import inquirer from 'inquirer';
import chalk from 'chalk';

export async function getApiResponseFilterFields(
  responseFilters: any,
): Promise<{ filterType: string; filterKey: string; fields: string[] } | null> {
  // Convert responseFilters to an array
  const filtersArray = Object.entries(responseFilters).flatMap(
    ([filterType, filters]) =>
      Object.entries(filters as any).map(
        ([filterKey, filterDetails]: [string, any]) => ({
          filterType,
          filterKey,
          expression: filterDetails.expression,
        }),
      ),
  );

  // Ask the user to select a filter key
  const { selectedFilter } = await inquirer.prompt([
    {
      type: 'list',
      name: 'selectedFilter',
      message: 'Select the response filter key you want to process:',
      choices: filtersArray.map((filter, i) => ({
        name: `${i + 1}. Filter Type: ${chalk.yellow(filter.filterType)}, Filter Key: ${chalk.yellow(filter.filterKey)}`,
        value: filter,
      })),
    },
  ]);

  // Find the selected filter
  const selectedFilterDetails = filtersArray.find(
    (filter) =>
      filter.filterType === selectedFilter.filterType &&
      filter.filterKey === selectedFilter.filterKey,
  );

  if (!selectedFilterDetails) {
    console.error(chalk.red('✗ Selected filter not found.'));
    return null;
  }

  const { filterType, filterKey, expression } = selectedFilterDetails;

  // Parse the expression to extract fields
  let fields: string[] = [];
  if (filterType === 'jsonata') {
    // Use regular expression to extract field names from JSONata expression
    const jsonataFieldRegex = /"([^"]+)":/g;
    let match;
    while ((match = jsonataFieldRegex.exec(expression)) !== null) {
      fields.push(match[1]);
    }
  } else if (filterType === 'xpath') {
    // Use regular expression to extract field names from XPath expression
    const xpathFieldRegex = /([a-zA-Z_][\w-]*)\s*:/g;
    let match;
    while ((match = xpathFieldRegex.exec(expression)) !== null) {
      fields.push(match[1]);
    }
  } else if (filterType === 'scriban') {
    console.error(
      chalk.red('✗ Scriban filters are not supported for field extraction.'),
    );
    return null;
  }

  return { filterType, filterKey, fields };
}