import SwiftUI

// MARK: - App Image Source Enum
enum AppImageSource: Equatable {
    case camera
    case photoLibrary
}

// MARK: - 通用底部 Tab 栏组件
public struct TabBarItem: Identifiable, Equatable {
    public let id: String
    public let title: String
    public let systemIconName: String
    public init(id: String, title: String, systemIconName: String) {
        self.id = id
        self.title = title
        self.systemIconName = systemIconName
    }
}

struct BottomTabBar: View {
    let items: [TabBarItem]
    @Binding var selectedId: String
    let onSelect: (String) -> Void
    var contentPadding: EdgeInsets = EdgeInsets(top: 12, leading: 0, bottom: 12, trailing: 0)
    var horizontalPadding: CGFloat = 0
    
    // 便捷初始化：内部固定 tabs，避免外部重复声明
    init(
        selectedId: Binding<String>,
        onSelect: @escaping (String) -> Void,
        contentPadding: EdgeInsets = EdgeInsets(top: 12, leading: 0, bottom: 12, trailing: 0),
        horizontalPadding: CGFloat = 0
    ) {
        self.items = BottomTabBar.defaultItems()
        self._selectedId = selectedId
        self.onSelect = onSelect
        self.contentPadding = contentPadding
        self.horizontalPadding = horizontalPadding
    }
    
    // 最简初始化：直接接受 viewModel，内部处理所有逻辑
    init(viewModel: MainViewModel) {
        self.items = BottomTabBar.defaultItems()
        self._selectedId = Binding(
            get: { viewModel.selectedTab.rawValue },
            set: { raw in
                if let tab = MainViewModel.Tab(rawValue: raw) {
                    viewModel.onTabChanged(tab)
                }
            }
        )
        self.onSelect = { _ in } // 保留但不再使用
        self.contentPadding = EdgeInsets(top: 12, leading: 0, bottom: 12, trailing: 0)
        self.horizontalPadding = 0
    }
    
    // 使用 BottomTabView.swift 中的图片资源名进行映射
    private func assetIconName(for item: TabBarItem, isSelected: Bool) -> String? {
        switch item.id {
        case "feed":
            return isSelected ? "feed selected" : "feed unselected"
        case "me":
            return isSelected ? "me selected" : "me unselected"
        default:
            return nil
        }
    }
    
    // 内部默认 items（与资源映射保持一致）
    private static func defaultItems() -> [TabBarItem] {
        return [
            TabBarItem(id: "feed", title: "Feed", systemIconName: "list.bullet"),
            TabBarItem(id: "me", title: "Me", systemIconName: "person.circle")
        ]
    }
    
    var body: some View {
        HStack(spacing: 8) {
            ForEach(items) { item in
                Button(action: {
                    selectedId = item.id
                    onSelect(item.id)
                }) {
                    Group {
                        if let name = assetIconName(for: item, isSelected: selectedId == item.id) {
                            Image(name)
                                .resizable()
                                .aspectRatio(contentMode: .fit)
                                .frame(width: 30, height: 30)
                        } else {
                            Image(systemName: item.systemIconName)
                                .font(.system(size: 24))
                                .foregroundColor(selectedId == item.id ? .white : .white.opacity(0.6))
                        }
                    }
                }
                .frame(maxWidth: .infinity)
                .padding(contentPadding)
                .contentShape(Rectangle())
            }
        }
        .padding(.horizontal, 8) // 按钮与边缘保持 8 间距
        .padding(.horizontal, horizontalPadding)
        .background(LiquidGlassBackground())
        .clipShape(Capsule())
        .contentShape(Capsule())
        .onTapGesture { /* 吸收空白区域点击，避免穿透 */ }
        .overlay(
            Capsule()
                .stroke(Color.white.opacity(0.12), lineWidth: 0.5)
        )
        .shadow(color: Color.black.opacity(0.2), radius: 12, x: 0, y: 6)
        .safeAreaInset(edge: .bottom) {
            Color.clear.frame(height: 0)
        }
    }
}

