import { execSync } from "node:child_process";
import { mkdtempSync, rmSync, cpSync, readdirSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

const SITE_BRANCH = process.env.SITE_BRANCH || "site";

if (!process.env.APP_URL) {
  console.error("APP_URL is required (e.g. https://cuducos.tngl.io/std-pub)");
  process.exit(1);
}

const run = (cmd, opts = {}) => execSync(cmd, { stdio: "inherit", ...opts });

const capture = (cmd, opts = {}) =>
  execSync(cmd, { stdio: ["ignore", "pipe", "inherit"], ...opts })
    .toString()
    .trim();

if (capture("git status --porcelain")) {
  console.error("Working tree has uncommitted changes. Commit or stash first.");
  process.exit(1);
}

let REMOTE;
try {
  const upstream = capture("git rev-parse --abbrev-ref @{upstream}");
  REMOTE = upstream.split("/")[0];
} catch {
  console.error(
    "Current branch has no upstream. Set one with `git push -u <remote> <branch>` first.",
  );
  process.exit(1);
}

run("npm run build");

const workdir = mkdtempSync(join(tmpdir(), "standard-publication-deploy-"));
let worktreeAdded = false;

try {
  const remoteHas =
    capture(`git ls-remote --heads ${REMOTE} ${SITE_BRANCH}`) !== "";

  if (remoteHas) {
    run(`git fetch ${REMOTE} ${SITE_BRANCH}`);
    run(`git worktree add --force ${workdir} ${REMOTE}/${SITE_BRANCH}`);
    run(`git -C ${workdir} checkout -B ${SITE_BRANCH}`);
  } else {
    run(`git worktree add --force --orphan -B ${SITE_BRANCH} ${workdir}`);
  }
  worktreeAdded = true;

  for (const entry of readdirSync(workdir)) {
    if (entry === ".git") continue;
    rmSync(join(workdir, entry), { recursive: true, force: true });
  }

  for (const entry of readdirSync("public")) {
    cpSync(join("public", entry), join(workdir, entry), { recursive: true });
  }

  run(`git -C ${workdir} add -A`);
  const hasChanges = capture(`git -C ${workdir} status --porcelain`) !== "";
  const sourceSha = capture("git rev-parse --short HEAD");

  if (!hasChanges && remoteHas) {
    console.log(
      `No changes to deploy on ${SITE_BRANCH} (source at ${sourceSha}).`,
    );
  } else {
    run(`git -C ${workdir} commit -m "Deploy ${sourceSha}" --allow-empty`, {
      env: {
        ...process.env,
        GIT_COMMITTER_NAME: process.env.GIT_COMMITTER_NAME || "deploy",
        GIT_COMMITTER_EMAIL: process.env.GIT_COMMITTER_EMAIL || "deploy@local",
      },
    });
    run(`git -C ${workdir} push ${REMOTE} ${SITE_BRANCH}`);
  }
} finally {
  if (worktreeAdded) {
    try {
      run(`git worktree remove --force ${workdir}`);
    } catch {
      rmSync(workdir, { recursive: true, force: true });
    }
  } else {
    rmSync(workdir, { recursive: true, force: true });
  }
}