#!/usr/bin/env node

import assert from "node:assert/strict";
import fs from "node:fs";
import indexToPosition from "index-to-position";
import { outdent } from "outdent";
import remarkParse from "remark-parse";
import unified from "unified";
import { CHANGELOG_CATEGORIES } from "./utilities/changelog.js";

const CHANGELOG_DIR = "changelog_unreleased";
const TEMPLATE_FILE = "TEMPLATE.md";
const BLOG_POST_INTRO_TEMPLATE_FILE = "BLOG_POST_INTRO_TEMPLATE.md";
const BLOG_POST_INTRO_FILE = "blog-post-intro.md";
const CHANGELOG_ROOT = new URL(`../${CHANGELOG_DIR}/`, import.meta.url);
const showErrorMessage = (message) => {
  console.error(message);
  process.exitCode = 1;
};

const files = fs.readdirSync(CHANGELOG_ROOT);
for (const file of files) {
  if (
    file !== TEMPLATE_FILE &&
    file !== BLOG_POST_INTRO_FILE &&
    file !== BLOG_POST_INTRO_TEMPLATE_FILE &&
    !CHANGELOG_CATEGORIES.includes(file)
  ) {
    showErrorMessage(`Please remove "${file}" from "${CHANGELOG_DIR}".`);
  }
}
for (const file of [
  TEMPLATE_FILE,
  BLOG_POST_INTRO_TEMPLATE_FILE,
  ...CHANGELOG_CATEGORIES,
]) {
  if (!files.includes(file)) {
    showErrorMessage(`Please don't remove "${file}" from "${CHANGELOG_DIR}".`);
  }
}

const authorRegex = /by @[\w-]+|by \[@([\w-]+)\]\(https:\/\/github\.com\/\1\)/;
const titleRegex = /^#{4} (.*?)\((#\d{4,}|\[#\d{4,}\])/;

const template = fs.readFileSync(
  new URL(TEMPLATE_FILE, CHANGELOG_ROOT),
  "utf8",
);
const templateComments = template.match(/<!--.*?-->/gs);
const [templateAuthorLink] = template.match(authorRegex);
const checkedFiles = new Map();

for (const category of CHANGELOG_CATEGORIES) {
  const files = fs.readdirSync(new URL(`${category}/`, CHANGELOG_ROOT));
  if (!files.includes(".gitkeep")) {
    showErrorMessage(
      `Please don't remove ".gitkeep" from "${CHANGELOG_DIR}/${category}".`,
    );
  }

  for (const prFile of files) {
    if (prFile === ".gitkeep") {
      continue;
    }

    const match = prFile.match(/^(\d{4,})(-\d+)?\.md$/);
    const displayPath = `${CHANGELOG_DIR}/${category}/${prFile}`;

    if (!match) {
      showErrorMessage(
        `[${displayPath}]: Filename is not in form of "{PR_NUMBER}.md".`,
      );
      continue;
    }
    const [, prNumber] = match;
    const prLink = `#${prNumber}`;
    if (checkedFiles.has(prFile)) {
      showErrorMessage(
        outdent`
          Duplicate files for ${prLink} found.
            - ${checkedFiles.get(prFile)}
            - ${displayPath}
        `,
      );
    }
    checkedFiles.set(prFile, displayPath);
    const content = fs.readFileSync(
      new URL(`${category}/${prFile}`, CHANGELOG_ROOT),
      "utf8",
    );

    if (!content.includes(prLink)) {
      showErrorMessage(`[${displayPath}]: PR link "${prLink}" is missing.`);
    }
    if (!authorRegex.test(content)) {
      showErrorMessage(`[${displayPath}]: Author link is missing.`);
    }
    for (const comment of templateComments) {
      if (comment !== "<!-- prettier-ignore -->" && content.includes(comment)) {
        showErrorMessage(
          `[${displayPath}]: Please remove ${getCommentDescription(
            content,
            comment,
          )}`,
        );
      }
    }
    if (content.includes(templateAuthorLink)) {
      showErrorMessage(
        `[${displayPath}]: Please change author link to your github account.`,
      );
    }
    if (!content.startsWith("#### ")) {
      showErrorMessage(`[${displayPath}]: Please use h4 ("####") for title.`);
    }
    const titleMatch = content.match(titleRegex);
    if (!titleMatch) {
      showErrorMessage(`[${displayPath}]: Something wrong in title.`);
      continue;
    }
    const [, title] = titleMatch;

    validateTitle(displayPath, title);

    const categoryInTitle = title.split(":").shift().trim();
    if (
      [...CHANGELOG_CATEGORIES, "js"].includes(categoryInTitle.toLowerCase())
    ) {
      showErrorMessage(
        `[${displayPath}]: Please remove "${categoryInTitle}:" in title.`,
      );
    }

    if (!title.endsWith(" ") || title.length - title.trimEnd().length !== 1) {
      showErrorMessage(
        `[${displayPath}]: Please put one space between title and PR link.`,
      );
    }

    if (/prettier master/i.test(content)) {
      showErrorMessage(
        `[${displayPath}]: Please use "main" instead of "master".`,
      );
    }
  }
}

function getCommentDescription(content, comment) {
  const start = content.indexOf(comment);
  const end = start + comment.length;
  const [startLine, endLine] = [start, end].map(
    (index) => indexToPosition(content, index, { oneBased: true }).line,
  );

  if (startLine === endLine) {
    return `template comment "${comment}" on line ${startLine}`;
  }

  return `template comment on line ${startLine}-${endLine}`;
}

// Forbid HTML in title
// https://github.com/prettier/prettier/issues/17089
function validateTitle(displayPath, title) {
  const processor = unified().use(remarkParse);
  const tree = processor.runSync(processor.parse(title));
  assert.equal(tree.children.length, 1);
  assert.equal(tree.children[0].type, "paragraph");
  const { children } = tree.children[0];
  for (const node of children) {
    if (node.type === "html") {
      showErrorMessage(
        `[${displayPath}]: HTML "${node.value}" is restricted in title.`,
      );
    }
  }
}