import { execFileSync } from 'node:child_process';
import { cp, readdir, readFile, rm, writeFile } from 'node:fs/promises';
import { fileURLToPath } from 'node:url';
import { join, resolve } from 'node:path';

const root=resolve(fileURLToPath(new URL('..',import.meta.url))),output=join(root,'.headless-dist');
await rm(output,{recursive:true,force:true});
execFileSync(process.execPath,[join(root,'node_modules/typescript/bin/tsc'),'-p',join(root,'tsconfig.headless.json')],{cwd:root,stdio:'inherit'});
async function declarations(directory){
  for(const entry of await readdir(directory,{withFileTypes:true})){
    const path=join(directory,entry.name);
    if(entry.isDirectory())await declarations(path);
    else if(entry.name.endsWith('.d.ts')){
      const source=await readFile(path,'utf8');
      // Native TS rewrites runtime imports, but leaves source suffixes in declarations.
      // Only module specifiers change; data/schema string literals remain intact.
      const next=source.replace(/((?:from\s+|import\s*\()\s*['"])(\.\.?\/[^'"]+)\.ts(['"])/g,'$1$2.js$3');
      await writeFile(path,next);
    }
  }
}
await declarations(join(output,'modules'));
for(const [module,worker]of [['browser-digests','digest.worker'],['browser-images','image.worker']]){
  const path=join(output,'modules/canvas-runtime',`${module}.js`),source=await readFile(path,'utf8'),before=`./${worker}.ts`;
  if(source.split(before).length!==2)throw Error(`Unexpected Worker URL in ${module}`);
  await readFile(join(output,'modules/canvas-runtime',`${worker}.js`));
  await writeFile(path,source.replace(before,`./${worker}.js`));
}
for(const name of ['package.json','consumer.mjs','README.md','STEP4_ACCEPTANCE.md','SERVICE_ACCEPTANCE.md'])await cp(join(root,'headless',name),join(output,name));
console.log('Built .headless-dist: ESM, declarations, browser adapters and Worker modules');