import SwiftUI
import PhotosUI

/// 上传结果，包含原图和压缩图的上传信息
struct UploadResults {
    let original: ImageUploaderGetID.UploadResult
    let compressed: ImageUploaderGetID.UploadResult
}

/// 照片选择器，封装了系统相册选择功能
/// 使用UIViewControllerRepresentable包装PHPickerViewController，提供SwiftUI兼容的图片选择界面
struct PhotoPicker: UIViewControllerRepresentable {
    // MARK: - Properties
    
    /// 绑定的已选图片数组，用于存储用户选择的图片
    @Binding var selectedImages: [UIImage]
    
    /// 最多可选图片数量，默认为1
    let selectionLimit: Int
    
    /// 图片过滤器，默认为图片类型，可过滤特定类型的媒体
    let filter: PHPickerFilter
    
    /// 图片上传完成回调，返回上传结果或错误
    var onImageUploaded: ((Result<UploadResults, Error>) -> Void)?
    
    // MARK: - Initialization
    
    /// 初始化照片选择器
    /// - Parameters:
    ///   - selectedImages: 绑定的图片数组，用于接收用户选择的图片
    ///   - selectionLimit: 最多可选图片数量，默认为1
    ///   - filter: 媒体类型过滤器，默认为图片
    ///   - onImageUploaded: 图片上传完成后的回调闭包
    init(
        selectedImages: Binding<[UIImage]>,
        selectionLimit: Int = 1,
        filter: PHPickerFilter = .images,
        onImageUploaded: ((Result<UploadResults, Error>) -> Void)? = nil
    ) {
        self._selectedImages = selectedImages
        self.selectionLimit = selectionLimit
        self.filter = filter
        self.onImageUploaded = onImageUploaded
    }
    
    // MARK: - UIViewControllerRepresentable
    
    /// 创建并返回配置好的PHPickerViewController
    func makeUIViewController(context: Context) -> PHPickerViewController {
        var configuration = PHPickerConfiguration(photoLibrary: PHPhotoLibrary.shared())
        configuration.filter = filter
        configuration.selectionLimit = selectionLimit
        configuration.preferredAssetRepresentationMode = .current
        
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = context.coordinator
        return picker
    }
    
    /// 更新视图控制器（空实现，因为不需要更新）
    func updateUIViewController(_ uiViewController: PHPickerViewController, context: Context) {}
    
    /// 创建协调器，用于处理PHPickerViewController的代理方法
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    // MARK: - Coordinator
    
    /// 协调器类，处理PHPickerViewController的代理方法
    class Coordinator: NSObject, PHPickerViewControllerDelegate {
        /// 对父视图的弱引用
        let parent: PhotoPicker
        
        /// 图片上传器实例
        private let uploader = ImageUploaderGetID()
        
        init(_ parent: PhotoPicker) {
            self.parent = parent
        }
        
        /// 当用户完成图片选择时调用
        func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
            // 清空已选图片
            parent.selectedImages.removeAll()
            
            // 使用DispatchGroup管理多个异步任务
            let group = DispatchGroup()
            var loadedImages: [Int: UIImage] = [:]  // 用于保持图片顺序的字典
            var uploadResults: [Int: (original: ImageUploaderGetID.UploadResult?, 
                                   compressed: ImageUploaderGetID.UploadResult?)] = [:]
            
            // 遍历所有选中的图片
            for (index, result) in results.enumerated() {
                group.enter()  // 进入组
                
                if result.itemProvider.canLoadObject(ofClass: UIImage.self) {
                    result.itemProvider.loadObject(ofClass: UIImage.self) { [weak self] (image, error) in
                        guard let self = self, let image = image as? UIImage else {
                            group.leave()
                            return
                        }
                        
                        // 1. 保存原始图片
                        loadedImages[index] = image
                        
                        // 2. 压缩图片（质量压缩到50%）
                        guard let compressedImage = image.jpegData(compressionQuality: 0.5).flatMap(UIImage.init(data:)) else {
                            group.leave()
                            return
                        }
                        
                        // 3. 上传原图
                        self.uploader.uploadImage(image) { [weak self] originalResult in
                            guard let self = self else {
                                group.leave()
                                return
                            }
                            
                            switch originalResult {
                            case .success(let originalUploadResult):
                                // 4. 原图上传成功后上传压缩图
                                self.uploader.uploadImage(compressedImage) { compressedResult in
                                    defer { group.leave() }
                                    
