/**
 * Data transformation functions for Reports API
 * Handles bidirectional mapping between frontend (Supabase) and backend (Django) formats
 */

import type {
  Report,
  LegacyReport,
  SubmitReportData,
  LegacySubmitReportData,
} from './types';

/**
 * Map legacy frontend submission data to Django format
 * Converts Supabase field names to Django field names
 * 
 * @param data - Report submission data with Supabase field names
 * @returns Report submission data with Django field names
 */
export function mapSubmitReportToBackend(
  data: LegacySubmitReportData
): SubmitReportData {
  return {
    entity_type: data.reported_entity_type,
    entity_id: data.reported_entity_id,
    report_type: data.report_type,
    description: data.reason || undefined,
  };
}

/**
 * Map Django report response to legacy frontend format
 * Converts Django field names to Supabase field names for backward compatibility
 * Adds synthetic profile structures from email data
 * 
 * @param report - Report data from Django API
 * @returns Report data in legacy Supabase format
 */
export function mapReportToLegacy(report: Report): LegacyReport {
  return {
    id: report.id,
    reported_entity_type: report.entity_type,
    reported_entity_id: report.entity_id,
    report_type: report.report_type,
    reason: report.description,
    status: report.status,
    reporter_id: report.reported_by_id,
    reviewed_by: report.reviewed_by_id,
    reviewed_at: report.reviewed_at,
    resolution_notes: report.resolution_notes,
    created_at: report.created_at,
    updated_at: report.updated_at,
    // Create synthetic profile objects from email data
    reporter_profile: report.reported_by_email
      ? {
          username: report.reported_by_email.split('@')[0],
          display_name: null,
        }
      : null,
    reviewer_profile: report.reviewed_by_email
      ? {
          username: report.reviewed_by_email.split('@')[0],
          display_name: null,
        }
      : null,
  };
}

/**
 * Map array of Django reports to legacy format
 * Convenience function for bulk transformations
 * 
 * @param reports - Array of reports from Django API
 * @returns Array of reports in legacy Supabase format
 */
export function mapReportsToLegacy(reports: Report[]): LegacyReport[] {
  return reports.map(mapReportToLegacy);
}

/**
 * Extract username from email address
 * Fallback for creating synthetic usernames
 * 
 * @param email - Email address
 * @returns Username (part before @) or null
 */
export function extractUsernameFromEmail(email: string | null): string | null {
  if (!email) return null;
  return email.split('@')[0];
}