using System;
using System.Collections.Generic;
using System.Linq;
using Avalonia;
using Avalonia.Controls;
using Avalonia.Interactivity;
using Avalonia.Markup.Xaml;
using kursovaya.Models;
using kursovaya.ModelsLocal;

namespace kursovaya;

public partial class AddTeacher : Window
{
    List<DisciplinePresenter> _disciplinePresenters = new List<DisciplinePresenter>();
    Teacher _teacher = new Teacher();
    List<Teacher> _teachers = new List<Teacher>();
    
    List<DisciplineGroupTeacher> _disciplineGroupTeachers = new List<DisciplineGroupTeacher>();
    public AddTeacher()
    {
        InitializeComponent();
        using var ctx = new DatabaseContext();
        
        var disciplineTeachers = ctx.DisciplineTeachers.ToList();
        _disciplinePresenters = ctx.Disciplines.Select(it => new DisciplinePresenter()
        {
            Discipline = it,
        }).ToList();
        
        ListBoxDisciplineGroup.ItemsSource = _disciplinePresenters;
    }

    private void ButtonAdd_OnClick(object? sender, RoutedEventArgs e)
    {
        if (ListBoxDisciplineGroup.SelectedItems == null || 
            ListBoxDisciplineGroup.SelectedItems.Count == 0 || 
            string.IsNullOrWhiteSpace(TeacherNameTextBox?.Text))
        {
            ErrorMessage.Text = "Поля не должны быть пустыми!";
            return;
        }
        
        var ctx = new DatabaseContext();
        
        var teacherName = TeacherNameTextBox.Text;
        var selectedItems = ListBoxDisciplineGroup.SelectedItems.Cast<DisciplinePresenter>().ToList();
        int lastUserId = ctx.Users.Max(u => u.Id);
        int lastTeacherId = ctx.Teachers.Max(u => u.Id);
        
        var user = new User(){ Id = lastUserId + 1, Login = $"user{lastUserId+1}", Password = "qwerty", Email = $"user{lastUserId+1}@mail.ru", RoleId = 2};
        ctx.Users.Add(user);
        
        _teacher = new Teacher(){Id = lastTeacherId+1, Fio = teacherName, Login = $"user{lastUserId+1}"};
        _teachers.Add(_teacher);
        ctx.Teachers.Add(_teacher);
        
        foreach (var item in selectedItems)
        {
            var studentsId = ctx.Attestations.Where(it => it.IdDiscipline == item.Discipline.Id).Select(it => it.IdUser).ToList();
            foreach (var id in studentsId)
            {
                var groupId = ctx.Students
                    .Where(s => s.Id == id)
                    .Select(s => s.IdGroup)
                    .FirstOrDefault();

                var group = ctx.Groups.FirstOrDefault(g => g.Id == groupId);

                bool alreadyExists = _disciplineGroupTeachers.Any(dgt =>
                    dgt.Group.Id == group.Id &&
                    dgt.Discipline.Id == item.Discipline.Id &&
                    dgt.Teacher.Id == _teacher.Id);

                if (!alreadyExists)
                {
                    _disciplineGroupTeachers.Add(new DisciplineGroupTeacher()
                    {
                        Group = group,
                        Teacher = _teacher,
                        Discipline = item.Discipline
                    });
                }
            }
            
            var disc_teach = new DisciplineTeacher() { IdDiscipline = item.Discipline.Id, IdTeacher = lastTeacherId+1 };
            ctx.DisciplineTeachers.Add(disc_teach);
        }

        foreach (var item in _disciplineGroupTeachers)
        {
            Console.WriteLine($"Discipline: {item.Discipline.Name} Teacher: {item.Teacher.Fio} Group: {item.Group.Id}");
        }
        
        var changes = ctx.SaveChanges();
        
        if (changes > 0)
        {
            SuccessMessage.Text = "Учитель успешно добавлен!";
            if (ErrorMessage != null)
            {
                ErrorMessage.Text = "";
            }
        }
        else
        {
            ErrorMessage.Text = "Не удалось добавить учителя.";
            SuccessMessage.Text = "";
        }
    }
    
    private void ButtonBack_OnClick(object? sender, RoutedEventArgs e)
    {
        Result res = new Result(){Teachers = _teachers, DisciplineGroupTeachers = _disciplineGroupTeachers};
        
        Close(res);
    }
    
    public class DisciplinePresenter()
    {
        public Discipline Discipline { get; set; }
        public string DisciplineName
        {
            get => Discipline.Name;
        }
    }
}