using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;

namespace LehrerApp.Data.Repositories;

public class StudentRepository(LiteDbContext db) : IStudentRepository
{
    public Student? GetById(Guid id) =>
        db.Students.FindById(id);

    public List<Student> GetAll(bool includeInactive = false) =>
        includeInactive
            ? db.Students.FindAll().OrderBy(s => s.LastName).ToList()
            : db.Students.Find(s => s.IsActive).OrderBy(s => s.LastName).ToList();

    public List<Student> GetByGroup(Guid groupId, string schoolYear)
    {
        // Enrollment als Bindeglied – Schüler-IDs der Gruppe ermitteln
        var studentIds = db.Enrollments
            .Find(e => e.GroupId == groupId && e.SchoolYear == schoolYear)
            .Select(e => e.StudentId)
            .ToHashSet();

        return db.Students
            .Find(s => studentIds.Contains(s.Id))
            .OrderBy(s => s.LastName)
            .ToList();
    }

    public void Save(Student student)
    {
        student.UpdatedAt = DateTime.UtcNow;
        db.Students.Upsert(student);
    }

    public void Delete(Guid id) =>
        db.Students.Delete(id);
}