Improve team identifier handling

WebApp/Components/Pages/MeetingSchedulePages/Index.razor

@@ -155,19 +155,10 @@
 
                 <MudDivider Class="my-4" />
 
-                <MudText Typo="Typo.h4">Absent Students</MudText>
+                <StudentToggleSelector Students="@_students"
-                <MudToggleGroup T="Student"
+                                      @bind-SelectedStudents="_absentStudents"
-                                SelectionMode="SelectionMode.MultiSelection"
+                                      Title="Absent Students"
-                                @bind-Values="_absentStudents"
+                                      ShowFullName="true" />
-                                Vertical="true"
-                                CheckMark>
-                    @foreach (var student in _students.OrderBy(e => e.FirstName))
-                    {
-                        <MudToggleItem Value="@student" Style="font-size: .75rem;">
-                            @student.FirstNameLastName
-                        </MudToggleItem>
-                    }
-                </MudToggleGroup>
             </MudStack>
         </MudItem>
 

WebApp/Components/Pages/TeamPages/Create.razor

@@ -15,18 +15,45 @@
     <MudGrid>
         <MudItem xs="12" sm="7">
             <MudPaper Class="pa-4">
-                <MudSelect T="EventDefinition" @bind-Value="@Team.Event" Label="Event">
+                <MudSelect T="EventDefinition" Value="@Team.Event" ValueChanged="OnEventChanged" Label="Event">
 
                     @foreach (var evt in _events)
                     {
                         <MudSelectItem T="EventDefinition" Value="@(evt)"></MudSelectItem>
                     }
                 </MudSelect>
-                <MudTextField T="string?" Label="Number" @bind-Value="Team.Identifier" For="@(() => Team.Identifier)"></MudTextField>
+                @if (_existingTeams?.Count == 1)
+                {
+                    <MudAlert Severity="Severity.Info" Class="my-2">
+                        A team for @Team.Event.Name already exists. This will be team 2, and the existing team will become team 1.
+                    </MudAlert>
+                }
+                else if (_existingTeams?.Count >= 2)
+                {
+                    <MudAlert Severity="Severity.Error" Class="my-2">
+                        Two teams for @Team.Event.Name already exist. Cannot create a third team.
+                    </MudAlert>
+                }
 
+                <MudDivider Class="my-4" />
+
+                <StudentToggleSelector Students="@_students"
+                                      @bind-SelectedStudents="_selectedStudents"
+                                      Title="Students"
+                                      ShowFullName="true" />
+
+                <MudStack Class="mt-4">
+                    <TeamCaptainSelector Students="@_selectedStudents"
+                                        @bind-SelectedCaptain="Team.Captain"
+                                        Title="Captain" />
+                </MudStack>
             </MudPaper>
         </MudItem>
     </MudGrid>
+    @if (!string.IsNullOrEmpty(_errorMessage))
+    {
+        <MudAlert Severity="Severity.Error" Class="mt-3">@_errorMessage</MudAlert>
+    }
     <MudButton StartIcon="@Icons.Material.Filled.ArrowBack" Href="students">Back</MudButton>
     <MudButton StartIcon="@Icons.Material.Filled.Add" OnClick="AddTeam">Add</MudButton>
 </EditForm>
@@ -36,6 +63,10 @@
     private Team Team { get; set; } = new();
 
     private List<EventDefinition>? _events;
+    private List<Student> _students = [];
+    private IEnumerable<Student> _selectedStudents = [];
+    private string? _errorMessage;
+    private List<Team>? _existingTeams;
 
     protected override async Task OnInitializedAsync()
     {
@@ -43,11 +74,76 @@
             await Context.Events
                 .OrderBy(e => e.Name)
                 .ToListAsync();
+
+        _students = await Context.Students.ToListAsync();
+    }
+
+    private async Task OnEventChanged(EventDefinition selectedEvent)
+    {
+        Team.Event = selectedEvent;
+
+        // Clear any previous error messages
+        _errorMessage = null;
+
+        // Get all existing teams for this event
+        _existingTeams = await Context.Teams
+            .Include(t => t.Event)
+            .Where(t => t.Event.Id == selectedEvent.Id)
+            .ToListAsync();
     }
 
