TechHelper/TechHelper.Client/Pages/Exam/ExamCheck.razor

@using Entities.DTO
@using TechHelper.Client.Exam
@using TechHelper.Client.Services
@page "/exam/check/{ExamID}"


<MudText Typo="Typo.h4" Class="mb-4">试卷批改预览: @Assignment.Title</MudText>
<MudDivider Class="my-4" />

@if (_isLoading)
{
    <MudProgressCircular Indeterminate="true" Color="Color.Primary" Class="d-flex justify-center my-8" />
    <MudText Class="text-center">正在加载试卷和学生数据...</MudText>
}
else if (_questionsForTable.Any() && _students.Any())
{
    <MudTable @ref="_table" T="QuestionRowData" Items="@_questionsForTable" Hover="true" Breakpoint="Breakpoint.Sm" Class="mud-elevation-2" Dense="true">
        <HeaderContent>
            <MudTh Style="width:100px;">序号</MudTh>
            <MudTh Style="width:80px; text-align:center;">分值</MudTh>
            @foreach (var student in _students)
            {
                <MudTh Style="width:120px; text-align:center;">
                    @student.Name
                    <MudTooltip Text="点击以切换此学生所有题目的对错">
                        <MudIconButton Icon="@Icons.Material.Filled.Info" Size="Size.Small" Class="ml-1"
                                       @onclick="() => ToggleStudentAllAnswers(student.Id)" />
                    </MudTooltip>
                </MudTh>
            }
        </HeaderContent>
        <RowTemplate>
            <MudTd DataLabel="序号">@context.QuestionItem.Sequence</MudTd>
            <MudTd DataLabel="分值" Style="text-align:center;">@context.QuestionItem.Score</MudTd>
            @foreach (var student in _students)
            {
                <MudTd DataLabel="@student.Name" Style="text-align:center;">
                    @if (context.StudentAnswers.ContainsKey(student.Id))
                    {
                        <MudCheckBox @bind-Value="context.StudentAnswers[student.Id]" Size="Size.Small" Color="Color.Primary"></MudCheckBox>
                    }
                    else
                    {
                        <MudText Color="Color.Warning">N/A</MudText>
                    }
                </MudTd>
            }
        </RowTemplate>
        <PagerContent>
            <MudTablePager />
        </PagerContent>
    </MudTable>

    <MudPaper Class="pa-4 mt-4 mud-elevation-2 d-flex flex-column align-end">
        <MudText Typo="Typo.h6">学生总分预览:</MudText>
        @foreach (var student in _students)
        {
            <MudText Typo="Typo.subtitle1">
                @student.Name: <MudText Typo="Typo.h5" Color="Color.Primary" Class="d-inline-block ml-2">@GetStudentTotalScore(student.Id)</MudText>
            </MudText>
        }
        <MudButton Variant="Variant.Filled" Color="Color.Success" Class="mt-4" @onclick="SubmitGrading">
            提交批改结果 (模拟)
        </MudButton>
    </MudPaper>

}
else
{
    <MudAlert Severity="Severity.Info" Class="mt-4">无法加载试卷或题目信息。</MudAlert>
    <MudButton Variant="Variant.Text" Color="Color.Primary" Class="mt-4" >返回试卷列表</MudButton>
}


@code {
    [Parameter]
    public string ExamId { get; set; } 

    [Inject]
    public IExamService ExamService { get; set; } 

    [Inject]
    private ISnackbar Snackbar { get; set; } 

    [Inject]
    private NavigationManager Navigation { get; set; } 

    private MudTable<QuestionRowData> _table = new(); 
    private AssignmentDto Assignment { get; set; } = new AssignmentDto(); 
    private ExamStruct _examStruct = new ExamStruct();

    private List<Student> _students = new List<Student>(); 
    private List<QuestionRowData> _questionsForTable = new List<QuestionRowData>();

    private bool _isLoading = true;


    protected override async Task OnInitializedAsync()
    {
        _isLoading = true;
        await LoadExamData();
        GenerateTemporaryStudentsAndAnswers(); 
        _isLoading = false;
    }


