# coding=utf-8
from __future__ import unicode_literals

import json
import os
from django.contrib.auth.views import redirect_to_login
from django.views.decorators.csrf import csrf_exempt
import ldap
import logging

from django.conf import settings
from django.core.exceptions import PermissionDenied
from django.core.urlresolvers import reverse
from django.core.cache import cache
from django.db.models import Q
from django.http.response import HttpResponse, HttpResponseBadRequest, HttpResponseRedirect, Http404, \
    HttpResponseForbidden
from django.shortcuts import render, get_object_or_404, resolve_url
from django.contrib.auth.decorators import login_required
from django.contrib.auth.models import User
from django.views.decorators.http import require_POST
from django.views.decorators.cache import cache_control

from adim.models import AnObj, AnObjMembership
from adim.permissions import get_permission_class, has_anobj_access, get_ttp_sharing_mode, SHARING_MODE_NONE
from adim_ttp.decorators import attp_login
from adim_utils.decorators import clear_function_cache

from .forms import UploadImageFileForm
from sendfile import sendfile
from .utils import add_image_border, create_image_thumbnail


logger = logging.getLogger(__name__)


def home(request):
    """
    Home page
    :param request:
    :return:
    """
    context = {}
    if request.user.is_anonymous():
        context['next'] = request.GET.get('next', "")
    return render(request, "adim/home.html", context)


def handle_404(request):
    if request.user.is_authenticated():
        return HttpResponseRedirect(reverse("adim_app:annotate-new"))
    else:
        return HttpResponseRedirect(reverse('adim_app:home'))


@login_required
def essai(request):
    """
    Page d'essais
    :param request:
    :return:
    """
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        return render(request, "adim/essai.html", {})
    else:
        raise Http404()


@login_required
def _get_anobj(request, anobj_uuid=None, anobj_id=None):
    """
    Returns an AnObj with the uuid or id passed in parameters if
    the request.user has sufficient permissions for it
    Raise a 404 if it cannot return the AnObj

    :param request:
    :param anobj_uuid:
    :return: AnObj
    :raise: PermissionDenied
    """
    q = {}
    if anobj_uuid is not None:
        q['uuid'] = anobj_uuid
    elif anobj_id is not None:
        q['id'] = anobj_id
    if not q:
        raise Http404()
    anobj = get_object_or_404(AnObj, **q)

    if not has_anobj_access(request, anobj):
        raise PermissionDenied()

    return anobj


@login_required
@cache_control(public=True, max_age=120)
def send_anobj_img(request, anobj_uuid):
    try:
        anobj = _get_anobj(request, anobj_uuid=anobj_uuid)
        return sendfile(request, anobj.image.path)
    except Http404:
        return HttpResponseForbidden('Sorry, you cannot access this file')


@login_required
def anobj_thumb(request, anobj_uuid):
    if request.method == 'GET':
        return send_anobj_thumb(request, anobj_uuid=anobj_uuid)
    elif request.method == 'POST':
        return upload_anobj_thumb(request, anobj_uuid=anobj_uuid)


@login_required
@cache_control(public=True, max_age=1)
def send_anobj_thumb(request, anobj_uuid):
    try:
        anobj = _get_anobj(request, anobj_uuid=anobj_uuid)
        thumb_name = "{name}__{user}.png".format(name=os.path.splitext(anobj.image.name)[0], user=request.user.id)
        thumb_path = os.path.join(
            settings.MEDIA_ROOT,
            thumb_name
        )
        # If there is not yet a thumbnail for the current user
        # return the original one
        if not os.path.isfile(thumb_path):
            thumb_name = "{name}__.png".format(name=os.path.splitext(anobj.image.name)[0])
            thumb_path = os.path.join(
                settings.MEDIA_ROOT,
                thumb_name
            )
        return sendfile(request, thumb_path)
    except Http404:
        return HttpResponseForbidden('Sorry, you cannot access this file')


@login_required
def annotate_new(request):
    return render(request, "adim/annotation_new.html", {})


# @login_required
def annotate(request, anobj_uuid=None):
    """
    Annotation page
    :param request:
    :param anobj_uuid:
    :return:
    """
    # ----- Some preliminary validations
    if anobj_uuid is None or len(anobj_uuid) < 8:
        raise Http404()

    try:
        anobj = AnObj.objects.select_related('owner').get(uuid__startswith=anobj_uuid)
    except AnObj.DoesNotExist:
        raise Http404()

    # In case of fragmentary uuid, redirect to the url with full uuid
    if len(anobj_uuid) < 32:
        return HttpResponseRedirect(reverse('adim_app:annotate', kwargs={'anobj_uuid': anobj.uuid}))

