import {existsSync, readFileSync} from 'node:fs';
import {createRequire} from 'node:module';
import {dirname, join, resolve} from 'node:path';
import {fileURLToPath} from 'node:url';

const root=resolve(dirname(fileURLToPath(import.meta.url)),'..');
/** Runtime packages that must match package-lock.json when building or deploying. */
export const LOCKED_RUNTIME=['next','react','react-dom','dotenv','hls.js','qrcode'];

export function packageLockVersions(rootDir=root) {
  const lock=JSON.parse(readFileSync(join(rootDir,'package-lock.json'),'utf8'));
  const versions={};
  for(const name of LOCKED_RUNTIME){
    const entry=lock.packages?.[`node_modules/${name}`];
    if(!entry?.version)throw new Error(`package-lock.json 缺少 ${name}`);
    versions[name]=entry.version;
  }
  return versions;
}

export function installedVersions(rootDir=root,names=LOCKED_RUNTIME) {
  const require=createRequire(join(rootDir,'package.json'));
  const versions={};
  for(const name of names){
    try{
      versions[name]=require(`${name}/package.json`).version;
    }catch{
      throw new Error(`未安装 ${name}，请先执行 npm ci 或 pnpm install`);
    }
  }
  return versions;
}

/** Best-effort read of direct dependency versions from pnpm-lock.yaml importers. */
export function pnpmLockVersions(rootDir=root) {
  const file=join(rootDir,'pnpm-lock.yaml');
  if(!existsSync(file))return null;
  const text=readFileSync(file,'utf8');
  const versions={};
  for(const name of LOCKED_RUNTIME){
    const escaped=name.replace(/[.*+?^${}()|[\]\\]/g,'\\$&');
    const match=text.match(new RegExp(`(?:^|\\n)\\s{6}${escaped}:\\n(?:\\s{8}.*\\n)*?\\s{8}version:\\s+(\\S+)`));
    if(!match)throw new Error(`pnpm-lock.yaml 缺少 ${name}`);
    versions[name]=match[1].replace(/\(.*$/,'');
  }
  return versions;
}

export function checkLockSync(rootDir=root) {
  const expected=packageLockVersions(rootDir);
  const installed=installedVersions(rootDir);
  const mismatches=[];
  for(const name of LOCKED_RUNTIME){
    if(installed[name]!==expected[name])mismatches.push(`${name}: 已安装 ${installed[name]}，package-lock.json 为 ${expected[name]}`);
  }
  const pnpm=pnpmLockVersions(rootDir);
  if(pnpm){
    for(const name of LOCKED_RUNTIME){
      if(pnpm[name]!==expected[name])mismatches.push(`${name}: pnpm-lock.yaml 为 ${pnpm[name]}，package-lock.json 为 ${expected[name]}`);
    }
  }
  if(mismatches.length){
    throw new Error(`依赖版本不一致（发版以 package-lock.json / npm ci 为准）：\n- ${mismatches.join('\n- ')}\n请用同一版本同步：npm install 与 pnpm install，或将 next 等依赖钉死后再更新两份 lock。`);
  }
  return {expected,installed,pnpm};
}

if(process.argv[1]&&resolve(process.argv[1])===fileURLToPath(import.meta.url)) {
  try {
    const result=checkLockSync();
    console.log(`lock sync ok (npm${result.pnpm?'+pnpm':''}): next@${result.expected.next}`);
  }catch(error) {
    console.error(error instanceof Error?error.message:error);
    process.exitCode=1;
  }
}