src/app/utils/index.ts

/**
 * Utility functions and helpers
 */

import { CsvParseResult, CsvRow } from '../types/index.ts';

// Export user utilities
export * from './user.utils.ts';

// Export analysis utilities
export * from './analysis.utils.ts';

// Export cache utilities
export * from './cache.utils.ts';

/**
 * Debounce function - delays execution until after wait time
 */
export function debounce<T extends (...args: any[]) => any>(
  func: T,
  wait: number
): (...args: Parameters<T>) => void {
  let timeout: NodeJS.Timeout | null = null;
  return function executedFunction(...args: Parameters<T>) {
    const later = () => {
      timeout = null;
      func(...args);
    };
    if (timeout) clearTimeout(timeout);
    timeout = setTimeout(later, wait);
  };
}

/**
 * Format error message from API error or string
 */
export function formatError(error: unknown): string {
  if (typeof error === 'string') return error;
  if (error && typeof error === 'object' && 'message' in error) {
    return String(error.message);
  }
  return 'An unexpected error occurred';
}

/**
 * Sleep/delay utility
 */
export function sleep(ms: number): Promise<void> {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

/**
 * Check if value is empty (null, undefined, empty string, empty array, empty object)
 */
export function isEmpty(value: unknown): boolean {
  if (value == null) return true;
  if (typeof value === 'string') return value.trim().length === 0;
  if (Array.isArray(value)) return value.length === 0;
  if (typeof value === 'object') return Object.keys(value).length === 0;
  return false;
}

/**
 * Parse a CSV string into headers and rows.
 * Supports quoted fields and trims whitespace around values.
 */
export function parseCsv(content: string): CsvParseResult {
  const lines = content.split(/\r?\n/).filter((line) => line.trim().length > 0);

  if (lines.length === 0) {
    return { headers: [], rows: [] };
  }

  const parseLine = (line: string): string[] => {
    const cells: string[] = [];
    let current = '';
    let inQuotes = false;

    for (let i = 0; i < line.length; i += 1) {
      const char = line[i];
      const nextChar = line[i + 1];

      if (char === '"') {
        if (inQuotes && nextChar === '"') {
          current += '"';
          i += 1;
        } else {
          inQuotes = !inQuotes;
        }
      } else if (char === ',' && !inQuotes) {
        cells.push(current.trim());
        current = '';
      } else {
        current += char;
      }
    }

    cells.push(current.trim());
    return cells;
  };

  const headers = parseLine(lines[0]).map((header, index) =>
    header ? header : `column_${index + 1}`
  );

  const rows: CsvRow[] = lines.slice(1).map((line) => {
    const values = parseLine(line);
    const row: CsvRow = {};

    headers.forEach((header, idx) => {
      row[header] = values[idx]?.trim() ?? '';
    });

    return row;
  });

  return {
    headers,
    rows: rows.filter((row) =>
      Object.values(row).some((value) => value !== undefined && value !== '')
    ),
  };
}