import {
  createExam,
  getAllExams,
  getExamById,
  updateExam,
  deleteExam,
  getLastExam, // 添加这一行
} from "../db/exam.js";

/**
 * 服务层：创建考试
 * @param {Object} examData 考试数据
 * @returns {Promise<Object>} 创建的考试
 */
export async function createNewExam(examData) {
  try {
    // 数据验证 - 修改为exam_minutes和exam_minutes_min必填
    if (!examData.exam_minutes || !examData.exam_minutes_min) {
      throw new Error("考试时长和最少考试时间为必填项");
    }

    // 移除默认值设置，因为现在是必填项
    if (typeof examData.exam_minutes_min !== "number") {
      throw new Error("最少考试时间必须是数字");
    }

    // 确保最少考试时间不大于考试时长
    if (examData.exam_minutes_min > examData.exam_minutes) {
      throw new Error("最少考试时间不能大于考试时长");
    }

    return await createExam(examData);
  } catch (error) {
    console.error("服务层: 创建考试失败", error);
    throw error;
  }
}

/**
 * 服务层：查询所有考试
 * @returns {Promise<Array>} 考试列表
 */
export async function fetchAllExams() {
  try {
    return await getAllExams();
  } catch (error) {
    console.error("服务层: 查询所有考试失败", error);
    throw error;
  }
}

/**
 * 服务层：根据ID查询考试
 * @param {number} id 考试ID
 * @returns {Promise<Object|null>} 考试数据
 */
export async function fetchExamById(id) {
  try {
    if (!id) {
      throw new Error("考试ID不能为空");
    }

    const exam = await getExamById(id);
    if (!exam) {
      throw new Error("未找到指定考试");
    }

    return exam;
  } catch (error) {
    console.error("服务层: 根据ID查询考试失败", error);
    throw error;
  }
}

/**
 * 服务层：更新考试
 * @param {number} id 考试ID
 * @param {Object} examData 更新的数据
 * @returns {Promise<boolean>} 是否更新成功
 */
export async function modifyExam(id, examData) {
  try {
    if (!id) {
      throw new Error("考试ID不能为空");
    }

    // 验证考试是否存在
    const existingExam = await getExamById(id);
    if (!existingExam) {
      throw new Error("未找到指定考试");
    }

    // 数据验证 - 修改为exam_minutes和exam_minutes_min必填
    if (!examData.exam_minutes || !examData.exam_minutes_min) {
      throw new Error("考试时长和最少考试时间为必填项");
    }

    // 移除默认值设置，因为现在是必填项
    if (typeof examData.exam_minutes_min !== "number") {
      throw new Error("最少考试时间必须是数字");
    }

    // 确保最少考试时间不大于考试时长
    if (examData.exam_minutes_min > examData.exam_minutes) {
      throw new Error("最少考试时间不能大于考试时长");
    }

    return await updateExam(id, examData);
  } catch (error) {
    console.error("服务层: 更新考试失败", error);
    throw error;
  }
}

/**
 * 服务层：删除考试
 * @param {number} id 考试ID
 * @returns {Promise<boolean>} 是否删除成功
 */
export async function removeExam(id) {
  try {
    if (!id) {
      throw new Error("考试ID不能为空");
    }

    // 验证考试是否存在
    const existingExam = await getExamById(id);
    if (!existingExam) {
      throw new Error("未找到指定考试");
    }

    return await deleteExam(id);
  } catch (error) {
    console.error("服务层: 删除考试失败", error);
    throw error;
  }
}

/**
 * 服务层：查询ID最大的考试记录
 * @returns {Promise<Object|null>} 考试数据
 */
export async function fetchLastExam() {
  try {
    return await getLastExam();
  } catch (error) {
    console.error("服务层: 查询ID最大的考试失败", error);
    throw error;
  }
}

export async function initExamIpc(ipcMain) {
  // 考试管理相关IPC
  ipcMain.handle("exam-create", async (event, examData) => {
    try {
      // 确保exam_notice是序列化的JSON字符串
      if (examData.exam_notice && typeof examData.exam_notice === "object") {
        examData.exam_notice = JSON.stringify(examData.exam_notice);
      }
      return await createNewExam(examData);
    } catch (error) {
      console.error("Failed to create exam:", error);
      throw error;
    }
  });

  ipcMain.handle("exam-update", async (event, { id, examData }) => {
    try {
      // 确保exam_notice是序列化的JSON字符串
      if (examData.exam_notice && typeof examData.exam_notice === "object") {
        examData.exam_notice = JSON.stringify(examData.exam_notice);
      }
      return await modifyExam(id, examData);
    } catch (error) {
      console.error("Failed to update exam:", error);
      throw error;
    }
  });

  ipcMain.handle("exam-fetch-last", async () => {
    try {
      const exam = await fetchLastExam();
      // 将exam_notice字符串解析为数组
      if (exam && exam.exam_notice) {
        try {
          exam.exam_notice = JSON.parse(exam.exam_notice);
        } catch (e) {
          console.error("解析考试须知失败:", e);
          exam.exam_notice = [];
        }
      }
      return exam;
    } catch (error) {
      console.error("Failed to fetch last exam:", error);
      throw error;
    }
  });

  ipcMain.handle("exam-fetch-all", async () => {
    try {
      return { success: true, data: await fetchAllExams() };
    } catch (error) {
      console.error("Failed to fetch all exams:", error);
      return { success: false, error: error.message };
    }
  });

  ipcMain.handle("exam-fetch-last", async () => {
    try {
      return { success: true, data: await fetchLastExam() };
    } catch (error) {
      console.error("Failed to fetch last exam:", error);
      return { success: false, error: error.message };
    }
  });

  ipcMain.handle("exam-fetch-by-id", async (event, id) => {
    try {
      return { success: true, data: await fetchExamById(id) };
    } catch (error) {
      console.error(`Failed to fetch exam by id ${id}:`, error);
      return { success: false, error: error.message };
    }
  });

  ipcMain.handle("exam-update", async (event, { id, examData }) => {
    try {
      const result = await modifyExam(id, examData);
      return { success: result, data: { id, ...examData } };
    } catch (error) {
      console.error(`Failed to update exam ${id}:`, error);
      return { success: false, error: error.message };
    }
  });

  ipcMain.handle("exam-delete", async (event, id) => {
    try {
      const result = await removeExam(id);
      return { success: result, data: { id } };
    } catch (error) {
      console.error(`Failed to delete exam ${id}:`, error);
      return { success: false, error: error.message };
    }
  });
}