const fs = require('fs-extra');
const path = require('path');
const chalk = require('chalk');
const util = require('./util.js');
const markdown = require('markdown-builder');
const snippets = require('../data/snippet_data.json');

const { headers, misc, lists } = markdown;
const TAG_NAMES = [...new Set(snippets.reduce((acc, v) => [...acc, v.tags[0]], []))].sort((a, b) =>
  a.localeCompare(b)
);
console.log(TAG_NAMES);

const STATIC_PARTS_PATH = './static-parts';

let startPart = '';
let endPart = '';
let output = '';

const detailsTOC = (title, snippetsArray) =>
  `\n${misc
    .collapsible(
      title,
      lists
        .ul(snippetsArray, snippet =>
          misc.link(
            snippet.title
              .replace('\n', '')
              .split('```')[0]
              .trim(),
            misc.anchor(
              snippet.title
                .replace('\n', '')
                .split('```')[0]
                .trim()
            )
          )
        )
        .trim()
    )
    .trim()}\n\n`;

console.time('Builder');

try {
  startPart = fs.readFileSync(path.join(STATIC_PARTS_PATH, 'README-start.md'), 'utf8');
  endPart = fs.readFileSync(path.join(STATIC_PARTS_PATH, 'README-end.md'), 'utf8');
} catch (err) {
  console.log(`${chalk.red('ERROR!')} During static part loading: ${err}`);
  process.exit(1);
}

try {
  // add static part for start
  output += `${startPart}\n`;

  const snippetsInTag = {};

  TAG_NAMES.forEach(tag => (snippetsInTag[tag] = snippets.filter(v => v.tags[0] == tag)));

  // write Table of Contents
  TAG_NAMES.forEach(tag => {
    const taggedSnippets = snippetsInTag[tag];
    output += headers.h3(util.capitalize(tag));
    output += detailsTOC('View contents', taggedSnippets);
  });

  // delimeter after TOC
  output += misc.hr();

  // write actual snippets
  TAG_NAMES.forEach(tag => {
    output += headers.h2(util.capitalize(tag));
    const taggedSnippets = snippetsInTag[tag];
    taggedSnippets.forEach(snippet => {
      output += headers.h3(snippet.title).trim();
      output += `\n\n${snippet.text}${snippet.codeBlocks.slice(0, -1).join('\n\n')}`;
      if (snippet.notes && snippet.notes.length) {
        output += headers.h4('Notes');
        output += `\n${snippet.notes}`;
      }
      output += misc.collapsible('Examples', snippet.codeBlocks.slice(-1));
      output += `\n<br>${misc.link('⬆ Back to top', misc.anchor('Table of Contents'))}\n\n`;
    });
  });

  // add static part for end
  output += `\n${endPart}\n`;

  fs.writeFileSync('README.md', output);
} catch (err) {
  console.log(`${chalk.red('ERROR!')} During README generation: ${err}`);
  process.exit(1);
}

console.log(`${chalk.green('SUCCESS!')} README file generated!`);
console.timeEnd('Builder');