// Bundles the compiled API (dist/, from `nest build`) into a self-contained .output/ that
// docker/api.Dockerfile copies as-is, so building the server image installs nothing:
//   .output/dist/main.js, migrate.js, seed/seed.js   all JS dependencies inlined
//   .output/node_modules/                             native packages, Linux (musl, x64) builds only
// The tsc output is bundled rather than src/ because esbuild does not emit the decorator
// metadata Nest's dependency injection relies on.
import { build } from "esbuild";
import { cpSync, existsSync, readFileSync, realpathSync, rmSync, writeFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const out = path.join(root, ".output");

// the docker/api.Dockerfile base image (node:*-alpine)
const TARGET = { os: "linux", cpu: "x64", libc: "musl" };
// loaded at runtime from .output/node_modules (platform-specific binaries)
const NATIVE = ["sharp", "@node-rs/argon2"];
// optional packages Nest and pg require inside try/catch; not installed, so left unresolved
const OPTIONAL = [
  "@nestjs/microservices",
  "@nestjs/microservices/*",
  "@nestjs/websockets",
  "@nestjs/websockets/*",
  "class-transformer",
  "class-transformer/*",
  "class-validator",
  "pg-native",
];

rmSync(out, { recursive: true, force: true });

await build({
  absWorkingDir: root,
  entryPoints: {
    main: "dist/main.js",
    migrate: "dist/migrate.js",
    "seed/seed": "dist/seed/seed.js",
  },
  outdir: path.join(out, "dist"),
  bundle: true,
  splitting: true,
  chunkNames: "chunks/[name]-[hash]",
  platform: "node",
  format: "esm",
  target: "node24",
  external: [...NATIVE, ...OPTIONAL],
  // Nest uses class names (logs, throttler keys)
  keepNames: true,
  // CommonJS dependencies call require() for Node built-ins (aliased: bundled code imports createRequire too)
  banner: {
    js: 'import { createRequire as __bundleCreateRequire } from "node:module"; const require = __bundleCreateRequire(import.meta.url);',
  },
  legalComments: "none",
  logLevel: "warning",
});
writeFileSync(
  path.join(out, "package.json"),
  JSON.stringify({ private: true, type: "module" }, null, 2) + "\n",
);

/** Node's lookup of `name` from `fromDir`; follows pnpm's symlinks to the real package folder */
function findPackage(name, fromDir) {
  for (let dir = fromDir; ; dir = path.dirname(dir)) {
    const candidate = path.join(dir, "node_modules", name);
    if (existsSync(path.join(candidate, "package.json"))) return realpathSync(candidate);
    if (path.dirname(dir) === dir) return null;
  }
}

/** package.json os/cpu/libc fields, e.g. ["linux"] or ["!win32"] */
const allows = (list, value) =>
  !list ||
  ((list.includes(value) || list.every((v) => v.startsWith("!"))) && !list.includes(`!${value}`));

const copied = new Map();
function copyPackage(name, fromDir) {
  const dir = findPackage(name, fromDir);
  if (!dir) return; // optional dependency for another platform, not installed
  const pkg = JSON.parse(readFileSync(path.join(dir, "package.json"), "utf8"));
  if (!allows(pkg.os, TARGET.os) || !allows(pkg.cpu, TARGET.cpu) || !allows(pkg.libc, TARGET.libc))
    return;
  if (copied.has(name)) {
    if (copied.get(name) !== pkg.version)
      throw new Error(`${name}: needs both ${copied.get(name)} and ${pkg.version}`);
    return;
  }
  copied.set(name, pkg.version);
  cpSync(dir, path.join(out, "node_modules", name), { recursive: true, dereference: true });
  for (const dep of Object.keys({ ...pkg.dependencies, ...pkg.optionalDependencies }))
    copyPackage(dep, dir);
}

for (const name of NATIVE) copyPackage(name, root);
for (const name of NATIVE) {
  if (!copied.has(name)) throw new Error(`${name} is not installed`);
}
// sharp and argon2 load their binary from a per-platform package; fail here, not in production
for (const name of [
  "@img/sharp-linuxmusl-x64",
  "@img/sharp-libvips-linuxmusl-x64",
  "@node-rs/argon2-linux-x64-musl",
]) {
  if (!copied.has(name)) {
    throw new Error(
      `${name} is missing; run \`pnpm install\` (pnpm-workspace.yaml supportedArchitectures adds it)`,
    );
  }
}
console.log(
  `bundled into .output (native: ${[...copied].map(([n, v]) => `${n}@${v}`).join(", ")})`,
);