import os
import sha
from django.core.files.uploadedfile import UploadedFile
from django.http import HttpResponse, HttpResponseServerError
from django.utils import simplejson
from uploadhandler import QuotaUploadHandler

def file_upload_view(request):
    """
    Check that a file upload can be updated into the POST dictionary without
    going pear-shaped.
    """
    form_data = request.POST.copy()
    form_data.update(request.FILES)
    if isinstance(form_data.get('file_field'), UploadedFile) and isinstance(form_data['name'], unicode):
        # If a file is posted, the dummy client should only post the file name,
        # not the full path.
        if os.path.dirname(form_data['file_field'].file_name) != '':
            return HttpResponseServerError()            
        return HttpResponse('')
    else:
        return HttpResponseServerError()

def file_upload_view_verify(request):
    """
    Use the sha digest hash to verify the uploaded contents.
    """
    form_data = request.POST.copy()
    form_data.update(request.FILES)

    # Check to see if unicode names worked out.
    if not request.FILES['file_unicode'].file_name.endswith(u'test_\u4e2d\u6587_Orl\xe9ans.jpg'):
        return HttpResponseServerError()

    for key, value in form_data.items():
        if key.endswith('_hash'):
            continue
        if key + '_hash' not in form_data:
            continue
        submitted_hash = form_data[key + '_hash']
        if isinstance(value, UploadedFile):
            new_hash = sha.new(value.read()).hexdigest()
        else:
            new_hash = sha.new(value).hexdigest()
        if new_hash != submitted_hash:
            return HttpResponseServerError()

    return HttpResponse('')

def file_upload_echo(request):
    """
    Simple view to echo back info about uploaded files for tests.
    """
    r = dict([(k, f.file_name) for k, f in request.FILES.items()])
    return HttpResponse(simplejson.dumps(r))
    
def file_upload_quota(request):
    """
    Dynamically add in an upload handler.
    """
    request.upload_handlers.insert(0, QuotaUploadHandler())
    return file_upload_echo(request)
        
def file_upload_quota_broken(request):
    """
    You can't change handlers after reading FILES; this view shouldn't work.
    """
    response = file_upload_echo(request)
    request.upload_handlers.insert(0, QuotaUploadHandler())
    return response