Create new service for cryptocurrency price monitoring

services/price_monitor.go

@@ -0,0 +1,68 @@
+package services
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"sync"
+	"time"
+)
+
+type PriceMonitor struct {
+	apiKey     string
+	httpClient *http.Client
+	prices     sync.Map
+}
+
+type CoinGeckoPrice struct {
+	Bitcoin struct {
+		USD float64 `json:"usd"`
+	} `json:"bitcoin"`
+	Ethereum struct {
+		USD float64 `json:"ethereum"`
+	} `json:"ethereum"`
+}
+
+func NewPriceMonitor(apiKey string) *PriceMonitor {
+	return &PriceMonitor{
+		apiKey: apiKey,
+		httpClient: &http.Client{
+			Timeout: 10 * time.Second,
+		},
+	}
+}
+
+func (pm *PriceMonitor) StartMonitoring(checkInterval time.Duration) {
+	ticker := time.NewTicker(checkInterval)
+	go func() {
+		for range ticker.C {
+			pm.updatePrices()
+		}
+	}()
+}
+
+func (pm *PriceMonitor) updatePrices() error {
+	url := fmt.Sprintf("https://api.coingecko.com/api/v3/simple/price?ids=bitcoin,ethereum&vs_currencies=usd")
+	resp, err := pm.httpClient.Get(url)
+	if err != nil {
+		return fmt.Errorf("failed to fetch prices: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var prices CoinGeckoPrice
+	if err := json.NewDecoder(resp.Body).Decode(&prices); err != nil {
+		return fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	pm.prices.Store("BTC", prices.Bitcoin.USD)
+	pm.prices.Store("ETH", prices.Ethereum.USD)
+	return nil
+}
+
+func (pm *PriceMonitor) GetPrice(cryptoID string) (float64, error) {
+	price, ok := pm.prices.Load(cryptoID)
+	if !ok {
+		return 0, fmt.Errorf("price not available for %s", cryptoID)
+	}
+	return price.(float64), nil
+}