import fs, {promises as fsp} from 'fs';
import {join} from 'path';
import cpy from 'cpy';
// @ts-expect-error
import htmlclean from 'htmlclean';
import marked from 'marked';
import nunjucks from 'nunjucks';
import refractor from 'refractor';
import rehype from 'rehype';
import sass from 'sass';
import {generateLove, LoveVariant} from './love';
import {getVersions, Versions} from './version';

export async function main(): Promise<void> {
  // Create all required directories for the website.
  await fsp.mkdir(join(__dirname, '../../public/css/'), {recursive: true});
  await fsp.copyFile(
    join(__dirname, '../../node_modules/modern-normalize/modern-normalize.css'),
    join(__dirname, '../../public/css/modern-normalize.css')
  );

  await fsp.mkdir(join(__dirname, '../../public/images/'), {recursive: true});

  // Configure Nunjucks to use the templates for `source/pages/`.
  nunjucks.configure(join(__dirname, '../pages/'), {
    lstripBlocks: true,
    trimBlocks: true,
    throwOnUndefined: true
  });

  const love: LoveVariant[] = generateLove();

  const versions: Versions = await getVersions();

  // Write the colors to file.
  await writeJSON(join(__dirname, '../../public/love.json'), love);

  // Render the Sass to CSS.
  let css: string = sass
    .renderSync({
      file: join(__dirname, '../pages/scss/style.scss'),
      sourceMap: false
    })
    .css.toString();

  // Generate the CSS custom properties.
  const cssProperties = `:root {
  --foreground-1: ${love[0].colors.foreground1};
  --foreground-2: ${love[0].colors.foreground2};
  --background-1: ${love[0].colors.background1};
  --background-2: ${love[0].colors.background2};
${love[0].colors.accents
  .map((value, index) => `  --dark-accent-${index + 1}: ${value};`)
  .join('\n')}
${love[0].colors.grays
  .map((value, index) => `  --dark-gray-${index + 1}: ${value};`)
  .join('\n')}
${love[1].colors.accents
  .map((value, index) => `  --light-accent-${index + 1}: ${value};`)
  .join('\n')}
${love[1].colors.grays
  .map((value, index) => `  --light-gray-${index + 1}: ${value};`)
  .join('\n')}
}\n`;

  // Replace the predefined `:root` location with our properties.
  css = css.replace(/\/\* :root-insert \*\//, cssProperties);

  // Write the CSS to file.
  await fsp.writeFile(join(__dirname, '../../public/css/style.css'), css);

  // Render and write the `index.html` file.
  await fsp.writeFile(
    join(__dirname, '../../public/index.html'),
    htmlclean(nunjucks.render('index.html', {love}))
  );

  const renderer: marked.Renderer = new marked.Renderer();

  renderer.code = (code: string, language: string | undefined): string => {
    if (language === undefined) {
      throw new Error('Markdown code block with no language detected');
    }

    const codeHTML: string = rehype()
      .stringify({type: 'root', children: refractor.highlight(code, language)})
      .toString();
    return `<pre><code class="language-${language}">${codeHTML}</code></pre>`;
  };

  await fsp.mkdir(join(__dirname, '../../public/get/'), {recursive: true});
  const pagesToCreate: string[] = (
    await fsp.readdir(join(__dirname, '../'))
  ).filter((value) => !['pages', 'scripts'].includes(value));
  for (const page of pagesToCreate) {
    const markdown: string = marked(
      nunjucks.renderString(
        await fsp.readFile(
          join(__dirname, `../${page}/SITE README.md`),
          'utf8'
        ),
        {versions}
      ),
      {renderer}
    );
    await fsp.mkdir(join(__dirname, `../../public/images/${page}/`), {
      recursive: true
    });
    if (fs.existsSync(join(__dirname, `../${page}/images/`))) {
      await cpy(
        join(__dirname, `../${page}/images/*`),
        join(__dirname, `../../public/images/${page}/`)
      );
    }

    let title = `Love for ${page
      .replace(/-/g, ' ')
      .split(' ')
      .map((value) => capitalize(value))
      .join(' ')}`;

    switch (page) {
      case 'vscode':
        title = 'Love for VS Code';
        break;
      default:
        break;
    }

    const directory = join(__dirname, `../../public/get/${page}/`);
    await fsp.mkdir(directory, {recursive: true});
    await fsp.writeFile(
      join(directory, 'index.html'),
      htmlclean(nunjucks.render('get.html', {love, markdown, title}))
    );
  }

  await writeCustomProperties(love, versions['css-custom-properties']);
}

export function capitalize(word: string): string {
  return `${word.slice(0, 1).toUpperCase()}${word.slice(1)}`;
}

// Utility helper function to write some data to file as JSON.
export async function writeJSON(path: string, data: unknown): Promise<void> {
  await fsp.writeFile(path, JSON.stringify(data, null, 2));
}

export async function writeCustomProperties(
  love: LoveVariant[],
  version: string
): Promise<void> {
  let css = `/*
  The Love Theme CSS Custom Properties
  https://love.holllo.cc - version ${version}
  MIT license
*/

.love {\n`;

  for (const variant of love) {
    const prefix = variant.name === 'dark' ? 'd' : 'l';
    css += `  /* Love ${capitalize(variant.name)} */\n`;
    css += `  --${prefix}f-1: ${variant.colors.foreground1};\n`;
    css += `  --${prefix}f-2: ${variant.colors.foreground2};\n`;
    css += `  --${prefix}b-1: ${variant.colors.background1};\n`;
    css += `  --${prefix}b-2: ${variant.colors.background2};\n`;

    for (const [index, color] of variant.colors.accents.entries()) {
      css += `  --${prefix}a-${index + 1}: ${color};\n`;
    }

    for (const [index, color] of variant.colors.grays.entries()) {
      css += `  --${prefix}g-${index + 1}: ${color};\n`;
    }

    css += '\n';
  }

  css = css.trim();
  css += '\n}\n';
  await fsp.writeFile(join(__dirname, '../../public/love.css'), css);
}

if (require.main === module) {
  void main();
}