package logging_test

import (
	"bytes"
	"encoding/json"
	"log/slog"
	"testing"
	"testing/slogtest"

	"go.sudomsg.com/kit/logging"
)

func TestWriterHandler(t *testing.T) {
	var buf bytes.Buffer

	slogtest.Run(t,
		func(t *testing.T) slog.Handler {
			buf.Reset()
			sink := logging.NewWriterSink(&buf, logging.JSONEncoder, slog.LevelDebug, nil)
			return logging.NewSinkHandler(sink)
		},
		func(t *testing.T) map[string]any {
			t.Helper()

			if buf.Len() == 0 {
				t.Fatal("buffer is empty; no log was written")
			}
			b := buf.Bytes()
			r := bytes.NewReader(b)
			dec := json.NewDecoder(r)
			m := make(map[string]any)
			if err := dec.Decode(&m); err != nil {
				t.Fatalf("%v", err)
			}

			return m
		},
	)
}