package handlers

import (
	"fmt"
	"net/http"
	"strconv"

	"ezops/internal/models"

	"github.com/gin-gonic/gin"
	"golang.org/x/crypto/bcrypt"
)

// ListUsers 获取用户列表
// @Summary 获取用户列表
// @Description 获取所有用户列表（管理员）
// @Tags 用户
// @Produce json
// @Security Bearer
// @Param page query int false "页码"
// @Param page_size query int false "每页数量"
// @Param keyword query string false "搜索关键词"
// @Success 200 {object} models.Response{data=models.ListResponse}
// @Router /users [get]
func (h *UserHandler) ListUsers(c *gin.Context) {
	var query models.PageQuery
	if err := c.ShouldBindQuery(&query); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误",
		})
		return
	}

	db := h.db.Model(&models.User{})
	if query.Keyword != "" {
		db = db.Where("username LIKE ? OR email LIKE ? OR real_name LIKE ?",
			"%"+query.Keyword+"%", "%"+query.Keyword+"%", "%"+query.Keyword+"%")
	}

	var total int64
	db.Count(&total)

	var users []models.User
	db.Preload("Roles").Offset(query.GetOffset()).Limit(query.GetLimit()).Find(&users)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data: models.ListResponse{
			List:  users,
			Total: total,
		},
	})
}

// GetUser 获取用户详情
// @Summary 获取用户详情
// @Description 获取指定用户的详细信息
// @Tags 用户
// @Produce json
// @Security Bearer
// @Param id path int true "用户ID"
// @Success 200 {object} models.Response{data=models.User}
// @Router /users/{id} [get]
func (h *UserHandler) GetUser(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var user models.User
	if err := h.db.Preload("Roles").First(&user, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "用户不存在",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data:    user,
	})
}

// CreateUser 创建用户
// @Summary 创建用户
// @Description 创建新用户（管理员）
// @Tags 用户
// @Accept json
// @Produce json
// @Security Bearer
// @Param request body models.CreateUserRequest true "创建请求"
// @Success 200 {object} models.Response{data=models.User}
// @Router /users [post]
func (h *UserHandler) CreateUser(c *gin.Context) {
	var req models.CreateUserRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	// 检查用户名是否已存在
	var existingUser models.User
	if err := h.db.Where("username = ?", req.Username).First(&existingUser).Error; err == nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "用户名已存在",
		})
		return
	}

	// 加密密码
	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
	if err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "密码加密失败",
		})
		return
	}

	user := models.User{
		Username: req.Username,
		Password: string(hashedPassword),
		Email:    req.Email,
		Phone:    req.Phone,
		RealName: req.RealName,
		Status:   1,
	}

	if err := h.db.Create(&user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "创建用户失败",
		})
		return
	}

	// 关联角色
	if len(req.RoleIDs) > 0 {
		var roles []models.Role
		h.db.Find(&roles, req.RoleIDs)
		h.db.Model(&user).Association("Roles").Append(roles)
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "创建成功",
		Data:    user,
	})
}

// UpdateUser 更新用户
// @Summary 更新用户
// @Description 更新指定用户信息（管理员）
// @Tags 用户
// @Accept json
// @Produce json
// @Security Bearer
// @Param id path int true "用户ID"
// @Param request body models.UpdateUserRequest true "更新请求"
// @Success 200 {object} models.Response{data=models.User}
// @Router /users/{id} [put]
func (h *UserHandler) UpdateUser(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var req models.UpdateUserRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	var user models.User
	if err := h.db.First(&user, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "用户不存在",
		})
		return
	}

	updates := map[string]interface{}{}
	if req.Email != "" {
		updates["email"] = req.Email
	}
	if req.Phone != "" {
		updates["phone"] = req.Phone
	}
	if req.RealName != "" {
		updates["real_name"] = req.RealName
	}
	if req.Status != nil {
		updates["status"] = *req.Status
	}

	if err := h.db.Model(&user).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "更新失败",
		})
		return
	}

