package webhook

// TikTok Gin webhook adapter — bridges HTTP requests from the Gin router
// to the TikTok channel package's WebhookHandler and IncomingProcessor.
// Reference: Facebook webhook adapter pattern (facebook_webhook.go)

import (
	"encoding/json"
	"io"
	"net/http"
	"strconv"

	tiktokchannel "github.com/gochat/gochat/internal/channel/tiktok"
	"github.com/gochat/gochat/internal/model"
	applogger "github.com/gochat/gochat/pkg/logger"

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

// TikTokWebhookHandler adapts TikTok webhook handling to Gin HTTP requests.
type TikTokWebhookHandler struct {
	tiktokWebhook *tiktokchannel.WebhookHandler
	pipeline      *tiktokchannel.IncomingProcessor
	db            *gorm.DB
}

// NewTikTokWebhookHandler creates a Gin-compatible TikTok webhook handler.
func NewTikTokWebhookHandler(tiktokWebhook *tiktokchannel.WebhookHandler, pipeline *tiktokchannel.IncomingProcessor, db *gorm.DB) *TikTokWebhookHandler {
	return &TikTokWebhookHandler{
		tiktokWebhook: tiktokWebhook,
		pipeline:      pipeline,
		db:            db,
	}
}

// HandleTikTokWebhook processes incoming TikTok webhook HTTP requests.
func (h *TikTokWebhookHandler) HandleTikTokWebhook(c *gin.Context) {
	inboxIDStr := c.Param("inbox_id")
	inboxID, err := strconv.ParseUint(inboxIDStr, 10, 32)
	if err != nil {
		applogger.L().Warnf("TikTok webhook: invalid inbox_id %s", inboxIDStr)
		c.JSON(http.StatusOK, gin.H{"status": "ignored"})
		return
	}

	// Lookup inbox from database
	inbox, err := h.lookupInbox(uint(inboxID))
	if err != nil {
		applogger.L().Warnf("TikTok webhook: inbox lookup failed for id %d: %v", inboxID, err)
		c.JSON(http.StatusOK, gin.H{"status": "ignored"})
		return
	}

	// Parse the webhook event using the channel-level handler
	event, err := h.tiktokWebhook.HandleWebhookRequest(c.Request)
	if err != nil {
		applogger.L().Errorf("TikTok webhook: parse request failed for inbox %d: %v", inboxID, err)
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}

	// Process the event via the pipeline
	if err := h.pipeline.ProcessUpdate(c.Request.Context(), inbox, *event); err != nil {
		applogger.L().Errorf("TikTok webhook: process event failed for inbox %d: %v", inboxID, err)
		c.JSON(http.StatusOK, gin.H{"status": "ignored"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"status": "processed"})
}

// HandleTikTokVerification handles TikTok webhook verification (challenge-response).
func (h *TikTokWebhookHandler) HandleTikTokVerification(c *gin.Context) {
	inboxIDStr := c.Param("inbox_id")
	inboxID, err := strconv.ParseUint(inboxIDStr, 10, 32)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid inbox_id"})
		return
	}

	body, err := io.ReadAll(c.Request.Body)
	if err != nil {
		c.JSON(http.StatusUnprocessableEntity, gin.H{"error": "failed to read body"})
		return
	}
	defer c.Request.Body.Close()

	// Parse verification challenge
	var verifyReq map[string]interface{}
	if err := json.Unmarshal(body, &verifyReq); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid JSON"})
		return
	}

	challenge, _ := verifyReq["challenge"].(string)
	applogger.L().Infof("TikTok webhook verification: inbox=%d challenge=%s", inboxID, challenge)

	c.JSON(http.StatusOK, gin.H{"challenge": challenge})
}

// lookupInbox fetches an Inbox record from the database.
func (h *TikTokWebhookHandler) lookupInbox(inboxID uint) (*model.Inbox, error) {
	var inbox model.Inbox
	if err := h.db.Where("id = ?", inboxID).First(&inbox).Error; err != nil {
		return nil, err
	}
	return &inbox, nil
}

// parseChannelConfig parses the JSON-encoded ChannelConfig string into a map.
func (h *TikTokWebhookHandler) parseChannelConfig(inbox *model.Inbox) map[string]interface{} {
	if inbox.ChannelConfig == "" {
		return map[string]interface{}{}
	}
	var config map[string]interface{}
	if err := json.Unmarshal([]byte(inbox.ChannelConfig), &config); err != nil {
		applogger.L().Warnf("TikTok: Failed to parse ChannelConfig for inbox %d: %v", inbox.ID, err)
		return map[string]interface{}{}
	}
	return config
}