     private async Task AddTeam()
     {
-        Team.Identifier = Team.Event.Name;
+        // Clear previous error message
+        _errorMessage = null;
+
+        // Get current count of teams for this event
+        var existingTeamCount = await Context.Teams
+            .CountAsync(t => t.Event.Id == Team.Event.Id);
+
+        // Prohibit creation of third team
+        if (existingTeamCount >= 2)
+        {
+            _errorMessage = $"Cannot create a third team for {Team.Event.Name}. Maximum of 2 teams allowed.";
+            return;
+        }
+
+        // Handle automatic numbering based on event format
+        if (Team.Event.EventFormat == EventFormat.Individual && _selectedStudents.Count() == 1)
+        {
+            // For individual events, use student's first name as identifier
+            var student = _selectedStudents.First();
+            Team.Identifier = student.FirstName;
+            Team.Captain = student;
+        }
+        else if (existingTeamCount == 1)
+        {
+            // This is the second team - assign numbers
+            var existingTeam = await Context.Teams
+                .FirstOrDefaultAsync(t => t.Event.Id == Team.Event.Id);
+
+            if (existingTeam != null)
+            {
+                // Update existing team to number 1
+                existingTeam.Identifier = "1";
+                Context.Teams.Update(existingTeam);
+            }
+
+            // Set new team to number 2
+            Team.Identifier = "2";
+        }
+        else
+        {
+            // This is the first team - no number
+            Team.Identifier = null;
+        }
+
+        // Add selected students to the team
+        foreach (var student in _selectedStudents)
+        {
+            Team.Students.Add(student);
+        }
+
         Context.Teams.Add(Team);
 
         await Context.SaveChangesAsync();

WebApp/Components/Pages/TeamPages/Edit.razor

@@ -20,28 +20,15 @@ else
         <MudGrid>
             <MudItem xs="12" sm="7">
                 <MudPaper Class="pa-4">
-                    <MudSelect 
+                    <StudentToggleSelector Students="@_students"
-                        T="Student"
+                                          @bind-SelectedStudents="_selectedStudents"
-                        MultiSelection="true" 
+                                          Title="Students"
-                        @bind-SelectedValues="@_selectedStudents"
+                                          ShowFullName="true" />
-                        ToStringFunc="e => e.Name"
+                    <MudStack Class="mt-4">
-                        Label="Students">
+                        <TeamCaptainSelector Students="@_selectedStudents"
-
+                                            @bind-SelectedCaptain="Team.Captain"
-                        @foreach (var student in _students.OrderBy(e => e.FirstName))
+                                            Title="Captain" />
-                        {
-                            <MudSelectItem T="Student" Value="@student">@student.Name</MudSelectItem>
-                        }
-                    </MudSelect>
-                    <MudStack>
-                        <MudText>Captain</MudText>
-                        <MudToggleGroup T="Student" SelectionMode="SelectionMode.ToggleSelection" @bind-Value="Team.Captain" CheckMark>
-                            @foreach (var student in _selectedStudents.OrderBy(e => e.FirstName))
-                            {
-                                <MudToggleItem Value="@(student)" Text="@student.Name" />
-                            }
-                        </MudToggleGroup>
                     </MudStack>
-                    <MudTextField T="string?" Label="Identifier" @bind-Value="Team.Identifier" For="@(() => Team.Identifier)" Required="false" Clearable="true"></MudTextField>
                 </MudPaper>
             </MudItem>
         </MudGrid>
@@ -57,7 +44,7 @@ else
     [SupplyParameterFromForm]
     private Team? Team { get; set; }
 
-    private IEnumerable<Student> _selectedStudents = new HashSet<Student>();
+    private IEnumerable<Student> _selectedStudents = [];
     private List<Student> _students = [];
 
     protected override async Task OnInitializedAsync()
@@ -67,10 +54,7 @@ else
             .Include(e => e.Students)
             .FirstOrDefaultAsync(m => m.Id == Id);
         _students = await Context.Students.ToListAsync();
-        foreach (var s in Team.Students)
+        _selectedStudents = Team.Students.ToList();
-        {
-            ((HashSet<Student>)_selectedStudents).Add(s);
-        }
 
         if (Team is null)
         {
@@ -97,6 +81,13 @@ else
             Team.Students.Add(s);
         }
 
