import SwiftUI

// MARK: - Ejemplo de Integración del Sistema de Descargas

// Este archivo muestra cómo integrar el sistema de descargas en tu app

/// Ejemplo 1: Agregar DownloadsView a un TabView
struct MainTabViewExample: View {
    @State private var selectedTab = 0

    var body: some View {
        TabView(selection: $selectedTab) {
            // Home/Library
            ContentView()
                .tabItem {
                    Label("Biblioteca", systemImage: "books.vertical")
                }
                .tag(0)

            // Downloads
            DownloadsView()
                .tabItem {
                    Label("Descargas", systemImage: "arrow.down.circle")
                }
                .tag(1)

            // Settings
            SettingsView()
                .tabItem {
                    Label("Ajustes", systemImage: "gear")
                }
                .tag(2)
        }
    }
}

/// Ejemplo 2: Navegación desde MangaDetailView
struct MangaDetailViewWithNavigation: View {
    let manga: Manga

    var body: some View {
        MangaDetailView(manga: manga)
            .toolbar {
                ToolbarItem(placement: .navigationBarTrailing) {
                    Menu {
                        Button {
                            // Navegar a descargas
                        } label: {
                            Label("Ver Descargas", systemImage: "arrow.down.circle")
                        }

                        Button {
                            // Descargar último capítulo
                        } label: {
                            Label("Descargar último", systemImage: "arrow.down.doc")
                        }
                    } label: {
                        Image(systemName: "ellipsis.circle")
                    }
                }
            }
    }
}

/// Ejemplo 3: Badge en TabView para mostrar descargas activas
struct MainTabViewWithBadge: View {
    @StateObject private var downloadManager = DownloadManager.shared
    @State private var selectedTab = 0

    var body: some View {
        TabView(selection: $selectedTab) {
            ContentView()
                .tabItem {
                    Label("Biblioteca", systemImage: "books.vertical")
                }
                .tag(0)

            DownloadsView()
                .tabItem {
                    Label("Descargas", systemImage: "arrow.down.circle")
                }
                .badge(downloadManager.activeDownloads.count)
                .tag(1)

            SettingsView()
                .tabItem {
                    Label("Ajustes", systemImage: "gear")
                }
                .tag(2)
        }
    }
}

/// Ejemplo 4: Sheet para mostrar descargas desde cualquier vista
struct DownloadsSheetExample: View {
    @State private var showingDownloads = false
    @StateObject private var downloadManager = DownloadManager.shared

    var body: some View {
        VStack {
            Text("Contenido Principal")

            Button("Ver Descargas") {
                showingDownloads = true
            }
            .disabled(downloadManager.activeDownloads.isEmpty)
        }
        .sheet(isPresented: $showingDownloads) {
            NavigationView {
                DownloadsView()
                    .toolbar {
                        ToolbarItem(placement: .navigationBarTrailing) {
                            Button("Cerrar") {
                                showingDownloads = false
                            }
                        }
                    }
            }
        }
    }
}

/// Ejemplo 5: Vista de configuración con opciones de descarga
struct SettingsView: View {
    @StateObject private var storage = StorageService.shared
    @StateObject private var downloadManager = DownloadManager.shared
    @State private var showingClearAlert = false

    var body: some View {
        Form {
            Section("Descargas") {
                HStack {
                    Text("Almacenamiento usado")
                    Spacer()
                    Text(storage.formatFileSize(storage.getStorageSize()))
                        .foregroundColor(.secondary)
                }

                Button(role: .destructive) {
                    showingClearAlert = true
                } label: {
                    Label("Limpiar todas las descargas", systemImage: "trash")
                }
                .disabled(storage.getStorageSize() == 0)
            }

            Section("Estadísticas") {
                HStack {
                    Text("Descargas activas")
                    Spacer()
                    Text("\(downloadManager.activeDownloads.count)")
                        .foregroundColor(.secondary)
                }

                HStack {
                    Text("Completadas")
                    Spacer()
                    Text("\(downloadManager.completedDownloads.count)")
                        .foregroundColor(.secondary)
                }

