import SwiftUI
import CoreData

struct CreateCodeView: View {
    @Environment(\.dismiss) private var dismiss
    @StateObject private var coreDataManager = CoreDataManager.shared
    
    @State private var selectedDataType: DataType = .qrcode
    @State private var selectedBarcodeType: BarcodeType = .ean13
    @State private var selectedQRCodeType: QRCodeType = .text
    @State private var content = ""
    @State private var showingAlert = false
    @State private var alertMessage = ""
    
    // 条形码验证相关状态
    @State private var validationResult: BarcodeValidator.ValidationResult?
    @State private var showValidationInfo = false
    
    // 输入焦点，确保进入页面自动弹出键盘
    @FocusState private var isContentFieldFocused: Bool
    
    var body: some View {
        Form {
                // 数据类型选择
                Section("数据类型") {
                    HStack(spacing: 0) {
                        ForEach(DataType.allCases, id: \.self) { type in
                            Button(action: {
                                selectedDataType = type
                                isContentFieldFocused = true
                                // 添加触觉反馈
                                let impactFeedback = UIImpactFeedbackGenerator(style: .light)
                                impactFeedback.impactOccurred()
                            }) {
                                HStack(spacing: 6) {
                                    Image(systemName: type.icon)
                                        .font(.system(size: 16, weight: .medium))
                                        .foregroundColor(selectedDataType == type ? .white : .primary)
                                    
                                    Text(type.displayName)
                                        .font(.system(size: 15, weight: .medium))
                                        .foregroundColor(selectedDataType == type ? .white : .primary)
                                }
                                .frame(maxWidth: .infinity)
                                .padding(.vertical, 12)
                                .background(
                                    RoundedRectangle(cornerRadius: 8)
                                        .fill(selectedDataType == type ? Color.blue : Color(.systemGray6))
                                )
                            }
                            .buttonStyle(PlainButtonStyle())
                        }
                    }
                    .background(
                        RoundedRectangle(cornerRadius: 8)
                            .fill(Color(.systemGray6))
                    )
                    .overlay(
                        RoundedRectangle(cornerRadius: 8)
                            .stroke(Color(.systemGray4), lineWidth: 0.5)
                    )
                }
                
                // 具体类型选择
                if selectedDataType == .barcode {
                    Section("条形码类型") {
                        Picker("条形码类型", selection: $selectedBarcodeType) {
                            ForEach(BarcodeType.allCases, id: \.self) { type in
                                HStack {
                                    Image(systemName: type.icon)
                                    Text(type.displayName)
                                }
                                .tag(type)
                            }
                        }
                        .pickerStyle(WheelPickerStyle())
                    }
                } else {
                    Section("二维码类型") {
                        Picker("二维码类型", selection: $selectedQRCodeType) {
                            ForEach(QRCodeType.allCases, id: \.self) { type in
                                HStack {
                                    Image(systemName: type.icon)
                                    Text(type.displayName)
                                }
                                .tag(type)
                            }
                        }
                        .pickerStyle(WheelPickerStyle())
                    }
                }
                
                // 内容输入
                Section("内容") {
                    VStack(alignment: .leading, spacing: 12) {
                        // 输入框和计数布局
                        VStack(alignment: .trailing, spacing: 4) {
                            // 条形码格式提示
                            if selectedDataType == .barcode {
                                HStack {
                                    Image(systemName: "info.circle")
                                        .font(.caption)
                                        .foregroundColor(.blue)
                                    
                                    Text(getBarcodeFormatHint())
                                        .font(.caption)
                                        .foregroundColor(.secondary)
                                        .lineLimit(2)
                                    
                                    Spacer()
                                }
                                .padding(.horizontal, 4)
                                .padding(.vertical, 6)
                                .background(
                                    RoundedRectangle(cornerRadius: 6)
                                        .fill(Color.blue.opacity(0.1))
                                )
                            }
                            
