import fs from 'fs'
import theme from '../themes'

const TARGET_FILE = "./themes/README.md";
const REPO_CARD_LINKS_FLAG = "<!-- REPO_CARD_LINKS -->";
const STAT_CARD_LINKS_FLAG = "<!-- STATS_CARD_LINKS -->";

const STAT_CARD_TABLE_FLAG = "<!-- STATS_CARD_TABLE -->";
const REPO_CARD_TABLE_FLAG = "<!-- REPO_CARD_TABLE -->";

const THEME_TEMPLATE = `## Available Themes

<!-- DO NOT EDIT THIS FILE DIRECTLY -->

With inbuilt themes you can customize the look of the card without doing any manual customization.

Use \`?theme=THEME_NAME\` parameter like so :-

\`\`\`md
![Anurag's github stats](https://codestats-readme.vercel.app/api?username=aviortheking&theme=dark&show_icons=true)
\`\`\`

## Stats

> These themes work both for the Stats Card and Repo Card.

| | | |
| :--: | :--: | :--: |
${STAT_CARD_TABLE_FLAG}

## Repo Card

> These themes work both for the Stats Card and Repo Card.

| | | |
| :--: | :--: | :--: |
${REPO_CARD_TABLE_FLAG}

${STAT_CARD_LINKS_FLAG}

${REPO_CARD_LINKS_FLAG}


[add-theme]: https://github.com/aviortheking/codestats-readme/edit/master/themes/index.js

Wanted to add a new theme? Consider reading the [contribution guidelines](../CONTRIBUTING.md#themes-contribution) :D
`;

const createRepoMdLink = (theme: string) => {
  return `\n[${theme}_repo]: https://codestats-readme.vercel.app/api/top-langs/?username=aviortheking&theme=${theme}`;
};
const createStatMdLink = (theme: string) => {
  return `\n[${theme}]: https://codestats-readme.vercel.app/api?username=aviortheking&show_icons=true&theme=${theme}`;
};

const generateLinks = (fn: Function) => {
  return Object.keys(theme)
    .map((name) => fn(name))
    .join("");
};

const createTableItem = ({ link, label, isRepoCard }: {link: string, label: string, isRepoCard?: boolean}) => {
  if (!link || !label) return "";
  return `\`${label}\` ![${link}][${link}${isRepoCard ? "_repo" : ""}]`;
};
const generateTable = ({ isRepoCard }: {isRepoCard?: boolean}) => {
  const rows = [];
  const themes = Object.keys(theme).filter(
    (name) => name !== (!isRepoCard ? "default_repocard" : "default")
  );

  for (let i = 0; i < themes.length; i += 3) {
    const one = themes[i];
    const two = themes[i + 1];
    const three = themes[i + 2];

    let tableItem1 = createTableItem({ link: one, label: one, isRepoCard });
    let tableItem2 = createTableItem({ link: two, label: two, isRepoCard });
    let tableItem3 = createTableItem({ link: three, label: three, isRepoCard });

    if (three === undefined) {
      tableItem3 = `[Add your theme][add-theme]`;
    }
    rows.push(`| ${tableItem1} | ${tableItem2} | ${tableItem3} |`);

    // if it's the last row & the row has no empty space push a new row
    if (three && i + 3 === themes.length) {
      rows.push(`| [Add your theme][add-theme] | | |`);
    }
  }

  return rows.join("\n");
};

const buildReadme = () => {
  return THEME_TEMPLATE.split("\n")
    .map((line) => {
      if (line.includes(REPO_CARD_LINKS_FLAG)) {
        return generateLinks(createRepoMdLink);
      }
      if (line.includes(STAT_CARD_LINKS_FLAG)) {
        return generateLinks(createStatMdLink);
      }
      if (line.includes(REPO_CARD_TABLE_FLAG)) {
        return generateTable({ isRepoCard: true });
      }
      if (line.includes(STAT_CARD_TABLE_FLAG)) {
        return generateTable({ isRepoCard: false });
      }
      return line;
    })
    .join("\n");
};

fs.writeFileSync(TARGET_FILE, buildReadme());