observer/pkg/exporters/console_exporter/multiline_formatter.go

package console_exporter

import (
	"fmt"
	"slices"

	"git.ma-al.com/maal-libraries/observer/pkg/console_fmt"
	"git.ma-al.com/maal-libraries/observer/pkg/level"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/sdk/trace"
)

func NewPrettyMultilineFormatter() TraceFormatter {
	return &PrettyMultilineFormatter{}
}

// A formatter that will print only events using a multiline format with colors.
// It uses attributes from the [attr] and [semconv] packages.
type PrettyMultilineFormatter struct{}

func AttrValueToString(val attribute.Value) string {
	switch val.Type() {
	case attribute.STRING:
		return val.AsString()
	case attribute.BOOL:
		if val.AsBool() {
			return "true"
		} else {
			return "false"
		}
	case attribute.BOOLSLICE, attribute.INT64SLICE, attribute.FLOAT64SLICE, attribute.STRINGSLICE:
		json, _ := val.MarshalJSON()
		return string(json)
	case attribute.FLOAT64:
		fmt.Sprintf("%f", val.AsFloat64())
	case attribute.INT64:
		return fmt.Sprintf("%d", val.AsInt64())
	default:
		json, _ := val.MarshalJSON()
		return string(json)
	}
	return ""
}

func (f *PrettyMultilineFormatter) FormatSpanStart(span trace.ReadOnlySpan, selectedAttrs []attribute.KeyValue, lvl level.SeverityLevel) (string, error) {
	attrs := ""
	slices.SortFunc(selectedAttrs, func(a, b attribute.KeyValue) int {
		if a.Key > b.Key {
			return 1
		} else {
			return -1
		}
	})

	for _, kv := range selectedAttrs {
		if len(kv.Key) > 0 {
			attrs += fmt.Sprintf("\t%s = %s\n", string(kv.Key), AttrValueToString(kv.Value))
		}
	}

	formattedSpanString := fmt.Sprintf(
		"%s\n%s",
		console_fmt.Bold(console_fmt.SeverityLevelToColor(lvl)+fmt.Sprintf("[%s][SpanStart] ", lvl.String())+span.Name()),
		attrs,
	)

	return formattedSpanString, nil
}
func (f *PrettyMultilineFormatter) FormatSpanEnd(span trace.ReadOnlySpan, selectedAttrs []attribute.KeyValue, lvl level.SeverityLevel) (string, error) {
	attrs := ""
	slices.SortFunc(selectedAttrs, func(a, b attribute.KeyValue) int {
		if a.Key > b.Key {
			return 1
		} else {
			return -1
		}
	})

	for _, kv := range selectedAttrs {
		if len(kv.Key) > 0 {
			attrs += fmt.Sprintf("\t%s = %s\n", string(kv.Key), AttrValueToString(kv.Value))
		}
	}

	formattedSpanString := fmt.Sprintf(
		"%s\n%s",
		console_fmt.Bold(console_fmt.SeverityLevelToColor(lvl)+fmt.Sprintf("[%s][SpanEnd] ", lvl.String())+span.Name()),
		attrs,
	)

	return formattedSpanString, nil

}
func (f *PrettyMultilineFormatter) FormatEvent(event trace.Event, span trace.ReadOnlySpan, selectedAttrs []attribute.KeyValue, lvl level.SeverityLevel) (string, error) {
	attrs := ""
	slices.SortFunc(selectedAttrs, func(a, b attribute.KeyValue) int {
		if a.Key > b.Key {
			return 1
		} else {
			return -1
		}
	})

	for _, kv := range selectedAttrs {
		if len(kv.Key) > 0 {
			attrs += fmt.Sprintf("\t%s = %s\n", string(kv.Key), AttrValueToString(kv.Value))
		}
	}

	formattedSpanString := fmt.Sprintf(
		"%s\n%s",
		console_fmt.Bold(console_fmt.SeverityLevelToColor(lvl)+fmt.Sprintf("[%s][Event] ", lvl.String())+event.Name),
		attrs,
	)

	return formattedSpanString, nil
}