/// A mailbox / folder within an account (maps to an IMAP mailbox).
class Mailbox {
  final String id; // "<accountId>:<path>"
  final String accountId;
  final String path; // e.g. "INBOX", "Sent", "INBOX/Work"
  final String name; // last path component
  final int unreadCount;
  final int totalCount;
  // JMAP role (RFC 8621) or mapped from IMAP special-use (RFC 6154).
  // e.g. "inbox", "sent", "drafts", "junk", "trash", "archive"
  final String? role;

  const Mailbox({
    required this.id,
    required this.accountId,
    required this.path,
    required this.name,
    required this.unreadCount,
    required this.totalCount,
    this.role,
  });

  Mailbox copyWith({
    String? id,
    String? accountId,
    String? path,
    String? name,
    int? unreadCount,
    int? totalCount,
    String? role,
  }) {
    return Mailbox(
      id: id ?? this.id,
      accountId: accountId ?? this.accountId,
      path: path ?? this.path,
      name: name ?? this.name,
      unreadCount: unreadCount ?? this.unreadCount,
      totalCount: totalCount ?? this.totalCount,
      role: role ?? this.role,
    );
  }

  factory Mailbox.fromJson(Map<String, dynamic> json) {
    return Mailbox(
      id: json['id'] as String,
      accountId: json['accountId'] as String,
      path: json['path'] as String,
      name: json['name'] as String,
      unreadCount: json['unreadCount'] as int,
      totalCount: json['totalCount'] as int,
      role: json['role'] as String?,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'accountId': accountId,
      'path': path,
      'name': name,
      'unreadCount': unreadCount,
      'totalCount': totalCount,
      'role': role,
    };
  }
}

/// Sorts mailboxes by role priority (Inbox first, etc) then alphabetically by path.
int compareMailboxes(Mailbox a, Mailbox b) {
  const roleOrder = ['inbox', 'drafts', 'sent', 'archive', 'junk', 'trash'];
  final idxA = a.role == null ? 99 : roleOrder.indexOf(a.role!);
  final idxB = b.role == null ? 99 : roleOrder.indexOf(b.role!);
  final prioA = idxA == -1 ? 99 : idxA;
  final prioB = idxB == -1 ? 99 : idxB;

  if (prioA != prioB) {
    return prioA.compareTo(prioB);
  }
  return a.path.toLowerCase().compareTo(b.path.toLowerCase());
}