package v1

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

	"github.com/gin-gonic/gin"
	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/service"
)

// NotificationSubscriptionHandler handles notification subscription API endpoints.
// Reference: Chatwoot app/controllers/api/v1/notification_subscriptions_controller.rb
// Routes: resource :notification_subscriptions, only: [:create, :destroy]
type NotificationSubscriptionHandler struct {
	svc *service.NotificationSubscriptionService
}

func NewNotificationSubscriptionHandler(svc *service.NotificationSubscriptionService) *NotificationSubscriptionHandler {
	return &NotificationSubscriptionHandler{svc: svc}
}

// Create adds a new notification subscription.
// POST /api/v1/notification_subscriptions
// Chatwoot: requires identifier, subscription_attributes, subscription_type
func (h *NotificationSubscriptionHandler) Create(c *gin.Context) {
	userID := getUserID(c)
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
		return
	}

	var req service.CreateSubscriptionRequest
	if err := bindJSONWrappedOrRaw(c, "notification_subscription", &req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// Validate subscription_attributes based on type
	if err := service.ValidateSubscriptionAttributes(req.SubscriptionType, req.SubscriptionAttributes); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	sub, err := h.svc.Create(c.Request.Context(), userID, &req)
	if err != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, notificationSubscriptionPayloadFromModel(sub))
}

// Destroy removes a notification subscription.
// DELETE /api/v1/notification_subscriptions/:identifier
// Chatwoot: finds by identifier and deletes
func (h *NotificationSubscriptionHandler) Destroy(c *gin.Context) {
	userID := getUserID(c)
	if userID == 0 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
		return
	}

	pushToken := c.Query("push_token")
	if pushToken == "" {
		pushToken = c.Param("identifier")
	}
	if pushToken == "" {
		pushToken = c.PostForm("push_token")
	}
	if pushToken == "" && c.Request.Body != nil {
		var body struct {
			PushToken string `json:"push_token"`
		}
		_ = c.ShouldBindJSON(&body)
		pushToken = body.PushToken
	}

	_ = h.svc.Destroy(c.Request.Context(), userID, pushToken)
	c.Status(http.StatusOK)
}

type notificationSubscriptionDTO struct {
	ID                     uint            `json:"id"`
	Identifier             string          `json:"identifier"`
	SubscriptionAttributes json.RawMessage `json:"subscription_attributes"`
	SubscriptionType       string          `json:"subscription_type"`
	UserID                 uint            `json:"user_id"`
	CreatedAt              time.Time       `json:"created_at"`
	UpdatedAt              time.Time       `json:"updated_at"`
}

func notificationSubscriptionPayloadFromModel(sub *model.NotificationSubscription) notificationSubscriptionDTO {
	return notificationSubscriptionDTO{
		ID:                     sub.ID,
		Identifier:             sub.Identifier,
		SubscriptionAttributes: sub.SubscriptionAttributes,
		SubscriptionType:       sub.SubscriptionType.String(),
		UserID:                 sub.UserID,
		CreatedAt:              sub.CreatedAt,
		UpdatedAt:              sub.UpdatedAt,
	}
}