import {
  copyFileSync,
  cpSync,
  existsSync,
  readFileSync,
  realpathSync,
  writeFileSync,
} from "node:fs";
import { resolve, dirname } from "node:path";
import { fileURLToPath } from "node:url";
import { execFileSync } from "node:child_process";

const __dirname = dirname(fileURLToPath(import.meta.url));
const src = resolve(__dirname, "../build/web");
const dest = resolve(__dirname, "../../../apps/web/public/flutter");

cpSync(src, dest, { recursive: true });
console.log(`Copied Flutter build: ${src} → ${dest}`);

// Copy flutter.js.map from the Flutter SDK (not included in build output)
const flutterBin = execFileSync("which", ["flutter"], {
  encoding: "utf-8",
}).trim();
const sdkBinDir = dirname(realpathSync(flutterBin));
const flutterJsMap = resolve(
  sdkBinDir,
  "cache/flutter_web_sdk/flutter_js/flutter.js.map",
);
if (existsSync(flutterJsMap)) {
  copyFileSync(flutterJsMap, resolve(dest, "flutter.js.map"));
  console.log("Copied flutter.js.map from SDK");
} else {
  console.warn(`flutter.js.map not found at ${flutterJsMap}`);
}

// Extract buildConfig from flutter_bootstrap.js so the React app can fetch it
const bootstrap = readFileSync(resolve(dest, "flutter_bootstrap.js"), "utf-8");
const match = bootstrap.match(/_flutter\.buildConfig\s*=\s*({.*?});/);
if (match) {
  writeFileSync(resolve(dest, "build_config.json"), match[1]);
  console.log("Extracted build_config.json");
} else {
  console.warn("Could not extract buildConfig from flutter_bootstrap.js");
}