Moved package log to logging

internal/logging/logging.go

@@ -0,0 +1,123 @@
+/*
+Copyright © 2026 Craig Williams <craig@avsdev.uk>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+package logging
+
+import (
+	"log/slog"
+	"os"
+	"reflect"
+	"unsafe"
+
+	"github.com/lmittmann/tint"
+)
+
+// ---------- Standard log handling (terminal or file based) ----------
+
+var logLevel slog.LevelVar
+var fileLogger *os.File
+
+// Set the logging to a particular level, quietly
+func SetLevel(level slog.Level) {
+	logLevel.Set(level)
+}
+
+// Enable debug level logging
+func EnableDebug() {
+	if logLevel.Level() > slog.LevelDebug {
+		logLevel.Set(slog.LevelDebug)
+		slog.Debug("Debug logging enabled")
+	}
+}
+
+func LogToFile(logfile string) error {
+	if fileLogger != nil {
+		(*fileLogger).Close()
+	}
+
+	// Open the log file
+	fileLogger, err := os.OpenFile(logfile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	if err != nil {
+		return err
+	}
+
+	opts := &slog.HandlerOptions{
+		Level: &logLevel,
+	}
+	handler := slog.NewJSONHandler(fileLogger, opts)
+	logger := slog.New(handler)
+	slog.SetDefault(logger)
+
+	return nil
+}
+
+func Shutdown() error {
+	var err error = nil
+	if fileLogger != nil {
+		err = (*fileLogger).Close()
+		fileLogger = nil
+	}
+	return err
+}
+
+func LogToTerminal() {
+	opts := &tint.Options{
+		Level:      &logLevel,
+		TimeFormat: "*",
+	}
+	handler := tint.NewTextHandler(os.Stdout, opts)
+	logger := slog.New(handler)
+	slog.SetDefault(logger)
+}
+
+func IsJSONHandler(h slog.Handler) bool {
+	val := reflect.ValueOf(h)
+
+	// Ensure we are working with a pointer to a struct (*JSONHandler or *TextHandler or derived)
+	if val.Kind() != reflect.Pointer || val.Elem().Kind() != reflect.Struct {
+		return false
+	}
+
+	// Both JSONHandler and TextHandler wrap an unexported field named 'commonHandler'
+	commonHandlerField := val.Elem().FieldByName("commonHandler")
+	if !commonHandlerField.IsValid() {
+		return false
+	}
+
+	// Get the underlying *commonHandler struct pointer
+	// commonHandlerField is unexported, so we must use unsafe to bypass Go's safety checks
+	ptr := reflect.NewAt(
+		commonHandlerField.Type().Elem(),
+		unsafe.Pointer(commonHandlerField.Pointer()),
+	)
+
+	// Find the unexported 'json' boolean field inside commonHandler
+	jsonField := ptr.Elem().FieldByName("json")
+	if !jsonField.IsValid() {
+		return false
+	}
+
+	// Read the boolean value using unsafe
+	return *(*bool)(unsafe.Pointer(jsonField.UnsafeAddr()))
+}
+
+func IsFileLogger() bool {
+	return fileLogger != nil
+}
+
+func IsDebugEnabled() bool {
+	return logLevel.Level() <= slog.LevelDebug
+}