first commit of restructured project

trahn-trade-backend/internal/api/server.go

@@ -0,0 +1,169 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/kjannette/trahn-backend/internal/repository"
+)
+
+const maxQueryLimit = 1000
+
+var dateRegexp = regexp.MustCompile(`^\d{4}-\d{2}-\d{2}$`)
+
+type Server struct {
+	pool       *pgxpool.Pool
+	priceRepo  *repository.PriceRepo
+	tradeRepo  *repository.TradeRepo
+	srRepo     *repository.SRRepo
+	gridRepo   *repository.GridStateRepo
+	httpServer *http.Server
+	apiKey     string
+}
+
+func NewServer(pool *pgxpool.Pool, port int, apiKey, corsOrigin string) *Server {
+	s := &Server{
+		pool:      pool,
+		priceRepo: repository.NewPriceRepo(pool),
+		tradeRepo: repository.NewTradeRepo(pool),
+		srRepo:    repository.NewSRRepo(pool),
+		gridRepo:  repository.NewGridStateRepo(pool),
+		apiKey:    apiKey,
+	}
+
+	mux := http.NewServeMux()
+
+	// Price routes
+	mux.HandleFunc("GET /v1/prices/today", s.handlePricesToday)
+	mux.HandleFunc("GET /v1/prices/day/{date}", s.handlePricesByDay)
+	mux.HandleFunc("GET /v1/prices/days", s.handleAvailableDays)
+	mux.HandleFunc("GET /v1/prices/latest", s.handleLatestPrice)
+
+	// Trade routes
+	mux.HandleFunc("GET /v1/trades/today", s.handleTradesToday)
+	mux.HandleFunc("GET /v1/trades/day/{date}", s.handleTradesByDay)
+	mux.HandleFunc("GET /v1/trades/all", s.handleAllTrades)
+	mux.HandleFunc("GET /v1/trades/stats", s.handleTradeStats)
+
+	// Grid routes
+	mux.HandleFunc("GET /v1/grid/current", s.handleGridCurrent)
+
+	// S/R routes
+	mux.HandleFunc("GET /v1/support-resistance/latest", s.handleSRLatest)
+	mux.HandleFunc("GET /v1/support-resistance/history", s.handleSRHistory)
+
+	// Health check (no auth required)
+	mux.HandleFunc("GET /health", s.handleHealth)
+
+	handler := s.authMiddleware(corsMiddleware(mux, corsOrigin))
+
+	s.httpServer = &http.Server{
+		Addr:         fmt.Sprintf(":%d", port),
+		Handler:      handler,
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+
+	return s
+}
+
+func (s *Server) Start() error {
+	fmt.Printf("[API] REST API server started on http://localhost%s\n", s.httpServer.Addr)
+	fmt.Printf("[API] Health check: http://localhost%s/health\n", s.httpServer.Addr)
+	if s.apiKey != "" {
+		fmt.Println("[API] Authentication: enabled (Bearer token)")
+	} else {
+		fmt.Println("[API] Authentication: disabled (no API_KEY configured)")
+	}
+	return s.httpServer.ListenAndServe()
+}
+
+func (s *Server) Shutdown(ctx context.Context) error {
+	return s.httpServer.Shutdown(ctx)
+}
+
+// --- middleware ---
+
+func (s *Server) authMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if s.apiKey == "" || r.URL.Path == "/health" {
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		auth := r.Header.Get("Authorization")
+		if auth == "" {
+			writeError(w, http.StatusUnauthorized, "missing Authorization header")
+			return
+		}
+
+		token := strings.TrimPrefix(auth, "Bearer ")
+		if token == auth || token != s.apiKey {
+			writeError(w, http.StatusUnauthorized, "invalid API key")
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func corsMiddleware(next http.Handler, allowOrigin string) http.Handler {
+	if allowOrigin == "" {
+		allowOrigin = "*"
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Access-Control-Allow-Origin", allowOrigin)
+		w.Header().Set("Access-Control-Allow-Methods", "GET, OPTIONS")
+		w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
+
+		if r.Method == http.MethodOptions {
+			w.WriteHeader(http.StatusOK)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// --- validation helpers ---
+
+func validateDate(date string) bool {
+	if !dateRegexp.MatchString(date) {
+		return false
+	}
+	_, err := time.Parse("2006-01-02", date)
+	return err == nil
+}
+
+func parseLimit(r *http.Request, defaultLimit int) int {
+	v := r.URL.Query().Get("limit")
+	if v == "" {
+		return defaultLimit
+	}
+	n, err := strconv.Atoi(v)
+	if err != nil || n <= 0 {
+		return defaultLimit
+	}
+	if n > maxQueryLimit {
+		return maxQueryLimit
+	}
+	return n
+}
+
+// --- response helpers ---
+
+func writeJSON(w http.ResponseWriter, status int, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(v)
+}
+
+func writeError(w http.ResponseWriter, status int, msg string) {
+	writeJSON(w, status, map[string]string{"error": msg})
+}