/// Domain Entity: Price Document
///
/// Pure business entity representing a price policy or price list document.
/// This entity is framework-independent and contains only business logic.
library;

/// Price policy document entity
class PriceDocument {
  /// Unique document ID
  final String id;

  /// Document title
  final String title;

  /// Document description
  final String description;

  /// Date the document was published
  final DateTime publishedDate;

  /// Type of document (PDF or Excel)
  final DocumentType documentType;

  /// Category (policy or price list)
  final DocumentCategory category;

  /// URL to download the document
  final String downloadUrl;

  /// Optional file size display string
  final String? fileSize;

  /// Constructor
  const PriceDocument({
    required this.id,
    required this.title,
    required this.description,
    required this.publishedDate,
    required this.documentType,
    required this.category,
    required this.downloadUrl,
    this.fileSize,
  });

  /// Check if document is a PDF
  bool get isPdf => documentType == DocumentType.pdf;

  /// Check if document is an Excel file
  bool get isExcel => documentType == DocumentType.excel;

  /// Check if document is a policy document
  bool get isPolicy => category == DocumentCategory.policy;

  /// Check if document is a price list
  bool get isPriceList => category == DocumentCategory.priceList;

  /// Get formatted published date (dd/MM/yyyy)
  String get formattedDate {
    return '${publishedDate.day.toString().padLeft(2, '0')}/'
        '${publishedDate.month.toString().padLeft(2, '0')}/'
        '${publishedDate.year}';
  }

  /// Get formatted date with prefix based on category
  String get formattedDateWithPrefix {
    final prefix = isPolicy ? 'Công bố' : 'Cập nhật';
    return '$prefix: $formattedDate';
  }

  /// Get icon name based on document type
  String get iconName => documentType == DocumentType.pdf ? 'PDF' : 'Excel';

  /// Copy with method for immutability
  PriceDocument copyWith({
    String? id,
    String? title,
    String? description,
    DateTime? publishedDate,
    DocumentType? documentType,
    DocumentCategory? category,
    String? downloadUrl,
    String? fileSize,
  }) {
    return PriceDocument(
      id: id ?? this.id,
      title: title ?? this.title,
      description: description ?? this.description,
      publishedDate: publishedDate ?? this.publishedDate,
      documentType: documentType ?? this.documentType,
      category: category ?? this.category,
      downloadUrl: downloadUrl ?? this.downloadUrl,
      fileSize: fileSize ?? this.fileSize,
    );
  }

  /// Equality operator
  @override
  bool operator ==(Object other) {
    if (identical(this, other)) return true;

    return other is PriceDocument &&
        other.id == id &&
        other.title == title &&
        other.description == description &&
        other.publishedDate == publishedDate &&
        other.documentType == documentType &&
        other.category == category &&
        other.downloadUrl == downloadUrl &&
        other.fileSize == fileSize;
  }

  /// Hash code
  @override
  int get hashCode {
    return Object.hash(
      id,
      title,
      description,
      publishedDate,
      documentType,
      category,
      downloadUrl,
      fileSize,
    );
  }

  /// String representation
  @override
  String toString() {
    return 'PriceDocument(id: $id, title: $title, description: $description, '
        'publishedDate: $publishedDate, documentType: $documentType, '
        'category: $category, downloadUrl: $downloadUrl, fileSize: $fileSize)';
  }
}

/// Document type enum
enum DocumentType { pdf, excel }

/// Document category enum
enum DocumentCategory {
  policy, // Chính sách giá
  priceList, // Bảng giá
}

// Extension for display
extension DocumentTypeX on DocumentType {
  String get displayName {
    switch (this) {
      case DocumentType.pdf:
        return 'PDF';
      case DocumentType.excel:
        return 'Excel';
    }
  }
}

extension DocumentCategoryX on DocumentCategory {
  String get displayName {
    switch (this) {
      case DocumentCategory.policy:
        return 'Chính sách giá';
      case DocumentCategory.priceList:
        return 'Bảng giá';
    }
  }
}