from __future__ import annotations # Python 3.10 (Production still on 3.9)

from dataclasses import asdict, dataclass, field
import datetime as dt
from django.db import models


class Subject(models.Model):
    identification = models.CharField(max_length=200, primary_key=True)
    initials = models.CharField(max_length=200, null=True)
    name = models.CharField(max_length=200, null=True)

    def __str__(self):
        return self.name


class Exam(models.Model):
    identification = models.CharField(max_length=200, null=True)
    date = models.DateField(blank=True, null=True)
    time = models.TimeField(blank=True, null=True)
    weekday = models.CharField(max_length=200, null=True)


class PartialExam(models.Model):
    identification = models.CharField(max_length=200, null=True)
    regStudCount = models.CharField(max_length=200, null=True)
    subjectIds = models.ManyToManyField(Subject)
    exam = models.ForeignKey("Exam", blank=True, null=True, on_delete=models.SET_NULL)


class Lecturer(models.Model):
    identification = models.CharField(max_length=200, primary_key=True)
    firstName = models.CharField(max_length=200, null=True)
    lastName = models.CharField(max_length=200, null=True)
    title = models.CharField(max_length=200, null=True)


class Attendance(models.Model):
    identification = models.CharField(max_length=200, primary_key=True)
    date = models.DateField(blank=True, null=True)
    time = models.TimeField(blank=True, null=True)
    dateTimeText = models.CharField(max_length=200, null=True)
    weekday = models.CharField(max_length=200, null=True)
    lecturer = models.ForeignKey(
        "Lecturer", blank=True, null=True, on_delete=models.SET_NULL
    )


class StudentExam(models.Model):
    examIdentification = models.CharField(max_length=200, null=True)
    date = models.DateField(blank=True, null=True)
    time = models.TimeField(blank=True, null=True)
    weekday = models.CharField(max_length=200, null=True)
    location = models.CharField(max_length=200, null=True)
    examExecution = models.ForeignKey(
        "ExamExecution", blank=True, null=True, on_delete=models.CASCADE
    )


class Student(models.Model):
    matrikel = models.CharField(max_length=200, primary_key=True)
    exams = models.ManyToManyField(StudentExam)


class ExamExecution(models.Model):
    lecturer = models.ForeignKey(
        "Lecturer", blank=True, null=True, on_delete=models.CASCADE
    )
    supervisorType = models.CharField(max_length=200, null=True)
    location = models.CharField(max_length=200, null=True)
    subjectIds = models.ManyToManyField(Subject)
    partialExam = models.ForeignKey(
        "PartialExam", blank=True, null=True, on_delete=models.SET_NULL
    )

    class Meta:
        ordering = ("partialExam__exam__date", "partialExam__exam__time")




# @dataclass()
# class API_ExamDataSet_ForStudent(models.Model):
#     date: dt.date
#     time: dt.time
#     weekday: str
#     room: str | None
#     location: str | None
#     subjectIdent: str | None
#     examIdent: str | None
#     examStudCount: int | None
#     supervisor: str
#     studMartNr: str | None
    
#     def to_dict(self):
#         return asdict(self)

        
class API_ExamDataSet_ForStudent(models.Model):
    date = models.DateField(blank=True, null=True)
    time = models.TimeField(blank=True, null=True)
    weekday = models.CharField(max_length=200, null=True)
    room = models.CharField(max_length=200, null=True)
    location = models.CharField(max_length=200, null=True)
    subjectIdent = models.CharField(max_length=200, null=True)
    examIdent = models.CharField(max_length=200, null=True)
    examStudCount = models.CharField(max_length=200, null=True)
    supervisor = models.CharField(max_length=200, null=True)
    studMartNr = models.CharField(max_length=200, null=True)
    
    def to_dict(self):
        return asdict(self)

        
        
@dataclass(order=True)
class ExamLines:
    sort_index: dt.datetime = field(init=False)
    date: dt.date
    time: dt.time
    weekday: str
    location: str | None
    subjectIds: list[Subject] | None
    examIdent: str | None
    examStudCound: int | None
    supervisorType: str
    executionSet: list | None
    partialExamIdent: str | None

    def __post_init__(self):
        self.sort_index = dt.datetime.combine(self.date, self.time)


def sort_and_group_datetime(examLines: list):

    examLine_Datetime_Groups = {}
    for examLine in examLines:
        if examLine.sort_index not in examLine_Datetime_Groups:
            examLine_Datetime_Groups[examLine.sort_index] = []
        examLine_Datetime_Groups[examLine.sort_index].append(examLine)

    sorted_groups = sorted(examLine_Datetime_Groups.items(), key=lambda x: x[0])

    sorted_result = []
    for _, group in sorted_groups:
        sorted_result.extend(group)

    return sorted_result