import SwiftUI
import CoreData

struct BarcodeDetailView: View {
    let historyItem: HistoryItem
    @StateObject private var coreDataManager = CoreDataManager.shared
    @State private var barcodeImage: UIImage?
    @State private var showingShareSheet = false
    @State private var showingAlert = false
    @State private var alertMessage = ""
    
    var body: some View {
        ScrollView {
            VStack(spacing: 20) {
                // 条形码图片
                barcodeImageView
                
                // 条形码类型信息
                barcodeTypeSection
                
                // 条形码内容信息
                barcodeContentSection
                
                // 原始内容
                originalContentSection
                
                // 操作按钮
                actionButtonsSection
            }
            .padding()
        }
        .navigationTitle("条形码详情")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button(action: {
                    showingShareSheet = true
                }) {
                    Image(systemName: "square.and.arrow.up")
                }
            }
        }
        .onAppear {
            generateBarcodeImage()
        }
        .sheet(isPresented: $showingShareSheet) {
            ShareSheet(activityItems: [historyItem.content ?? ""])
        }
        .alert("提示", isPresented: $showingAlert) {
            Button("确定") { }
        } message: {
            Text(alertMessage)
        }
    }
    
    // MARK: - 条形码图片视图
    private var barcodeImageView: some View {
        VStack(spacing: 16) {
            if let barcodeImage = barcodeImage {
                Image(uiImage: barcodeImage)
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .frame(height: 120)
                    .cornerRadius(12)
                    .shadow(radius: 8)
            } else {
                RoundedRectangle(cornerRadius: 12)
                    .fill(Color.gray.opacity(0.3))
                    .frame(height: 120)
                    .overlay(
                        ProgressView()
                            .scaleEffect(1.5)
                    )
            }
            
            Text("扫描此条形码")
                .font(.caption)
                .foregroundColor(.secondary)
        }
    }
    
    // MARK: - 条形码类型信息
    private var barcodeTypeSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack {
                Image(systemName: "barcode")
                    .font(.title2)
                    .foregroundColor(.green)
                
                Text("条形码类型")
                    .font(.headline)
                
                Spacer()
            }
            
            if let barcodeTypeString = historyItem.barcodeType {
                HStack {
                    Image(systemName: getBarcodeIcon(for: barcodeTypeString))
                        .font(.title3)
                        .foregroundColor(.green)
                    
                    Text(barcodeTypeString)
                        .font(.title3)
                        .fontWeight(.medium)
                    
                    Spacer()
                }
                .padding()
                .background(Color.green.opacity(0.1))
                .cornerRadius(8)
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
    
    // MARK: - 条形码内容信息
    private var barcodeContentSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack {
                Image(systemName: "info.circle")
                    .font(.title2)
                    .foregroundColor(.blue)
                
                Text("条形码内容")
                    .font(.headline)
                
                Spacer()
            }
            
            if let content = historyItem.content {
                VStack(alignment: .leading, spacing: 8) {
                    HStack {
                        Image(systemName: "number")
                            .font(.title3)
                            .foregroundColor(.blue)
                        
                        Text("内容长度: \(content.count) 字符")
                            .font(.title3)
                            .fontWeight(.medium)
                        
                        Spacer()
                    }
                    
                    Text("数据内容")
                        .font(.subheadline)
                        .foregroundColor(.secondary)
                        .padding(.top, 4)
                }
                .padding()
                .background(Color.blue.opacity(0.1))
                .cornerRadius(8)
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
    
    // MARK: - 原始内容
    private var originalContentSection: some View {
        VStack(alignment: .leading, spacing: 12) {
            HStack {
                Image(systemName: "doc.text")
                    .font(.title2)
                    .foregroundColor(.purple)
                
                Text("原始内容")
                    .font(.headline)
                
                Spacer()
            }
            
            if let content = historyItem.content {
                ScrollView {
                    Text(content)
                        .font(.system(.body, design: .monospaced))
                        .foregroundColor(.secondary)
                        .multilineTextAlignment(.leading)
                        .padding()
                        .frame(maxWidth: .infinity, alignment: .leading)
                }
                .frame(maxHeight: 200)
                .background(Color.purple.opacity(0.1))
                .cornerRadius(8)
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
    
    // MARK: - 操作按钮
    private var actionButtonsSection: some View {
        VStack(spacing: 12) {
            // 收藏按钮
            Button(action: toggleFavorite) {
                HStack {
                    Image(systemName: historyItem.isFavorite ? "heart.fill" : "heart")
                        .foregroundColor(historyItem.isFavorite ? .red : .gray)
                    
