import SwiftUI
import os.log

/// 多图上传示例视图
/// 展示如何使用 MultiImageUploader 组件实现多图上传功能
@available(iOS 16.0, *)
struct MultiImageUploadExampleView: View {
    // MARK: - 状态属性
    
    @State private var uploadResults: [UploadResult] = []
    @State private var isShowingUploader = false
    @State private var showUploadAlert = false
    @State private var alertMessage = ""
    @State private var isUploading = false
    
    private let logger = Logger(subsystem: "com.yourapp.uploader", category: "MultiImageUploadExample")
    
    // MARK: - 视图主体
    
    var body: some View {
        NavigationView {
            VStack(spacing: 16) {
                // 上传按钮和状态
                uploadButton
                
                // 上传统计信息
                if !uploadResults.isEmpty {
                    uploadStatsView
                }
                
                // 上传进度列表
                uploadProgressList
                
                Spacer()
            }
            .navigationTitle("多图上传示例")
            .toolbar {
                // 清空按钮
                if !uploadResults.isEmpty && !isUploading {
                    Button("清空") {
                        withAnimation {
                            uploadResults.removeAll()
                        }
                    }
                }
            }
            .sheet(isPresented: $isShowingUploader) {
                // 多图上传组件
                MultiImageUploader(
                    maxSelection: 10
                ) { results in
                    processUploadResults(results)
                }
            }
            .alert("上传结果", isPresented: $showUploadAlert) {
                Button("确定", role: .cancel) { }
            } message: {
                Text(alertMessage)
            }
        }
    }
    
    // MARK: - 子视图
    
    /// 上传按钮
    private var uploadButton: some View {
        Button(action: { isShowingUploader = true }) {
            Label("选择并上传图片", systemImage: "photo.on.rectangle.angled")
                .font(.headline)
                .foregroundColor(.white)
                .padding()
                .frame(maxWidth: .infinity)
                .background(Color.blue)
                .cornerRadius(10)
        }
        .padding(.horizontal)
        .padding(.top)
    }
    
    /// 上传统计信息
    private var uploadStatsView: some View {
        VStack(alignment: .leading, spacing: 8) {
            let successCount = uploadResults.filter { $0.status == .success }.count
            let inProgressCount = uploadResults.filter { 
                if case .uploading = $0.status { return true }
                return false
            }.count
            let failedCount = uploadResults.count - successCount - inProgressCount
            
            Text("上传统计")
                .font(.headline)
            
            HStack {
                StatView(
                    value: "\(uploadResults.count)",
                    label: "总数量",
                    color: .blue
                )
                
                StatView(
                    value: "\(successCount)",
                    label: "成功",
                    color: .green
                )
                
                StatView(
                    value: "\(inProgressCount)",
                    label: "上传中",
                    color: .orange
                )
                
                StatView(
                    value: "\(failedCount)",
                    label: "失败",
                    color: .red
                )
            }
            
            // 总进度条
            if inProgressCount > 0 {
                let progress = uploadResults.reduce(0.0) { result, uploadResult in
                    if case .uploading(let progress) = uploadResult.status {
                        return result + progress
                    } else if uploadResult.status == .success {
                        return result + 1.0
                    }
                    return result
                } / Double(uploadResults.count)
                
                VStack(alignment: .leading, spacing: 4) {
                    Text("总进度: \(Int(progress * 100))%")
                        .font(.subheadline)
                    ProgressView(value: progress)
                        .progressViewStyle(LinearProgressViewStyle(tint: .blue))
                }
                .padding(.top, 8)
            }
        }
        .padding()
        .background(Color(.systemGray6))
        .cornerRadius(10)
        .padding(.horizontal)
    }
    
    /// 上传进度列表
    private var uploadProgressList: some View {
        List {
            ForEach($uploadResults) { $result in
                VStack(alignment: .leading, spacing: 8) {
                    // 图片缩略图和状态
                    HStack {
                        // 图片缩略图
                        Image(uiImage: result.image)
                            .resizable()
                            .scaledToFill()
                            .frame(width: 60, height: 60)
                            .clipped()
                            .cornerRadius(8)
                            .overlay(
                                RoundedRectangle(cornerRadius: 8)
                                    .stroke(borderColor(for: result.status), lineWidth: 1)
                            )
                        
                        // 状态和进度
                        VStack(alignment: .leading, spacing: 4) {
                            Text("图片 \(result.id.uuidString.prefix(8))...")
                                .font(.subheadline)
                            
                            switch result.status {
                            case .uploading(let progress):
                                VStack(alignment: .leading, spacing: 4) {
                                    Text("上传中: \(Int(progress * 100))%")
                                        .font(.caption)
                                    ProgressView(value: progress)
                                        .progressViewStyle(LinearProgressViewStyle())
                                }
                            case .success:
                                HStack {
                                    Image(systemName: "checkmark.circle.fill")
                                        .foregroundColor(.green)
                                    Text("上传成功")
                                        .font(.caption)
                                        .foregroundColor(.green)
                                }
                            case .failure(let error):
                                HStack {
                                    Image(systemName: "exclamationmark.triangle.fill")
                                        .foregroundColor(.red)
                                    Text("上传失败: \(error.localizedDescription)")
                                        .font(.caption)
                                        .foregroundColor(.red)
                                }
                            case .idle:
                                Text("等待上传...")
                                    .font(.caption)
                                    .foregroundColor(.secondary)
                            }
                        }
                        
                        Spacer()
                    }
                    .padding(.vertical, 4)
                }
                .padding(.vertical, 8)
                .listRowSeparator(.hidden)
            }
        }
        .listStyle(PlainListStyle())
        .animation(.easeInOut, value: uploadResults)
    }
    
    // MARK: - 辅助方法
    
    /// 获取状态对应的边框颜色
    private func borderColor(for status: UploadStatus) -> Color {
        switch status {
        case .success: return .green
        case .failure: return .red
        case .uploading: return .blue
        case .idle: return .gray
        }
    }
    
    /// 处理上传结果
    private func processUploadResults(_ results: [UploadResult]) {
        // 更新状态
        isUploading = results.contains { result in
            if case .uploading = result.status { return true }
            return false
        }
        
        // 更新结果
        withAnimation {
            uploadResults = results
            isShowingUploader = false
        }
        
        // 检查是否全部完成
        let allFinished = !results.contains { result in
            if case .uploading = result.status { return true }
            if case .idle = result.status { return true }
            return false
        }
        
        if allFinished {
            let successCount = results.filter { $0.status == .success }.count
            let totalCount = results.count
            alertMessage = "上传完成\n成功: \(successCount)/\(totalCount)"
            showUploadAlert = true
            isUploading = false
            
            logger.info("上传完成，成功: \(successCount)/\(totalCount)")
        }
    }
}

// MARK: - 子视图

/// 统计信息视图
private struct StatView: View {
    let value: String
    let label: String
    let color: Color
    
    var body: some View {
        VStack {
            Text(value)
                .font(.title3.bold())
                .foregroundColor(color)
            Text(label)
                .font(.caption)
                .foregroundColor(.secondary)
        }
        .frame(maxWidth: .infinity)
    }
}

// MARK: - 预览
@available(iOS 16.0, *)
struct MultiImageUploadExampleView_Previews: PreviewProvider {
    static var previews: some View {
        MultiImageUploadExampleView()
    }
}