import fs from 'node:fs';
import path from 'node:path';
import { createHash } from 'node:crypto';
import { fileURLToPath } from 'node:url';
import { copyArtifactAtomically, writeManifestIfChanged } from '../web/tools/artifact-assets.mjs';

const root=path.resolve(path.dirname(fileURLToPath(import.meta.url)),'..');
const publicRoot=path.join(root,'web/public'), dist=path.join(root,'web/dist');
const modules=[...new Set(process.argv.slice(2))];
if(!modules.length) throw Error('Specify modules to synchronize into an existing production preview');
const source=JSON.parse(fs.readFileSync(path.join(publicRoot,'modules/manifest.json')));
const targetPath=path.join(dist,'modules/manifest.json');
const target=JSON.parse(fs.readFileSync(targetPath));
if(source.schema!==target.schema) throw Error('Preview manifest schema differs; run the full frontend build');
const hash=file=>createHash('sha256').update(fs.readFileSync(file)).digest('hex');
const assets=new Map();
const fields={runtimeUrl:'runtime',wasmUrl:'wasm',dataUrl:'data',pthreadWorkerUrl:'pthreadWorker'};
for(const name of modules) {
  const entry=source.modules[name];
  if(!entry || !target.modules[name]) throw Error(`Module is not present in both manifests: ${name}`);
  for(const artifact of [entry,...Object.values(entry.workers??{})]) for(const [field,key] of Object.entries(fields)) {
    if(!artifact[field]) continue;
    const url=artifact[field];
    if(!/^\/kernel\/[A-Za-z0-9_.-]+$/.test(url)) throw Error(`Unsupported local artifact path: ${url}`);
    const expected=artifact.hashes?.[key];
    if(!expected || hash(path.join(publicRoot,url.slice(1)))!==expected) throw Error(`Published artifact hash mismatch: ${url}`);
    assets.set(url.slice(1),expected);
  }
}
let copied=0;
for(const [name,expected] of assets) {
  const destination=path.join(dist,name);
  if(fs.existsSync(destination) && hash(destination)===expected) continue;
  fs.mkdirSync(path.dirname(destination),{recursive:true});
  copyArtifactAtomically(path.join(publicRoot,name),destination);
  if(hash(destination)!==expected) throw Error(`Preview copy verification failed: ${name}`);
  copied++;
}
// Publish revision metadata only after every selected runtime file is verified.
for(const name of modules) target.modules[name]=source.modules[name];
target.generatedAt=new Date().toISOString();
writeManifestIfChanged(targetPath,target);
console.log(JSON.stringify({modules,verifiedArtifacts:assets.size,copied,manifest:'web/dist/modules/manifest.json'}));