                    Text(historyItem.isFavorite ? "取消收藏" : "收藏")
                        .fontWeight(.medium)
                }
                .frame(maxWidth: .infinity)
                .padding()
                .background(historyItem.isFavorite ? Color.red.opacity(0.1) : Color.gray.opacity(0.1))
                .foregroundColor(historyItem.isFavorite ? .red : .gray)
                .cornerRadius(10)
            }
            
            // 复制内容按钮
            Button(action: copyContent) {
                HStack {
                    Image(systemName: "doc.on.doc")
                        .foregroundColor(.blue)
                    
                    Text("复制内容")
                        .fontWeight(.medium)
                }
                .frame(maxWidth: .infinity)
                .padding()
                .background(Color.blue.opacity(0.1))
                .foregroundColor(.blue)
                .cornerRadius(10)
            }
            
            // 分享条形码图片按钮
            if barcodeImage != nil {
                Button(action: {
                    showingShareSheet = true
                }) {
                    HStack {
                        Image(systemName: "photo")
                            .foregroundColor(.green)
                        
                        Text("分享条形码图片")
                            .fontWeight(.medium)
                    }
                    .frame(maxWidth: .infinity)
                    .padding()
                    .background(Color.green.opacity(0.1))
                    .foregroundColor(.green)
                    .cornerRadius(10)
                }
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .cornerRadius(12)
        .shadow(radius: 2)
    }
    
    // MARK: - 生成条形码图片
    private func generateBarcodeImage() {
        guard let content = historyItem.content else { return }
        
        // 使用条形码生成器
        let barcodeType = historyItem.barcodeType ?? ""
        let size = CGSize(width: 300, height: 120)
        
        if let image = BarcodeGenerator.shared.generateBarcode(from: content, type: barcodeType, size: size) {
            self.barcodeImage = image
        }
    }
    
    // MARK: - 获取条形码图标
    private func getBarcodeIcon(for type: String) -> String {
        return BarcodeGenerator.shared.getBarcodeIcon(for: type)
    }
    
    // MARK: - 切换收藏状态
    private func toggleFavorite() {
        historyItem.isFavorite.toggle()
        coreDataManager.save()
        
        let message = historyItem.isFavorite ? "已添加到收藏" : "已取消收藏"
        alertMessage = message
        showingAlert = true
    }
    
    // MARK: - 复制内容
    private func copyContent() {
        if let content = historyItem.content {
            UIPasteboard.general.string = content
            alertMessage = "内容已复制到剪贴板"
            showingAlert = true
        }
    }
}

// MARK: - 分享表单
struct BarcodeShareSheet: UIViewControllerRepresentable {
    let activityItems: [Any]
    
    func makeUIViewController(context: Context) -> UIActivityViewController {
        let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)
        return controller
    }
    
    func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {}
}

#Preview("EAN-13") {
    let ctx = PreviewData.context
    let item = PreviewData.ean13Sample(in: ctx)
    return NavigationView { BarcodeDetailView(historyItem: item) }
}

#Preview("Code 128") {
    let ctx = PreviewData.context
    let item = PreviewData.code128Sample(in: ctx)
    return NavigationView { BarcodeDetailView(historyItem: item) }
}

// MARK: - Preview Data
private enum PreviewData {
    static let context: NSManagedObjectContext = {
        let container = NSPersistentContainer(name: "MyQrCode")
        let description = NSPersistentStoreDescription()
        description.type = NSInMemoryStoreType
        container.persistentStoreDescriptions = [description]
        container.loadPersistentStores { _, _ in }
        return container.viewContext
    }()

    private static func makeBaseItem(in context: NSManagedObjectContext, content: String, barcodeType: BarcodeType, favorite: Bool = false) -> HistoryItem {
        let item = HistoryItem(context: context)
        item.id = UUID()
        item.content = content
        item.dataType = DataType.barcode.rawValue
        item.dataSource = DataSource.created.rawValue
        item.createdAt = Date()
        item.isFavorite = favorite
        item.barcodeType = barcodeType.rawValue
        return item
    }

    static func ean13Sample(in context: NSManagedObjectContext) -> HistoryItem {
        let content = "1234567890128"
        return makeBaseItem(in: context, content: content, barcodeType: .ean13, favorite: true)
    }

    static func code128Sample(in context: NSManagedObjectContext) -> HistoryItem {
        let content = "ABC123"
        return makeBaseItem(in: context, content: content, barcodeType: .code128)
    }
}