initial commit

internal/geo/geo.go

@@ -0,0 +1,68 @@
+package geo
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/oschwald/geoip2-golang"
+)
+
+// GeoPoint holds geographic information for an IP address.
+type GeoPoint struct {
+	IP          string
+	Lat         float64
+	Lon         float64
+	Country     string
+	CountryCode string
+	Count       int
+}
+
+// GeoLookup wraps the geoip2 database reader.
+// If no database path is configured, all lookups return nil (no-op).
+type GeoLookup struct {
+	db *geoip2.Reader
+}
+
+// NewGeoLookup creates a GeoLookup. If path is empty, returns a disabled (no-op) lookup.
+// Returns an error if path is non-empty but the file cannot be opened.
+func NewGeoLookup(path string) (*GeoLookup, error) {
+	if path == "" {
+		return &GeoLookup{}, nil
+	}
+	db, err := geoip2.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("geoip2 open %q: %w", path, err)
+	}
+	return &GeoLookup{db: db}, nil
+}
+
+// IsEnabled returns true if a GeoIP2 database is loaded.
+func (g *GeoLookup) IsEnabled() bool {
+	return g.db != nil
+}
+
+// Close releases the database if open.
+func (g *GeoLookup) Close() {
+	if g.db != nil {
+		g.db.Close()
+	}
+}
+
+// Lookup returns a GeoPoint for the given IP, or nil if the database is not loaded
+// or the IP is nil/not found.
+func (g *GeoLookup) Lookup(ip net.IP) *GeoPoint {
+	if g.db == nil || ip == nil {
+		return nil
+	}
+	record, err := g.db.City(ip)
+	if err != nil {
+		return nil
+	}
+	return &GeoPoint{
+		IP:          ip.String(),
+		Lat:         record.Location.Latitude,
+		Lon:         record.Location.Longitude,
+		Country:     record.Country.Names["en"],
+		CountryCode: record.Country.IsoCode,
+	}
+}

internal/geo/geo_test.go

@@ -0,0 +1,59 @@
+package geo
+
+import (
+	"net"
+	"testing"
+)
+
+func TestNewGeoLookup_NilPath(t *testing.T) {
+	gl, err := NewGeoLookup("")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if gl == nil {
+		t.Fatal("expected non-nil GeoLookup")
+	}
+	if gl.IsEnabled() {
+		t.Error("expected IsEnabled() = false for empty path")
+	}
+}
+
+func TestGeoLookup_LookupWithNoDb(t *testing.T) {
+	gl, _ := NewGeoLookup("")
+	result := gl.Lookup(net.ParseIP("8.8.8.8"))
+	if result != nil {
+		t.Errorf("expected nil result when no db, got %+v", result)
+	}
+}
+
+func TestGeoLookup_LookupNilIP(t *testing.T) {
+	gl, _ := NewGeoLookup("")
+	result := gl.Lookup(nil)
+	if result != nil {
+		t.Errorf("expected nil result for nil IP, got %+v", result)
+	}
+}
+
+func TestNewGeoLookup_InvalidPath(t *testing.T) {
+	_, err := NewGeoLookup("/nonexistent/path/GeoLite2-City.mmdb")
+	if err == nil {
+		t.Error("expected error for nonexistent db file, got nil")
+	}
+}
+
+func TestGeoPoint_Fields(t *testing.T) {
+	gp := GeoPoint{
+		IP:        "1.2.3.4",
+		Lat:       37.751,
+		Lon:       -97.822,
+		Country:   "United States",
+		CountryCode: "US",
+		Count:     42,
+	}
+	if gp.IP != "1.2.3.4" {
+		t.Errorf("IP = %q", gp.IP)
+	}
+	if gp.Count != 42 {
+		t.Errorf("Count = %d", gp.Count)
+	}
+}