    # ----- Login check. Not using decorator so we can delegate to Trusted Third Party if needed
    permission = get_permission_class(anobj.sharing_mode)
    if request.user.is_anonymous():
        if permission and permission.ttp:
            check_url = settings.ATTP.get(permission.ttp_id, {}).get('CHECK_URL')
            return HttpResponseRedirect(check_url.format(uuid=anobj.uuid))
        else:
            return redirect_to_login(resolve_url('adim_app:annotate', anobj_uuid=anobj.uuid))

    # ----- Build context
    context = {
        'membership': False
    }
    # is_owner = request.user == anobj.owner
    # is_owner = request.user in anobj.owners.all()
    is_owner = anobj.is_owned(request.user.id)

    # ----- Detailed check for permissions
    membership = None
    # User is owner and anobj is not shared via Trusted Third Party
    if is_owner and not (permission and permission.ttp):
        if anobj.sharing_mode != SHARING_MODE_NONE:
            membership, _ = AnObjMembership.objects.get_or_create(anobj=anobj, user=request.user)
    # User is guest or owner and anobj shared via TTP
    else:
        if permission is None:
            # AnObj not shared
            raise Http404()
            # raise PermissionDenied()

        elif not permission.has_permission(request, anobj):
            # AnObj shared but user has no permission yet
            if permission.has_interactive_registration:
                # Interactive registration exists, call it
                return permission.get_interactive_registration_response(request, anobj)
            # No interactive registration for this sharing model, deny access
            raise PermissionDenied()

        else:
            # AnObj shared, user authorized and registered
            pass

        #  TTP permission may have changed ownership
        if permission.ttp:
            clear_function_cache(f='adim.models.annotablesis_owned', args=(anobj, request.user.id))
            is_owner = anobj.is_owned(request.user.id)

        membership = AnObjMembership.objects.get(anobj=anobj, user=request.user)

    # Interactive registration may post credentials, if so redirect to current view with GET method
    if request.method == 'POST':
        return HttpResponseRedirect(reverse('adim_app:annotate', kwargs={'anobj_uuid': anobj_uuid}))

    context.update({
        'is_owner': is_owner,
        'membership': membership,
        'anobj': anobj
    })

    # ----- Determine if we may display shared annotations
    if is_owner:
        owner_membership = membership
    else:
        try:
            owner_membership = AnObjMembership.objects.get(anobj=anobj, user=anobj.owner)
        except AnObjMembership.DoesNotExist:
            owner_membership = None

    context.update({'display_shared_annotations':
        (anobj.sharing_mode != SHARING_MODE_NONE) and
        (
            anobj.is_owned(request.user.id) or
            anobj.allow_public_publishing or
            (
                owner_membership and owner_membership.publish_mode == 2
            )
        )
    })

    # ----- Environment specific settings
    template_path = ['adim']
    if anobj.env:
        # select template from adim/env/<env_name>/
        template_path.extend(['env', anobj.env])
        # add env-settings to the context if it exists
        env_settings = settings.ADIM_ENV.get(anobj.env)
        if env_settings:
            context.update({'env_settings': env_settings})

    template_path.append("annotation.html")
    return render(request, "/".join(template_path), context)


@csrf_exempt
@attp_login
@login_required
def upload_file(request, anobj_uuid=None):
    """
    -- inspired by: https://github.com/miki725/Django-jQuery-File-Uploader-Integration-demo/blob/master/upload/views.py
    :param request:
    :return:
    """
    if request.method != 'POST':
        return HttpResponseBadRequest()

    response_type = "application/json"
    response_data = {}

    user = request.user  # if request.user.is_authenticated() else moodle_meta.get('user')

    form = UploadImageFileForm(request.POST, request.FILES)
    if form.is_valid():
        image_file = request.FILES['image_file']
        file_response = _validate_uploaded_file(image_file)
        response_data.update({
            'error': file_response.get('error'),
            'files': [file_response],
        })
        anobj_name = form.cleaned_data['name']

        # Create AnObj
        if not file_response['error']:
            anobj = None
            if anobj_uuid:
                try:
                    anobj = _get_anobj(request, anobj_uuid=anobj_uuid)
                except Http404:
                    anobj = None

            if anobj:
                anobj.image = image_file
                if anobj_name:
                    anobj.name = anobj_name
                anobj.save()
            else:
                anobj = AnObj.objects.create(
                    owner=user,
                    name=anobj_name or os.path.splitext(image_file.name)[0],
                    image=image_file
                )

            if hasattr(request, 'attp_message'):
                ttp_id = request.attp_message.get('attp_id')
                sharing_mode = get_ttp_sharing_mode(ttp_id=ttp_id)
                if sharing_mode:
                    anobj.sharing_mode = sharing_mode
                    sharing_opts = request.attp_message.get('sharing_opts')
                    if sharing_opts:
                        anobj.sharing_opts = sharing_opts
                    anobj.save()

            # Create original thumbnail, returned to user who has not yet annotated
            create_image_thumbnail(anobj.image.path)
            response_data['next'] = reverse('adim_app:annotate', kwargs={'anobj_uuid': anobj.uuid})
            response_data['uuid'] = anobj.uuid

