import { type ChildProcess, exec, execSync } from "node:child_process";
import { readdir, mkdir, mkdtemp, writeFile, readFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join as pathJoin, normalize } from "node:path";
import { setTimeout } from "node:timers/promises";
import { program } from "commander";
import fetchRetryWrapper from "fetch-retry";

function getRTFStyles(rtfSource: string) {
  const matches = rtfSource.matchAll(
    /\\s(\d+)(?:\\sbasedon\d+)?\\snext\d+((?:\\[a-z0-9]+ ?)+)(?: ([A-Z][a-zA-Z ]*));/g,
  );
  let hasMatches = false;
  const rtfStyles: Record<number | string, string> = {};
  for (const [_, styleNumber, partialRTFStyle, styleName] of matches) {
    hasMatches = true;
    const rtfStyle = `\\s${styleNumber}${partialRTFStyle}`;
    rtfStyles[Number.parseInt(styleNumber)] = rtfStyle;
    rtfStyles[styleName] = rtfStyle;
  }
  if (!hasMatches) {
    throw new Error("Couldn't find valid RTF styles!");
  }
  return rtfStyles;
}

const fetchRetry = fetchRetryWrapper(global.fetch);

async function exportStory(slug: string, options: { outputDir: string }) {
  /* Check that outputDir is valid */
  const outputDir = normalize(options.outputDir);
  let files: string[];
  try {
    files = await readdir(outputDir);
  } catch {
    files = [];
    console.log(`Created directory at ${await mkdir(outputDir, { recursive: true })}`);
  }
  if (files.length > 1) {
    console.error(`Directory ${outputDir} is not empty!`);
    process.exit(1);
  }
  /* Check if Astro development server needs to be spawned */
  const healthcheckURL = `http://localhost:4321/healthcheck`;
  let devServerProcess: ChildProcess | null = null;
  try {
    await fetchRetry(healthcheckURL, { retries: 3, retryDelay: 1000 });
  } catch {
    /* Spawn Astro dev server */
    console.log("Starting Astro development server...");
    devServerProcess = exec("npm run dev");
    await setTimeout(2000);
    try {
      await fetchRetry(healthcheckURL, { retries: 5, retryDelay: 2000 });
    } catch {
      console.error("Astro dev server didn't respond in time!");
      devServerProcess && devServerProcess.kill("SIGINT");
      devServerProcess = null;
      process.exit(1);
    }
  }
  /* Get data (story, thumbnail, descriptions) from Astro development server */
  let storyText = "";
  try {
    console.log("Getting data from Astro...");

    const exportStoryURL = `http://localhost:4321/stories/export/story/${slug}`;
    const exportThumbnailURL = `http://localhost:4321/stories/export/thumbnail/${slug}`;
    const exportDescriptionURLs = (website: string) =>
      `http://localhost:4321/stories/export/description/${website}/${slug}`;

    await Promise.all(
      ["eka", "furaffinity", "inkbunny", "sofurry", "weasyl"].map(async (website) => {
        const description = await fetch(exportDescriptionURLs(website));
        if (!description.ok) {
          throw new Error(`Failed to get description for "${website}"`);
        }
        const descriptionExt = description.headers.get("Content-Type")?.startsWith("text/markdown") ? "md" : "txt";
        return await writeFile(
          pathJoin(outputDir, `description_${website}.${descriptionExt}`),
          await description.text(),
        );
      }),
    );
    const thumbnail = await fetch(exportThumbnailURL);
    if (!thumbnail.ok) {
      throw new Error("Failed to get thumbnail");
    }
    const thumbnailExt = thumbnail.headers.get("Content-Type")?.startsWith("image/png") ? "png" : "jpg";
    writeFile(pathJoin(outputDir, `thumbnail.${thumbnailExt}`), Buffer.from(await thumbnail.arrayBuffer()));
    const story = await fetch(exportStoryURL);
    if (!story.ok) {
      throw new Error("Failed to get story");
    }
    storyText = await story.text();
    writeFile(pathJoin(outputDir, `${slug}.txt`), storyText);
  } finally {
    if (devServerProcess) {
      console.log("Shutting down the Astro development server...");
      if (!devServerProcess.kill("SIGINT")) {
        console.error("Unable to shut down Astro dev server!");
      }
      devServerProcess = null;
    }
  }

  /* Parse story into output formats */
  console.log("Parsing story into output formats...");
  await writeFile(pathJoin(outputDir, `${slug}.md`), storyText.replaceAll(/=(?==)/g, "= ").replaceAll("*", "\\*"));
  const tempDir = await mkdtemp(pathJoin(tmpdir(), "export-story-"));
  await writeFile(pathJoin(tempDir, "temp.txt"), storyText.replaceAll(/\n\n+/g, "\n"));
  execSync(`libreoffice --convert-to "rtf:Rich Text Format" --outdir ${tempDir} ${pathJoin(tempDir, "temp.txt")}`);
  const rtfText = await readFile(pathJoin(tempDir, "temp.rtf"), "utf-8");
  const rtfStyles = getRTFStyles(rtfText);
  await writeFile(
    pathJoin(outputDir, `${slug}.rtf`),
    rtfText.replaceAll(rtfStyles["Preformatted Text"], rtfStyles["Normal"]),
  );
  console.log("Success!");
  process.exit(0);
}

await program
  .name("export-story")
  .description("Generate and export formatted upload files for a story")
  .argument("<story-slug>", `Slug portion of the story's URL (eg. "the-lost-of-the-marshes/chapter-1")`)
  .option("-o, --output-dir <directory>", `Empty or inexistent directory path to export files to`)
  .action(exportStory)
  .parseAsync();