import 'dart:io';
import 'package:flutter/services.dart';
import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:nearle/background/backgroundservice.dart';

/// Helper class to schedule/cancel shift end alarms
/// Works even when app is killed (uses Android AlarmManager)
class ShiftEndAlarm {
  static const MethodChannel _channel = MethodChannel('nearle/shift_end');

  /// Schedule an alarm for shift end time
  /// This alarm will fire even if the app is killed
  /// If shift end time has already passed today, it will trigger immediately
  static Future<bool> scheduleAlarm({
    required String endTime, // Format: "HH:mm:ss" or "HH:mm"
    String startTime = '', // Format: "HH:mm:ss" or "HH:mm" (for overnight shift detection)
  }) async {
    if (!Platform.isAndroid) {
      debugPrint('[SHIFT_END_ALARM] Only supported on Android');
      return false;
    }

    try {
      debugPrint('[SHIFT_END_ALARM] 📅 scheduleAlarm called - endTime: "$endTime", startTime: "$startTime"');
      
      // Check if shift end time has already passed today
      final now = DateTime.now();
      debugPrint('[SHIFT_END_ALARM] 📅 Current time: ${now.toString()}');
      
      final endParts = endTime.split(':');
      if (endParts.length >= 2) {
        final int endHour = int.tryParse(endParts[0]) ?? 0;
        final int endMinute = int.tryParse(endParts[1]) ?? 0;
        final int endSecond = endParts.length > 2 ? (int.tryParse(endParts[2]) ?? 0) : 0;
        
        final DateTime endToday = DateTime(
          now.year,
          now.month,
          now.day,
          endHour,
          endMinute,
          endSecond,
        );
        
        debugPrint('[SHIFT_END_ALARM] 📅 Shift end time today: ${endToday.toString()}');
        debugPrint('[SHIFT_END_ALARM] 📅 Time comparison: now.isAfter(endToday) = ${now.isAfter(endToday)}');
        
        // If shift end time has passed, trigger immediately
        if (now.isAfter(endToday) || now.isAtSameMomentAs(endToday)) {
          debugPrint('[SHIFT_END_ALARM] ⚡ Shift end time ($endTime) has already passed - triggering break log immediately');
          await handleShiftEnd();
        } else {
          debugPrint('[SHIFT_END_ALARM] ⏰ Shift end time ($endTime) has not passed yet - will schedule alarm');
        }
      } else {
        debugPrint('[SHIFT_END_ALARM] ⚠️ Invalid endTime format: "$endTime"');
      }
      
      final result = await _channel.invokeMethod<bool>(
        'scheduleShiftEndAlarm',
        {
          'endTime': endTime,
          'startTime': startTime,
        },
      );
      final success = result ?? false;
      if (success) {
        debugPrint('[SHIFT_END_ALARM] ✅ Successfully scheduled alarm for shift end: $endTime');
      } else {
        debugPrint('[SHIFT_END_ALARM] ⚠️ Failed to schedule alarm for shift end: $endTime');
      }
      return success;
    } on PlatformException catch (e) {
      debugPrint('[SHIFT_END_ALARM] ❌ Error scheduling alarm: ${e.message}');
      return false;
    } catch (e) {
      debugPrint('[SHIFT_END_ALARM] ❌ Unexpected error: $e');
      return false;
    }
  }

  /// Cancel the scheduled shift end alarm
  static Future<bool> cancelAlarm() async {
    if (!Platform.isAndroid) {
      return false;
    }

    try {
      final result = await _channel.invokeMethod<bool>('cancelShiftEndAlarm');
      debugPrint('[SHIFT_END_ALARM] ✅ Cancelled shift end alarm');
      return result ?? false;
    } on PlatformException catch (e) {
      debugPrint('[SHIFT_END_ALARM] ❌ Error cancelling alarm: ${e.message}');
      return false;
    } catch (e) {
      debugPrint('[SHIFT_END_ALARM] ❌ Unexpected error: $e');
      return false;
    }
  }

  /// Handle shift end when alarm fires (called by BroadcastReceiver)
  /// This will create the break log and set rider offline
  static Future<void> handleShiftEnd() async {
    try {
      debugPrint('[SHIFT_END_ALARM] 🔔 Shift end alarm fired - creating break log...');
      
      final prefs = await SharedPreferences.getInstance();
      
      // Check if still on duty (might have been manually set offline)
      final int onduty = prefs.getInt('onduty') ?? 0;
      if (onduty != 1) {
        debugPrint('[SHIFT_END_ALARM] Already offline, skipping break log creation');
        return;
      }

      // Call the background service to create break log
      // This will create break log and set offline
      await BackgroundDeliveryLog.checkShiftEnd();
      
      debugPrint('[SHIFT_END_ALARM] ✅ Break log created successfully');
    } catch (e) {
      debugPrint('[SHIFT_END_ALARM] ❌ Error handling shift end: $e');
    }
  }
}