import { ensureDir } from "@std/fs";
import { serveDir, serveFile } from "@std/http/file-server";

import * as z from "@zod/mini";
import vento from "ventojs";
import { db } from "./db.ts";

import { getPdsUrl, resolveHandle } from "../common/identity.ts";
import type { VideoRecord } from "../common/lexicons.ts";
import { VIDEO_PATTERN } from "../common/routes.ts";
import { getVideoRecord } from "../common/video.ts";

const vto = vento({ includes: "./web" });

async function getOrFetchVideo(did: string, blobCid: string): Promise<string> {
  const cached = db.getVideo(did, blobCid);
  if (cached) return cached;

  const pdsUrl = await getPdsUrl(did);
  if (!pdsUrl) throw new Error("Could not resolve PDS");

  let filename: string = crypto.randomUUID();

  const getBlobURL = new URL("/xrpc/com.atproto.sync.getBlob", pdsUrl);
  getBlobURL.searchParams.set("did", did);
  getBlobURL.searchParams.set("cid", blobCid);

  const blobResponse = await fetch(getBlobURL, {
    headers: { "user-agent": "video.cerulea.app" },
  });

  const contentType = blobResponse.headers.get("content-type");
  if (contentType === "video/mp4") filename += ".mp4";
  if (contentType === "video/webm") filename += ".webm";

  await ensureDir("./data/videos");
  using file = await Deno.open("./data/videos/" + filename, {
    write: true,
    createNew: true,
  });

  await blobResponse.body?.pipeTo(file.writable);

  db.addVideo(did, blobCid, filename);
  return filename;
}

async function fetchVideo(req: Request): Promise<Response> {
  if (req.method === "OPTIONS") {
    return new Response(null, {
      headers: {
        "access-control-allow-origin": "*",
      },
    });
  }

  if (req.method !== "POST") {
    return new Response("Method Not Allowed", { status: 405 });
  }

  const BodySchema = z.object({
    repo: z.string().check(z.startsWith("did:")),
    blob: z.string(),
  });
  const body = BodySchema.parse(await req.json());

  if (!db.inAllowlist(body.repo)) {
    return new Response(
      JSON.stringify({
        error: "Denied",
        message: "repo is not allowlisted on AppView",
      }),
      {
        status: 400,
        headers: {
          "content-type": "application/json",
          "access-control-allow-origin": "*",
        },
      },
    );
  }

  const filename = await getOrFetchVideo(body.repo, body.blob);
  return new Response(JSON.stringify({ filename }), {
    headers: {
      "content-type": "application/json",
      "access-control-allow-origin": "*",
    },
  });
}

export default {
  async fetch(req: Request, _info): Promise<Response> {
    const pathname = new URL(req.url).pathname;
    if (pathname === "/xrpc/blue.cerulea.video.fetchVideo") {
      return await fetchVideo(req);
    }

    if (pathname.startsWith("/user-content/")) {
      return await serveDir(req, {
        fsRoot: "./data/videos",
        quiet: true,
        enableCors: true,
        urlRoot: "user-content",
      });
    }

    const videoRoute = VIDEO_PATTERN.exec(req.url);
    if (videoRoute) {
      const { repo, rkey } = videoRoute.pathname.groups as Record<"repo" | "rkey", string>;
      const did = repo.startsWith("did:") ? repo : await resolveHandle(repo);

      if (!db.inAllowlist(did)) {
        return await serveFile(req, "./web/viewer.html");
      }

      let record = db.getRecord<VideoRecord>(did, rkey);
      if (!record) {
        record = await getVideoRecord(did, rkey);
        db.addRecord(did, rkey, record);
      }

      let videoUrl: string | undefined;
      let videoType: string | undefined;
      if ("$type" in record.video && record.video?.$type === "blob") {
        const blobCid = record.video.ref.$link;
        const filename = await getOrFetchVideo(did, blobCid);
        videoUrl = `${new URL(req.url).origin}/user-content/${filename}`;
        videoType = record.video.mimeType;
      }

      const result = await vto.run("viewer.vto", {
        title: record.title,
        description: record.description,
        pageUrl: req.url,
        videoUrl,
        videoType,
      });

      return new Response(result.content, {
        headers: { "content-type": "text/html; charset=utf-8" },
      });
    }

    return await serveDir(req, { fsRoot: "./web", quiet: true });
  },
} satisfies Deno.ServeDefaultExport;