Added core data models, repositories, and utilities

lifetimer/lib/core/utils/date_time_utils.dart

@@ -0,0 +1,77 @@
+import 'package:intl/intl.dart';
+
+class DateTimeUtils {
+  static const int countdownDays = 1356;
+
+  static DateTime calculateEndDate(DateTime startDate) {
+    return startDate.add(const Duration(days: countdownDays));
+  }
+
+  static Duration calculateRemainingTime(DateTime endDate) {
+    return endDate.difference(DateTime.now());
+  }
+
+  static String formatCountdown(Duration duration) {
+    final days = duration.inDays;
+    final hours = duration.inHours % 24;
+    final minutes = duration.inMinutes % 60;
+    final seconds = duration.inSeconds % 60;
+
+    return '${days}d ${hours}h ${minutes}m ${seconds}s';
+  }
+
+  static String formatCountdownCompact(Duration duration) {
+    final days = duration.inDays;
+    final hours = duration.inHours % 24;
+    final minutes = duration.inMinutes % 60;
+
+    if (days > 0) {
+      return '${days}d ${hours}h';
+    } else if (hours > 0) {
+      return '${hours}h ${minutes}m';
+    } else {
+      return '${minutes}m';
+    }
+  }
+
+  static double calculateProgress(DateTime startDate, DateTime endDate) {
+    final now = DateTime.now();
+    final totalDuration = endDate.difference(startDate).inSeconds;
+    final elapsedDuration = now.difference(startDate).inSeconds;
+
+    if (elapsedDuration >= totalDuration) {
+      return 1.0;
+    }
+
+    return elapsedDuration / totalDuration;
+  }
+
+  static String formatDate(DateTime date) {
+    return DateFormat('MMM dd, yyyy').format(date);
+  }
+
+  static String formatDateTime(DateTime dateTime) {
+    return DateFormat('MMM dd, yyyy • HH:mm').format(dateTime);
+  }
+
+  static String formatRelativeTime(DateTime dateTime) {
+    final now = DateTime.now();
+    final difference = now.difference(dateTime);
+
+    if (difference.inSeconds < 60) {
+      return 'Just now';
+    } else if (difference.inMinutes < 60) {
+      return '${difference.inMinutes}m ago';
+    } else if (difference.inHours < 24) {
+      return '${difference.inHours}h ago';
+    } else if (difference.inDays < 7) {
+      return '${difference.inDays}d ago';
+    } else {
+      return formatDate(dateTime);
+    }
+  }
+
+  static bool isCountdownFinished(DateTime endDate) {
+    return DateTime.now().isAfter(endDate);
+  }
+}

lifetimer/lib/core/utils/validators.dart

@@ -0,0 +1,87 @@
+class Validators {
+  static String? validateEmail(String? value) {
+    if (value == null || value.isEmpty) {
+      return 'Email is required';
+    }
+    
+    final emailRegex = RegExp(r'^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$');
+    if (!emailRegex.hasMatch(value)) {
+      return 'Please enter a valid email address';
+    }
+    
+    return null;
+  }
+
+  static String? validatePassword(String? value) {
+    if (value == null || value.isEmpty) {
+      return 'Password is required';
+    }
+    
+    if (value.length < 6) {
+      return 'Password must be at least 6 characters';
+    }
+    
+    return null;
+  }
+
+  static String? validateUsername(String? value) {
+    if (value == null || value.isEmpty) {
+      return 'Username is required';
+    }
+    
+    if (value.length < 3) {
+      return 'Username must be at least 3 characters';
+    }
+    
+    if (value.length > 20) {
+      return 'Username must not exceed 20 characters';
+    }
+    
+    final usernameRegex = RegExp(r'^[a-zA-Z0-9_]+$');
+    if (!usernameRegex.hasMatch(value)) {
+      return 'Username can only contain letters, numbers, and underscores';
+    }
+    
+    return null;
+  }
+
+  static String? validateGoalTitle(String? value) {
+    if (value == null || value.isEmpty) {
+      return 'Goal title is required';
+    }
+    
+    if (value.length > 100) {
+      return 'Goal title must not exceed 100 characters';
+    }
+    
+    return null;
+  }
+
+  static String? validateGoalDescription(String? value) {
+    if (value != null && value.length > 500) {
+      return 'Description must not exceed 500 characters';
+    }
+    
+    return null;
+  }
+
+  static String? validateGoalProgress(int? value) {
+    if (value == null) {
+      return 'Progress is required';
+    }
+    
+    if (value < 0 || value > 100) {
+      return 'Progress must be between 0 and 100';
+    }
+    
+    return null;
+  }
+
+  static String? validateRequired(String? value, String fieldName) {
+    if (value == null || value.isEmpty) {
+      return '$fieldName is required';
+    }
+    
+    return null;
+  }
+}