重构项目结构，移除Assignment相关功能，优化Submission模块

TechHelper.Server/Controllers/GradeController.cs

@@ -0,0 +1,144 @@
+using Entities.Contracts;
+using Entities.DTO;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.AspNetCore.Mvc;
+using System.Diagnostics;
+using System.Net;
+using System.Security.Claims;
+using TechHelper.Services.Beta;
+using TechHelper.Services;
+
+namespace TechHelper.Server.Controllers
+{
+    /// <summary>
+    /// 年级管理控制器
+    /// 处理年级相关的操作，如创建、更新、删除年级等
+    /// </summary>
+    [Route("api/grade")]
+    [ApiController]
+    public class GradeController : ControllerBase
+    {
+        private TechHelper.Services.Beta.IGradeService _gradeService;
+        private UserManager<User> _userManager;
+
+        /// <summary>
+        /// 初始化年级控制器
+        /// </summary>
+        /// <param name="gradeService">年级服务</param>
+        /// <param name="userManager">用户管理服务</param>
+        public GradeController(TechHelper.Services.Beta.IGradeService gradeService, UserManager<User> userManager)
+        {
+            _gradeService = gradeService;
+            _userManager = userManager;
+        }
+
+        #region 年级基本信息CRUD操作
+
+        /// <summary>
+        /// 获取年级列表（支持搜索）
+        /// </summary>
+        /// <param name="query">查询参数</param>
+        /// <returns>年级列表</returns>
+        /// <response code="200">成功获取年级列表</response>
+        /// <response code="400">获取失败</response>
+        [HttpGet]
+        [Authorize(Roles = "Teacher,Admin")]
+        public async Task<IActionResult> GetAll([FromQuery] QueryParameter query)
+        {
+            var result = await _gradeService.GetAllAsync(query);
+            
+            if (!result.Status)
+            {
+                return BadRequest(result.Message);
+            }
+
+            return Ok(result.Result);
+        }
+
+        /// <summary>
+        /// 根据ID获取年级详细信息
+        /// </summary>
+        /// <param name="id">年级ID</param>
+        /// <returns>年级详细信息</returns>
+        /// <response code="200">成功获取年级信息</response>
+        /// <response code="400">年级未找到或获取失败</response>
+        [HttpGet("{id}")]
+        [Authorize(Roles = "Teacher,Admin")]
+        public async Task<IActionResult> GetById(Guid id)
+        {
+            var result = await _gradeService.GetAsync(id);
+            
+            if (!result.Status)
+            {
+                return BadRequest(result.Message);
+            }
+
+            return Ok(result.Result);
+        }
+
+        /// <summary>
+        /// 创建新年级
+        /// </summary>
+        /// <param name="model">年级数据传输对象</param>
+        /// <returns>创建结果</returns>
+        /// <response code="200">创建成功</response>
+        /// <response code="400">创建失败</response>
+        [HttpPost]
+        public async Task<IActionResult> Create([FromBody] GradeDto model)
+        {
+            var result = await _gradeService.AddAsync(model);
+            
+            if (!result.Status)
+            {
+                return BadRequest(result.Message);
+            }
+
+            return Ok(result.Result);
+        }
+
+        /// <summary>
+        /// 更新年级信息
+        /// </summary>
+        /// <param name="model">年级数据传输对象</param>
+        /// <returns>更新结果</returns>
+        /// <response code="200">更新成功</response>
+        /// <response code="400">更新失败</response>
+        [HttpPut]
+        [Authorize(Roles = "Admin")]
+        public async Task<IActionResult> Update([FromBody] GradeDto model)
+        {
+            var result = await _gradeService.UpdateAsync(model);
+            
+            if (!result.Status)
+            {
+                return BadRequest(result.Message);
+            }
+
+            return Ok(result.Result);
+        }
+
+        /// <summary>
+        /// 删除年级
+        /// </summary>
+        /// <param name="id">年级ID</param>
+        /// <returns>删除结果</returns>
+        /// <response code="200">删除成功</response>
+        /// <response code="400">删除失败</response>
+        [HttpDelete("{id}")]
+        [Authorize(Roles = "Admin")]
+        public async Task<IActionResult> Delete(Guid id)
+        {
+            var result = await _gradeService.DeleteAsync(id);
+            
+            if (!result.Status)
+            {
+                return BadRequest(result.Message);
+            }
+
+            return Ok(result.Message);
+        }
+
+        #endregion
+    }
+}