package logging

import (
	"fmt"
	"io"
	"log/slog"
	"sync"
)

type WriterSink struct {
	Writer      io.Writer
	mu          sync.Mutex
	Encoder     Encoder
	Level       slog.Level
	ReplaceAttr func(groups []string, a slog.Attr) slog.Attr
}

var _ Sink = &WriterSink{}

func NewWriterSink(w io.Writer, encoder Encoder, level slog.Leveler, replaceAttr func(groups []string, a slog.Attr) slog.Attr) *WriterSink {
	return &WriterSink{
		Writer:  w,
		Encoder: encoder,
		Level:   level.Level(),
		ReplaceAttr: replaceAttr,
	}
}

func (s *WriterSink) Enabled(level slog.Level) bool {
	return s.Level <= level
}

func (s *WriterSink) Append(r slog.Record) error {
	it := RecordAll(r, s.ReplaceAttr)
	out, err := s.Encoder(it)
	if err != nil {
		return fmt.Errorf("failed to encode: %w", err)
	}

	s.mu.Lock()
	defer s.mu.Unlock()

	_, err = fmt.Fprintln(s.Writer, out)
	return err
}