/**
 * --------------------------------------------------------------------
 * docmd : the zero-config documentation engine.
 *
 * @package     @docmd/core (and ecosystem)
 * @website     https://docmd.io
 * @repository  https://github.com/docmd-io/docmd
 * @license     MIT
 * @copyright   Copyright (c) 2025-present docmd.io
 *
 * [docmd-source] - Please do not remove this header.
 * --------------------------------------------------------------------
 *
 * Resolves the external (non-@docmd) runtime dependencies of @docmd/core
 * and its transitive deps, then either:
 *
 *   node tools/print-okf-runtime-deps.js
 *     → prints `name@range` lines to stdout (human readable / CI log)
 *
 *   node tools/print-okf-runtime-deps.js --emit-pkg=<path>
 *     → writes a package.json to <path> listing all external deps under
 *       `dependencies`.  Used by the Docker builder stage so the
 *       production stage can do a single `npm install --prefix /usr/local`
 *       instead of maintaining a hand-rolled list in the Dockerfile.
 *
 * The script is the single source of truth for what external deps the
 * Docker image needs.  Run it after adding a new dep to any @docmd/*
 * package — the next Docker build will pick up the change automatically
 * because the builder stage regenerates the package.json fresh.
 */

const fs = require("fs");
const path = require("path");

const root = process.cwd();
const emitArg = process.argv.find((a) => a.startsWith("--emit-pkg="));
const emitPath = emitArg ? emitArg.slice("--emit-pkg=".length) : null;

function findPackageDir(name, dir = path.join(root, "packages")) {
  for (const entry of fs.readdirSync(dir, {withFileTypes: true})) {
    if (!entry.isDirectory()) continue;
    const full = path.join(dir, entry.name);
    const pj = path.join(full, "package.json");
    if (fs.existsSync(pj)) {
      const pkg = JSON.parse(fs.readFileSync(pj, "utf8"));
      if (pkg.name === name) return full;
    }
    const r = findPackageDir(name, full);
    if (r) return r;
  }
  return null;
}

function collectDeps(name, seen = new Set()) {
  if (seen.has(name)) return seen;
  seen.add(name);
  const dir = findPackageDir(name);
  if (!dir) return seen;
  const pkg = JSON.parse(fs.readFileSync(path.join(dir, "package.json"), "utf8"));
  for (const dep of Object.keys(pkg.dependencies || {})) {
    if (dep.startsWith("@docmd/")) collectDeps(dep, seen);
  }
  return seen;
}

const internal = collectDeps("@docmd/core");
const external = new Map();

for (const name of internal) {
  const dir = findPackageDir(name);
  if (!dir) continue;
  const pkg = JSON.parse(fs.readFileSync(path.join(dir, "package.json"), "utf8"));
  for (const [dep, range] of Object.entries(pkg.dependencies || {})) {
    if (dep.startsWith("@docmd/")) continue;
    if (dep.startsWith("@mgks/")) continue;
    if (!external.has(dep)) external.set(dep, range);
  }
}

const lines = [...external].sort(([a], [b]) => a.localeCompare(b));

if (emitPath) {
  // Write a package.json the production stage can `npm install` directly.
  // `name` and `version` are required by npm but otherwise arbitrary.
  const pkg = {
    name: "docmd-runtime-deps",
    version: "0.0.0",
    private: true,
    description: "Auto-generated by tools/print-okf-runtime-deps.js — do not edit.",
    dependencies: Object.fromEntries(lines)
  };
  fs.mkdirSync(path.dirname(emitPath), { recursive: true });
  fs.writeFileSync(emitPath, JSON.stringify(pkg, null, 2) + "\n");
  console.log(`[generate-runtime-pkg] wrote ${lines.length} deps → ${emitPath}`);
} else {
  for (const [dep, range] of lines) {
    console.log(`${dep}@${range}`);
  }
}