improve readability of the web package

web/session.go

@@ -0,0 +1,78 @@
+package web
+
+// Functions that handle browser login sessions
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+
+	"muzi/db"
+)
+
+type Session struct {
+	Username string
+}
+
+func createSession(username string) string {
+	sessionID, err := generateID()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error generating sessionID: %v\n", err)
+		return ""
+	}
+	_, err = db.Pool.Exec(
+		context.Background(),
+		"INSERT INTO sessions (session_id, username, expires_at) VALUES ($1, $2, NOW() + INTERVAL '30 days');",
+		sessionID,
+		username,
+	)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error creating session: %v\n", err)
+		return ""
+	}
+	return sessionID
+}
+
+func getSession(ctx context.Context, sessionID string) *Session {
+	var username string
+	err := db.Pool.QueryRow(
+		ctx,
+		"SELECT username FROM sessions WHERE session_id = $1 AND expires_at > NOW();",
+		sessionID,
+	).Scan(&username)
+	if err != nil {
+		return nil
+	}
+	return &Session{Username: username}
+}
+
+func deleteSession(sessionID string) {
+	_, err := db.Pool.Exec(
+		context.Background(),
+		"DELETE FROM sessions WHERE session_id = $1;",
+		sessionID,
+	)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error deleting session: %v\n", err)
+	}
+}
+
+func getLoggedInUsername(r *http.Request) string {
+	cookie, err := r.Cookie("session")
+	if err != nil {
+		return ""
+	}
+	session := getSession(r.Context(), cookie.Value)
+	if session == nil {
+		return ""
+	}
+	return session.Username
+}
+
+func getUserIdByUsername(ctx context.Context, username string) (int, error) {
+	var userId int
+	err := db.Pool.QueryRow(ctx, "SELECT pk FROM users WHERE username = $1;", username).
+		Scan(&userId)
+	return userId, err
+}