        # Needed when using iFrame transport
        if "text/html" in request.META["HTTP_ACCEPT"]:
            response_type = "text/html"
    else:
        response_data['error'] = "invalid"

    if 'application/json' in request.META.get('HTTP_ACCEPT', ''):
        return HttpResponse(json.dumps(response_data), content_type=response_type)
    else:
        return HttpResponseRedirect(response_data['next'])
    

def _validate_uploaded_file(image_file):
    options = {
        # the maximum file size (must be in bytes)
        "maxfilesize": settings.ADIM_UPLOAD_MAX_FILESIZE * 2 ** 20,  # 2 Mb
        # the file types which are going to be allowed for upload
        # must be a mimetype
        "acceptedformats": (
            "image/jpeg",
            "image/jpg",
            "image/png",
        )
    }

    error_id = False
    if image_file.size > options["maxfilesize"]:
        error_id = "maxFileSize"
    # allowed file type
    if image_file.content_type not in options["acceptedformats"]:
        error_id = "acceptFileTypes"

    response_data = {
        "name": image_file.name,
        "size": image_file.size,
        "type": image_file.content_type,
        "error": error_id,
    }

    return response_data


@login_required
@require_POST
def upload_anobj_thumb(request, anobj_uuid=None):
    if anobj_uuid:
        anobj = _get_anobj(request, anobj_uuid=anobj_uuid)
    else:
        try:
            anobj_id = int(request.POST.get('aid'))
            anobj = _get_anobj(request, anobj_id=anobj_id)
        except TypeError:
            return HttpResponseBadRequest()

    thumb_name = "{name}__{user}.png".format(name=os.path.splitext(anobj.image.name)[0], user=request.user.id)
    # thumb_name = "{name}__.png".format(name=os.path.splitext(anobj.image.name)[0])
    thumb_path = os.path.join(settings.MEDIA_ROOT, thumb_name)

    # thumb_url = reverse('adim.app:ao_thumb', kwargs={'anobj_uuid': anobj.uuid})

    thumb_file = request.FILES['file']
    response_data = _validate_uploaded_file(thumb_file)
    if response_data['error']:
        return HttpResponseBadRequest()

    with open(thumb_path, 'wb+') as destination:
        for chunk in thumb_file.chunks():
            destination.write(chunk)

    add_image_border(thumb_path, save=True)
    return HttpResponse()


def _handle_uploaded_file(image_file, destination):
    destination_path = os.path.join(settings.MEDIA_ROOT, destination, image_file.name)
    with open(destination_path, 'wb+') as destination:
        for chunk in image_file.chunks():
            destination.write(chunk)


@login_required
def suggest_users(request):
    """
    Return a list of usernames that match a query passed in as a query string
    This is the end point for the Bloodhound suggestion engine used for user suggestion
    while adding users to a shared AnObj
    :param request:
    :return:
    """
    query_str = request.GET.get('q', "")
    # tokens = filter(bool, re.compile("\W+").split(query_str))  ## Use this for nonword limit instead of whitespace
    tokens = query_str.split()
    matching_users = []
    usernames = []

    if not tokens:
        return HttpResponse(content=json.dumps(matching_users), content_type="application/json")

    # -- Search for local users
    q = Q()
    for token in tokens:
        q = q & Q(username__icontains=token)

    for user in User.objects.filter(q):
        matching_users.append({'username': user.username, 'id': user.id})
        usernames.append(user.username)

    # -- Search for ldap users
    if len(matching_users) < settings.ADIM_SUGGESTION['LIMIT']:
        cache_key = "ldapusers_" + "_".join(tokens)
        ldap_users = cache.get(cache_key)

        if ldap_users is None:
            filter_str = "(mail=*{}*)".format("*".join(tokens))
            print "\n{h} HIT LDAP: {q} {h}\n".format(h="#" * 30, q=filter_str)

            ldap_object = ldap.initialize(settings.ADIM_SUGGESTION['LDAP']['URL'])
            try:
                results = ldap_object.search_st(
                    base=settings.ADIM_SUGGESTION['LDAP']['BASE'],
                    scope=ldap.SCOPE_SUBTREE,
                    filterstr=filter_str,
                    attrlist=(str("mail"),),
                    timeout=settings.ADIM_SUGGESTION['LDAP']['TIMEOUT']
                )
            except ldap.TIMEOUT:
                results = []
            ldap_users = map(lambda r: r[1].get('mail', [""])[0], results)

            # ldap_users = [
            #     "Julien.Furrer@unil.ch",
            #     "Julien.Furrer.1@unil.ch",
            #     "Julien.Furrer.2@unil.ch",
            # ]

            cache.set(cache_key, ldap_users, 3600 * 24)

        matching_users += [
            {'username': user}
            for user in ldap_users if user not in usernames
        ]

    return HttpResponse(content=json.dumps(matching_users), content_type="application/json")