// Build script for @fmode/openclaw-wechat-agent.
//
// We intentionally NOT use `tsc` to emit the runtime bundle. The plugin is
// installed into `~/.openclaw/extensions/wechat-agent/` at the user's home,
// which is NOT a descendant of the host `openclaw` package's `node_modules`
// tree. Node's standard ESM resolver therefore cannot resolve bare specifiers
// like `openclaw/plugin-sdk/channel-plugin-common` at runtime and channel
// processes exit with `Cannot find package 'openclaw'` in a 5s restart loop.
//
// Mitigation: bundle every `openclaw/*` import into a single self-contained
// `dist/index.js` at build time against the dev-time `openclaw` install.
// The plugin tgz ships with zero runtime dependency on the host's openclaw
// package tree. See README "Build & release" for details.
//
// Externals: only Node built-ins. Everything else (openclaw/*, our own
// ./src/*, any npm deps we might add later) gets inlined.

import { build } from "esbuild";
import { readFileSync, rmSync, mkdirSync, existsSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, resolve } from "node:path";

const __dirname = dirname(fileURLToPath(import.meta.url));
const projectRoot = resolve(__dirname, "..");

const pkg = JSON.parse(
  readFileSync(resolve(projectRoot, "package.json"), "utf8")
);

const outfile = resolve(projectRoot, "dist", "index.js");
const distDir = resolve(projectRoot, "dist");

if (existsSync(distDir)) {
  rmSync(distDir, { recursive: true, force: true });
}
mkdirSync(distDir, { recursive: true });

const result = await build({
  entryPoints: [resolve(projectRoot, "index.ts")],
  outfile,
  bundle: true,
  format: "esm",
  platform: "node",
  // OpenClaw requires node >= 22; node20 baseline keeps us compatible with
  // any reasonable distro openclaw ships on.
  target: "node20",
  // Channel processes are short-lived children; inline-source-map aids post-
  // mortem from journalctl without requiring a separate .map file.
  sourcemap: "inline",
  legalComments: "none",
  // Keep names readable so `channel exited` stack traces from journalctl
  // still point at recognizable helpers.
  minify: false,
  keepNames: true,
  // Only Node built-ins stay external. Everything else — including every
  // `openclaw/plugin-sdk*` subpath — gets inlined. This is the whole point.
  //
  // A handful of optional/native dependencies are reachable via SDK
  // side-effect imports (image/canvas/audio/voice-call paths we never
  // trigger from wechat-agent). We mark them external so esbuild doesn't
  // try to parse their .node binaries or platform-specific install stubs.
  // At runtime these modules would fail to resolve from the customer's
  // ~/.openclaw/extensions/ tree, but the code paths are dead for a pure
  // text channel — they are only ever touched lazily by unrelated SDK
  // features (voice-call, speech, web-media, etc.). If a future feature
  // brings us into those code paths, the resulting `Cannot find package`
  // error will be immediate and loud rather than silent.
  external: [
    "node:*",
    "@napi-rs/canvas",
    "@napi-rs/canvas-*",
    "@img/sharp-*",
    "sharp",
    "@discordjs/opus",
    "node-llama-cpp",
    "@matrix-org/matrix-sdk-crypto-nodejs",
    "@lancedb/lancedb",
    "@lancedb/lancedb-*",
    "silk-wasm",
    "sqlite-vec",
    "sqlite-vec-*",
    "playwright-core",
    "pdfjs-dist",
    "jimp",
    "fake-indexeddb",
    "@mariozechner/pi-tui",
    "@lydell/node-pty",
  ],
  // `.node` native bindings must not be parsed by esbuild; stub them out.
  // If execution ever actually hits one of these at runtime, we want a
  // proper ERR_MODULE_NOT_FOUND from the node loader, not a silent miss.
  loader: {
    ".node": "empty",
  },
  // Bundle the plugin as ES module; emit .js (package.json has type:module).
  mainFields: ["module", "main"],
  conditions: ["import", "node", "default"],
  // Silence the "direct eval" / "unsupported" warnings from SDK internals
  // unless they are new; we compile against a pinned openclaw version.
  logLevel: "info",
  metafile: true,
  treeShaking: true,
  // Reminder in the banner: the file is generated and should not be hand-edited.
  banner: {
    js: `// @fmode/openclaw-wechat-agent v${pkg.version} — generated by scripts/build.mjs. Do not edit by hand.`,
  },
});

// Quick sanity check: the output must not contain any unbundled `openclaw/*`
// import. If it does, our build config is wrong and the plugin will crash at
// runtime on the customer host in the exact same way the symlink-less install
// does today.
const bundled = readFileSync(outfile, "utf8");
const leaks = Array.from(
  bundled.matchAll(/(?:from|require\()\s*["']openclaw(?:\/[^"']*)?["']/g),
  (m) => m[0]
);
if (leaks.length > 0) {
  console.error(
    `\n\u274c build-check failed: bundle still imports openclaw/* at runtime:`
  );
  for (const l of leaks.slice(0, 10)) console.error(`   ${l}`);
  process.exit(1);
}

const inputCount = Object.keys(result.metafile.inputs).length;
const outputSize = bundled.length;
console.log(
  `\n\u2705 bundled ${inputCount} modules -> dist/index.js (${(outputSize / 1024).toFixed(1)} KiB)`
);
console.log(
  `   zero openclaw/* runtime imports; plugin is fully self-contained.`
);