package handler

import (
	"encoding/json"
	"log"
	"net/http"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/yourname/cyrene-ai/gateway/internal/config"
	"github.com/yourname/cyrene-ai/gateway/internal/ws"
)

// NotificationHandler 通知推送处理器
type NotificationHandler struct {
	cfg *config.Config
	hub *ws.Hub
}

// NewNotificationHandler 创建通知处理器
func NewNotificationHandler(cfg *config.Config, hub *ws.Hub) *NotificationHandler {
	return &NotificationHandler{cfg: cfg, hub: hub}
}

// PushNotificationRequest 推送通知请求体
type PushNotificationRequest struct {
	UserID string                 `json:"user_id" binding:"required"`
	Type   string                 `json:"type" binding:"required,oneof=info warning success thinking reminder"`
	Title  string                 `json:"title" binding:"required"`
	Body   string                 `json:"body" binding:"required"`
	Data   map[string]interface{} `json:"data,omitempty"`
}

// Push 推送通知到指定用户 (需要 JWT 认证)
// POST /api/v1/notifications/push
func (h *NotificationHandler) Push(c *gin.Context) {
	var req PushNotificationRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return
	}

	// 生成通知
	notif := h.buildNotification(req)

	// 序列化 WS 消息
	msg := ws.ServerMessage{
		Type:         "notification",
		MessageID:    "notif_" + generateID(),
		Timestamp:    time.Now().UnixMilli(),
		Notification: notif,
	}

	data, err := json.Marshal(msg)
	if err != nil {
		log.Printf("[notification] 序列化通知失败: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "内部错误"})
		return
	}

	// 通过 Hub 推送给指定用户
	h.hub.SendToUser(req.UserID, data)

	log.Printf("[notification] 通知已推送: user=%s type=%s title=%s", req.UserID, req.Type, req.Title)

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"notification": gin.H{
			"id":        notif.ID,
			"type":      notif.Type,
			"title":     notif.Title,
			"user_id":   req.UserID,
			"timestamp": notif.Timestamp,
			"delivered": h.hub.UserClientCount(req.UserID) > 0,
		},
	})
}

// InternalNotify 内部服务推送通知 (使用内部 service token)
// POST /api/v1/internal/notify
func (h *NotificationHandler) InternalNotify(c *gin.Context) {
	var req PushNotificationRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return
	}

	// 生成通知
	notif := h.buildNotification(req)

	// 序列化 WS 消息
	msg := ws.ServerMessage{
		Type:         "notification",
		MessageID:    "notif_" + generateID(),
		Timestamp:    time.Now().UnixMilli(),
		Notification: notif,
	}

	data, err := json.Marshal(msg)
	if err != nil {
		log.Printf("[notification] 序列化通知失败: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "内部错误"})
		return
	}

	// 通过 Hub 推送给指定用户
	h.hub.SendToUser(req.UserID, data)

	log.Printf("[notification] 内部通知已推送: user=%s type=%s title=%s", req.UserID, req.Type, req.Title)

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"notification": gin.H{
			"id":        notif.ID,
			"type":      notif.Type,
			"title":     notif.Title,
			"user_id":   req.UserID,
			"timestamp": notif.Timestamp,
			"delivered": h.hub.UserClientCount(req.UserID) > 0,
		},
	})
}

// InternalNotifyAuth 内部服务认证中间件
func (h *NotificationHandler) InternalNotifyAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		token := c.GetHeader("X-Internal-Token")
		if token == "" {
			token = c.GetHeader("Authorization")
			if len(token) > 7 && token[:7] == "Bearer " {
				token = token[7:]
			}
		}

		if token != h.cfg.InternalServiceToken {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "内部认证失败"})
			c.Abort()
			return
		}
		c.Next()
	}
}

// buildNotification 构建 NotificationInfo
func (h *NotificationHandler) buildNotification(req PushNotificationRequest) *ws.NotificationInfo {
	notifID := "notif_" + generateID()
	now := time.Now().UTC().Format(time.RFC3339)

	if req.Data == nil {
		req.Data = make(map[string]interface{})
	}

	return &ws.NotificationInfo{
		ID:        notifID,
		Type:      req.Type,
		Title:     req.Title,
		Body:      req.Body,
		Timestamp: now,
		Data:      req.Data,
	}
}