const path = require('path');
const fs = require('fs');
const os = require('os');
const JoyCon = require('joycon');
const globParent = require('glob-parent');

exports.getRootPath = () => process.cwd();

exports.getHomeDir = () => os.homedir();

exports.getDataDir = () => path.join(exports.getHomeDir(), '.local/share');

exports.canAccessFile = (p, flag) => {
  try {
    fs.accessSync(p, flag || fs.constants.R_OK);
    return true;
  } catch (e) {
    return false;
  }
};

exports.getFileContents = (filePath, opts = {}) => {
  if (!exports.canAccessFile(filePath)) throw new Error(`File not found: ${filePath}`);

  const content = fs.readFileSync(filePath);
  if (opts.format === 'json') return JSON.parse(content);
  if (opts.format === 'text') return content.toString();
  return content;
};

exports.getPackageInfo = () => {
  const { name, workspaces } = exports.getFileContents(
    path.join(exports.getRootPath(), 'package.json'),
    {
      format: 'json',
    }
  );
  if (!name) throw new Error('Unable to read project name from package.json');
  return { name, workspaces };
};

exports.getPackageWorkspaces = () => {
  const { workspaces } = exports.getPackageInfo();
  if (!workspaces) return [];

  return workspaces.reduce((acc, glob) => {
    const parent = globParent(glob);
    const packages = fs
      .readdirSync(parent)
      .map(package => {
        const packageJson = path.join(parent, package, 'package.json');
        if (!exports.canAccessFile(packageJson)) return false;
        return {
          name: package,
          package: packageJson,
        };
      })
      .filter(Boolean);
    return acc.concat(packages);
  }, []);
};

exports.getConfig = (overrides = {}) => {
  const joycon = new JoyCon();
  const defaults = {
    checkFiles: ['package-lock.json', 'yarn.lock'],
    rootDir: process.cwd(),
    dataDir: exports.getDataDir(),
    cmd: false,
  };

  const result = joycon.loadSync({
    packageKey: 'pkgcomp',
    files: ['.config/pkgcomp.json', '.pkgcomp.json', 'pkgcomp.json', 'package.json'],
  });

  return Object.assign(defaults, result.data, overrides);
};