package handler

import (
	"accounting-app/internal/models"
	"accounting-app/internal/service"
	"accounting-app/pkg/api"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
)

type NotificationHandler struct {
	service *service.NotificationService
}

func NewNotificationHandler(service *service.NotificationService) *NotificationHandler {
	return &NotificationHandler{service: service}
}

// GetNotifications returns a list of notifications for the user
func (h *NotificationHandler) GetNotifications(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "10"))

	var isRead *bool
	if val, ok := c.GetQuery("is_read"); ok {
		parsedVal, err := strconv.ParseBool(val)
		if err == nil {
			isRead = &parsedVal
		}
	}

	notifications, total, err := h.service.GetNotifications(userID.(uint), page, limit, isRead)
	if err != nil {
		api.Error(c, http.StatusInternalServerError, "FETCH_ERROR", "Failed to fetch notifications")
		return
	}

	api.Success(c, gin.H{
		"notifications": notifications,
		"total":         total,
		"page":          page,
		"limit":         limit,
	})
}

// GetUnreadCount returns the number of unread notifications
func (h *NotificationHandler) GetUnreadCount(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	count, err := h.service.GetUnreadCount(userID.(uint))
	if err != nil {
		api.Error(c, http.StatusInternalServerError, "FETCH_ERROR", "Failed to count unread notifications")
		return
	}

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

// MarkAsRead marks a specific notification as read
func (h *NotificationHandler) MarkAsRead(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		api.Error(c, http.StatusBadRequest, "INVALID_ID", "Invalid notification ID")
		return
	}

	if err := h.service.MarkAsRead(uint(id), userID.(uint)); err != nil {
		api.Error(c, http.StatusInternalServerError, "UPDATE_ERROR", "Failed to mark as read")
		return
	}

	api.Success(c, gin.H{"message": "Marked as read"})
}

// MarkAllAsRead marks all notifications as read
func (h *NotificationHandler) MarkAllAsRead(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	if err := h.service.MarkAllAsRead(userID.(uint)); err != nil {
		api.Error(c, http.StatusInternalServerError, "UPDATE_ERROR", "Failed to mark all as read")
		return
	}

	api.Success(c, gin.H{"message": "All marked as read"})
}

// CreateNotificationRequest represents the request body for creating a notification (internal/admin use primarily)
type CreateNotificationRequest struct {
	Title   string `json:"title" binding:"required"`
	Content string `json:"content" binding:"required"`
	Type    string `json:"type" binding:"required"`
	Link    string `json:"link"`
}

// CreateNotification creates a new notification (For testing/admin purposes)
func (h *NotificationHandler) CreateNotification(c *gin.Context) {
	userID, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	var req CreateNotificationRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		api.Error(c, http.StatusBadRequest, "INVALID_REQUEST", "Invalid request")
		return
	}

	err := h.service.CreateNotification(
		userID.(uint),
		req.Title,
		req.Content,
		models.NotificationType(req.Type),
		req.Link,
	)
	if err != nil {
		api.Error(c, http.StatusInternalServerError, "CREATE_ERROR", "Failed to create notification")
		return
	}

	api.Success(c, gin.H{"message": "Notification created"})
}

// RegisterRoutes registers the notification routes
func (h *NotificationHandler) RegisterRoutes(r *gin.RouterGroup) {
	notifications := r.Group("/notifications")
	{
		notifications.GET("", h.GetNotifications)
		notifications.GET("/unread-count", h.GetUnreadCount)
		notifications.PUT("/:id/read", h.MarkAsRead)
		notifications.PUT("/read-all", h.MarkAllAsRead)
		notifications.POST("", h.CreateNotification) // Admin/Internal use
	}
}