const fs = require('fs-extra');

const SNIPPETS_PATH = './snippets';
const TEST_PATH = './test';

const snippetFiles = fs.readdirSync(SNIPPETS_PATH, 'utf8').map(fileName => fileName.slice(0, -3));

const errSnippets = ['JSONToFile', 'readFileLines', 'UUIDGeneratorNode'];

snippetFiles
  .filter(fileName => !errSnippets.includes(fileName))
  .map(fileName => {
    fs.ensureDirSync(`${TEST_PATH}/${fileName}`);
    return fileName;
  })
  .map(fileName => {
    const fileData = fs.readFileSync(`${SNIPPETS_PATH}/${fileName}.md`, 'utf8');
    const fileCode = fileData.slice(fileData.indexOf('```js'), fileData.lastIndexOf('```') + 3);
    const blockMarkers = fileCode
      .split('\n')
      .map((line, lineIndex) => (line.slice(0, 3) === '```' ? lineIndex : '//CLEAR//'))
      .filter(x => !(x === '//CLEAR//'));
    const fileFunction = fileCode
      .split('\n')
      .map(line => line.trim())
      .filter((_, i) => blockMarkers[0] < i && i < blockMarkers[1]);
    const fileExample = fileCode
      .split('\n')
      .map(line => line.trim())
      .filter((_, i) => blockMarkers[2] < i && i < blockMarkers[3]);

    const exportFile = `module.exports = ${fileFunction.join('\n').slice(9 + fileName.length)}`;
    const exportTest = [
      `const test = require('tape');`,
      `const ${fileName} = require('./${fileName}.js');`,
      `test('Testing ${fileName}', (t) => {`,
      `//For more information on all the methods supported by tape\n//Please go to https://github.com/substack/tape`,
      `t.true(typeof ${fileName} === 'function', '${fileName} is a Function');`,   
      `//t.deepEqual(${fileName}(args..), 'Expected');`,
      `//t.equal(${fileName}(args..), 'Expected');`,
      `//t.false(${fileName}(args..), 'Expected');`,
      `//t.throws(${fileName}(args..), 'Expected');`,
      `t.end();`,
      `});`
    ].join('\n');

    fs.writeFileSync(`${TEST_PATH}/${fileName}/${fileName}.js`, exportFile);

    if ( !fs.existsSync(`${TEST_PATH}/${fileName}/${fileName}.test.js`) ) {
      fs.writeFileSync(`${TEST_PATH}/${fileName}/${fileName}.test.js`, exportTest);
    }

    return fileName;
  });