group-files-by-owners

const fs = require("fs");
const path = require("path");
const { minimatch } = require("minimatch");

// Function to parse CODEOWNERS file
function parseCodeowners(codeownersFile) {
  const rules = [];
  const lines = fs.readFileSync(codeownersFile, "utf-8").split("\n");

  lines.forEach((line) => {
    line = line.trim();
    if (!line || line.startsWith("#")) return; // Ignore comments and empty lines

    const parts = line.split(/\s+/);
    const pattern = parts[0];
    const owners = parts.slice(1);
    rules.push({ pattern, owners });
  });

  return rules;
}

// Function to group files by code owners
function groupFilesByOwners(files, codeownersRules) {
  const filesByOwner = {};

  files.forEach((file) => {
    let matched = false;

    // Check each rule in CODEOWNERS
    codeownersRules.forEach((rule) => {
      const _file  = '/' + file;
      if (minimatch(_file, rule.pattern) || _file.includes(rule.pattern)) {
        matched = true;
        rule.owners.forEach((owner) => {
          if (!filesByOwner[owner]) {
            filesByOwner[owner] = [];
          }
          filesByOwner[owner].push(file);
        });
      }
    });

    // If no owner is found, categorize as 'unowned'
    if (!matched) {
      if (!filesByOwner["unowned"]) {
        filesByOwner["unowned"] = [];
      }
      filesByOwner["unowned"].push(file);
    }
  });

  return filesByOwner;
}

// Function to read file list from a text file
function readFileList(filePath) {
  const fileContent = fs.readFileSync(filePath, "utf-8");
  return fileContent
    .split("\n")
    .map((file) => file.trim())
    .filter(Boolean);
}

// Path to the CODEOWNERS file and file list
const codeownersFilePath = path.join(__dirname, "CODEOWNERS");
const fileListPath = path.join(__dirname, "files.txt");

// Parse the CODEOWNERS file and the file list
const codeownersRules = parseCodeowners(codeownersFilePath);

const fileList = readFileList(fileListPath);

// Group the files by owners
const groupedFiles = groupFilesByOwners(fileList, codeownersRules);

// Output the results
console.log("Files grouped by owners:");
Object.entries(groupedFiles)
  .sort(([, a], [, b]) => b.length - a.length)
  .forEach(([owner, files]) => {
    console.log(`Owner: ${owner}`);
    files.forEach((file) => {
      console.log(`  - ${file}`);
    });
  });