Attendance validation involving Location Detection + Facial Recoginition with Liveness Detection

lib/providers/verification_session_provider.dart

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+import 'dart:async';
+import 'dart:typed_data';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:supabase_flutter/supabase_flutter.dart';
+
+import '../models/verification_session.dart';
+import 'supabase_provider.dart';
+
+/// Provider for the verification session controller.
+final verificationSessionControllerProvider =
+    Provider<VerificationSessionController>((ref) {
+      final client = ref.watch(supabaseClientProvider);
+      return VerificationSessionController(client);
+    });
+
+/// Controller for creating, completing, and listening to verification sessions.
+class VerificationSessionController {
+  VerificationSessionController(this._client);
+
+  final SupabaseClient _client;
+
+  /// Create a new verification session and return it.
+  Future<VerificationSession> createSession({
+    required String type,
+    String? contextId,
+  }) async {
+    final userId = _client.auth.currentUser!.id;
+    final data = await _client
+        .from('verification_sessions')
+        .insert({'user_id': userId, 'type': type, 'context_id': contextId})
+        .select()
+        .single();
+    return VerificationSession.fromMap(data);
+  }
+
+  /// Fetch a session by ID.
+  Future<VerificationSession?> getSession(String sessionId) async {
+    final data = await _client
+        .from('verification_sessions')
+        .select()
+        .eq('id', sessionId)
+        .maybeSingle();
+    return data == null ? null : VerificationSession.fromMap(data);
+  }
+
+  /// Listen for realtime changes on a specific session (used by web to detect
+  /// when mobile completes the verification).
+  Stream<VerificationSession> watchSession(String sessionId) {
+    return _client
+        .from('verification_sessions')
+        .stream(primaryKey: ['id'])
+        .eq('id', sessionId)
+        .map(
+          (rows) => rows.isEmpty
+              ? throw Exception('Session not found')
+              : VerificationSession.fromMap(rows.first),
+        );
+  }
+
+  /// Complete a session: upload the face photo and mark the session as
+  /// completed. Called from the mobile verification screen.
+  Future<void> completeSession({
+    required String sessionId,
+    required Uint8List bytes,
+    required String fileName,
+  }) async {
+    final userId = _client.auth.currentUser!.id;
+    final ext = fileName.split('.').last.toLowerCase();
+    final path = '$userId/$sessionId.$ext';
+
+    // Upload to face-enrollment bucket (same bucket used for face photos)
+    await _client.storage
+        .from('face-enrollment')
+        .uploadBinary(
+          path,
+          bytes,
+          fileOptions: const FileOptions(upsert: true),
+        );
+    final url = _client.storage.from('face-enrollment').getPublicUrl(path);
+
+    // Mark session completed with the image URL
+    await _client
+        .from('verification_sessions')
+        .update({'status': 'completed', 'image_url': url})
+        .eq('id', sessionId);
+  }
+
+  /// After a session completes, apply the result based on the session type.
+  /// For 'enrollment': update the user's face photo.
+  /// For 'verification': update the attendance log.
+  Future<void> applySessionResult(VerificationSession session) async {
+    if (session.imageUrl == null) return;
+
+    if (session.type == 'enrollment') {
+      // Update profile face photo
+      await _client
+          .from('profiles')
+          .update({
+            'face_photo_url': session.imageUrl,
+            'face_enrolled_at': DateTime.now().toUtc().toIso8601String(),
+          })
+          .eq('id', session.userId);
+    } else if (session.type == 'verification' && session.contextId != null) {
+      // Update attendance log verification status
+      await _client
+          .from('attendance_logs')
+          .update({
+            'verification_status': 'verified',
+            'verification_photo_url': session.imageUrl,
+          })
+          .eq('id', session.contextId!);
+    }
+  }
+
+  /// Expire a session (called when dialog is closed prematurely).
+  Future<void> expireSession(String sessionId) async {
+    await _client
+        .from('verification_sessions')
+        .update({'status': 'expired'})
+        .eq('id', sessionId);
+  }
+}