/**
 * Auth utilities - safe JSON parsing and error display
 * Following the pattern from static/js/watchlist.js (global exports)
 */

// API base URL - use relative path for same-origin
const API_BASE = '/api';

/**
 * Safely parse JSON string with fallback
 * @param {string} text - The JSON string to parse
 * @param {*} fallback - The fallback value if parsing fails (default: null)
 * @returns {*} Parsed object or fallback value
 */
function safeJsonParse(text, fallback = null) {
  try {
    if (text === undefined || text === null || text === '') {
      return fallback;
    }
    return JSON.parse(text);
  } catch (error) {
    console.error('JSON parse error:', error.message);
    return fallback;
  }
}

/**
 * Display error message in the specified element
 * Handles string, object, and array errors properly
 * @param {string} elementId - The ID of the element to display error in
 * @param {*} error - The error (string, object, or array)
 * @param {string} defaultMessage - Default message if error is invalid
 */
function displayError(elementId, error, defaultMessage = 'Une erreur est survenue') {
  const errorDiv = document.getElementById(elementId);
  if (!errorDiv) {
    console.error('Error element not found:', elementId);
    return;
  }

  let message = defaultMessage;

  if (error === null || error === undefined) {
    message = defaultMessage;
  } else if (typeof error === 'string') {
    message = error;
  } else if (typeof error === 'object') {
    // Handle array errors
    if (Array.isArray(error)) {
      message = error.join('\n');
    } 
    // Handle FastAPI HTTPException detail (can be string or object)
    else if (error.detail) {
      if (typeof error.detail === 'string') {
        message = error.detail;
      } else if (typeof error.detail === 'object' && error.detail.msg) {
        message = error.detail.msg;
      } else {
        // Stringify the object to avoid "[object Object]"
        message = JSON.stringify(error.detail);
      }
    }
    // Handle generic object
    else {
      message = JSON.stringify(error);
    }
  }

  errorDiv.textContent = message;
  errorDiv.classList.remove('hidden');

  // Hide success message if visible
  const successDiv = document.getElementById(elementId.replace('Error', 'Success'));
  if (successDiv) {
    successDiv.classList.add('hidden');
  }
}

/**
 * Display success message in the specified element
 * @param {string} elementId - The ID of the element to display success in
 * @param {string} message - The success message
 */
function displaySuccess(elementId, message) {
  const successDiv = document.getElementById(elementId);
  if (!successDiv) {
    console.error('Success element not found:', elementId);
    return;
  }

  successDiv.textContent = message;
  successDiv.classList.remove('hidden');

  // Hide error message if visible
  const errorDiv = document.getElementById(elementId.replace('Success', 'Error'));
  if (errorDiv) {
    errorDiv.classList.add('hidden');
  }
}

// Export globally (following watchlist.js pattern)
window.safeJsonParse = safeJsonParse;
window.displayError = displayError;
window.displaySuccess = displaySuccess;
window.API_BASE = API_BASE;