import readdir from 'readdir-enhanced';
import fs from 'fs';
import crypto from 'crypto';
import multimatch from 'multimatch';
import { cfg } from './repo-config.js';

function applyExcludeFilter(stat, excludeFilters) {
  // match exclude, return immediatley
  if (excludeFilters.length > 0) {
    // todo this could be a performance problem...
    const pathWithFolderSlash = stat.path + (stat.isDirectory() ? '/' : '');
    const excludeMatch = multimatch(pathWithFolderSlash, excludeFilters, { matchBase: true, dot: true });

    if (excludeMatch.length > 0) {
      return false;
    }
  }

  return true;
}

/**
 * @param algorithm : "md5" | "sha1" | "sha256" | "sha512"
 */
async function fileHash(filename, algorithm) {
  return new Promise((resolve, reject) => {
    // Algorithm depends on availability of OpenSSL on platform
    // Another algorithms: "sha1", "md5", "sha256", "sha512" ...
    let shasum = crypto.createHash(algorithm);
    try {
      let s = fs.createReadStream(filename);
      s.on('data', function (data) {
        shasum.update(data);
      });

      s.on('error', function (error) {
        reject(error);
      });

      // making digest
      s.on('end', function () {
        const hash = shasum.digest('hex');
        return resolve(hash);
      });
    } catch (error) {
      return reject('calc fail');
    }
  });
}

function createLocalState(localFiles, args) {
  console.log(`Creating local state at ${args['local-dir']}${args['state-name']}`);
  fs.writeFileSync(`${args['local-dir']}${args['state-name']}`, JSON.stringify(localFiles, undefined, 4), { encoding: 'utf8' });
  console.log('Local state created');
}
async function getLocalFiles(args) {
  const files = await readdir.async(args['local-dir'], { deep: true, stats: true, sep: '/', filter: (stat) => applyExcludeFilter(stat, args.exclude) });
  let records = [];
  console.log(files.length, 'items');
  for (let stat of files) {
    if (stat.isDirectory()) {
      records.push({
        type: 'folder',
        name: stat.path,
        size: undefined,
      });

      continue;
    }

    if (stat.isFile()) {
      records.push({
        type: 'file',
        name: stat.path,
        size: stat.size,
        hash: await fileHash(args['local-dir'] + stat.path, 'sha256'),
      });

      continue;
    }

    if (stat.isSymbolicLink()) {
      console.warn('This script is currently unable to handle symbolic links - please add a feature request if you need this');
    }
  }

  return {
    description: "Don't delete. Generate local",
    version: '1.0.0',
    generatedTime: new Date().getTime(),
    generatedTimeString: new Date().toLocaleString(),
    data: records,
  };
}

try {
  const [, , repoArg] = process.argv;
  if (!repoArg) {
    throw "error: Pls input repo: info | ghh | XX";
  }
  const filename = `.generate-file-hash.json`;
  const _args = {
    'local-dir': `./../${cfg[repoArg].folder}/`,
    'state-name': filename,
    'exclude': [filename, 'ftp-state/**'].concat(cfg[repoArg].exclude),
  };
  const localFiles = await getLocalFiles(_args);
  createLocalState(localFiles, _args);
} catch (error) {
  console.log(error);
}