from typing import Optional

from sqlalchemy.orm import Session

from app.application.course_students_repository import CourseStudentsRepository
from app.domain.entities.course_students_entity import CourseStudentEntity
from app.domain.models.course_students import CourseStudent


class CourseStudentsService:
    def __init__(self, db: Session):
        self.course_students_repository = CourseStudentsRepository(db)

    def get_all(self) -> list[CourseStudentEntity]:
        course_students = self.course_students_repository.get_all()
        return [
            CourseStudentEntity(
                id=course_student.id,
                enrollment_date=course_student.enrollment_date,
                is_finished=course_student.is_finished,
                course_id=course_student.course_id,
                user_id=course_student.user_id,
            ) for course_student in course_students
        ]

    def get_by_id(self, course_student_id: int) -> Optional[CourseStudentEntity]:
        course_student = self.course_students_repository.get_by_id(course_student_id)
        if course_student:
            return CourseStudentEntity(
                id=course_student.id,
                enrollment_date=course_student.enrollment_date,
                is_finished=course_student.is_finished,
                course_id=course_student.course_id,
                user_id=course_student.user_id,
            )

        return None

    def create(self, course_student: CourseStudentEntity) -> CourseStudentEntity:
        course_student_model = CourseStudent(
            enrollment_date=course_student.enrollment_date,
            is_finished=course_student.is_finished,
            course_id=course_student.course_id,
            user_id=course_student.user_id,
        )
        created_course_student = self.course_students_repository.create(course_student_model)
        return CourseStudentEntity(
            id=created_course_student.id,
            enrollment_date=created_course_student.enrollment_date,
            is_finished=created_course_student.is_finished,
            course_id=created_course_student.course_id,
            user_id=created_course_student.user_id,
        )

    def update(self, course_student_id: int, course_student: CourseStudentEntity) -> Optional[CourseStudentEntity]:
        course_student_model = self.course_students_repository.get_by_id(course_student_id)
        if course_student_model:
            course_student_model.enrollment_date = course_student.enrollment_date
            course_student_model.is_finished = course_student.is_finished
            course_student_model.course_id = course_student.course_id
            course_student_model.user_id = course_student.user_id
            updated_course_student = self.course_students_repository.update(course_student_model)
            return CourseStudentEntity(
                id=updated_course_student.id,
                enrollment_date=updated_course_student.enrollment_date,
                is_finished=updated_course_student.is_finished,
                course_id=updated_course_student.course_id,
                user_id=updated_course_student.user_id,
            )

        return None

    def delete(self, course_student_id: int) -> bool:
        return self.course_students_repository.delete(course_student_id) is not None