import SwiftUI
import PhotosUI
import os.log

@available(iOS 16.0, *)
public struct MultiImageUploader: View {
    @State private var selectedImages: [UIImage] = []
    @State private var uploadResults: [UploadResult] = []
    @State private var isUploading = false
    @State private var showingImagePicker = false
    @State private var uploadProgress: [UUID: Double] = [:] // 跟踪每个上传任务的进度
    
    private let maxSelection: Int
    private let onUploadComplete: ([UploadResult]) -> Void
    private let uploadService = ImageUploadService.shared
    private let logger = Logger(subsystem: "com.yourapp.uploader", category: "MultiImageUploader")
    
    public init(
        maxSelection: Int = 10,
        onUploadComplete: @escaping ([UploadResult]) -> Void
    ) {
        self.maxSelection = maxSelection
        self.onUploadComplete = onUploadComplete
    }
    
    public var body: some View {
        VStack(spacing: 16) {
            // 上传按钮
            Button(action: {
                showingImagePicker = true
            }) {
                Label("选择图片", systemImage: "photo.on.rectangle")
                    .font(.headline)
                    .foregroundColor(.white)
                    .padding()
                    .frame(maxWidth: .infinity)
                    .background(Color.blue)
                    .cornerRadius(10)
            }
            .padding(.horizontal)
            .sheet(isPresented: $showingImagePicker) {
                ImagePicker(images: $selectedImages, selectionLimit: maxSelection) {
                    // 当选择完成时，开始上传
                    if !selectedImages.isEmpty {
                        uploadImages()
                    }
                }
            }
            
            // 上传进度和图片网格
            ScrollView {
                LazyVStack(spacing: 16) {
                    ForEach($uploadResults) { $result in
                        VStack(spacing: 8) {
                            // 图片预览
                            Image(uiImage: result.image)
                                .resizable()
                                .scaledToFill()
                                .frame(height: 200)
                                .frame(maxWidth: .infinity)
                                .clipped()
                                .cornerRadius(8)
                            
                            // 上传进度条
                            if case .uploading = result.status {
                                ProgressView(value: uploadProgress[result.id] ?? 0, total: 1.0)
                                    .progressViewStyle(LinearProgressViewStyle())
                                    .padding(.horizontal)
                                
                                Text("上传中: \(Int((uploadProgress[result.id] ?? 0) * 100))%")
                                    .font(.caption)
                                    .foregroundColor(.secondary)
                            } else if case .success = result.status {
                                HStack {
                                    Image(systemName: "checkmark.circle.fill")
                                        .foregroundColor(.green)
                                    Text("上传成功")
                                        .font(.caption)
                                        .foregroundColor(.green)
                                }
                            } else if case .failure = result.status {
                                HStack {
                                    Image(systemName: "exclamationmark.triangle.fill")
                                        .foregroundColor(.red)
                                    Text("上传失败")
                                        .font(.caption)
                                        .foregroundColor(.red)
                                }
                            }
                        }
                        .padding()
                        .background(Color(.systemBackground))
                        .cornerRadius(12)
                        .shadow(radius: 2)
                    }
                }
                .padding()
            }
            
            // 上传按钮
            if !selectedImages.isEmpty && !isUploading {
                Button(action: uploadImages) {
                    Text("开始上传 (\(selectedImages.count)张)")
                        .font(.headline)
                        .foregroundColor(.white)
                        .padding()
                        .frame(maxWidth: .infinity)
                        .background(Color.blue)
                        .cornerRadius(10)
                }
                .padding(.horizontal)
                .padding(.bottom)
            }
        }
        .background(Color(.systemGroupedBackground))
    }
    
    private func uploadImages() {
        guard !isUploading else { return }
        
        isUploading = true
        let group = DispatchGroup()
        var results = selectedImages.map { image in
            UploadResult(fileId: "", previewFileId: "", image: image, status: .uploading(progress: 0))
        }
        
