import datetime

import csv
from django.http import HttpResponse
from django.shortcuts import render

# Create your views here.
from rest_framework.exceptions import ValidationError
from rest_framework.renderers import JSONRenderer
from rest_framework.response import Response
from rest_framework.views import APIView

from courses.api import CourseProgressApi
from progress.models import Progress, ProgressLesson
from progress.serializers import ProgressLessonSerializer, ProgressAnalyticSerializer


class UpdateProgress(APIView):
    renderer_classes = (JSONRenderer,)

    @staticmethod
    def post(request):
        """
            На вход обязательно передаётся параметр id (id узла).
        """
        lesson_token = request.JSON.get('lesson_token', None)
        course_token = request.JSON.get('course_token', None)
        if lesson_token is None or course_token is None:
            return Response('Не передан слаг курса или токен урока', status=400)
        try:
            p = Progress.objects.get(user=request.user, course_token=course_token)
            try:
                pv = ProgressLesson.objects.get(
                    progress=p,
                    lesson_token=lesson_token,
                )

            except ProgressLesson.DoesNotExist:
                pv = ProgressLesson.objects.create(
                    date=datetime.datetime.now(),
                    teacher=p.teacher,
                    progress=p,
                    lesson_token=lesson_token,
                )
            pv.status = ProgressLesson.STATUSES.done
            pv.save()
            return Response(ProgressLessonSerializer(pv).data, status=200)

        except Progress.DoesNotExist:
            return Response('Не найден прогресс по заданным параметрам', status=404)


class CourseProgressDynamicView(APIView):
    renderer_classes = (JSONRenderer,)

    @staticmethod
    def get(request, token):
        if request.user.is_authenticated() and request.user.is_staff:
            try:
                progresses = Progress.objects.filter(course_token=token)
                res = {}
                for i in progresses:
                    key = i.progresslesson_set.filter(status="done").count()
                    res[key] = 1 if not key in res.keys() else res[key] + 1
                return Response(res, status=200)
            except ValidationError:
                return Response("Bad request", status=400)

        return Response(status=403)


class CourseProgressUserView(APIView):
    renderer_classes = (JSONRenderer,)

    @staticmethod
    def get(request, token):
        if request.user.is_authenticated() and request.user.is_staff:
            try:
                res = []
                sorted_token_list = CourseProgressApi.get_topic_lesson(token)
                for p in Progress.objects.filter(course_token=token):
                    progress = ProgressAnalyticSerializer(p).data
                    progress['progress_course'] = p.progress_status(sorted_token_list)
                    res.append(progress)
                return Response(res, status=200)
            except ValidationError:
                return Response("Bad request", status=400)

        return Response(status=403)


class UploadCourseProgressUserView(APIView):
    renderer_classes = (JSONRenderer,)

    @staticmethod
    def get(request, token):
        if request.user.is_authenticated() and request.user.is_staff:
            try:
                response = HttpResponse(content_type='text/csv')
                response['Content-Disposition'] = 'attachment; filename="%s.csv"' % token
                sorted_token_list = CourseProgressApi.get_topic_lesson(token)
                writer = csv.writer(response)
                writer.writerow(['Имя', 'Почта', 'Последняя тема', 'Последний урок'])

                for p in Progress.objects.filter(course_token=token):
                    progress = ProgressAnalyticSerializer(p).data
                    progress['progress_course'] = p.progress_status(sorted_token_list)
                    writer.writerow([
                        progress['name'],
                        progress['email'],
                        progress['progress_course'] and progress['progress_course'][0],
                        progress['progress_course'] and progress['progress_course'][1],
                    ])
                return response
            except ValidationError:
                return Response("Bad request", status=400)
        return Response(status=403)