import SwiftUI
import os.log

/// 媒体上传示例视图
struct ExampleView: View {
    /// 是否显示媒体选择器
    @State private var showMediaPicker = false
    /// 已选媒体文件
    @State private var selectedMedia: [MediaType] = []
    /// 上传状态
    @State private var uploadStatus: [String: UploadStatus] = [:]
    /// 上传管理器
    private let uploader = ImageUploadService()
    
    /// 上传状态
    private enum UploadStatus: Equatable {
        case pending
        case uploading(progress: Double)
        case completed(fileId: String)
        case failed(Error)
        
        static func == (lhs: UploadStatus, rhs: UploadStatus) -> Bool {
            switch (lhs, rhs) {
            case (.pending, .pending):
                return true
            case (.uploading(let lhsProgress), .uploading(let rhsProgress)):
                return lhsProgress == rhsProgress
            case (.completed(let lhsId), .completed(let rhsId)):
                return lhsId == rhsId
            default:
                return false
            }
        }
        
        var description: String {
            switch self {
            case .pending: return "等待上传"
            case .uploading(let progress): return "上传中 \(Int(progress * 100))%"
            case .completed(let fileId): return "上传完成 (ID: \(fileId.prefix(8))...)"
            case .failed(let error): return "上传失败: \(error.localizedDescription)"
            }
        }
    }
    
    var body: some View {
        NavigationView {
            VStack(spacing: 20) {
                // 选择媒体按钮
                Button(action: {
                    showMediaPicker = true
                }) {
                    Label("选择媒体", systemImage: "photo.on.rectangle")
                        .font(.headline)
                        .frame(maxWidth: .infinity)
                        .padding()
                        .background(Color.blue)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                }
                .padding(.horizontal)
                
                // 显示已选媒体数量
                if !selectedMedia.isEmpty {
                    VStack(spacing: 10) {
                        Text("已选择 \(selectedMedia.count) 个媒体文件")
                            .font(.headline)
                        
                        // 显示媒体缩略图和上传状态
                        List {
                            ForEach(0..<selectedMedia.count, id: \.self) { index in
                                let media = selectedMedia[index]
                                let mediaId = "\(index)"
                                let status = uploadStatus[mediaId] ?? .pending
                                
                                HStack {
                                    // 缩略图
                                    MediaThumbnailView(media: media, onDelete: nil)
                                        .frame(width: 60, height: 60)
                                    
                                    VStack(alignment: .leading, spacing: 4) {
                                        Text(media.isVideo ? "视频" : "图片")
                                            .font(.subheadline)
                                        
                                        // 上传状态
                                        Text(status.description)
                                            .font(.caption)
                                            .foregroundColor(statusColor(status))
                                        
                                        // 上传进度条
                                        if case .uploading(let progress) = status {
                                            ProgressView(value: progress, total: 1.0)
                                                .progressViewStyle(LinearProgressViewStyle())
                                                .frame(height: 4)
                                        }
                                    }
                                    .frame(maxWidth: .infinity, alignment: .leading)
                                }
                                .padding(.vertical, 8)
                            }
                        }
                        .frame(height: 300)
                    }
                    .padding(.top)
                } else {
                    Text("未选择任何媒体")
                        .foregroundColor(.secondary)
                        .padding(.top, 50)
                }
                
                Spacer()
            }
            .navigationTitle("媒体上传")
            .sheet(isPresented: $showMediaPicker) {
                MediaPickerWithLogging(
                    selectedMedia: $selectedMedia,
                    selectionLimit: 5,
                    onDismiss: {
                        // 媒体选择完成后的处理
                        showMediaPicker = false
                        // 开始上传所有选中的文件
                        uploadAllMedia()
                    }
                )
            }
            .onChange(of: selectedMedia) { _ in
                // 当 selectedMedia 变化时，重置上传状态
                uploadStatus.removeAll()
            }
        }
    }
    
    // 上传单个媒体文件
    private func uploadMedia(_ media: ImageUploadService.MediaType, id: String) {
        print("🔄 开始处理媒体: \(id)")
        uploadStatus[id] = .uploading(progress: 0)
        
        uploader.uploadMedia(
            media,
            progress: { progress in
                print("📊 上传进度 (\(id)): \(progress.current)%")
                uploadStatus[id] = .uploading(progress: progress.progress)
            },
            completion: { result in
                switch result {
                case .success(let uploadResult):
                    print("✅ 上传成功 (\(id)): \(uploadResult.fileId)")
                    uploadStatus[id] = .completed(fileId: uploadResult.fileId)
                case .failure(let error):
                    print("❌ 上传失败 (\(id)): \(error.localizedDescription)")
                    uploadStatus[id] = .failed(error)
                }
            }
        )
    }
    
    // 上传所有媒体文件
    private func uploadAllMedia() {
        print("🔄 开始批量上传 \(selectedMedia.count) 个文件")
        for (index, media) in selectedMedia.enumerated() {
            let id = "\(index)"
            if case .pending = uploadStatus[id] ?? .pending {
                // Convert MediaType to ImageUploadService.MediaType
                let uploadMediaType: ImageUploadService.MediaType
                switch media {
                case .image(let image):
                    uploadMediaType = .image(image)
                case .video(let url, let thumbnail):
                    uploadMediaType = .video(url, thumbnail)
                }
                uploadMedia(uploadMediaType, id: id)
            }
        }
    }
    
    // 获取状态对应的颜色
    private func statusColor(_ status: UploadStatus) -> Color {
        switch status {
        case .pending: return .secondary
        case .uploading: return .blue
        case .completed: return .green
        case .failed: return .red
        }
    }
}

/// 媒体缩略图视图
private struct MediaThumbnailView: View {
    let media: MediaType
    let onDelete: (() -> Void)?
    
    var body: some View {
        ZStack(alignment: .topTrailing) {
            if let thumbnail = media.thumbnail {
                Image(uiImage: thumbnail)
                    .resizable()
                    .scaledToFill()
                    .frame(width: 80, height: 80)
                    .cornerRadius(8)
                    .clipped()
                
                if media.isVideo {
                    Image(systemName: "video.fill")
                        .foregroundColor(.white)
                        .padding(4)
                        .background(Color.black.opacity(0.6))
                        .clipShape(Circle())
                        .padding(4)
                }
            }
        }
    }
}

#Preview {
    ExampleView()
        .environmentObject(AuthState.shared)
}