Implement IP API daemon with GeoIP database support

- Create modular architecture with separate packages for config, database, HTTP, logging, and state management
- Implement Cobra CLI with daemon command
- Set up Uber FX dependency injection
- Add Chi router with health check and IP lookup endpoints
- Implement GeoIP database downloader with automatic updates
- Add state persistence for tracking database download times
- Include comprehensive test coverage for all components
- Configure structured logging with slog
- Add Makefile with test, lint, and build targets
- Support both IPv4 and IPv6 lookups
- Return country, city, ASN, and location data in JSON format

internal/log/log.go

@@ -0,0 +1,49 @@
+// Package log provides structured logging functionality.
+package log
+
+import (
+	"log/slog"
+	"os"
+	"strings"
+
+	"git.eeqj.de/sneak/ipapi/internal/config"
+)
+
+// New creates a new logger instance based on configuration.
+func New(cfg *config.Config) *slog.Logger {
+	var level slog.Level
+	switch strings.ToLower(cfg.LogLevel) {
+	case "debug":
+		level = slog.LevelDebug
+	case "info":
+		level = slog.LevelInfo
+	case "warn", "warning":
+		level = slog.LevelWarn
+	case "error":
+		level = slog.LevelError
+	default:
+		level = slog.LevelInfo
+	}
+
+	opts := &slog.HandlerOptions{
+		Level: level,
+	}
+
+	var handler slog.Handler
+	if isTerminal() {
+		handler = slog.NewTextHandler(os.Stdout, opts)
+	} else {
+		handler = slog.NewJSONHandler(os.Stdout, opts)
+	}
+
+	return slog.New(handler)
+}
+
+func isTerminal() bool {
+	fileInfo, err := os.Stdout.Stat()
+	if err != nil {
+		return false
+	}
+
+	return (fileInfo.Mode() & os.ModeCharDevice) != 0
+}

internal/log/log_test.go

@@ -0,0 +1,38 @@
+package log
+
+import (
+	"testing"
+
+	"git.eeqj.de/sneak/ipapi/internal/config"
+)
+
+func TestNew(t *testing.T) {
+	tests := []struct {
+		name     string
+		logLevel string
+	}{
+		{"debug level", "debug"},
+		{"info level", "info"},
+		{"warn level", "warn"},
+		{"warning level", "warning"},
+		{"error level", "error"},
+		{"invalid level", "invalid"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			cfg := &config.Config{
+				LogLevel: tt.logLevel,
+			}
+			logger := New(cfg)
+			if logger == nil {
+				t.Fatal("expected logger, got nil")
+			}
+		})
+	}
+}
+
+func TestIsTerminal(t *testing.T) {
+	// Just test that it doesn't panic
+	_ = isTerminal()
+}