// MARK: - Liquid Glass Background (iOS 26 优先，向下优雅降级)
struct LiquidGlassBackground: View {
    var body: some View {
        Group {
            if #available(iOS 26.0, *) {
                // iOS 26+：使用系统液态玻璃效果
                Rectangle()
                    .fill(Color.clear)
                    .glassEffect()
            } else
            if #available(iOS 17.0, *) {
                // iOS 17-25：使用超薄材质 + 轻微高光层
                ZStack {
                    Rectangle().fill(.ultraThinMaterial)
                    LinearGradient(
                        colors: [Color.white.opacity(0.06), Color.clear, Color.white.opacity(0.04)],
                        startPoint: .topLeading,
                        endPoint: .bottomTrailing
                    )
                    .blendMode(.softLight)
                }
            } else {
                // 更低版本：半透明备选
                Rectangle()
                    .fill(Color.black.opacity(0.2))
            }
        }
    }
}

// MARK: - 背景视图组件
struct LoginBackgroundView: View {
    var body: some View {
        Image("bg")
            .resizable()
            .aspectRatio(contentMode: .fill)
//            .ignoresSafeArea(.all)
    }
}

// MARK: - 顶部导航栏组件
struct LoginHeaderView: View {
    let onBack: () -> Void
    
    var body: some View {
        HStack {
            Button(action: onBack) {
                Image(systemName: "chevron.left")
                    .font(.system(size: 24, weight: .medium))
                    .foregroundColor(.white)
                    .frame(width: 44, height: 44)
            }
            Spacer()
        }
        .padding(.horizontal, 16)
        .padding(.top, 8)
    }
}

// MARK: - 通用输入框组件
enum InputFieldType {
    case text
    case number
    case password
    case verificationCode
}

struct CustomInputField: View {
    let type: InputFieldType
    let placeholder: String
    let text: Binding<String>
    let isPasswordVisible: Binding<Bool>?
    let onGetCode: (() -> Void)?
    let isCodeButtonEnabled: Bool
    let isCodeLoading: Bool
    let getCodeButtonText: String
    
    init(
        type: InputFieldType,
        placeholder: String,
        text: Binding<String>,
        isPasswordVisible: Binding<Bool>? = nil,
        onGetCode: (() -> Void)? = nil,
        isCodeButtonEnabled: Bool = false,
        isCodeLoading: Bool = false,
        getCodeButtonText: String = ""
    ) {
        self.type = type
        self.placeholder = placeholder
        self.text = text
        self.isPasswordVisible = isPasswordVisible
        self.onGetCode = onGetCode
        self.isCodeButtonEnabled = isCodeButtonEnabled
        self.isCodeLoading = isCodeLoading
        self.getCodeButtonText = getCodeButtonText
    }
    
    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 25)
                .fill(Color.white.opacity(0.1))
                .overlay(
                    RoundedRectangle(cornerRadius: 25)
                        .stroke(Color.white.opacity(0.3), lineWidth: 1)
                )
                .frame(height: 56)
            
            HStack {
                // 输入框
                Group {
                    switch type {
                    case .text, .number:
                        TextField("", text: text)
                            .placeholder(when: text.wrappedValue.isEmpty) {
                                Text(placeholder)
                                    .foregroundColor(.white.opacity(0.6))
                            }
                            .keyboardType(type == .number ? .numberPad : .default)
                    case .password:
                        if let isPasswordVisible = isPasswordVisible {
                            if isPasswordVisible.wrappedValue {
                                TextField("", text: text)
                                    .placeholder(when: text.wrappedValue.isEmpty) {
                                        Text(placeholder)
                                            .foregroundColor(.white.opacity(0.6))
                                    }
                            } else {
                                SecureField("", text: text)
                                    .placeholder(when: text.wrappedValue.isEmpty) {
                                        Text(placeholder)
                                            .foregroundColor(.white.opacity(0.6))
                                    }
                            }
                        }
                    case .verificationCode:
                        TextField("", text: text)
                            .placeholder(when: text.wrappedValue.isEmpty) {
                                Text(placeholder)
                                    .foregroundColor(.white.opacity(0.6))
                            }
                            .keyboardType(.numberPad)
                    }
                }
                .foregroundColor(.white)
                .font(.system(size: 16))
                
