from django.shortcuts import render
from django.template.defaulttags import register
from django.http import Http404
from django.contrib.auth.decorators import login_required
from .models import ExamLines, Lecturer, Subject, Exam, Student, sort_and_group_datetime
import datetime as dt


@login_required
def lecturer(request):
    lecturers = Lecturer.objects.all()
    context = {"lecturers": lecturers}
    return render(request, "pruefplan/lecturer.html", context)


@login_required
def subject(request):
    subjects = Subject.objects.all()
    context = {"subjects": subjects}
    return render(request, "pruefplan/subject.html", context)


@login_required
def student(request):
    students = Student.objects.all()
    context = {"students": students}
    return render(request, "pruefplan/student.html", context)


@login_required
def exam(request):
    exams = Exam.objects.all()
    supervisorSetDict = {}
    for ex in exams:
        examSupervisors = []
        for partialExam in ex.partialexam_set.all():
            for examExe in partialExam.examexecution_set.all():
                supervisor = (
                    examExe.lecturer.firstName + " " + examExe.lecturer.lastName
                )
                if supervisor not in examSupervisors:
                    examSupervisors.append(supervisor)
        supervisorSetDict[ex.identification] = examSupervisors

    context = {"exams": exams, "supervisorSetDict": supervisorSetDict}
    return render(request, "pruefplan/exam.html", context)


@register.filter
def get_item(dictionary, key):
    return dictionary.get(key)


def examsForLecturer(request, lecturer_id):
    lecturer = Lecturer.objects.filter(pk=lecturer_id).first()
    if lecturer is not None:
        lecExamExes = lecturer.examexecution_set.all()
        lecAttendance = lecturer.attendance_set.all()
        lecExamLines = mergeModels(lecExamExes, lecAttendance)
        context = {
            "lecturer": lecturer,
            "lecExamLines": lecExamLines,
            "lecExamExes": lecExamExes,
        }
        return render(request, "pruefplan/lecturerExam.html", context)
    else:
        raise Http404("Dozentenkennung ungültig.")


def examsForStudent(request, student_id):
    student = Student.objects.all().filter(matrikel=student_id).first()
    if student is not None:
        exams = student.exams.all()
        context = {"student": student, "exams": exams}
        return render(request, "pruefplan/studentExam.html", context)
    else:
        raise Http404("Matrikelnummer ungültig.")


def mergeModels(lecExamExes, lecAttendance):
    result = [
        ExamLines(
            date=examExes.partialExam.exam.date,
            time=examExes.partialExam.exam.time,
            weekday=examExes.partialExam.exam.weekday,
            location=examExes.location,
            subjectIds=examExes.subjectIds,
            examIdent=examExes.partialExam.identification,
            examStudCound=examExes.partialExam.regStudCount,
            supervisorType=examExes.supervisorType,
            executionSet=list(examExes.partialExam.examexecution_set.all()),
            partialExamIdent=examExes.partialExam.exam.identification,
        )
        for examExes in lecExamExes
    ]

    result += [
        ExamLines(
            date=attendance.date,
            time=attendance.time,
            weekday=attendance.weekday,
            location=None,
            subjectIds=None,
            examIdent=None,
            examStudCound=None,
            supervisorType="PRÄSENZ",
            executionSet=None,
            partialExamIdent=None,
        )
        for attendance in lecAttendance
    ]

    result = sort_and_group_datetime(result)

    return result