                                    switch compressedResult {
                                    case .success(let compressedUploadResult):
                                        // 保存两个上传结果
                                        uploadResults[index] = (originalUploadResult, compressedUploadResult)
                                        print("✅ 原图和压缩图上传成功！")
                                        print("📂 原图信息：")
                                        print("   - 文件ID: \(originalUploadResult.fileId)")
                                        print("   - 文件大小: \(originalUploadResult.fileSize) 字节")
                                        print("📦 压缩图信息：")
                                        print("   - 文件ID: \(compressedUploadResult.fileId)")
                                        print("   - 文件大小: \(compressedUploadResult.fileSize) 字节")
                                        
                                        // 使用MaterialService上传文件信息到后端
                                        MaterialService.shared.uploadMaterialInfo(
                                            fileId: originalUploadResult.fileId,
                                            previewFileId: compressedUploadResult.fileId
                                        ) { success, errorMessage in
                                            if success {
                                                print("✅ 文件信息上传成功 素材上传成功！！！！！")
                                            } else if let errorMessage = errorMessage {
                                                print("❌ 文件信息上传失败: \(errorMessage)")
                                            }
                                        }
                                        
                                    case .failure(let error):
                                        print("❌ 压缩图上传失败: \(error.localizedDescription)")
                                        uploadResults[index] = (originalUploadResult, nil)
                                    }
                                }
                                
                            case .failure(let error):
                                print("❌ 原图上传失败: \(error.localizedDescription)")
                                group.leave()
                            }
                        }
                    }
                } else {
                    group.leave()
                }
            }
            
            // 所有上传任务完成后的处理
            group.notify(queue: .main) { [weak self] in
                guard let self = self else { return }
                
                // 1. 更新选中的图片（只显示原图）
                let sortedImages = loadedImages.sorted { $0.key < $1.key }.map { $0.value }
                self.parent.selectedImages.append(contentsOf: sortedImages)
                
                // 2. 检查是否所有上传都成功
                if let firstResult = uploadResults.first?.value,
                   let original = firstResult.original,
                   let compressed = firstResult.compressed {
                    // 3. 如果成功，返回上传结果
                    let results = UploadResults(original: original, compressed: compressed)
                    self.parent.onImageUploaded?(.success(results))
                } else {
                    // 4. 如果失败，返回错误
                    self.parent.onImageUploaded?(.failure(NSError(domain: "com.wake.upload", 
                                                               code: -1, 
                                                               userInfo: [NSLocalizedDescriptionKey: "上传过程中出现错误"])))
                }
                
                // 5. 关闭图片选择器
                picker.dismiss(animated: true)
            }
        }
    }
}

// MARK: - AvatarUploader

/// 头像上传视图，提供头像选择功能
/// 封装了头像显示和选择逻辑，支持点击选择新头像
struct AvatarUploader: View {
    // MARK: - Properties
    
    /// 绑定的当前选中头像图片
    @Binding var selectedImage: UIImage?
    
    /// 头像显示尺寸
    let size: CGFloat
    
    /// 上传完成回调，返回上传结果或错误
    var onUploadComplete: ((Result<UploadResults, Error>) -> Void)?
    
    // MARK: - State
    
    /// 控制图片选择器的显示状态
    @State private var isImagePickerPresented = false
    
    // MARK: - Body
    
    var body: some View {
        // 头像按钮，点击后显示图片选择器
        Button(action: { isImagePickerPresented = true }) {
            ZStack {
                if let selectedImage = selectedImage {
                    // 显示已选中的头像
                    Image(uiImage: selectedImage)
                        .resizable()
                        .scaledToFill()
                        .frame(width: size, height: size)
                        .clipShape(RoundedRectangle(cornerRadius: size * 0.1))
                } else {
                    // 默认头像占位视图
                    Color.gray.opacity(0.1)
                        .frame(width: size, height: size)
                        .overlay(
                            SVGImage(svgName: "Avatar")
                                .frame(width: size * 0.8, height: size * 0.8)
                        )
                        .clipShape(RoundedRectangle(cornerRadius: size * 0.1))
                        .overlay(
                            RoundedRectangle(cornerRadius: size * 0.1)
                                .stroke(Color.gray.opacity(0.3), lineWidth: 1)
                        )
                }
            }
            .frame(width: size, height: size)
            .contentShape(Rectangle())  // 确保整个区域都可点击
        }
        .buttonStyle(PlainButtonStyle())  // 使用无样式按钮
        .sheet(isPresented: $isImagePickerPresented) {
            // 显示图片选择器
            PhotoPicker(
                selectedImages: Binding(
                    get: { [selectedImage].compactMap { $0 } },
                    set: { images in
                        selectedImage = images.first
                    }
                ),
                selectionLimit: 1,  // 限制只能选择一张图片
                onImageUploaded: { result in
                    // 图片上传完成后的处理
                    onUploadComplete?(result)
                }
            )
        }
    }
}