#!/usr/bin/env node
// Publish the jars attached to a Gitea release to Modrinth.
//
// Creates one Modrinth version per jar (saturn-client-<version>+<mc>.jar), for
// that Minecraft version, with Fabric API as a required dependency and the
// Gitea release notes as the changelog. Versions that already exist on
// Modrinth are skipped, so the script is safe to re-run.
//
// Runs on plain Node (>= 18: fetch, FormData, Blob) with no dependencies, since
// every Gitea Actions runner has Node to run JavaScript actions.
//
// Environment:
//   TAG               release tag, e.g. 0.1.1-beta
//   SERVER_URL        public Gitea URL, e.g. https://git.selimaj.dev
//   REPO              owner/name, e.g. saturnclientmc/saturnclient
//   MODRINTH_TOKEN    Modrinth PAT with the "Create versions" scope
//   DRY_RUN           "true" to check everything and print what would be
//                     published without uploading (no token needed)

const MODRINTH_API = "https://api.modrinth.com/v2";
const MODRINTH_PROJECT_ID = "i6JDSY9x"; // saturnclient
const FABRIC_API_PROJECT_ID = "P7dR8mSH";
const USER_AGENT =
  "saturnclientmc/saturnclient release workflow (https://git.selimaj.dev/saturnclientmc/saturnclient)";

const JAR_NAME = /^saturn-client-(?<version>.+)\+(?<mc>\d+\.\d+(?:\.\d+)?)\.jar$/;

function fail(message) {
  console.error(message);
  process.exit(1);
}

async function http(url, options = {}) {
  const res = await fetch(url, {
    ...options,
    headers: { "User-Agent": USER_AGENT, ...options.headers },
  });
  if (!res.ok) {
    const error = new Error(`${options.method ?? "GET"} ${url} returned ${res.status}: ${await res.text()}`);
    error.status = res.status;
    throw error;
  }
  return res;
}

async function getJson(url) {
  return (await http(url)).json();
}

function versionType(tag) {
  const t = tag.toLowerCase();
  if (t.includes("alpha")) return "alpha";
  if (t.includes("beta") || t.includes("rc") || t.includes("pre")) return "beta";
  return "release";
}

function compareMc(a, b) {
  const pa = a.split(".").map(Number);
  const pb = b.split(".").map(Number);
  for (let i = 0; i < Math.max(pa.length, pb.length); i++) {
    const diff = (pa[i] ?? 0) - (pb[i] ?? 0);
    if (diff !== 0) return diff;
  }
  return 0;
}

async function main() {
  const { TAG: tag, SERVER_URL, REPO: repo } = process.env;
  const serverUrl = (SERVER_URL ?? "").replace(/\/+$/, "");
  const dryRun = (process.env.DRY_RUN ?? "").toLowerCase() === "true";
  const token = process.env.MODRINTH_TOKEN ?? "";

  if (!tag || !serverUrl || !repo) fail("TAG, SERVER_URL and REPO must be set.");
  if (!token && !dryRun) {
    fail("MODRINTH_TOKEN is not set. Add it as a repository secret (Settings → Actions → Secrets).");
  }

  let release;
  try {
    release = await getJson(`${serverUrl}/api/v1/repos/${repo}/releases/tags/${encodeURIComponent(tag)}`);
  } catch (e) {
    if (e.status === 404) fail(`No Gitea release with tag ${tag}.`);
    throw e;
  }
  const changelog = release.body ?? "";

  const jars = (release.assets ?? [])
    .map((asset) => ({ name: asset.name, match: JAR_NAME.exec(asset.name) }))
    .filter(({ match }) => match)
    .map(({ name, match }) => ({ name, version: match.groups.version, mc: match.groups.mc }))
    .sort((a, b) => compareMc(a.mc, b.mc));

  if (jars.length === 0) fail(`Release ${tag} has no saturn-client-*.jar assets. Run the Release workflow first.`);

  for (const jar of jars) {
    if (jar.version !== tag.replace(/^v/, "")) fail(`${jar.name} is version ${jar.version}, but the release tag is ${tag}.`);
  }

  const knownGameVersions = new Set((await getJson(`${MODRINTH_API}/tag/game_version`)).map((g) => g.version));
  const unknown = [...new Set(jars.map((j) => j.mc))].filter((mc) => !knownGameVersions.has(mc));
  if (unknown.length > 0) fail(`Modrinth doesn't know these Minecraft versions: ${unknown.join(", ")}`);

  const existing = new Set(
    (await getJson(`${MODRINTH_API}/project/${MODRINTH_PROJECT_ID}/version`)).map((v) => v.version_number),
  );
  const kind = versionType(tag);
  const failed = [];

  for (const { name, version, mc } of jars) {
    const versionNumber = `${version}+${mc}`;

    if (existing.has(versionNumber)) {
      console.log(`skip    ${versionNumber}: already on Modrinth`);
      continue;
    }

    // Gitea's own download URLs use its internal ROOT_URL, so build a public one.
    const downloadUrl = `${serverUrl}/${repo}/releases/download/${encodeURIComponent(tag)}/${encodeURIComponent(name)}`;

    const data = {
      project_id: MODRINTH_PROJECT_ID,
      name: `Saturn Client ${versionNumber}`,
      version_number: versionNumber,
      changelog,
      dependencies: [{ project_id: FABRIC_API_PROJECT_ID, dependency_type: "required" }],
      game_versions: [mc],
      version_type: kind,
      loaders: ["fabric"],
      featured: false,
      status: "listed",
      file_parts: ["file"],
      primary_file: "file",
    };

    if (dryRun) {
      const probe = await http(downloadUrl, { headers: { Range: "bytes=0-0" } });
      await probe.arrayBuffer();
      console.log(`would publish ${versionNumber} (${kind}, Minecraft ${mc}) from ${downloadUrl} [reachable]`);
      continue;
    }

    try {
      const jarBytes = await (await http(downloadUrl)).arrayBuffer();

      const form = new FormData();
      form.append("data", JSON.stringify(data));
      form.append("file", new Blob([jarBytes], { type: "application/java-archive" }), name);

      await http(`${MODRINTH_API}/version`, {
        method: "POST",
        headers: { Authorization: token },
        body: form,
      });
      console.log(`publish ${versionNumber}: done (${(jarBytes.byteLength / 1_000_000).toFixed(1)} MB)`);
    } catch (e) {
      console.error(`publish ${versionNumber}: FAILED ${e.message}`);
      failed.push(versionNumber);
    }
  }

  if (failed.length > 0) fail(`Failed to publish: ${failed.join(", ")}`);
}

main().catch((e) => fail(e.stack ?? String(e)));