package com.student.servlet.admin;

import com.student.service.ImportService;
import com.student.servlet.BaseServlet;
import com.student.util.IpUtil;
import com.student.util.ParamUtil;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 管理员 - 导入预览（G-03）
 */
@WebServlet("/admin/importPreview")
public class ImportPreviewServlet extends BaseServlet {

    private final ImportService importService = new ImportService();

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String batchId = ParamUtil.getString(request, "batchId");
        if (batchId.isEmpty()) {
            Object lastBatch = request.getSession().getAttribute("lastImportBatchId");
            if (lastBatch instanceof String && !((String) lastBatch).isEmpty()) {
                batchId = (String) lastBatch;
            }
        }
        if (batchId.isEmpty()) {
            request.setAttribute("msg", "请先上传 CSV 文件");
            request.getRequestDispatcher("/admin/user_upload.jsp").forward(request, response);
            return;
        }
        request.setAttribute("batchId", batchId);
        request.setAttribute("importList", importService.preview(batchId));
        request.getRequestDispatcher("/admin/import_preview.jsp").forward(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String batchId = ParamUtil.getString(request, "batchId");
        String action = ParamUtil.getString(request, "action");

        if (batchId.isEmpty()) {
            redirectWithMsg(response, request, "/admin/importPreview", "批次ID无效");
            return;
        }

        if ("confirm".equals(action)) {
            int count = importService.confirm(batchId);
            request.getSession().removeAttribute("lastImportBatchId");
            logOperation(getLoginUser(request), "admin", "确认导入:" + count + "条", IpUtil.getClientIp(request));
            redirectWithMsg(response, request, "/admin/userList", "成功导入 " + count + " 条记录");
        } else if ("cancel".equals(action)) {
            importService.rollback(batchId);
            request.getSession().removeAttribute("lastImportBatchId");
            redirectWithMsg(response, request, "/admin/importPreview", "已取消导入");
        } else {
            redirectWithMsg(response, request, "/admin/importPreview", "无效操作");
        }
    }
}