chore: Move private packages to internal (#1664)

internal/log/eventlog/eventlog.go

@@ -0,0 +1,53 @@
+//go:build windows
+
+// Package eventlog provides a Logger that writes to Windows Event Log.
+package eventlog
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"golang.org/x/sys/windows"
+)
+
+const (
+	// NeLogOemCode is a generic error log entry for OEMs to use to
+	// elog errors from OEM value added services.
+	// See: https://github.com/microsoft/win32metadata/blob/2f3c5282ce1024a712aeccd90d3aa50bf7a49e27/generation/WinSDK/RecompiledIdlHeaders/um/LMErrlog.h#L824-L845
+	neLogOemCode = uint32(3299)
+)
+
+// Interface guard.
+var _ io.Writer = (*Writer)(nil)
+
+type Writer struct {
+	handle windows.Handle
+}
+
+// NewEventLogWriter returns a new Writer which writes to Windows EventLog.
+func NewEventLogWriter(handle windows.Handle) *Writer {
+	return &Writer{handle: handle}
+}
+
+func (w *Writer) Write(p []byte) (int, error) {
+	var eType uint16
+
+	switch {
+	case bytes.Contains(p, []byte(" level=error")) || bytes.Contains(p, []byte(`"level":"error"`)):
+		eType = windows.EVENTLOG_ERROR_TYPE
+	case bytes.Contains(p, []byte(" level=warn")) || bytes.Contains(p, []byte(`"level":"warn"`)):
+		eType = windows.EVENTLOG_WARNING_TYPE
+	default:
+		eType = windows.EVENTLOG_INFORMATION_TYPE
+	}
+
+	msg, err := windows.UTF16PtrFromString(string(p))
+	if err != nil {
+		return 0, fmt.Errorf("error convert string to UTF-16: %w", err)
+	}
+
+	ss := []*uint16{msg, nil, nil, nil, nil, nil, nil, nil, nil}
+
+	return len(p), windows.ReportEvent(w.handle, eType, 0, neLogOemCode, 0, 9, 0, &ss[0], nil)
+}