const { build } = require("esbuild");
const fs = require("fs");
const path = require("path");

const buildOptions = parseBuildOptions(process.argv.slice(2));

function loadEnvFile(filePath) {
  if (!fs.existsSync(filePath)) return {};
  return fs.readFileSync(filePath, "utf8").split(/\r?\n/).reduce((acc, line) => {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith("#")) return acc;
    const index = trimmed.indexOf("=");
    if (index <= 0) return acc;
    const key = trimmed.slice(0, index).trim();
    const value = trimmed.slice(index + 1).trim();
    if (key) acc[key] = value;
    return acc;
  }, {});
}

function buildEmbeddedEnvBanner(envFilePath) {
  const env = loadEnvFile(envFilePath);
  const lines = Object.entries(env).map(([key, value]) => `process.env[${JSON.stringify(key)}]=${JSON.stringify(value)};`);
  if (!lines.length) return "";
  return `/* embedded ${path.basename(envFilePath)} */\n${lines.join("\n")}`;
}

function parseBuildOptions(args) {
  const raw = {};
  for (let i = 0; i < args.length; i += 1) {
    const arg = args[i];
    if (arg === "--env" || arg === "--env-file" || arg === "--out" || arg === "--outfile") {
      raw[arg.slice(2)] = args[i + 1];
      i += 1;
      continue;
    }
    if (arg.startsWith("--env=")) raw.env = arg.slice("--env=".length);
    if (arg.startsWith("--env-file=")) raw["env-file"] = arg.slice("--env-file=".length);
    if (arg.startsWith("--out=")) raw.out = arg.slice("--out=".length);
    if (arg.startsWith("--outfile=")) raw.outfile = arg.slice("--outfile=".length);
  }

  const envName = normalizeName(raw.env || process.env.CONFIG_BUILD_ENV || "");
  const envFileInput = raw["env-file"] || process.env.CONFIG_BUILD_ENV_FILE || (envName ? `.env.${envName}` : ".env.production");
  const envFilePath = path.resolve(__dirname, envFileInput);
  const outfile = raw.outfile || raw.out || process.env.CONFIG_BUILD_OUTFILE || path.resolve(__dirname, "dist", envName ? `bundle.${envName}.js` : "bundle.js");

  if ((raw.env || raw["env-file"] || process.env.CONFIG_BUILD_ENV || process.env.CONFIG_BUILD_ENV_FILE) && !fs.existsSync(envFilePath)) {
    console.error(`[build] env file not found: ${envFilePath}`);
    process.exit(1);
  }

  return {
    envName,
    envFilePath,
    outfile: path.resolve(__dirname, outfile),
  };
}

function normalizeName(input) {
  const text = String(input || "").trim();
  if (!text) return "";
  return text.replace(/^\.env\./, "").replace(/[^a-zA-Z0-9_-]/g, "_");
}

console.log(`[build] env: ${buildOptions.envFilePath}`);
console.log(`[build] outfile: ${buildOptions.outfile}`);

build({
  entryPoints: ["./index.js"],
  outfile: buildOptions.outfile,
  platform: "node",
  bundle: true,
  minify: true,
  sourcemap: false,
  target: ["node16", "node18", "node20"],
  banner: {
    js: buildEmbeddedEnvBanner(buildOptions.envFilePath),
  },
  external: ["mysql2", "pg"],
  plugins: [
    {
      name: "bundle-oracledb-js",
      setup(build) {
        build.onResolve({ filter: /^oracledb$/ }, () => ({
          path: path.resolve(__dirname, "node_modules", "oracledb", "index.js"),
        }));
      },
    },
  ],
}).catch(() => process.exit(1));