import { Octokit } from "@octokit/rest";
import slugify from "@sindresorhus/slugify";
import { readFile } from "fs-extra";
import { safeLoad } from "js-yaml";
import { join } from "path";

export const generateSummary = async () => {
  const config = safeLoad(
    await readFile(join(".", ".statusrc.yml"), "utf8")
  ) as {
    sites: { name: string; url: string }[];
    owner: string;
    repo: string;
    userAgent?: string;
    PAT?: string;
    assignees?: string[];
  };
  const owner = config.owner;
  const repo = config.repo;

  const octokit = new Octokit({
    auth: config.PAT || process.env.GH_PAT || process.env.GITHUB_TOKEN,
    userAgent: config.userAgent || process.env.USER_AGENT || "KojBot",
  });

  let readmeContent = await readFile(join(".", "README.md"), "utf8");

  const startText = readmeContent.split("<!--start: status pages-->")[0];
  const endText = readmeContent.split("<!--end: status pages-->")[1];

  const pageStatuses: Array<{
    url: string;
    status: string;
    slug: string;
    time: number;
    uptime: string;
    name: string;
  }> = [];

  let numberOfDown = 0;
  for await (const site of config.sites) {
    const slug = slugify(site.name);
    let startTime = new Date().toISOString();
    try {
      startTime =
        (await readFile(join(".", "history", `${slug}.yml`), "utf8"))
          .split("\n")
          .find((line) => line.toLocaleLowerCase().includes("- starttime"))
          ?.split("startTime:")[1]
          .trim() || new Date().toISOString();
    } catch (error) {}
    let secondsDown = 0;
    const history = await octokit.repos.listCommits({
      owner,
      repo,
      path: `history/${slug}.yml`,
      per_page: 100,
    });
    const issues = await octokit.issues.listForRepo({
      owner,
      repo,
      labels: slug,
      filter: "all",
      per_page: 100,
    });
    issues.data.forEach((issue) => {
      if (issue.closed_at)
        secondsDown += Math.floor(
          (new Date(issue.closed_at).getTime() -
            new Date(issue.created_at).getTime()) /
            1000
        );
      else
        secondsDown += Math.floor(
          (new Date().getTime() - new Date(issue.created_at).getTime()) / 1000
        );
    });
    const uptime = (
      100 -
      100 *
        (secondsDown /
          ((new Date().getTime() - new Date(startTime).getTime()) / 1000))
    ).toFixed(2);
    if (!history.data.length) continue;
    const averageTime =
      history.data
        .filter(
          (item) =>
            item.commit.message.includes(" in ") &&
            Number(item.commit.message.split(" in ")[1].split("ms")[0]) !== 0 &&
            !isNaN(Number(item.commit.message.split(" in ")[1].split("ms")[0]))
        )
        .map((item) =>
          Number(item.commit.message.split(" in ")[1].split("ms")[0])
        )
        .reduce((p, c) => p + c, 0) / history.data.length;
    const status = history.data[0].commit.message.split(" ")[0].includes("🟩")
      ? "up"
      : "down";
    pageStatuses.push({
      name: site.name,
      url: site.url,
      slug,
      status,
      uptime,
      time: Math.floor(averageTime),
    });
    if (status === "down") {
      numberOfDown++;
    }
  }

  if (readmeContent.includes("<!--start: status pages-->")) {
    readmeContent = `${startText}<!--start: status pages-->

| URL | Status | History | Response Time | Uptime |
| --- | ------ | ------- | ------------- | ------ |
${pageStatuses
  .map(
    (page) =>
      `| ${
        page.url.startsWith("$") ? page.name : `[${page.name}](${page.url})`
      } | ${page.status === "up" ? "🟩 Up" : "🟥 Down"} | [${
        page.slug
      }.yml](https://github.com/${owner}/${repo}/commits/master/history/${
        page.slug
      }.yml) | <img alt="Response time graph" src="./graphs/${
        page.slug
      }.png" height="20"> ${page.time}ms | ${page.uptime}%`
  )
  .join("\n")}

<!--end: status pages-->${endText}`;
  }

  // Add live status line
  readmeContent = readmeContent
    .split("\n")
    .map((line) => {
      if (line.includes("<!--live status-->")) {
        line = `Live status: <!--live status--> **${
          numberOfDown === 0
            ? "🟩 All systems operational"
            : numberOfDown === config.sites.length
            ? "🟥 Complete outage"
            : "🟨 Partial outage"
        }**`;
      }
      return line;
    })
    .join("\n");

  const sha = (
    await octokit.repos.getContent({
      owner,
      repo,
      path: "README.md",
    })
  ).data.sha;
  await octokit.repos.createOrUpdateFileContents({
    owner,
    repo,
    path: "README.md",
    message: ":pencil: Update summary in README [skip ci]",
    content: Buffer.from(readmeContent).toString("base64"),
    sha,
  });
  let summarySha: string | undefined = undefined;
  try {
    summarySha = (
      await octokit.repos.getContent({
        owner,
        repo,
        path: "history/summary.json",
      })
    ).data.sha;
  } catch (error) {}
  await octokit.repos.createOrUpdateFileContents({
    owner,
    repo,
    path: "history/summary.json",
    message: ":card_file_box: Update status summary [skip ci]",
    content: Buffer.from(JSON.stringify(pageStatuses, null, 2)).toString(
      "base64"
    ),
    sha: summarySha,
  });
};