import { chromium, devices } from "playwright";
import { prisma } from "./db";
import createFile from "./storage/createFile";
import sendToWayback from "./sendToWayback";
import { Readability } from "@mozilla/readability";
import { JSDOM } from "jsdom";
import DOMPurify from "dompurify";
import { Collection, Link, User } from "@prisma/client";
import validateUrlSize from "./validateUrlSize";
import removeFile from "./storage/removeFile";

type LinksAndCollectionAndOwner = Link & {
  collection: Collection & {
    owner: User;
  };
};

export default async function archiveHandler(link: LinksAndCollectionAndOwner) {
  const browser = await chromium.launch();
  const context = await browser.newContext(devices["Desktop Chrome"]);
  const page = await context.newPage();

  try {
    const validatedUrl = link.url ? await validateUrlSize(link.url) : undefined;

    if (validatedUrl === null) throw "File is too large to be stored.";

    const contentType = validatedUrl?.get("content-type");
    let linkType = "url";
    let imageExtension = "png";

    if (!link.url) linkType = link.type;
    else if (contentType === "application/pdf") linkType = "pdf";
    else if (contentType?.startsWith("image")) {
      linkType = "image";
      if (contentType === "image/jpeg") imageExtension = "jpeg";
      else if (contentType === "image/png") imageExtension = "png";
    }

    const user = link.collection?.owner;

    // send to archive.org
    if (user.archiveAsWaybackMachine && link.url) sendToWayback(link.url);

    const targetLink = await prisma.link.update({
      where: { id: link.id },
      data: {
        type: linkType,
        screenshotPath:
          user.archiveAsScreenshot &&
          !link.screenshotPath?.startsWith("archive")
            ? "pending"
            : undefined,
        pdfPath:
          user.archiveAsPDF && !link.pdfPath?.startsWith("archive")
            ? "pending"
            : undefined,
        readabilityPath: !link.readabilityPath?.startsWith("archive")
          ? "pending"
          : undefined,
        lastPreserved: new Date().toISOString(),
      },
    });

    if (linkType === "image") {
      await imageHandler(link, imageExtension); // archive image (jpeg/png)
      return;
    } else if (linkType === "pdf") {
      await pdfHandler(link); // archive pdf
      return;
    } else if (user.archiveAsPDF || user.archiveAsScreenshot) {
      // archive url
      link.url &&
        (await page.goto(link.url, { waitUntil: "domcontentloaded" }));

      const content = await page.content();

      // TODO single file
      // const session = await page.context().newCDPSession(page);
      // const doc = await session.send("Page.captureSnapshot", {
      //   format: "mhtml",
      // });
      // const saveDocLocally = (doc: any) => {
      //   console.log(doc);
      //   return createFile({
      //     data: doc,
      //     filePath: `archives/${targetLink.collectionId}/${link.id}.mhtml`,
      //   });
      // };
      // saveDocLocally(doc.data);

      // Readability
      const window = new JSDOM("").window;
      const purify = DOMPurify(window);
      const cleanedUpContent = purify.sanitize(content);
      const dom = new JSDOM(cleanedUpContent, { url: link.url || "" });
      const article = new Readability(dom.window.document).parse();
      const articleText = article?.textContent
        .replace(/ +(?= )/g, "") // strip out multiple spaces
        .replace(/(\r\n|\n|\r)/gm, " "); // strip out line breaks
      if (articleText && articleText !== "") {
        await createFile({
          data: JSON.stringify(article),
          filePath: `archives/${targetLink.collectionId}/${link.id}_readability.json`,
        });

        await prisma.link.update({
          where: { id: link.id },
          data: {
            readabilityPath: `archives/${targetLink.collectionId}/${link.id}_readability.json`,
            textContent: articleText,
          },
        });
      }

