import fs from "fs";
import os from "os";
import path from "path";
import minimatch from "minimatch";
import AdmZip from "adm-zip";
import { Readable } from "stream";
import {
  S3Client,
  GetObjectCommand,
  PutObjectCommand,
} from "@aws-sdk/client-s3";
import type { BaseSiteReplaceProps } from "../../src/constructs/BaseSite";

const s3 = new S3Client({ logger: console });
const zipPath = path.join(os.tmpdir(), "asset.zip");

export async function AssetReplacer(cfnRequest: any) {
  switch (cfnRequest.RequestType) {
    case "Create":
    case "Update":
      const { bucket, key, replacements } = cfnRequest.ResourceProperties;
      if (replacements.length === 0) {
        return;
      }

      console.log({ zipPath });

      // Clean up old files
      fs.rmSync(zipPath, { force: true });

      await download(bucket, key);
      replaceValues(replacements);
      await upload(bucket, key);
      break;
    case "Delete":
      break;
    default:
      throw new Error("Unsupported request type");
  }
}

function replaceValues(replacements: BaseSiteReplaceProps[]) {
  const zip = new AdmZip(zipPath);
  zip
    .getEntries()
    .filter((entry) => !entry.entryName.includes("node_modules/"))
    .forEach((entry) => {
      console.log(entry.entryName);
      for (let r of replacements) {
        if (minimatch(entry.entryName, r.files, { dot: true })) {
          console.log("replace file", r.files, entry.entryName);
          const data = entry
            .getData()
            .toString("utf-8")
            .replaceAll(r.search, r.replace);
          zip.updateFile(entry.entryName, Buffer.from(data, "utf-8"));
        }
      }
    });
  zip.writeZip();
}

async function download(bucket: string, key: string) {
  console.log("download");

  const result = await s3.send(
    new GetObjectCommand({
      Key: key,
      Bucket: bucket,
    })
  );
  const stream = result.Body as Readable;
  await new Promise<void>((resolve, reject) =>
    stream
      .pipe(fs.createWriteStream(zipPath))
      .on("error", reject)
      .on("close", () => resolve())
  );
}

async function upload(bucket: string, key: string) {
  console.log("upload");

  await s3.send(
    new PutObjectCommand({
      Key: key,
      Bucket: bucket,
      Body: fs.createReadStream(zipPath),
    })
  );
}