                HStack {
                    Text("Fallidas")
                    Spacer()
                    Text("\(downloadManager.failedDownloads.count)")
                        .foregroundColor(.secondary)
                }
            }

            Section("Preferencias") {
                Toggle("Descargar solo en Wi-Fi", isOn: .constant(true))
                Toggle("Notificar descargas completadas", isOn: .constant(true))
            }
        }
        .navigationTitle("Ajustes")
        .alert("Limpiar descargas", isPresented: $showingClearAlert) {
            Button("Cancelar", role: .cancel) { }
            Button("Limpiar", role: .destructive) {
                storage.clearAllDownloads()
                downloadManager.clearCompletedHistory()
                downloadManager.clearFailedHistory()
            }
        } message: {
            Text("Esta acción eliminará todos los capítulos descargados. ¿Estás seguro?")
        }
    }
}

/// Ejemplo 6: Widget de descargas activas en home
struct ActiveDownloadsWidget: View {
    @ObservedObject var downloadManager = DownloadManager.shared

    var body: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Descargas Activas")
                .font(.headline)

            if downloadManager.activeDownloads.isEmpty {
                Text("No hay descargas activas")
                    .font(.caption)
                    .foregroundColor(.secondary)
            } else {
                ForEach(downloadManager.activeDownloads.prefix(3)) { task in
                    HStack {
                        VStack(alignment: .leading) {
                            Text(task.mangaTitle)
                                .font(.subheadline)
                                .lineLimit(1)

                            Text("Cap. \(task.chapterNumber)")
                                .font(.caption)
                                .foregroundColor(.secondary)
                        }

                        Spacer()

                        ProgressView(value: task.progress)
                            .frame(width: 50)
                    }
                }

                if downloadManager.activeDownloads.count > 3 {
                    Text("+\(downloadManager.activeDownloads.count - 3) más")
                        .font(.caption)
                        .foregroundColor(.secondary)
                }

                Button("Ver todas") {
                    // Navegar a DownloadsView
                }
                .buttonStyle(.bordered)
            }
        }
        .padding()
        .background(
            RoundedRectangle(cornerRadius: 12)
                .fill(Color(.systemGray6))
        )
    }
}

/// Ejemplo 7: Modificador para mostrar banner de descargas activas
struct ActiveDownloadsBannerModifier: ViewModifier {
    @ObservedObject var downloadManager = DownloadManager.shared
    @State private var isVisible = false

    func body(content: Content) -> some View {
        ZStack(alignment: .top) {
            content

            if downloadManager.hasActiveDownloads && isVisible {
                HStack {
                    Image(systemName: "arrow.down.circle.fill")
                        .foregroundColor(.blue)

                    Text("\(downloadManager.activeDownloads.count) descarga(s) en progreso")
                        .font(.caption)

                    Spacer()

                    Button("Ver") {
                        // Navegar a DownloadsView
                    }
                    .font(.caption)
                }
                .padding()
                .background(
                    RoundedRectangle(cornerRadius: 10)
                        .fill(.blue)
                        .shadow(color: .black.opacity(0.2), radius: 5, x: 0, y: 2)
                )
                .foregroundColor(.white)
                .padding(.horizontal)
                .padding(.top, 50)
                .transition(.move(edge: .top).combined(with: .opacity))
            }
        }
        .onAppear {
            if downloadManager.hasActiveDownloads {
                withAnimation(.spring()) {
                    isVisible = true
                }
            }
        }
        .onChange(of: downloadManager.hasActiveDownloads) { hasActive in
            withAnimation(.spring()) {
                isVisible = hasActive
            }
        }
    }
}

extension View {
    func activeDownloadsBanner() -> some View {
        modifier(ActiveDownloadsBannerModifier())
    }
}

// MARK: - Preview

#Preview {
    MainTabViewWithBadge()
}

#Preview("Downloads Widget") {
    ActiveDownloadsWidget()
        .padding()
}

#Preview("Settings") {
    NavigationView {
        SettingsView()
    }
}