import SwiftUI
import XuqmSDK

@MainActor
final class UpdateViewModel: ObservableObject {
    @Published var isChecking = false
    @Published var updateInfo: AppUpdateInfo?
    @Published var message: String?

    func checkUpdate() {
        isChecking = true
        message = nil
        Task {
            do {
                let info = try await UpdateSDK.shared.checkAppUpdate(currentVersionCode: 1)
                updateInfo = info
                if !info.needsUpdate {
                    message = "已是最新版本"
                }
                isChecking = false
            } catch {
                message = "检查失败: \(error.localizedDescription)"
                isChecking = false
            }
        }
    }

    func openAppStore() {
        if let url = updateInfo?.appStoreUrl, !url.isEmpty {
            UpdateSDK.shared.openAppStore(url: url)
        }
    }
}

struct UpdateCheckView: View {
    @StateObject private var viewModel = UpdateViewModel()

    var body: some View {
        VStack(spacing: 20) {
            Spacer().frame(height: 40)

            Text("版本更新")
                .font(.title2)
                .fontWeight(.bold)

            if let info = viewModel.updateInfo, info.needsUpdate {
                VStack(alignment: .leading, spacing: 12) {
                    Text("发现新版本: \(info.versionName ?? "")")
                        .font(.headline)

                    if let changeLog = info.changeLog, !changeLog.isEmpty {
                        Text("更新说明: \(changeLog)")
                            .font(.body)
                            .foregroundStyle(.secondary)
                    }

                    if info.forceUpdate == true {
                        Text("强制更新")
                            .font(.caption)
                            .foregroundStyle(.red)
                    }

                    Button {
                        viewModel.openAppStore()
                    } label: {
                        Text("前往 App Store")
                            .frame(maxWidth: .infinity)
                            .padding()
                            .background(Color.accentColor)
                            .foregroundStyle(.white)
                            .clipShape(RoundedRectangle(cornerRadius: 12))
                    }
                }
                .padding()
                .background(Color.gray.opacity(0.15))
                .clipShape(RoundedRectangle(cornerRadius: 16))
                .padding(.horizontal)
            } else {
                if let msg = viewModel.message {
                    Text(msg)
                        .foregroundStyle(.secondary)
                }

                Button {
                    viewModel.checkUpdate()
                } label: {
                    HStack {
                        if viewModel.isChecking {
                            ProgressView()
                        }
                        Text(viewModel.isChecking ? "检查中…" : "检查更新")
                    }
                    .frame(maxWidth: .infinity)
                    .padding()
                    .background(Color.accentColor)
                    .foregroundStyle(.white)
                    .clipShape(RoundedRectangle(cornerRadius: 12))
                }
                .disabled(viewModel.isChecking)
                .padding(.horizontal)
            }

            Spacer()
        }
        .padding()
        .onAppear {
            if viewModel.updateInfo == nil && !viewModel.isChecking {
                viewModel.checkUpdate()
            }
        }
    }
}