                            TextField(getPlaceholderText(), text: $content)
                                .textFieldStyle(RoundedBorderTextFieldStyle())
                                .keyboardType(getKeyboardType())
                                .textInputAutocapitalization(getAutocapitalization())
                                .disableAutocorrection(true)
                                .focused($isContentFieldFocused)
                                .toolbar {
                                    ToolbarItemGroup(placement: .keyboard) {
                                        Spacer()
                                        Button("完成") {
                                            isContentFieldFocused = false
                                        }
                                        .foregroundColor(.blue)
                                        .font(.system(size: 16, weight: .medium))
                                    }
                                }
                                .foregroundColor(.black)
                                .onChange(of: content) { newValue in
                                    // 针对有固定长度与数字要求的类型，进行输入规范化（仅保留数字并按最大长度截断）
                                    if selectedDataType == .barcode, let maxLen = getMaxLength(), requiresDigitsOnly() {
                                        let digits = newValue.filter { $0.isNumber }
                                        let truncated = String(digits.prefix(maxLen))
                                        if truncated != newValue { 
                                            content = truncated
                                            // 播放输入提示音
                                            playInputSound()
                                        }
                                    } else if selectedDataType == .barcode {
                                        // 播放输入提示音
                                        playInputSound()
                                    }
                                    validateBarcodeContent(content)
                                }
                            
                            // 计数显示在输入框下方，右对齐
                            if let maxLen = getMaxLength(), selectedDataType == .barcode {
                                Text("\(normalizedInputCount())/\(maxLen)")
                                    .font(.caption2)
                                    .foregroundColor(.blue)
                                    .fontWeight(.medium)
                            }
                        }
                        
                        // 输入统计与验证状态
                        HStack {
                            if let result = validationResult, result.isValid {
                                Text("✓ 格式正确")
                                    .font(.caption2)
                                    .foregroundColor(.green)
                            } else if !content.isEmpty {
                                Text("⚠ 格式检查中...")
                                    .font(.caption2)
                                    .foregroundColor(.orange)
                            }
                        }
                        
                        // 条形码验证信息（仅在格式不正确时显示）
                        if selectedDataType == .barcode && !content.isEmpty && (validationResult == nil || !validationResult!.isValid) {
                            BarcodeValidationInfoView(
                                validationResult: validationResult,
                                barcodeType: selectedBarcodeType
                            )
                        }
                    }
                }
                
                // 预览
                if !content.isEmpty {
                    Section("预览") {
                        VStack(alignment: .leading, spacing: 12) {
                            HStack {
                                Image(systemName: selectedDataType.icon)
                                Text(selectedDataType.displayName)
                                Spacer()
                                if selectedDataType == .barcode {
                                    Text(selectedBarcodeType.displayName)
                                        .font(.caption)
                                        .padding(.horizontal, 8)
                                        .padding(.vertical, 2)
                                        .background(Color.green.opacity(0.1))
                                        .foregroundColor(.green)
                                        .cornerRadius(8)
                                } else {
                                    Text(selectedQRCodeType.displayName)
                                        .font(.caption)
                                        .padding(.horizontal, 8)
                                        .padding(.vertical, 2)
                                        .background(Color.orange.opacity(0.1))
                                        .foregroundColor(.orange)
                                        .cornerRadius(8)
                                }
                            }
                            
                            if selectedDataType == .barcode && !content.isEmpty && isInputComplete() {
                                // 条形码图片预览（仅在输入完成时显示）
                                BarcodePreviewView(
                                    content: content,
                                    barcodeType: selectedBarcodeType
                                )
                                .frame(height: 120)
                                .frame(maxWidth: .infinity)
                            } else {
                                // 二维码或文本预览
                                Text(content)
                                    .font(.body)
                                    .foregroundColor(.secondary)
                                    .padding()
                                    .frame(maxWidth: .infinity, alignment: .leading)
                            }
                        }
                        .padding()
                        .background(Color(.systemGray6))
                        .cornerRadius(8)
                    }
                }
        }
        .navigationTitle("创建\(selectedDataType.displayName)")
        .navigationBarTitleDisplayMode(.inline)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button("创建") { createCode() }
                    .disabled(content.isEmpty)
            }
        }
        .alert("提示", isPresented: $showingAlert) {
            Button("确定") { }
        } message: { Text(alertMessage) }
        .onAppear {
            // 稍延迟以确保进入页面时自动聚焦
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
                isContentFieldFocused = true
            }
        }
        .onChange(of: selectedDataType) { _ in
            isContentFieldFocused = true
        }
        .onChange(of: selectedBarcodeType) { _ in
            isContentFieldFocused = true
        }
        .onTapGesture {
            // 点击外部关闭键盘
            isContentFieldFocused = false
        }
    }
    
    // MARK: - 条形码验证方法
    private func validateBarcodeContent(_ newContent: String) {
        guard selectedDataType == .barcode else { return }
        validationResult = BarcodeValidator.validateBarcode(newContent, type: selectedBarcodeType)
        // 如果验证通过，自动格式化内容
        if let result = validationResult, result.isValid {
            content = result.formattedContent
        }
    }
    