    private async Task LoadExamData()
    {
        if (Guid.TryParse(ExamId, out Guid parsedExamId))
        {
            try
            {
                var result = await ExamService.GetExam(parsedExamId);
                if (result.Status)
                {
                    Assignment = result.Result as AssignmentDto ?? new AssignmentDto();
                    _examStruct = Assignment.GetStruct();
                }
                else
                {
                    Snackbar?.Add($"获取试卷失败: {result.Message}", Severity.Error);
                    Navigation.NavigateTo("/exam/manager");
                }
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine($"获取试卷时发生错误: {ex.Message}");
                Snackbar?.Add($"获取试卷失败: {ex.Message}", Severity.Error);
                Navigation.NavigateTo("/exam/manager");
            }
        }
        else
        {
            Console.Error.WriteLine($"错误：路由参数 ExamId '{ExamId}' 不是一个有效的 GUID 格式。");
            Snackbar?.Add("无效的试卷ID，无法加载。", Severity.Error);
            Navigation.NavigateTo("/exam/manager");
        }
    }

    // 生成临时学生和作答数据
    private void GenerateTemporaryStudentsAndAnswers()
    {
        _students = new List<Student>();
        // 生成 40 个学生
        for (int i = 1; i <= 40; i++)
        {
            _students.Add(new Student { Name = $"学生{i}" });
        }

        _questionsForTable = _examStruct.Questions.Select(qItem =>
        {
            var rowData = new QuestionRowData
            {
                QuestionItem = qItem,
                StudentAnswers = new Dictionary<Guid, bool>()
            };

            // 为每个学生随机生成初始的对错状态
            var random = new Random();
            foreach (var student in _students)
            {
                // 模拟随机对错，50%的概率
                rowData.StudentAnswers[student.Id] = random.Next(0, 2) == 1;
            }
            return rowData;
        }).ToList();
    }

    // 当某个学生的某个题目的作答状态改变时触发
    private void OnAnswerChanged(string questionSequence, Guid studentId, bool isCorrect)
    {
        // 可以在这里添加额外的逻辑，例如记录更改
        Console.WriteLine($"题目 {questionSequence}, 学生 {studentId} 的答案变为: {isCorrect}");
        // 由于是 @bind-Checked，数据模型已经自动更新，这里只是日志
    }

    // 计算某个学生的总分
    private float GetStudentTotalScore(Guid studentId)
    {
        float totalScore = 0;
        foreach (var row in _questionsForTable)
        {
            if (row.StudentAnswers.TryGetValue(studentId, out bool isCorrect) && isCorrect)
            {
                totalScore += row.QuestionItem.Score;
            }
        }
        return totalScore;
    }

    // 切换某个学生所有题目的对错状态 (用于快速批改)
    private void ToggleStudentAllAnswers(Guid studentId)
    {
        bool allCorrect = _questionsForTable.All(row => row.StudentAnswers.ContainsKey(studentId) && row.StudentAnswers[studentId]);

        foreach (var row in _questionsForTable)
        {
            if (row.StudentAnswers.ContainsKey(studentId))
            {
                row.StudentAnswers[studentId] = !allCorrect; // 全部取反
            }
        }
        StateHasChanged(); // 手动通知 Blazor 刷新 UI
    }

    // 提交批改结果（模拟）
    private void SubmitGrading()
    {
        Console.WriteLine("--- 提交批改结果 ---");
        foreach (var student in _students)
        {
            Console.WriteLine($"学生: {student.Name}, 总分: {GetStudentTotalScore(student.Id)}");
            foreach (var row in _questionsForTable)
            {
                if (row.StudentAnswers.TryGetValue(student.Id, out bool isCorrect))
                {
                    Console.WriteLine($"  - 题目 {row.QuestionItem.Sequence}: {(isCorrect ? "正确" : "错误")}");
                }
            }
        }
        Snackbar?.Add("批改结果已提交（模拟）", Severity.Success);
        // 实际应用中，这里会将 _questionsForTable 和 _students 的数据发送到后端API
    }
}