# Create your views here.

from django.contrib.auth.decorators import login_required
from django.http import FileResponse, HttpResponse, HttpResponseRedirect
from django.shortcuts import get_object_or_404, render

import os
import blake3

from .forms import UploadFileForm
from .models import Submission_File


def compute_file_hash(file):
    '''
    Compute BLAKE3 hash of the file
    '''
    try:
        hasher = blake3.blake3()
        for chunk in file.chunks(chunk_size=65536):
            hasher.update(chunk)
        return hasher.hexdigest()
    except Exception as e:
        print(f"Error computing file hash: {e}")
        return None


@login_required(login_url="/login/")
def serve_submission_file(request, file_hash):
    '''
    View function to serve submission files for download or inline viewing
    '''
    download = request.GET.get('d')

    try:
        submission_file = get_object_or_404(Submission_File, file_hash=file_hash)
        file = submission_file.file.file
        file_name = submission_file.file_name

        response = FileResponse(file)
        if download == "1":
            response['Content-Disposition'] = f'attachment; filename="{file_name}"'
        else:
            response['Content-Disposition'] = f'inline; filename="{file_name}"'

        return response

    except:
        return HttpResponse("File not found", status=404)


@login_required(login_url="/login/")
def fileUpload(request):
    '''
    View function for handling file uploads
    '''
    if request.method == 'POST':
        form = UploadFileForm(request.POST, request.FILES)
        if form.is_valid():
            file = form.cleaned_data['file']
            
            file_name = file.name
            file_hash = compute_file_hash(file)
            
            Null, file_ext = os.path.splitext(file_name)
            hash_file_name = file_hash + file_ext
            
            new_submission_file, created = Submission_File.objects.get_or_create(file_hash=file_hash)
            
            new_submission_file.file_hash = file_hash
            new_submission_file.file_name = file_name
            new_submission_file.file.save(hash_file_name, file) 
            
            new_submission_file.save
            
            return HttpResponseRedirect("/")
            
    else:
        form = UploadFileForm()
        
    return render(request, 'files/upload.html', {'form': form})