                // 右侧按钮
                if type == .password, let isPasswordVisible = isPasswordVisible {
                    Button(action: {
                        isPasswordVisible.wrappedValue.toggle()
                    }) {
                        Image(systemName: isPasswordVisible.wrappedValue ? "eye.slash" : "eye")
                            .foregroundColor(.white.opacity(0.7))
                            .font(.system(size: 18))
                    }
                } else if type == .verificationCode, let onGetCode = onGetCode {
                    Button(action: onGetCode) {
                        ZStack {
                            if isCodeLoading {
                                ProgressView()
                                    .progressViewStyle(CircularProgressViewStyle(tint: .white))
                                    .scaleEffect(0.7)
                            } else {
                                Text(getCodeButtonText)
                                    .font(.system(size: 14, weight: .medium))
                                    .foregroundColor(.white)
                            }
                        }
                        .frame(width: 60, height: 36)
                        .background(
                            RoundedRectangle(cornerRadius: 15)
                                .fill(Color.white.opacity(isCodeButtonEnabled ? 0.2 : 0.1))
                        )
                    }
                    .disabled(!isCodeButtonEnabled || isCodeLoading)
                }
            }
            .padding(.horizontal, 24)
        }
    }
}

// MARK: - 登录按钮组件
struct LoginButtonView: View {
    let isLoading: Bool
    let isEnabled: Bool
    let onTap: () -> Void
    
    var body: some View {
        Button(action: onTap) {
            Group {
                if isLoading {
                    ProgressView()
                        .progressViewStyle(CircularProgressViewStyle(tint: .white))
                        .scaleEffect(1.2)
                } else {
                    Text("Login")
                        .font(.system(size: 16, weight: .medium))
                        .foregroundColor(.white)
                }
            }
        }
        .frame(maxWidth: .infinity)
        .padding(.vertical, 16)
        .background(isEnabled ? Color(red: 0.5, green: 0.3, blue: 0.8) : Color.gray)
        .cornerRadius(8)
        .disabled(!isEnabled)
    }
}

// MARK: - 设置行组件
struct SettingRow: View {
    let title: String
    let subtitle: String
    let action: (() -> Void)?
    
    var body: some View {
        Button(action: {
            action?()
        }) {
            HStack(spacing: 16) {
                HStack {
                    Text(title)
                        .font(.system(size: 16))
                        .foregroundColor(.white)
                        .multilineTextAlignment(.leading)
                    
                    Spacer()
                    
                    if !subtitle.isEmpty {
                        Text(subtitle)
                            .font(.system(size: 14))
                            .foregroundColor(.white.opacity(0.7))
                    }
                }
                
                Spacer()
                
                if action != nil {
                    Image(systemName: "chevron.right")
                        .font(.system(size: 14))
                        .foregroundColor(.white.opacity(0.5))
                }
            }
            .padding(.horizontal, 16)
            .padding(.vertical, 12)
        }
        .disabled(action == nil)
    }
}

// MARK: - Camera Picker
struct CameraPicker: UIViewControllerRepresentable {
    let onImagePicked: (UIImage?) -> Void
    
    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.sourceType = .camera
        picker.delegate = context.coordinator
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator(onImagePicked: onImagePicked)
    }
    
    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        let onImagePicked: (UIImage?) -> Void
        
        init(onImagePicked: @escaping (UIImage?) -> Void) {
            self.onImagePicked = onImagePicked
        }
        
        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            if let image = info[.originalImage] as? UIImage {
                onImagePicked(image)
            } else {
                onImagePicked(nil)
            }
            picker.dismiss(animated: true)
        }
        
        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            onImagePicked(nil)
            picker.dismiss(animated: true)
        }
    }
}

#Preview {
    VStack(spacing: 20) {
        LoginBackgroundView()
        
        LoginHeaderView(onBack: {})
        
        CustomInputField(
            type: .text,
            placeholder: "Test Input",
            text: .constant("")
        )
        
        LoginButtonView(
            isLoading: false,
            isEnabled: true,
            onTap: {}
        )
    }
}