import { createRequire } from "node:module";
import { dirname, join } from "node:path";

const require = createRequire(import.meta.url);

const PLATFORM_TARGETS: Record<string, { packageName: string; triple: string }> = {
  "darwin-arm64": {
    packageName: "@openai/codex-darwin-arm64",
    triple: "aarch64-apple-darwin",
  },
  "darwin-x64": {
    packageName: "@openai/codex-darwin-x64",
    triple: "x86_64-apple-darwin",
  },
  "linux-arm64": {
    packageName: "@openai/codex-linux-arm64",
    triple: "aarch64-unknown-linux-musl",
  },
  "linux-x64": {
    packageName: "@openai/codex-linux-x64",
    triple: "x86_64-unknown-linux-musl",
  },
  "win32-arm64": {
    packageName: "@openai/codex-win32-arm64",
    triple: "aarch64-pc-windows-msvc",
  },
  "win32-x64": {
    packageName: "@openai/codex-win32-x64",
    triple: "x86_64-pc-windows-msvc",
  },
};

export const CODEX_APPLY_PATCH_FLAG = "--codex-run-as-apply-patch";

export function resolveCodexExecutable(
  platform = process.platform,
  arch = process.arch,
): string {
  const target = PLATFORM_TARGETS[`${platform}-${arch}`];
  if (!target) {
    throw new Error(`OpenAI Codex does not support ${platform}-${arch}`);
  }

  let packageJson: string;
  try {
    packageJson = require.resolve(`${target.packageName}/package.json`);
  } catch (error) {
    throw new Error(
      `Missing ${target.packageName}, the native optional dependency of @openai/codex`,
      { cause: error },
    );
  }

  return join(
    dirname(packageJson),
    "vendor",
    target.triple,
    "bin",
    platform === "win32" ? "codex.exe" : "codex",
  );
}