Restructured

backend/go.mod

@@ -0,0 +1,3 @@
+module stock-analyzer
+
+go 1.21

backend/main.go

@@ -0,0 +1,180 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type StockPriceRequest struct {
+	Tickers []string `json:"tickers"`
+}
+
+type StockPrice struct {
+	Ticker  string  `json:"ticker"`
+	USD     float64 `json:"usd"`
+	EUR     float64 `json:"eur"`
+	Success bool    `json:"success"`
+	Error   string  `json:"error,omitempty"`
+}
+
+type StockPricesResponse struct {
+	Prices       map[string]StockPrice `json:"prices"`
+	ExchangeRate float64               `json:"exchangeRate"`
+}
+
+type YahooChartResponse struct {
+	Chart struct {
+		Result []struct {
+			Meta struct {
+				RegularMarketPrice float64 `json:"regularMarketPrice"`
+			} `json:"meta"`
+		} `json:"result"`
+		Error *struct {
+			Description string `json:"description"`
+		} `json:"error"`
+	} `json:"chart"`
+}
+
+type ExchangeRateResponse struct {
+	Rates map[string]float64 `json:"rates"`
+}
+
+func fetchExchangeRate() (float64, error) {
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Get("https://api.exchangerate-api.com/v4/latest/USD")
+	if err != nil {
+		return 0.92, fmt.Errorf("failed to fetch exchange rate: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var rateData ExchangeRateResponse
+	if err := json.NewDecoder(resp.Body).Decode(&rateData); err != nil {
+		return 0.92, fmt.Errorf("failed to decode exchange rate: %w", err)
+	}
+
+	if eurRate, ok := rateData.Rates["EUR"]; ok {
+		return eurRate, nil
+	}
+
+	return 0.92, fmt.Errorf("EUR rate not found")
+}
+
+func fetchStockPrice(ticker string) (float64, error) {
+	client := &http.Client{Timeout: 10 * time.Second}
+
+	// Try Yahoo Finance API
+	url := fmt.Sprintf("https://query1.finance.yahoo.com/v8/finance/chart/%s?interval=1d&range=1d", ticker)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return 0, err
+	}
+
+	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return 0, fmt.Errorf("failed to fetch from Yahoo: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return 0, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var chartData YahooChartResponse
+	if err := json.Unmarshal(body, &chartData); err != nil {
+		return 0, fmt.Errorf("failed to decode Yahoo response: %w", err)
+	}
+
+	if chartData.Chart.Error != nil {
+		return 0, fmt.Errorf("Yahoo API error: %s", chartData.Chart.Error.Description)
+	}
+
+	if len(chartData.Chart.Result) > 0 {
+		price := chartData.Chart.Result[0].Meta.RegularMarketPrice
+		if price > 0 {
+			return price, nil
+		}
+	}
+
+	return 0, fmt.Errorf("price not found in response")
+}
+
+func stockPricesHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var req StockPriceRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "Invalid request body", http.StatusBadRequest)
+		return
+	}
+
+	// Fetch exchange rate
+	exchangeRate, err := fetchExchangeRate()
+	if err != nil {
+		log.Printf("Warning: Using fallback exchange rate: %v", err)
+		exchangeRate = 0.92 // Fallback
+	}
+
+	prices := make(map[string]StockPrice)
+
+	// Fetch prices for each ticker
+	for _, ticker := range req.Tickers {
+		ticker = strings.TrimSpace(ticker)
+		if ticker == "" {
+			continue
+		}
+
+		usdPrice, err := fetchStockPrice(ticker)
+		if err != nil {
+			log.Printf("Error fetching price for %s: %v", ticker, err)
+			prices[ticker] = StockPrice{
+				Ticker:  ticker,
+				Success: false,
+				Error:   err.Error(),
+			}
+		} else {
+			prices[ticker] = StockPrice{
+				Ticker:  ticker,
+				USD:     usdPrice,
+				EUR:     usdPrice * exchangeRate,
+				Success: true,
+			}
+		}
+
+		// Small delay to avoid rate limiting
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	response := StockPricesResponse{
+		Prices:       prices,
+		ExchangeRate: exchangeRate,
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(response)
+}
+
+func main() {
+	// API endpoint
+	http.HandleFunc("/api/stock-prices", stockPricesHandler)
+
+	// Serve static files from /app/static directory
+	fs := http.FileServer(http.Dir("/app/static"))
+	http.Handle("/", fs)
+
+	port := ":8080"
+	log.Printf("Server starting on port %s", port)
+	if err := http.ListenAndServe(port, nil); err != nil {
+		log.Fatal(err)
+	}
+}