erp-platform/api/src/Kurs.Platform.Domain/VirtualClass/ClassSession.cs

using System;
using System.Collections.Generic;
using Volo.Abp.Domain.Entities.Auditing;

namespace Kurs.Platform.Entities;

public class ClassSession : FullAuditedEntity<Guid>
{
    public string Name { get; set; }
    public string Description { get; set; }
    public string Subject { get; set; }
    public Guid? TeacherId { get; set; }
    public string TeacherName { get; set; }
    public DateTime ScheduledStartTime { get; set; }
    public DateTime? ActualStartTime { get; set; }
    public DateTime? EndTime { get; set; }
    public int Duration { get; set; } // minutes
    public int MaxParticipants { get; set; }
    public bool IsActive { get; set; }
    public bool IsScheduled { get; set; }
    public int ParticipantCount { get; set; }

    public virtual ICollection<Participant> Participants { get; set; }
    public virtual ICollection<AttendanceRecord> AttendanceRecords { get; set; }
    public virtual ICollection<ChatMessage> ChatMessages { get; set; }

    protected ClassSession()
    {
        Participants = new HashSet<Participant>();
        AttendanceRecords = new HashSet<AttendanceRecord>();
        ChatMessages = new HashSet<ChatMessage>();
    }

    public ClassSession(
        Guid id,
        string name,
        string description,
        string subject,
        Guid? teacherId,
        string teacherName,
        DateTime scheduledStartTime,
        int duration,
        int maxParticipants
    ) : base(id)
    {
        Name = name;
        Description = description;
        Subject = subject;
        TeacherId = teacherId;
        TeacherName = teacherName;
        ScheduledStartTime = scheduledStartTime;
        Duration = duration;
        MaxParticipants = maxParticipants;
        IsActive = false;
        IsScheduled = true;
        ParticipantCount = 0;

        Participants = new HashSet<Participant>();
        AttendanceRecords = new HashSet<AttendanceRecord>();
        ChatMessages = new HashSet<ChatMessage>();
    }

    public void StartClass()
    {
        if (IsActive)
            throw new InvalidOperationException("Class is already active");

        IsActive = true;
        ActualStartTime = DateTime.UtcNow;
    }

    public void EndClass()
    {
        if (!IsActive)
            throw new InvalidOperationException("Class is not active");

        IsActive = false;
        EndTime = DateTime.UtcNow;
    }

    public bool CanJoin()
    {
        var now = DateTime.UtcNow;
        var tenMinutesBefore = ScheduledStartTime.AddMinutes(-10);
        var twoHoursAfter = ScheduledStartTime.AddHours(2);

        return now >= tenMinutesBefore && now <= twoHoursAfter && ParticipantCount < MaxParticipants;
    }
}