import 'dart:math' as math;
import 'package:flutter/material.dart';
import 'package:geolocator/geolocator.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

class TecsMobileInterlockingCore {
  final supabase = Supabase.instance.client;

  // COMPONENT A: MOBILE CLINICIAN SIGNUP & SYSTEM CLOUD INTEGRATION
  Future<bool> executeNurseProfileSignup({
    required String fullName,
    required String licenseNumber,
    required DateTime blsExpiration,
    required DateTime tbExpiration,
  }) async {
    try {
      if (fullName.isEmpty || licenseNumber.isEmpty) return false;

      // Ingest structural data models directly into core profile table rows
      await supabase.from('nurses').insert({
        'name': fullName,
        'license_number': licenseNumber,
        'license_status': 'Active',
        'compliance_status': 'Green',
        'bls_expiration': blsExpiration.toIso8601String(),
        'tb_expiration': tbExpiration.toIso8601String(),
      });

      return true;
    } catch (e) {
      debugPrint('Mobile registration structural fault: $e');
      return false;
    }
  }

  // COMPONENT B: FRAUD-PROOF GEOFENCED PROXIMITY ATTENDANCE CLOCK
  Future<String> executeGeofencedClockIn({
    required String shiftId,
    required String nurseId,
    required String facilityId,
  }) async {
    try {
      // Step 1: Verify smartphone geolocation hardware permission states are active
      LocationPermission permission = await Geolocator.checkPermission();
      if (permission == LocationPermission.denied) {
        permission = await Geolocator.requestPermission();
        if (permission == LocationPermission.denied) {
          return "CLOCK_IN_DENIED: Location verification parameters are mandatory to calculate attendance timestamps.";
        }
      }

      // Step 2: Query highly accurate positioning coordinates of the mobile device
      Position currentPosition = await Geolocator.getCurrentPosition(
        desiredAccuracy: LocationAccuracy.high,
      );

      // Step 3: Fetch facility coordinates from secure multi-tenant profiles table
      final facilityData = await supabase
          .from('facilities')
          .select('gps_latitude, gps_longitude')
          .eq('id', facilityId)
          .single();

      if (facilityData == null) return "ERROR: Facility tracking parameters not located.";

      double facilityLat = facilityData['gps_latitude'] as double;
      double facilityLng = facilityData['gps_longitude'] as double;

      // Step 4: Run mathematical Haversine calculations to find real distance parameters
      double distanceInMeters = Geolocator.distanceBetween(
        currentPosition.latitude,
        currentPosition.longitude,
        facilityLat,
        facilityLng,
      );

      // CRITICAL RADIUS GEOFENCE INTERLOCK: 200 Meters Absolute Threshold Margin
      if (distanceInMeters > 200.0) {
        return "CLOCK_IN_DENIED: Proximity lock activated. You are currently ${distanceInMeters.toStringAsFixed(1)} meters outside your designated facility zone.";
      }

      // Step 5: Clock-in verified. Commit attendance markers to database shift timeline
      await supabase.from('shifts').update({
        'nurse_id': nurseId,
        'is_locked': true,
      }).eq('id', shiftId);

      return "CLOCK_IN_SUCCESSFUL: Geometric footprint approved. Shift billing logs are live.";
    } catch (e) {
      return "SYSTEM_FAULT_EXCEPTION: Connection dropped during GPS validation routing: $e";
    }
  }
}