logging.go

/*
Copyright IBM Corp. All Rights Reserved.

SPDX-License-Identifier: Apache-2.0
*/

package sdk

import (
	"log"
	"testing"
)

// Logger is the logging interface used throughout the SDK.
// This interface is compatible with the fabric logger from fabric-lib-go.
//
// Users can provide any logger implementation that supports formatted logging at different levels.
type Logger interface {
	Debugf(template string, args ...any)
	Infof(template string, args ...any)
	Warnf(template string, args ...any)
	Errorf(template string, args ...any)
}

// NoOpLogger is a logger implementation that discards all log output.
// Use this when you want to disable logging entirely.
type NoOpLogger struct{}

func (NoOpLogger) Debugf(template string, args ...any) {}
func (NoOpLogger) Infof(template string, args ...any)  {}
func (NoOpLogger) Warnf(template string, args ...any)  {}
func (NoOpLogger) Errorf(template string, args ...any) {}

// StdLogger is a logger implementation that uses Go's standard library log package.
// It prefixes all messages with the component name and log level.
type StdLogger struct {
	prefix string
}

// NewStdLogger creates a new logger that uses the standard library log package.
// All log messages will be prefixed with the given component name.
func NewStdLogger(component string) Logger {
	return &StdLogger{prefix: component}
}

func (l *StdLogger) Debugf(template string, args ...any) {
	log.Printf("[%s] [DEBUG] "+template, append([]any{l.prefix}, args...)...)
}

func (l *StdLogger) Infof(template string, args ...any) {
	log.Printf("[%s] [INFO] "+template, append([]any{l.prefix}, args...)...)
}

func (l *StdLogger) Warnf(template string, args ...any) {
	log.Printf("[%s] [WARN] "+template, append([]any{l.prefix}, args...)...)
}

func (l *StdLogger) Errorf(template string, args ...any) {
	log.Printf("[%s] [ERROR] "+template, append([]any{l.prefix}, args...)...)
}

// TestLogger is a logger implementation that uses testing.T's Log function.
// Use this in tests to have log output captured and displayed by the test runner.
type TestLogger struct {
	t      *testing.T
	prefix string
}

// NewTestLogger creates a new logger that writes to testing.T's log output.
// All log messages will be prefixed with the given component name.
func NewTestLogger(t *testing.T, component string) Logger {
	return &TestLogger{t: t, prefix: component}
}

func (l *TestLogger) Debugf(template string, args ...any) {
	l.t.Logf("[%s] [DEBUG] "+template, append([]any{l.prefix}, args...)...)
}

func (l *TestLogger) Infof(template string, args ...any) {
	l.t.Logf("[%s] [INFO] "+template, append([]any{l.prefix}, args...)...)
}

func (l *TestLogger) Warnf(template string, args ...any) {
	l.t.Logf("[%s] [WARN] "+template, append([]any{l.prefix}, args...)...)
}

func (l *TestLogger) Errorf(template string, args ...any) {
	l.t.Logf("[%s] [ERROR] "+template, append([]any{l.prefix}, args...)...)
}