/**
 * DSS Error Handler
 *
 * Converts technical errors into user-friendly, actionable messages.
 * Integrates with the messaging system for structured error reporting.
 *
 * @module error-handler
 */

import { notifyError, ErrorCode } from './messaging.js';

/**
 * Error message templates with user-friendly descriptions
 */
const errorMessages = {
  // Figma API Errors
  figma_403: {
    title: 'Access Denied',
    message: 'Cannot access the Figma file. Your access credentials lack permission.',
    actions: [
      'Verify your Figma authentication token in Settings',
      'Confirm you have access to this file in Figma',
      'Check if the file still exists',
    ],
    code: ErrorCode.FIGMA_API_ERROR,
  },
  figma_404: {
    title: 'File Not Found',
    message: 'The Figma file doesn\'t exist or is inaccessible.',
    actions: [
      'Double-check your Figma file key in Settings',
      'Verify the file hasn\'t been deleted in Figma',
      'Confirm you have access to the file in Figma',
    ],
    code: ErrorCode.FIGMA_API_ERROR,
  },
  figma_401: {
    title: 'Authentication Failed',
    message: 'Figma authentication failed. Your access token is invalid or expired.',
    actions: [
      'Refresh your Figma authentication token in Settings',
      'Get a fresh token from figma.com/settings (Account -> Personal Access Tokens)',
      'Ensure you copied the full token without truncation',
    ],
    code: ErrorCode.FIGMA_CONNECTION_FAILED,
  },
  figma_429: {
    title: 'Rate Limit Exceeded',
    message: 'Too many requests. Figma\'s rate limits have been triggered.',
    actions: [
      'Wait 1-2 minutes before trying again',
      'Reduce how frequently you extract data',
    ],
    code: ErrorCode.FIGMA_API_ERROR,
  },
  figma_500: {
    title: 'Figma Server Error',
    message: 'Figma\'s servers are experiencing issues. This is external to DSS.',
    actions: [
      'Wait and try again later',
      'Check Figma status: status.figma.com',
    ],
    code: ErrorCode.FIGMA_API_ERROR,
  },
  figma_demo: {
    title: 'Invalid Configuration',
    message: 'The Figma file key is configured to "demo" which doesn\'t exist in Figma.',
    actions: [
      'Update Settings with your real Figma file key',
      'Find your file key in the Figma URL: figma.com/file/[FILE_KEY]/...',
      'Use the Figma file selector in Settings',
    ],
    code: ErrorCode.FIGMA_INVALID_KEY,
  },

  // API Connection Errors
  api_network: {
    title: 'Server Not Responding',
    message: 'Cannot connect to the DSS server.',
    actions: [
      'Verify the server is running: curl http://localhost:3456/health',
      'Restart the server: ./scripts/dss start',
      'Check your network connection',
    ],
    code: ErrorCode.SYSTEM_NETWORK,
  },
  api_timeout: {
    title: 'Request Timeout',
    message: 'The server took too long to respond.',
    actions: [
      'Try again in a few moments',
      'Check the server logs: ./scripts/dss logs',
      'Try processing smaller batches',
    ],
    code: ErrorCode.API_TIMEOUT,
  },
  api_500: {
    title: 'Server Error',
    message: 'The server encountered an error while processing your request.',
    actions: [
      'Check the server logs: ./scripts/dss logs',
      'Retry the operation',
      'Report the issue if it persists',
    ],
    code: ErrorCode.API_SERVER_ERROR,
  },

  // Validation Errors
  validation_missing_field: {
    title: 'Missing Required Field',
    message: 'The configuration is missing required information.',
    actions: [
      'Fill in all fields marked as required',
      'Ensure each input field contains valid information',
    ],
    code: ErrorCode.VALIDATION_MISSING_FIELD,
  },
  validation_invalid_format: {
    title: 'Invalid Format',
    message: 'One or more configuration values have an invalid format.',
    actions: [
      'Verify URLs start with http:// or https://',
      'Check email addresses follow standard format',
      'Ensure file keys contain only letters, numbers, and hyphens',
    ],
    code: ErrorCode.VALIDATION_INVALID_FORMAT,
  },

  // Generic fallback
  unknown: {
    title: 'Unexpected Error',
    message: 'An unexpected problem occurred.',
    actions: [
      'Try the operation again',
      'Refresh the page if the issue persists',
      'Check browser console for details',
    ],
    code: ErrorCode.SYSTEM_UNEXPECTED,
  },
};

