import Flutter
import UIKit
import ScreenTime

@available(iOS 14.0, *)
public class TimeTrackingPlugin: NSObject, FlutterPlugin {
    public static func register(with registrar: FlutterPluginRegistrar) {
        let channel = FlutterMethodChannel(
            name: "autotime_tracker/time_tracking",
            binaryMessenger: registrar.messenger()
        )
        let instance = TimeTrackingPlugin()
        registrar.addMethodCallDelegate(instance, channel: channel)
    }

    public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        switch call.method {
        case "hasPermission":
            hasPermission(result: result)
        case "requestPermission":
            requestPermission(result: result)
        case "getAppUsage":
            getAppUsage(call: call, result: result)
        case "startBackgroundTracking":
            startBackgroundTracking(result: result)
        case "stopBackgroundTracking":
            stopBackgroundTracking(result: result)
        case "isBackgroundTrackingActive":
            isBackgroundTrackingActive(result: result)
        default:
            result(FlutterMethodNotImplemented)
        }
    }

    // MARK: - Permission Methods

    private func hasPermission(result: @escaping FlutterResult) {
        if #available(iOS 14.0, *) {
            let authorizationStatus = STScreenTime.getAuthorizationStatus()
            result(authorizationStatus == .authorized)
        } else {
            result(false)
        }
    }

    private func requestPermission(result: @escaping FlutterResult) {
        if #available(iOS 14.0, *) {
            STScreenTime.requestAuthorization { success, error in
                if let error = error {
                    result(FlutterError(
                        code: "AUTHORIZATION_FAILED",
                        message: error.localizedDescription,
                        details: nil
                    ))
                } else {
                    result(success)
                }
            }
        } else {
            result(FlutterError(
                code: "UNSUPPORTED_VERSION",
                message: "Screen Time API requires iOS 14.0 or later",
                details: nil
            ))
        }
    }

    // MARK: - App Usage Methods

    @available(iOS 14.0, *)
    private func getAppUsage(call: FlutterMethodCall, result: @escaping FlutterResult) {
        guard let args = call.arguments as? [String: Any],
              let startTimeMs = args["startTime"] as? Int64,
              let endTimeMs = args["endTime"] as? Int64 else {
            result(FlutterError(
                code: "INVALID_ARGUMENTS",
                message: "Invalid arguments",
                details: nil
            ))
            return
        }

        let startTime = Date(timeIntervalSince1970: Double(startTimeMs) / 1000.0)
        let endTime = Date(timeIntervalSince1970: Double(endTimeMs) / 1000.0)

        // 检查权限
        guard STScreenTime.getAuthorizationStatus() == .authorized else {
            result(FlutterError(
                code: "PERMISSION_DENIED",
                message: "Screen Time permission not granted",
                details: nil
            ))
            return
        }

        // 获取应用使用数据
        STScreenTime.getAppUsage(from: startTime, to: endTime) { usage, error in
            if let error = error {
                result(FlutterError(
                    code: "GET_USAGE_FAILED",
                    message: error.localizedDescription,
                    details: nil
                ))
                return
            }

            guard let usage = usage else {
                result([])
                return
            }

            // 转换为 Flutter 可用的格式
            var appUsageList: [[String: Any]] = []
            
            // 遍历应用使用数据
            // 注意：实际的 Screen Time API 使用方式可能不同
            // 这里提供基本框架，需要根据实际 API 调整
            
            // 示例数据结构
            for (bundleId, timeInterval) in usage {
                let appName = Bundle.main.object(forInfoDictionaryKey: "CFBundleDisplayName") as? String ?? bundleId
                
                appUsageList.append([
                    "packageName": bundleId,
                    "appName": appName,
                    "startTime": startTime.timeIntervalSince1970 * 1000,
                    "endTime": endTime.timeIntervalSince1970 * 1000,
                    "duration": Int(timeInterval),
                    "deviceUnlockCount": 0
                ])
            }

            result(appUsageList)
        }
    }

    // MARK: - Background Tracking Methods

    private func startBackgroundTracking(result: @escaping FlutterResult) {
        // iOS 后台追踪实现
        // 注意：iOS 对后台运行有严格限制
        // 可以使用 Background Tasks 或 Notification Service Extension
        result(true)
    }

    private func stopBackgroundTracking(result: @escaping FlutterResult) {
        result(true)
    }

    private func isBackgroundTrackingActive(result: @escaping FlutterResult) {
        result(false)
    }
}