/* Shared direct multipart transport for customer originals/corrections and operator finals. */
window.dtfUpload = async (file, {api, prefix='/uploads', startPath=prefix, progress=()=>{}, onBytes=()=>{}, scope='guest', resume=true}) => {
  const samples=new Blob([file.slice(0,65536),file.slice(Math.max(0,file.size-65536))]);
  const hash=Array.from(new Uint8Array(await crypto.subtle.digest('SHA-256',await samples.arrayBuffer())),b=>b.toString(16).padStart(2,'0')).join('');
  const key='dtf-upload:'+JSON.stringify([scope,file.name,file.size,file.lastModified,hash]);
  let id=resume?localStorage.getItem(key):null,state;
  if(id){try{state=await api(prefix+'/'+id);}catch(error){if(![404,410].includes(error.status))throw error;id=null;}}
  if(!id){state=await api(startPath,{name:file.name,size:file.size});id=state.id;if(resume)localStorage.setItem(key,id);}
  async function waitForScan(){
    onBytes(file.size);
    // The antivirus streams the whole file: about a second per 2 MB, and at
    // least two and a half minutes.
    const attempts=Math.max(150,Math.ceil(file.size/2e6));
    for(let attempt=0;attempt<attempts;attempt++){
      const checked=await api(prefix+'/'+id);
      if(checked.scan_state==='clean')return id;
      if(['rejected','error'].includes(checked.scan_state))throw new Error(checked.scan_reason||'Arquivo bloqueado pela verificação de segurança.');
      progress('Verificando segurança de '+file.name+'…');
      await new Promise(resolve=>setTimeout(resolve,1000));
    }
    throw new Error('Verificação de segurança pendente. Tente novamente para consultar o resultado.');
  }
  if(state.complete)return waitForScan();
  const done=new Set(state.parts||[]),size=state.part_bytes;
  onBytes(Math.min(file.size,done.size*size));
  for(let offset=0,part=1;offset<file.size;offset+=size,part++){
    if(done.has(part))continue;
    progress('Enviando '+file.name+' · parte '+part+'/'+Math.ceil(file.size/size));
    const signed=await api(prefix+'/'+id+'/parts/'+part,{});
    const response=await fetch(signed.url,{method:'PUT',body:file.slice(offset,offset+size)});
    if(!response.ok)throw new Error('Upload interrompido. Tente novamente para retomar.');
    done.add(part);
    onBytes(Math.min(file.size,done.size*size));
  }
  await api(prefix+'/'+id+'/complete',{});
  return waitForScan();
};