	// 更新角色
	if len(req.RoleIDs) > 0 {
		var roles []models.Role
		h.db.Find(&roles, req.RoleIDs)
		h.db.Model(&user).Association("Roles").Replace(roles)
	}

	h.db.Preload("Roles").First(&user, id)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "更新成功",
		Data:    user,
	})
}

// DeleteUser 删除用户
// @Summary 删除用户
// @Description 删除指定用户（管理员）
// @Tags 用户
// @Produce json
// @Security Bearer
// @Param id path int true "用户ID"
// @Success 200 {object} models.Response
// @Router /users/{id} [delete]
func (h *UserHandler) DeleteUser(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	if err := h.db.Delete(&models.User{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "删除失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "删除成功",
	})
}

// BatchImportUsers 批量导入用户
// POST /api/v1/admin/users/batch-import
func (h *UserHandler) BatchImportUsers(c *gin.Context) {
	var req struct {
		Users []struct {
			Username string `json:"username"`
			Nickname string `json:"nickname"`
			Email    string `json:"email"`
			Phone    string `json:"phone"`
			Password string `json:"password"`
			Role     string `json:"role"`
		} `json:"users"`
		SkipExisting bool `json:"skip_existing"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	imported := 0
	skipped := 0
	var errors []string

	for i, u := range req.Users {
		if u.Username == "" {
			errors = append(errors, fmt.Sprintf("第%d行: 用户名为空", i+1))
			continue
		}
		// Check if exists
		var existing models.User
		if err := h.db.Where("username = ?", u.Username).First(&existing).Error; err == nil {
			if req.SkipExisting {
				skipped++
				continue
			}
			errors = append(errors, fmt.Sprintf("第%d行: 用户 %s 已存在", i+1, u.Username))
			skipped++
			continue
		}

		// Default password
		pwd := u.Password
		if pwd == "" {
			pwd = "admin123"
		}
		hashed, err := bcrypt.GenerateFromPassword([]byte(pwd), bcrypt.DefaultCost)
		if err != nil {
			errors = append(errors, fmt.Sprintf("第%d行: 密码加密失败", i+1))
			continue
		}

		user := models.User{
			Username:   u.Username,
			Password:   string(hashed),
			Email:      u.Email,
			Phone:      u.Phone,
			RealName:   u.Nickname,
			Status:     1,
			AuthSource: "local",
		}
		if err := h.db.Create(&user).Error; err != nil {
			errors = append(errors, fmt.Sprintf("第%d行: 创建用户 %s 失败", i+1, u.Username))
			continue
		}
		imported++
	}

	msg := fmt.Sprintf("导入完成: %d 成功, %d 跳过", imported, skipped)
	if len(errors) > 0 {
		msg += fmt.Sprintf(", %d 个错误", len(errors))
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: msg,
		Data: gin.H{
			"imported": imported,
			"skipped":  skipped,
			"errors":   errors,
		},
	})
}

// ImportTemplate 下载导入模板
// （已有实现，在文件末尾追加 ListRoles）

// ListRoles 获取角色列表（供前端下拉选择） // Logan.Li
func (h *UserHandler) ListRoles(c *gin.Context) {
	var roles []models.Role
	h.db.Where("status = ?", 1).Order("id ASC").Find(&roles)
	c.JSON(http.StatusOK, models.Response{
		Code: 200, Data: models.ListResponse{List: roles, Total: int64(len(roles))},
	})
}
// GET /api/v1/admin/users/import-template
func (h *UserHandler) ImportTemplate(c *gin.Context) {
	// UTF-8 BOM for Excel compatibility
	bom := "\xEF\xBB\xBF"
	csv := bom + "用户名,昵称,邮箱,手机号,角色,密码\n"
	csv += "zhangsan,张三,zhangsan@example.com,13800138000,developer,123456\n"
	csv += "lisi,李四,lisi@example.com,13800138001,developer,123456\n"

	c.Header("Content-Type", "text/csv; charset=utf-8")
	c.Header("Content-Disposition", "attachment; filename=users_import_template.csv")
	c.String(http.StatusOK, csv)
}