const fs = require('fs');

const pa11y = require('pa11y');
const htmlReporter = require('pa11y-reporter-html');

const { pa11y: baseConfig, reportsPath } = require('../config').get();

/**
 * Runs an a11y test using pa11y.
 * @param {A11yTestDefinition} testDefinition The test to run
 * @return {*} The raw test results
 */
async function test(testDefinition) {
  const result = await pa11y(testDefinition.url, Object.assign({
    screenCapture: reportsPath ? `${reportsPath}/capture-${testDefinition.id}.png` : undefined,
  }, baseConfig, testDefinition.config));

  if (reportsPath) {
    // Generate file report
    await reportToFile(result, testDefinition.id);
  }

  return result;
}

/**
 * Generates the HTML reports from the pa11y result.
 * @param {Object} pa11yResult The result generated by pa11y
 * @param {string} name The name of the result file
 */
async function reportToFile(pa11yResult, name) {
  const htmlResult = await htmlReporter.results(pa11yResult);
  const reportsFile = fs.openSync(reportsPath + `/report-${name}.html`, 'w');
  fs.writeSync(reportsFile, htmlResult);
  fs.closeSync(reportsFile);
}

/**
 * Generates the A11yTestResult from the pa11y result.
 * @param {Object} pa11yResult The result generated by pa11y
 * @returns {A11yTestResult}
 */
function resultCount(pa11yResult) {
  return {
    errors: pa11yResult.issues.filter(issue => issue.type === 'error').length,
    warnings: pa11yResult.issues.filter(issue => issue.type === 'warning').length,
    notices: pa11yResult.issues.filter(issue => issue.type === 'notice').length,
  };
}

module.exports = {
  test,
  resultCount
};