#!/usr/bin/env node

import fs from 'node:fs';
import path from 'node:path';
import { spawnSync } from 'node:child_process';
import { createRequire } from 'node:module';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const root = path.resolve(__dirname, '..');
const require = createRequire(import.meta.url);
const outputDir = path.join(root, 'build', 'opencode-ai');
const rootPackageJson = JSON.parse(fs.readFileSync(path.join(root, 'package.json'), 'utf8'));

const targetArgs = process.argv.slice(2);
for (const arg of targetArgs) {
  if (!/^--(?:platform|arch)=\S+$/.test(arg)) {
    throw new Error(`Unknown bundle target option: ${arg}`);
  }
}

function targetOption(name, fallback) {
  const prefix = `--${name}=`;
  const option = targetArgs.find((arg) => arg.startsWith(prefix));
  return option ? option.slice(prefix.length) : fallback;
}

const targetPlatform = targetOption('platform', process.platform);
const targetArch = targetOption('arch', process.arch);

function fail(message) {
  console.error(`[bundle-opencode] ${message}`);
  process.exit(1);
}

if (targetPlatform !== process.platform) {
  fail(`Cross-OS OpenCode staging is not supported: host ${process.platform}, target ${targetPlatform}.`);
}

function resolvePackageRoot(packageName) {
  try {
    return path.dirname(require.resolve(`${packageName}/package.json`, {
      paths: [root],
    }));
  } catch {
    return null;
  }
}

const packageRoot = resolvePackageRoot('opencode-ai');
if (!packageRoot) {
  fail('Missing dependency "opencode-ai". Run npm install or pnpm install before packaging.');
}

const packageJsonPath = path.join(packageRoot, 'package.json');
const packageJson = JSON.parse(fs.readFileSync(packageJsonPath, 'utf8'));
const declaredVersion = rootPackageJson.devDependencies?.['opencode-ai']
  ?? rootPackageJson.dependencies?.['opencode-ai'];
if (declaredVersion !== packageJson.version) {
  fail(
    `The opencode-ai dependency must be pinned exactly to the bundled version. Declared ${declaredVersion ?? 'missing'}, installed ${packageJson.version ?? 'unknown'}.`,
  );
}
const packageRequire = createRequire(packageJsonPath);
const bin = packageJson.bin;
const hasOpencodeBin = typeof bin === 'string'
  || (bin && typeof bin === 'object' && typeof bin.opencode === 'string');

if (!hasOpencodeBin) {
  fail('Installed "opencode-ai" package does not expose an "opencode" binary.');
}

fs.rmSync(outputDir, { recursive: true, force: true });
fs.mkdirSync(path.dirname(outputDir), { recursive: true });
fs.cpSync(packageRoot, outputDir, {
  recursive: true,
  dereference: true,
  filter: (src) => {
    if (src.includes(`${path.sep}.git${path.sep}`)) return false;
    if (path.relative(packageRoot, src).split(path.sep)[0] === 'node_modules') return false;
    return true;
  },
});

const platformMap = {
  darwin: 'darwin',
  linux: 'linux',
  win32: 'windows',
};
const archMap = {
  x64: 'x64',
  arm64: 'arm64',
  arm: 'arm',
};

function getNativePackageCandidates() {
  const platform = platformMap[targetPlatform] ?? targetPlatform;
  const arch = archMap[targetArch] ?? targetArch;
  const base = `opencode-${platform}-${arch}`;

  if (arch === 'x64') {
    return [`${base}-baseline`, base];
  }

  return [base];
}

function bundleNativeLauncher() {
  const binaryName = targetPlatform === 'win32' ? 'opencode.exe' : 'opencode';
  const outputBinary = path.join(outputDir, 'bin', binaryName);

  for (const packageName of getNativePackageCandidates()) {
    let dependencyPackageJsonPath;
    try {
      dependencyPackageJsonPath = packageRequire.resolve(`${packageName}/package.json`);
    } catch {
      continue;
    }

    const dependencyRoot = path.dirname(dependencyPackageJsonPath);
    const nativeBinary = path.join(dependencyRoot, 'bin', binaryName);
    if (!fs.existsSync(nativeBinary)) {
      continue;
    }

    fs.copyFileSync(nativeBinary, outputBinary);
    fs.chmodSync(outputBinary, 0o755);
    return { packageName, outputBinary };
  }

  fail(
    `Missing native opencode binary for ${targetPlatform}/${targetArch}. Tried ${getNativePackageCandidates().join(', ')}.`,
  );
}

const nativeLauncher = bundleNativeLauncher();
const verificationEnv = {
  ...process.env,
  PATH: process.platform === 'win32'
    ? [process.env.SystemRoot && path.join(process.env.SystemRoot, 'System32'), process.env.SystemRoot]
        .filter(Boolean)
        .join(path.delimiter)
    : '/usr/bin:/bin',
};
delete verificationEnv.NODE_PATH;
delete verificationEnv.BUN_INSTALL;
const versionProbe = spawnSync(nativeLauncher.outputBinary, ['--version'], {
  cwd: outputDir,
  encoding: 'utf8',
  env: verificationEnv,
});
if (versionProbe.error || versionProbe.status !== 0) {
  fail(
    `Bundled native launcher failed its self-contained version probe: ${versionProbe.error?.message ?? versionProbe.stderr ?? versionProbe.stdout}`,
  );
}
const reportedVersion = `${versionProbe.stdout ?? ''}${versionProbe.stderr ?? ''}`.trim();
if (reportedVersion !== packageJson.version) {
  fail(`Bundled native launcher reported ${reportedVersion || 'no version'}, expected ${packageJson.version}.`);
}
console.log(
  `[bundle-opencode] bundled and verified self-contained opencode-ai@${packageJson.version} launcher ${nativeLauncher.packageName} -> ${path.relative(root, outputDir)}`,
);