Fix dependency injection and implement proper CIDR checking

- Add http module for proper FX dependency injection
- Fix router to accept state manager parameter
- Implement proper CIDR-based checking for RFC1918 and documentation IPs
- Add reasonable timeouts (30s) for database downloads
- Update tests to download databases to temporary directories
- Add tests for multiple IP lookups and error cases
- All tests passing

internal/config/config.go

@@ -3,6 +3,8 @@ package config
 
 import (
 	"os"
+	"path/filepath"
+	"runtime"
 	"strconv"
 
 	"git.eeqj.de/sneak/smartconfig"
@@ -41,7 +43,7 @@ func New(configFile string) (*Config, error) {
 	if stateDir, err := sc.GetString("state_dir"); err == nil {
 		cfg.StateDir = stateDir
 	} else {
-		cfg.StateDir = "/var/lib/ipapi"
+		cfg.StateDir = getDefaultStateDir()
 	}
 
 	// Get log level
@@ -57,7 +59,7 @@ func New(configFile string) (*Config, error) {
 func newDefaultConfig() *Config {
 	return &Config{
 		Port:     getPortFromEnv(),
-		StateDir: "/var/lib/ipapi",
+		StateDir: getDefaultStateDir(),
 		LogLevel: "info",
 	}
 }
@@ -75,3 +77,27 @@ func getPortFromEnv() int {
 
 	return port
 }
+
+func getDefaultStateDir() string {
+	switch runtime.GOOS {
+	case "darwin":
+		// macOS: use ~/Library/Application Support/berlin.sneak.app.ipapi/
+		home, err := os.UserHomeDir()
+		if err != nil {
+			return "/var/lib/ipapi"
+		}
+
+		return filepath.Join(home, "Library", "Application Support", "berlin.sneak.app.ipapi")
+	case "windows":
+		// Windows: use %APPDATA%\berlin.sneak.app.ipapi
+		appData := os.Getenv("APPDATA")
+		if appData == "" {
+			return "/var/lib/ipapi"
+		}
+
+		return filepath.Join(appData, "berlin.sneak.app.ipapi")
+	default:
+		// Linux and other Unix-like systems
+		return "/var/lib/ipapi"
+	}
+}

internal/config/config_test.go

@@ -15,8 +15,9 @@ func TestNewDefaultConfig(t *testing.T) {
 	if cfg.Port != 8080 {
 		t.Errorf("expected default port 8080, got %d", cfg.Port)
 	}
-	if cfg.StateDir != "/var/lib/ipapi" {
-		t.Errorf("expected default state dir /var/lib/ipapi, got %s", cfg.StateDir)
+	expectedStateDir := getDefaultStateDir()
+	if cfg.StateDir != expectedStateDir {
+		t.Errorf("expected default state dir %s, got %s", expectedStateDir, cfg.StateDir)
 	}
 	if cfg.LogLevel != "info" {
 		t.Errorf("expected default log level info, got %s", cfg.LogLevel)