    // MARK: - 键盘配置方法
    private func getKeyboardType() -> UIKeyboardType {
        guard selectedDataType == .barcode else { return .default }
        switch selectedBarcodeType {
        case .ean13, .ean8, .upce, .itf14:
            return .numberPad
        case .code39, .code128, .pdf417:
            return .asciiCapable
        }
    }
    
    private func getAutocapitalization() -> TextInputAutocapitalization {
        guard selectedDataType == .barcode else { return .sentences }
        switch selectedBarcodeType {
        case .ean13, .ean8, .upce, .itf14:
            return .never
        case .code39, .code128, .pdf417:
            return .characters
        }
    }
    
    // MARK: - 计数/规则
    private func getMaxLength() -> Int? {
        guard selectedDataType == .barcode else { return nil }
        switch selectedBarcodeType {
        case .ean13: return 13
        case .ean8: return 8
        case .upce: return 8
        case .itf14: return 14
        default: return nil
        }
    }
    
    private func requiresDigitsOnly() -> Bool {
        guard selectedDataType == .barcode else { return false }
        switch selectedBarcodeType {
        case .ean13, .ean8, .upce, .itf14:
            return true
        default:
            return false
        }
    }
    
    private func normalizedInputCount() -> Int {
        if requiresDigitsOnly() {
            return content.filter { $0.isNumber }.count
        }
        return content.count
    }
    
    // MARK: - 条形码格式提示
    private func getBarcodeFormatHint() -> String {
        switch selectedBarcodeType {
        case .ean13:
            return "请输入13位数字，如：1234567890123"
        case .ean8:
            return "请输入8位数字，如：12345678"
        case .upce:
            return "请输入8位数字，如：12345678"
        case .code39:
            return "请输入字母、数字、空格和特殊字符"
        case .code128:
            return "请输入任意ASCII字符"
        case .itf14:
            return "请输入14位数字，如：12345678901234"
        case .pdf417:
            return "请输入任意ASCII字符"
        }
    }
    
    // MARK: - 输入框占位符文本
    private func getPlaceholderText() -> String {
        if selectedDataType == .barcode {
            switch selectedBarcodeType {
            case .ean13:
                return "输入13位数字"
            case .ean8:
                return "输入8位数字"
            case .upce:
                return "输入8位数字"
            case .code39:
                return "输入字母、数字等"
            case .code128:
                return "输入任意字符"
            case .itf14:
                return "输入14位数字"
            case .pdf417:
                return "输入任意字符"
            }
        } else {
            return "请输入内容"
        }
    }
    
    // MARK: - 播放输入提示音
    private func playInputSound() {
        // 使用系统触觉反馈作为输入提示音
        let impactFeedback = UIImpactFeedbackGenerator(style: .light)
        impactFeedback.impactOccurred()
    }
    
    // MARK: - 判断输入是否完成
    private func isInputComplete() -> Bool {
        if selectedDataType == .barcode {
            // 条形码需要验证格式正确
            return validationResult?.isValid == true
        } else {
            // 二维码只要有内容就算完成
            return !content.isEmpty
        }
    }
    
    private func createCode() {
        guard !content.isEmpty else { return }
        // 如果是条形码，验证格式
        if selectedDataType == .barcode {
            let validation = BarcodeValidator.validateBarcode(content, type: selectedBarcodeType)
            if !validation.isValid {
                alertMessage = validation.errorMessage ?? "条形码格式不正确"
                showingAlert = true
                return
            }
        }
        let context = coreDataManager.container.viewContext
        let historyItem = HistoryItem(context: context)
        historyItem.id = UUID()
        historyItem.content = content
        historyItem.dataType = selectedDataType.rawValue
        historyItem.dataSource = DataSource.created.rawValue
        historyItem.createdAt = Date()
        historyItem.isFavorite = false
        if selectedDataType == .barcode {
            historyItem.barcodeType = selectedBarcodeType.rawValue
        } else {
            historyItem.qrCodeType = selectedQRCodeType.rawValue
        }
        coreDataManager.addHistoryItem(historyItem)
        alertMessage = "\(selectedDataType.displayName)创建成功！"
        showingAlert = true
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) { dismiss() }
    }
}

#Preview {
    CreateCodeView()
}