            // Thumbnail
            CachedAsyncImage(url: service.imageProxyURL(
                path: item.mediaItem?.imageUrl,
                provider: item.mediaItem?.imageProvider,
                size: 96
            )) { image in
                image.resizable().scaledToFill()
            } placeholder: {
                RoundedRectangle(cornerRadius: 6)
                    .fill(Color.gray.opacity(0.2))
                    .overlay {
                        Image(systemName: "music.note")
                            .font(.caption)
                            .foregroundStyle(.secondary)
                    }
            }
            .frame(width: 48, height: 48)
            .clipShape(RoundedRectangle(cornerRadius: 6))

            // Track info
            VStack(alignment: .leading, spacing: 3) {
                HStack(spacing: 5) {
                    if isCurrent {
                        Image(systemName: "waveform")
                            .font(.caption2)
                            .foregroundStyle(.green)
                    }
                    Text(item.name)
                        .font(.body)
                        .fontWeight(isCurrent ? .semibold : .regular)
                        .foregroundStyle(.primary)
                        .lineLimit(1)
                }

                if let artists = item.mediaItem?.artists, !artists.isEmpty {
                    Text(artists.map { $0.name }.joined(separator: ", "))
                        .font(.caption)
                        .foregroundStyle(.secondary)
                        .lineLimit(1)
                }
            }

            Spacer()

            // Duration
            if let duration = item.duration ?? item.mediaItem?.duration {
                Text(formatDuration(duration))
                    .font(.caption)
                    .foregroundStyle(.secondary)
                    .monospacedDigit()
            }
        }
        .padding(.vertical, 8)
        .padding(.horizontal, 16)
        .background(isCurrent ? Color.primary.opacity(0.08) : Color.clear)
    }

    private func formatDuration(_ seconds: Int) -> String {
        let minutes = seconds / 60
        let remainingSeconds = seconds % 60
        return String(format: "%d:%02d", minutes, remainingSeconds)
    }
}