package handler

import (
	"strconv"

	"github.com/gin-gonic/gin"

	"with_you/internal/dto"
	"with_you/internal/pkg/cursor"
	"with_you/internal/pkg/response"
	"with_you/internal/service"
)

// NotificationHandler 通知处理器
type NotificationHandler struct {
	notificationService *service.NotificationService
}

// NewNotificationHandler 创建通知处理器
func NewNotificationHandler(notificationService *service.NotificationService) *NotificationHandler {
	return &NotificationHandler{
		notificationService: notificationService,
	}
}

// GetNotifications 获取通知列表
func (h *NotificationHandler) GetNotifications(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	unreadOnly := c.Query("unread_only") == "true"

	notifications, total, err := h.notificationService.GetByUserID(c.Request.Context(), userID, page, pageSize, unreadOnly)
	if err != nil {
		response.InternalServerError(c, "failed to get notifications")
		return
	}

	response.Paginated(c, notifications, total, page, pageSize)
}

// MarkAsRead 标记为已读
func (h *NotificationHandler) MarkAsRead(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	id := c.Param("id")

	err := h.notificationService.MarkAsReadWithUserID(c.Request.Context(), id, userID)
	if err != nil {
		response.HandleError(c, err, "failed to mark as read")
		return
	}

	response.SuccessWithMessage(c, "marked as read", nil)
}

// MarkAllAsRead 标记所有为已读
func (h *NotificationHandler) MarkAllAsRead(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	err := h.notificationService.MarkAllAsRead(c.Request.Context(), userID)
	if err != nil {
		response.InternalServerError(c, "failed to mark all as read")
		return
	}

	response.SuccessWithMessage(c, "all marked as read", nil)
}

// GetUnreadCount 获取未读数量
func (h *NotificationHandler) GetUnreadCount(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	count, err := h.notificationService.GetUnreadCount(c.Request.Context(), userID)
	if err != nil {
		response.InternalServerError(c, "failed to get unread count")
		return
	}

	response.Success(c, gin.H{"count": count})
}

// DeleteNotification 删除通知
func (h *NotificationHandler) DeleteNotification(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	id := c.Param("id")

	err := h.notificationService.DeleteNotification(c.Request.Context(), id, userID)
	if err != nil {
		response.HandleError(c, err, "failed to delete notification")
		return
	}

	response.Success(c, gin.H{"success": true})
}

// ClearAllNotifications 清空所有通知
func (h *NotificationHandler) ClearAllNotifications(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	err := h.notificationService.ClearAllNotifications(c.Request.Context(), userID)
	if err != nil {
		response.InternalServerError(c, "failed to clear notifications")
		return
	}

	response.Success(c, gin.H{"success": true})
}

// GetNotificationsByCursor 游标分页获取通知列表
func (h *NotificationHandler) GetNotificationsByCursor(c *gin.Context) {
	userID := c.GetString("user_id")
	if userID == "" {
		response.Unauthorized(c, "")
		return
	}

	// 解析游标分页请求
	req := h.parseCursorRequest(c)

	unreadOnly := c.Query("unread_only") == "true"

	// 调用游标分页服务
	result, err := h.notificationService.GetNotificationsByCursor(c.Request.Context(), userID, unreadOnly, req)
	if err != nil {
		response.InternalServerError(c, "failed to get notifications")
		return
	}

	// 转换为响应结构
	notificationResponses := dto.ConvertNotificationsToResponse(result.Items)

	// 构建游标分页响应
	cursorResp := &dto.NotificationCursorPageResponse{
		Items:      notificationResponses,
		NextCursor: result.NextCursor,
		PrevCursor: result.PrevCursor,
		HasMore:    result.HasMore,
	}

	response.Success(c, cursorResp)
}

// parseCursorRequest 解析游标分页请求参数
func (h *NotificationHandler) parseCursorRequest(c *gin.Context) *cursor.PageRequest {
	cursorStr := c.Query("cursor")
	direction := cursor.Direction(c.DefaultQuery("direction", "forward"))
	pageSize, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))

	return cursor.NewPageRequest(cursorStr, direction, pageSize)
}