//
// Copyright (C) Stanislaw Adaszewski, 2020
// Contact: s.adaszewski@gmail.com
// Website: https://adared.ch/wba
// License: GNU Affero General Public License, Version 3
//

class WBRootDirWrapper {
  constructor(rootDir, streams) {
    this.rootDir = rootDir;
    this.streams = streams;
  }

  findDir(path) {
    if (typeof(path) === 'string')
      path = path.split('/');
    if (path[0] !== '.')
      throw Error('Path must begin with a dot component');
    let dir = this.rootDir;
    for (let i = 1; i < path.length; i++) {
      if (!(path[i] in dir))
        throw Error('Directory not found');
      if (dir[path[i]] instanceof Array)
        throw Error('Path is a file not directory');
      dir = dir[path[i]];
    }
    return dir;
  }

  listDirectory(path) {
    let dir = this.findDir(path);
    let keys = Object.keys(dir);
    keys.sort();
    let subdirs = keys.filter(k => !(dir[k] instanceof Array));
    let files = keys.filter(k => (dir[k] instanceof Array));
    let res = subdirs.map(k => [ 'd', k, null ]);
    res = res.concat(files.map(k => [ 'f', k, dir[k][1] ]));
    return res;
  }

  unescapeName(name) {
    return name.replace(/(\\\\|\\[0-9]{3})/g, (_, $1) => ($1 === '\\\\' ? '\\' : String.fromCharCode(parseInt($1.substr(1), 8))));
  }

  escapeName(name) {
    return name.replace(/ /g, '\\040');
  }

  getFile(path) {
    if (typeof(path) === 'string')
      path = path.split('/');

    if (path.length < 2)
      throw Error('Invalid file path');

    const name = path[path.length - 1];

    const dir = this.findDir(path.slice(0, path.length - 1));

    if (!(name in dir))
      throw Error('File not found');

    if (!(dir[name] instanceof Array))
      throw Error('Path points to a directory not a file');

    const streams = this.streams;
    let file = dir[name];
    file = [ file[0].map(seg => {
      const stm = streams[seg[0]];
      const used = stm.map(loc => !( loc[2] <= seg[1] || loc[1] >= seg[1] + seg[2] ) );
      const start = used.indexOf(true);
      const end = used.lastIndexOf(true) + 1;
      if (start === -1)
        return [];
      const res = [];
      for (let i = start; i < end; i++) {
        const loc = stm[i];
        res.push([ loc[0], Math.max(0, seg[1] - loc[1]),
          Math.min(loc[2] - loc[1], seg[1] + seg[2] - loc[1]) ]);
      }
      return res;
    }), file[1] ];
    file[0] = file[0].reduce((a, b) => a.concat(b));

    return file;
  }
}

export default WBRootDirWrapper;