      // Screenshot/PDF
      await page.evaluate(
        autoScroll,
        Number(process.env.AUTOSCROLL_TIMEOUT) || 30
      );
      // Check if the user hasn't deleted the link by the time we're done scrolling
      const linkExists = await prisma.link.findUnique({
        where: { id: link.id },
      });
      if (linkExists) {
        const processingPromises = [];

        if (user.archiveAsScreenshot) {
          processingPromises.push(
            page.screenshot({ fullPage: true }).then((screenshot) => {
              return createFile({
                data: screenshot,
                filePath: `archives/${linkExists.collectionId}/${link.id}.png`,
              });
            })
          );
        }
        if (user.archiveAsPDF) {
          processingPromises.push(
            page
              .pdf({
                width: "1366px",
                height: "1931px",
                printBackground: true,
                margin: { top: "15px", bottom: "15px" },
              })
              .then((pdf) => {
                return createFile({
                  data: pdf,
                  filePath: `archives/${linkExists.collectionId}/${link.id}.pdf`,
                });
              })
          );
        }
        await Promise.allSettled(processingPromises);
        await prisma.link.update({
          where: { id: link.id },
          data: {
            screenshotPath: user.archiveAsScreenshot
              ? `archives/${linkExists.collectionId}/${link.id}.png`
              : undefined,
            pdfPath: user.archiveAsPDF
              ? `archives/${linkExists.collectionId}/${link.id}.pdf`
              : undefined,
          },
        });
      }
    }
  } catch (err) {
    console.log(err);
    console.log("Failed Link details:", link);
    throw err;
  } finally {
    const finalLink = await prisma.link.findUnique({
      where: { id: link.id },
    });

    if (finalLink)
      await prisma.link.update({
        where: { id: link.id },
        data: {
          readabilityPath: !finalLink.readabilityPath?.startsWith("archives")
            ? "unavailable"
            : undefined,
          screenshotPath: !finalLink.screenshotPath?.startsWith("archives")
            ? "unavailable"
            : undefined,
          pdfPath: !finalLink.pdfPath?.startsWith("archives")
            ? "unavailable"
            : undefined,
        },
      });
    else {
      removeFile({ filePath: `archives/${link.collectionId}/${link.id}.png` });
      removeFile({ filePath: `archives/${link.collectionId}/${link.id}.pdf` });
      removeFile({
        filePath: `archives/${link.collectionId}/${link.id}_readability.json`,
      });
    }

    await browser.close();
  }
}

const autoScroll = async (AUTOSCROLL_TIMEOUT: number) => {
  const timeoutPromise = new Promise<void>((_, reject) => {
    setTimeout(() => {
      reject(new Error(`Webpage was too long to be archived.`));
    }, AUTOSCROLL_TIMEOUT * 1000);
  });

  const scrollingPromise = new Promise<void>((resolve) => {
    let totalHeight = 0;
    let distance = 100;
    let scrollDown = setInterval(() => {
      let scrollHeight = document.body.scrollHeight;
      window.scrollBy(0, distance);
      totalHeight += distance;
      if (totalHeight >= scrollHeight) {
        clearInterval(scrollDown);
        window.scroll(0, 0);
        resolve();
      }
    }, 100);
  });

  await Promise.race([scrollingPromise, timeoutPromise]);
};

const imageHandler = async ({ url, id }: Link, extension: string) => {
  const image = await fetch(url as string).then((res) => res.blob());

  const buffer = Buffer.from(await image.arrayBuffer());

  const linkExists = await prisma.link.findUnique({
    where: { id },
  });

  if (linkExists) {
    await createFile({
      data: buffer,
      filePath: `archives/${linkExists.collectionId}/${id}.${extension}`,
    });

    await prisma.link.update({
      where: { id },
      data: {
        screenshotPath: `archives/${linkExists.collectionId}/${id}.${extension}`,
      },
    });
  }
};

const pdfHandler = async ({ url, id }: Link) => {
  const pdf = await fetch(url as string).then((res) => res.blob());

  const buffer = Buffer.from(await pdf.arrayBuffer());

  const linkExists = await prisma.link.findUnique({
    where: { id },
  });

  if (linkExists) {
    await createFile({
      data: buffer,
      filePath: `archives/${linkExists.collectionId}/${id}.pdf`,
    });

    await prisma.link.update({
      where: { id },
      data: {
        pdfPath: `archives/${linkExists.collectionId}/${id}.pdf`,
      },
    });
  }
};