//
//  PlaylistsView.swift
//  Mobile Music Assistant
//
//  Created by Sven Hanold on 26.03.26.
//

import SwiftUI

struct PlaylistsView: View {
    @Environment(MAService.self) private var service
    @State private var errorMessage: String?
    @State private var showError = false
    
    private var playlists: [MAPlaylist] {
        service.libraryManager.playlists
    }
    
    private var isLoading: Bool {
        service.libraryManager.isLoadingPlaylists
    }
    
    var body: some View {
        Group {
            if isLoading && playlists.isEmpty {
                ProgressView()
            } else if playlists.isEmpty {
                ContentUnavailableView(
                    "No Playlists",
                    systemImage: "music.note.list",
                    description: Text("Your library doesn't contain any playlists yet")
                )
            } else {
                List {
                    ForEach(playlists) { playlist in
                        NavigationLink(value: playlist) {
                            PlaylistRow(playlist: playlist)
                        }
                    }
                }
                .listStyle(.plain)
            }
        }
        .navigationDestination(for: MAPlaylist.self) { playlist in
            PlaylistDetailView(playlist: playlist)
        }
        .refreshable {
            await loadPlaylists(refresh: true)
        }
        .task {
            if playlists.isEmpty {
                await loadPlaylists(refresh: false)
            }
        }
        .alert("Error", isPresented: $showError) {
            Button("OK", role: .cancel) { }
        } message: {
            if let errorMessage {
                Text(errorMessage)
            }
        }
    }
    
    private func loadPlaylists(refresh: Bool) async {
        do {
            try await service.libraryManager.loadPlaylists(refresh: refresh)
        } catch {
            errorMessage = error.localizedDescription
            showError = true
        }
    }
}

// MARK: - Playlist Row

struct PlaylistRow: View {
    @Environment(MAService.self) private var service
    let playlist: MAPlaylist
    
    var body: some View {
        HStack(spacing: 12) {
            // Playlist Cover
            if let imageUrl = playlist.imageUrl {
                let coverURL = service.imageProxyURL(path: imageUrl, size: 128)
                
                CachedAsyncImage(url: coverURL) { image in
                    image
                        .resizable()
                        .aspectRatio(contentMode: .fill)
                } placeholder: {
                    Rectangle()
                        .fill(Color.gray.opacity(0.2))
                }
                .frame(width: 64, height: 64)
                .clipShape(RoundedRectangle(cornerRadius: 8))
            } else {
                RoundedRectangle(cornerRadius: 8)
                    .fill(Color.gray.opacity(0.2))
                    .frame(width: 64, height: 64)
                    .overlay {
                        Image(systemName: "music.note.list")
                            .font(.title2)
                            .foregroundStyle(.secondary)
                    }
            }
            
            // Playlist Info
            VStack(alignment: .leading, spacing: 4) {
                Text(playlist.name)
                    .font(.headline)
                    .lineLimit(1)
                
                if let owner = playlist.owner {
                    Text("By \(owner)")
                        .font(.caption)
                        .foregroundStyle(.secondary)
                        .lineLimit(1)
                }
                
                if playlist.isEditable {
                    Label("Editable", systemImage: "pencil")
                        .font(.caption2)
                        .foregroundStyle(.blue)
                }
            }
            
            Spacer()
        }
        .padding(.vertical, 4)
    }
}

#Preview {
    NavigationStack {
        PlaylistsView()
            .environment(MAService())
    }
}