+        // Update identifier for individual events
+        if (Team.Event.EventFormat == EventFormat.Individual && Team.Students.Count == 1)
+        {
+            Team.Captain ??= Team.Students[0];
+            Team.Identifier = Team.Captain.FirstName;
+        }
+
         try
         {
             await Context.SaveChangesAsync();

WebApp/Components/Pages/TeamPages/Index.razor

@@ -83,6 +83,20 @@
 
         if (result == true)
         {
+            // If deleting a numbered team (1 or 2), clear the identifier of the remaining team
+            if (team.Identifier == "1" || team.Identifier == "2")
+            {
+                var remainingTeam = await Context.Teams
+                    .Include(t => t.Event)
+                    .FirstOrDefaultAsync(t => t.Event.Id == team.Event.Id && t.Id != team.Id);
+
+                if (remainingTeam != null)
+                {
+                    remainingTeam.Identifier = null;
+                    Context.Teams.Update(remainingTeam);
+                }
+            }
+
             Context.Teams.Remove(team!);
             await Context.SaveChangesAsync();
             Snackbar.Add($"Delete event: Delete of Team {team}", Severity.Info);

WebApp/Components/StudentToggleSelector.razor

@@ -0,0 +1,48 @@
+@if (Title != null)
+{
+    <MudText Typo="Typo.h4">@Title</MudText>
+}
+
+<MudToggleGroup T="Student"
+                SelectionMode="SelectionMode.MultiSelection"
+                Values="@SelectedStudents"
+                ValuesChanged="@OnSelectedStudentsChanged"
+                Vertical="true"
+                CheckMark>
+    @foreach (var student in Students.OrderBy(e => e.FirstName))
+    {
+        <MudToggleItem Value="@student" Style="font-size: .75rem;">
+            @if (ShowFullName)
+            {
+                @student.FirstNameLastName
+            }
+            else
+            {
+                @student.FirstName
+            }
+        </MudToggleItem>
+    }
+</MudToggleGroup>
+
+@code {
+    [Parameter]
+    public IEnumerable<Student> Students { get; set; } = [];
+
+    [Parameter]
+    public IEnumerable<Student> SelectedStudents { get; set; } = [];
+
+    [Parameter]
+    public EventCallback<IEnumerable<Student>> SelectedStudentsChanged { get; set; }
+
+    [Parameter]
+    public string? Title { get; set; }
+
+    [Parameter]
+    public bool ShowFullName { get; set; } = true;
+
+    private async Task OnSelectedStudentsChanged(IEnumerable<Student> value)
+    {
+        SelectedStudents = value;
+        await SelectedStudentsChanged.InvokeAsync(value);
+    }
+}

WebApp/Components/TeamCaptainSelector.razor

@@ -0,0 +1,38 @@
+@if (Title != null)
+{
+    <MudText Typo="@TitleTypo">@Title</MudText>
+}
+
+<MudToggleGroup T="Student"
+                SelectionMode="SelectionMode.ToggleSelection"
+                Value="@SelectedCaptain"
+                ValueChanged="@OnSelectedCaptainChanged"
+                CheckMark>
+    @foreach (var student in Students.OrderBy(e => e.FirstName))
+    {
+        <MudToggleItem Value="@student" Text="@student.Name" />
+    }
+</MudToggleGroup>
+
+@code {
+    [Parameter]
+    public IEnumerable<Student> Students { get; set; } = [];
+
+    [Parameter]
+    public Student? SelectedCaptain { get; set; }
+
+    [Parameter]
+    public EventCallback<Student?> SelectedCaptainChanged { get; set; }
+
+    [Parameter]
+    public string? Title { get; set; } = "Captain";
+
+    [Parameter]
+    public Typo TitleTypo { get; set; } = Typo.body1;
+
+    private async Task OnSelectedCaptainChanged(Student? value)
+    {
+        SelectedCaptain = value;
+        await SelectedCaptainChanged.InvokeAsync(value);
+    }
+}