Create price alert service

Author: Jetlum

services/price_alert.go

@@ -0,0 +1,97 @@
+package services
+
+import (
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	"github.com/Jetlum/WalletAlertService/models"
+	"github.com/Jetlum/WalletAlertService/repository"
+)
+
+type PriceAlertService struct {
+	priceMonitor  *PriceMonitor
+	alertRepo     *repository.PriceAlertRepository
+	emailNotifier EmailNotifier
+}
+
+func NewPriceAlertService(
+	priceMonitor *PriceMonitor,
+	alertRepo *repository.PriceAlertRepository,
+	emailNotifier EmailNotifier,
+) *PriceAlertService {
+	return &PriceAlertService{
+		priceMonitor:  priceMonitor,
+		alertRepo:     alertRepo,
+		emailNotifier: emailNotifier,
+	}
+}
+
+func (s *PriceAlertService) StartMonitoring() {
+	ticker := time.NewTicker(1 * time.Minute)
+	go func() {
+		for range ticker.C {
+			s.checkAlerts()
+		}
+	}()
+}
+
+func (s *PriceAlertService) checkAlerts() {
+	alerts, err := s.alertRepo.GetActiveAlerts()
+	if err != nil {
+		log.Printf("Error fetching active alerts: %v", err)
+		return
+	}
+
+	for _, alert := range alerts {
+		price, err := s.priceMonitor.GetPrice(alert.CryptocurrencyID)
+		if err != nil {
+			log.Printf("Error getting price for %s: %v", alert.CryptocurrencyID, err)
+			continue
+		}
+
+		threshold, _ := strconv.ParseFloat(alert.ThresholdPrice, 64)
+		if s.shouldTriggerAlert(price, threshold, alert.IsUpperBound) {
+			s.triggerAlert(&alert, price)
+		}
+	}
+}
+
+func (s *PriceAlertService) shouldTriggerAlert(currentPrice, threshold float64, isUpperBound bool) bool {
+	if isUpperBound {
+		return currentPrice >= threshold
+	}
+	return currentPrice <= threshold
+}
+
+func (s *PriceAlertService) triggerAlert(alert *models.PriceAlert, currentPrice float64) {
+	message := fmt.Sprintf(
+		"Price Alert: %s has reached $%.2f (Threshold: $%s)",
+		alert.CryptocurrencyID,
+		currentPrice,
+		alert.ThresholdPrice,
+	)
+
+	if alert.EmailNotification {
+		// Create event for notification
+		event := &models.Event{
+			EventType: "PRICE_ALERT",
+			Value:     fmt.Sprintf("%.2f", currentPrice),
+		}
+
+		userPref := &models.UserPreference{
+			UserID:            alert.UserID,
+			EmailNotification: true,
+		}
+
+		if err := s.emailNotifier.Send(event, userPref); err != nil {
+			log.Printf("Failed to send price alert email: %v", err)
+		}
+	}
+
+	// Deactivate the alert after triggering
+	if err := s.alertRepo.DeactivateAlert(alert.ID); err != nil {
+		log.Printf("Failed to deactivate alert: %v", err)
+	}
+}