/**
 * @module computeStatistics
 * @description Summarizes the changes to files in the PR by platform.
 *
 * @param {Map} groupedFiles - map of platforms for containing info about the changes to files in that platform, from call to categorize
 * @param {[FileMetadata]} fileMetadatas - gitStream's list of metadata about file changes in the PR including path
 * @returns {[Object]} Returns list of computed summary statistic objects for each platform in the input groupedFiles

 *
 * The table should be in descending order of the number of lines changed, and should only include platforms with non-0 changes.
 *
 * @param {[Object]} statistics - list of summary data objects from computeStatistics
 * @param {String} title - description of how data is grouped
 * @returns {String} Returns the formatted HTMl table string.

 * @param {Object} pr - the gitStream's pr context variable
 * @param {string} token - access token with repo:read scope, used to read the CODEOWNERS file
 * @param {string} pathToCodeOwners - path from repo root to CODEOWNERS file
 * @returns {Map} - Map from owner name to list of files they own
 * @example {{ files | byCodeowner(pr, env.CODEOWNERS_TOKEN, '.github/CODEOWNERS') }}
 **/

const { Octokit } = require("@octokit/rest");

/**
 * @module byPlatform
 * @description Groups the PR's files by platform based on the file's path.
 * @param {string[]} files - the gitStream's files context variable
 * @returns {Map} - Map from platform to list of files in this PR in it
 * @example {{ owners | byPlatform }}
 */
function byPlatform(files) {
    const result = new Map();
    files.forEach(file => {
        const platform = getPlatform(file);
        if (!result.has(platform)) {

const RETURN_FALSE = () => false

// Sanitize the range of a regular expression
// The cases are complicated, see test cases for details
const sanitizeRange = range => range.replace(
    REGEX_REGEXP_RANGE,
    (match, from, to) => from.charCodeAt(0) <= to.charCodeAt(0)
        ? match
        // Invalid range (out of order) which is ok for gitignore rules but
        //   fatal for JavaScript regular expression, so eliminate it.
        : EMPTY
)