import { readdir, readFile, mkdir, writeFile, stat } from "node:fs/promises";
import { fileURLToPath } from "node:url";
import path from "node:path";
import * as esbuild from "esbuild";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, "..");
const PRESENCES_DIR = path.join(ROOT, "presences");
const SDK_RUNTIME = path.join(ROOT, "scripts", "sdk-runtime.mjs");

async function listPresences() {
  const entries = await readdir(PRESENCES_DIR, { withFileTypes: true });
  return entries.filter((e) => e.isDirectory()).map((e) => e.name);
}

async function readMetadata(presenceDir) {
  const metaPath = path.join(presenceDir, "metadata.json");
  const json = JSON.parse(await readFile(metaPath, "utf8"));
  return json;
}

async function findEntry(presenceDir) {
  const candidates = ["src/presence.ts", "src/index.ts", "presence.ts", "index.ts"];
  for (const candidate of candidates) {
    const full = path.join(presenceDir, candidate);
    try {
      await stat(full);
      return full;
    } catch {
      // try next
    }
  }
  throw new Error(`No entry script found in ${presenceDir} (tried ${candidates.join(", ")})`);
}

async function buildPresence(slug) {
  const presenceDir = path.join(PRESENCES_DIR, slug);
  const meta = await readMetadata(presenceDir);
  if (meta.id !== slug) {
    throw new Error(`metadata.id "${meta.id}" does not match folder name "${slug}"`);
  }
  const entry = await findEntry(presenceDir);
  const distDir = path.join(presenceDir, "dist");
  await mkdir(distDir, { recursive: true });
  await esbuild.build({
    entryPoints: [entry],
    outfile: path.join(distDir, "presence.js"),
    bundle: true,
    platform: "browser",
    format: "cjs",
    target: ["chrome120", "firefox115"],
    minify: true,
    legalComments: "none",
    alias: {
      "@source/presence-sdk": SDK_RUNTIME,
    },
  });
  console.log(`✓ ${slug} v${meta.version}`);
}

async function main() {
  const list = await listPresences();
  if (list.length === 0) {
    console.log("No presences found.");
    return;
  }
  for (const slug of list) {
    await buildPresence(slug);
  }
}

await main();