parsei18n

'use strict';
const _ = require('lodash');
const path = require('path');
const estraverse = require('estraverse');
const esprima = require('esprima');
const recursive = require('recursive-readdir');
const babel = require('babel-core')
const fs = require('fs');


const traverseFileSystem = function (currentPath, onJs) {
  var files = fs.readdirSync(currentPath);
  for (var i in files) {
    var currentFile = currentPath + '/' + files[i];
    var stats = fs.statSync(currentFile);
    if (stats.isFile()) {
      if (/\.js$/.test(currentFile)) {
        onJs(currentFile);

      }
    }
    else if (stats.isDirectory()) {
      traverseFileSystem(currentFile, onJs);
    }
  }
};

const keys = {};
function parseFile(name) {

  const a = babel.transformFileSync(name);
  const ast = a.ast;

  function fromPluralNode(node) {

    const strs = node.arguments[0].elements
      .filter(e => e.type === 'Literal' && _.isString(e.value))
      .map(e => e.value);
    return strs.length ? strs : null;
  }

  function process(node) {
    const v = node.arguments[0].value;
    keys[v] = { msgid: v, msgstr: v };
  }

  function processPlural(node) {
    var k = [];
    for (var i = 0; i < 3; i++) {
      k.push(node.arguments[i].value);
    }
    const arg = i => node.arguments[i];
    const av = i => arg(i).value

      keys[av(0) + ' plural ' + av(2)] = {
        msgid: av(0),
        msgid_plural: av(2),
        msgstr: [av(0), av(1), av(2)]
      };
  }
  estraverse.traverse(esprima.parse(a.code), {
    leave: function (node, parent) {
      if (node.type === 'CallExpression' && node.callee.name === 't') {
        const arg = node.arguments[0];
        const type = node.arguments[0].type;
        const value = node.arguments[0].value;
        if (type === 'Literal' && _.isString(value)) {
          process(node);
        } else {
          console.error(node);
          throw new Error('Wrong node');
        }
      }
      if (node.type === 'CallExpression' && node.callee.name === 'tp') {
        processPlural(node)
      }
    }
  });

}
traverseFileSystem(path.join(__dirname, '../app'), parseFile);
const data = _.values(keys)
  .map((k,i) => {
    const s = JSON.stringify;
    let text = `#: test ${i}\nmsgid ${s(k.msgid)}\n`;
    if (k.msgid_plural) {
      const plural = k.msgstr.map((m,i) => `msgstr[${i}] ${s(m)}`).join('\n');
      text += `msgid_plural ${s(k.msgid_plural)}\n` + plural;
    }
    else
      text += `msgstr ${s(k.msgstr)}`;
    return text;
  })
  .join('\n\n') + '\n';
fs.writeFileSync(path.join(__dirname, '../locales/exchange.po'), data);