        // 更新UI显示上传中的状态
        uploadResults = results
        
        // 创建并发的DispatchQueue
        let uploadQueue = DispatchQueue(label: "com.wake.uploadQueue", attributes: .concurrent)
        let semaphore = DispatchSemaphore(value: 3) // 限制并发数为3
        
        for (index, image) in selectedImages.enumerated() {
            semaphore.wait()
            group.enter()
            
            uploadQueue.async {
                let resultId = results[index].id
                
                // 更新状态为上传中
                DispatchQueue.main.async {
                    if let idx = results.firstIndex(where: { $0.id == resultId }) {
                        results[idx].status = .uploading(progress: 0)
                        uploadProgress[resultId] = 0
                        uploadResults = results
                    }
                }
                
                // 上传原图
                uploadService.uploadImage(image, progress: { progress in
                    DispatchQueue.main.async {
                        uploadProgress[resultId] = progress.progress
                        if let idx = results.firstIndex(where: { $0.id == resultId }) {
                            results[idx].status = .uploading(progress: progress.progress)
                            uploadResults = results
                        }
                    }
                }) { uploadResult in
                    defer {
                        semaphore.signal()
                        group.leave()
                    }
                    
                    DispatchQueue.main.async {
                        if let idx = results.firstIndex(where: { $0.id == resultId }) {
                            switch uploadResult {
                            case .success(let uploadResult):
                                // 上传成功，更新结果
                                results[idx].fileId = uploadResult.fileId
                                // 使用空字符串作为 previewFileId，因为 ImageUploaderGetID.UploadResult 没有这个属性
                                results[idx].previewFileId = ""
                                results[idx].status = .success
                                uploadResults = results
                                
                                logger.info("图片上传成功: \(uploadResult.fileId)")
                                
                            case .failure(let error):
                                // 上传失败
                                results[idx].status = .failure(error)
                                uploadResults = results
                                logger.error("图片上传失败: \(error.localizedDescription)")
                            }
                        }
                    }
                }
            }
        }
        
        // 所有上传任务完成后的处理
        group.notify(queue: .main) {
            self.isUploading = false
            let successCount = results.filter { $0.status == .success }.count
            logger.info("上传完成，成功: \(successCount)/\(results.count)")
            self.onUploadComplete(results)
        }
    }
}

// MARK: - 图片选择器
@available(iOS 14.0, *)
struct ImagePicker: UIViewControllerRepresentable {
    @Binding var images: [UIImage]
    var selectionLimit: Int = 10
    var onDismiss: (() -> Void)?
    
    func makeUIViewController(context: Context) -> PHPickerViewController {
        var config = PHPickerConfiguration(photoLibrary: .shared())
        config.filter = .images
        config.selectionLimit = selectionLimit
        config.preferredAssetRepresentationMode = .current
        
        let picker = PHPickerViewController(configuration: config)
        picker.delegate = context.coordinator
        return picker
    }
    
    func updateUIViewController(_ uiViewController: PHPickerViewController, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    class Coordinator: NSObject, PHPickerViewControllerDelegate {
        let parent: ImagePicker
        
        init(_ parent: ImagePicker) {
            self.parent = parent
        }
        
        func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
            picker.dismiss(animated: true)
            
            let group = DispatchGroup()
            var newImages: [UIImage] = []
            
            for result in results {
                group.enter()
                let itemProvider = result.itemProvider
                
                if itemProvider.canLoadObject(ofClass: UIImage.self) {
                    itemProvider.loadObject(ofClass: UIImage.self) { [weak self] (image, error) in
                        if let image = image as? UIImage {
                            newImages.append(image)
                        }
                        group.leave()
                    }
                } else {
                    group.leave()
                }
            }
            
            group.notify(queue: .main) {
                self.parent.images = newImages
                self.parent.onDismiss?()
            }
        }
    }
}