/**
 * Parse error and return user-friendly message
 * @param {Error} error - The error to parse
 * @param {Object} context - Additional context (operation, endpoint, etc.)
 * @returns {Object} Parsed error with user-friendly message
 */
export function parseError(error, context = {}) {
  const errorStr = error.message || String(error);

  // Figma API Errors
  if (context.service === 'figma' || errorStr.includes('figma.com')) {
    // Demo file key
    if (context.fileKey === 'demo' || errorStr.includes('/demo/')) {
      return errorMessages.figma_demo;
    }

    // HTTP status codes
    if (errorStr.includes('403')) {
      return errorMessages.figma_403;
    }
    if (errorStr.includes('404')) {
      return errorMessages.figma_404;
    }
    if (errorStr.includes('401')) {
      return errorMessages.figma_401;
    }
    if (errorStr.includes('429')) {
      return errorMessages.figma_429;
    }
    if (errorStr.includes('500') || errorStr.includes('502') || errorStr.includes('503')) {
      return errorMessages.figma_500;
    }
  }

  // Network Errors
  if (errorStr.includes('NetworkError') || errorStr.includes('Failed to fetch')) {
    return errorMessages.api_network;
  }

  // Timeout Errors
  if (errorStr.includes('timeout') || errorStr.includes('Timeout')) {
    return errorMessages.api_timeout;
  }

  // API Server Errors
  if (errorStr.includes('500') || errorStr.includes('Internal Server Error')) {
    return errorMessages.api_500;
  }

  // Validation Errors
  if (errorStr.includes('required') || errorStr.includes('missing')) {
    return errorMessages.validation_missing_field;
  }
  if (errorStr.includes('invalid') || errorStr.includes('format')) {
    return errorMessages.validation_invalid_format;
  }

  // Fallback
  return errorMessages.unknown;
}

/**
 * Format user-friendly error message
 * @param {Object} parsedError - Parsed error from parseError()
 * @returns {string} Formatted message
 */
export function formatErrorMessage(parsedError) {
  let message = `${parsedError.title}\n\n${parsedError.message}`;

  if (parsedError.actions && parsedError.actions.length > 0) {
    message += '\n\nWhat to do:\n';
    parsedError.actions.forEach((action, index) => {
      message += `${index + 1}. ${action}\n`;
    });
  }

  return message.trim();
}

/**
 * Handle error and notify user with friendly message
 * @param {Error} error - The error to handle
 * @param {Object} context - Additional context
 * @param {string} context.operation - What operation failed (e.g., "extract tokens")
 * @param {string} context.service - Which service (e.g., "figma")
 * @param {string} context.fileKey - Figma file key if applicable
 */
export function handleError(error, context = {}) {
  const parsed = parseError(error, context);

  // Create user-friendly message
  let userMessage = parsed.title;

  if (parsed.actions && parsed.actions.length > 0) {
    userMessage += '. ' + parsed.actions[0]; // Show first action in notification
  }

  // Notify user with structured error
  notifyError(userMessage, parsed.code, {
    operation: context.operation,
    service: context.service,
    originalError: error.message,
    actions: parsed.actions,
  });

  // Log full details to console for debugging
  console.group(`[ERROR] ${parsed.title}`);
  console.log('Message:', parsed.message);
  if (parsed.actions) {
    console.log('Actions:', parsed.actions);
  }
  console.log('Context:', context);
  console.log('Original Error:', error);
  console.groupEnd();

  return parsed;
}

/**
 * Try-catch wrapper with automatic error handling
 * @param {Function} fn - Async function to execute
 * @param {Object} context - Error context
 * @returns {Promise<*>} Result of function or null on error
 */
export async function tryWithErrorHandling(fn, context = {}) {
  try {
    return await fn();
  } catch (error) {
    handleError(error, context);
    return null;
  }
}

/**
 * Get user-friendly HTTP status message
 * @param {number} status - HTTP status code
 * @returns {string} User-friendly message
 */
export function getStatusMessage(status) {
  const messages = {
    400: 'Bad Request - invalid input data',
    401: 'Authentication Failed - invalid credentials',
    403: 'Access Forbidden - permission denied',
    404: 'Not Found - resource doesn\'t exist',
    429: 'Rate Limited - too many requests',
    500: 'Server Error - internal processing failure',
    502: 'Bad Gateway - server not responding',
    503: 'Service Unavailable - temporarily unable to handle requests',
  };

  return messages[status] || `Unknown Error - HTTP ${status}`;
}

export default {
  parseError,
  formatErrorMessage,
  handleError,
  tryWithErrorHandling,
  getStatusMessage,
};