from __future__ import unicode_literals

import contextlib
import hashlib
import json
import os

from django.core.files.uploadedfile import UploadedFile
from django.http import HttpResponse, HttpResponseServerError
from django.utils import six
from django.utils.encoding import force_bytes, smart_str

from .models import FileModel
from .tests import UNICODE_FILENAME, UPLOAD_TO
from .uploadhandler import ErroringUploadHandler, 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'], six.text_type):
        # 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'].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)

    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 = hashlib.sha1(value.read()).hexdigest()
        else:
            new_hash = hashlib.sha1(force_bytes(value)).hexdigest()
        if new_hash != submitted_hash:
            return HttpResponseServerError()

    # Adding large file to the database should succeed
    largefile = request.FILES['file_field2']
    obj = FileModel()
    obj.testfile.save(largefile.name, largefile)

    return HttpResponse('')


def file_upload_unicode_name(request):

    # Check to see if unicode name came through properly.
    if not request.FILES['file_unicode'].name.endswith(UNICODE_FILENAME):
        return HttpResponseServerError()

    response = None

    # Check to make sure the exotic characters are preserved even
    # through file save.
    uni_named_file = request.FILES['file_unicode']
    obj = FileModel.objects.create(testfile=uni_named_file)
    full_name = '%s/%s' % (UPLOAD_TO, uni_named_file.name)
    if not os.path.exists(full_name):
        response = HttpResponseServerError()

    # Cleanup the object with its exotic file name immediately.
    # (shutil.rmtree used elsewhere in the tests to clean up the
    # upload directory has been seen to choke on unicode
    # filenames on Windows.)
    obj.delete()
    os.unlink(full_name)

    if response:
        return response
    else:
        return HttpResponse('')


def file_upload_echo(request):
    """
    Simple view to echo back info about uploaded files for tests.
    """
    r = {k: f.name for k, f in request.FILES.items()}
    return HttpResponse(json.dumps(r))


def file_upload_echo_content(request):
    """
    Simple view to echo back the content of uploaded files for tests.
    """
    def read_and_close(f):
        with contextlib.closing(f):
            return f.read().decode('utf-8')
    r = {k: read_and_close(f) for k, f in request.FILES.items()}
    return HttpResponse(json.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


def file_upload_getlist_count(request):
    """
    Check the .getlist() function to ensure we receive the correct number of files.
    """
    file_counts = {}

    for key in request.FILES.keys():
        file_counts[key] = len(request.FILES.getlist(key))
    return HttpResponse(json.dumps(file_counts))


def file_upload_errors(request):
    request.upload_handlers.insert(0, ErroringUploadHandler())
    return file_upload_echo(request)


def file_upload_filename_case_view(request):
    """
    Check adding the file to the database will preserve the filename case.
    """
    file = request.FILES['file_field']
    obj = FileModel()
    obj.testfile.save(file.name, file)
    return HttpResponse('%d' % obj.pk)


def file_upload_content_type_extra(request):
    """
    Simple view to echo back extra content-type parameters.
    """
    params = {}
    for file_name, uploadedfile in request.FILES.items():
        params[file_name] = {
            k: smart_str(v) for k, v in uploadedfile.content_type_extra.items()
        }
    return HttpResponse(json.dumps(params))


def file_upload_fd_closing(request, access):
    if access == 't':
        request.FILES  # Trigger file parsing.
    return HttpResponse('')