/**

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */

'use strict';

const minimatch = require('minimatch');

const {ESLint} = require('eslint');

const listChangedFiles = require('../shared/listChangedFiles');

const allPaths = ['**/*.js'];

let changedFiles = null;

async function runESLintOnFilesWithOptions(filePatterns, onlyChanged, options) {

  const eslint = new ESLint(options);

  const formatter = await eslint.loadFormatter();

  if (onlyChanged && changedFiles === null) {

    // Calculate lazily.

    changedFiles = [...listChangedFiles()];

  }

  const finalFilePatterns = onlyChanged

    ? intersect(changedFiles, filePatterns)

    : filePatterns;

  const results = await eslint.lintFiles(finalFilePatterns);

  if (options != null && options.fix === true) {

    await ESLint.outputFixes(results);

  }

  // When using `ignorePattern`, eslint will show `File ignored...` warnings for any ignores.

  // We don't care because we *expect* some passed files will be ignores if `ignorePattern` is used.

  const messages = results.filter(item => {

    if (!onlyChanged) {

      // Don't suppress the message on a full run.

      // We only expect it to happen for "only changed" runs.

      return true;

    }

    const ignoreMessage =

      'File ignored because of a matching ignore pattern. Use "--no-ignore" to override.';

    return !(item.messages[0] && item.messages[0].message === ignoreMessage);

  });

  const errorCount = results.reduce(

    (count, result) => count + result.errorCount,

    0

  );

  const warningCount = results.reduce(

    (count, result) => count + result.warningCount,

    0

  );

  const ignoredMessageCount = results.length - messages.length;

  return {

    output: formatter.format(messages),

    errorCount: errorCount,

    warningCount: warningCount - ignoredMessageCount,

  };

}

function intersect(files, patterns) {

  let intersection = [];

  patterns.forEach(pattern => {

    intersection = [

      ...intersection,

      ...minimatch.match(files, pattern, {matchBase: true}),

    ];

  });

  return [...new Set(intersection)];

}

async function runESLint({onlyChanged, ...options}) {

  if (typeof onlyChanged !== 'boolean') {

    throw new Error('Pass options.onlyChanged as a boolean.');

  }

  const {errorCount, warningCount, output} = await runESLintOnFilesWithOptions(

    allPaths,

    onlyChanged,

    options

  );

  console.log(output);

  return errorCount === 0 && warningCount === 0;

}

module.exports = runESLint;