package logger

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

type MyJsonHandler struct {
	output      io.Writer
	mu          sync.Mutex
	jsonHandler slog.Handler
}

var stackChan = make(chan string, 100)

func newMyJsonHandler(output io.Writer, opts *slog.HandlerOptions) *MyJsonHandler {
	if opts == nil {
		opts = &slog.HandlerOptions{}
	}
	ra := opts.ReplaceAttr
	opts.ReplaceAttr = func(groups []string, a slog.Attr) slog.Attr {
		if a.Key == "stack" {
			stackChan <- a.Value.String()
			return slog.Attr{}
		} else {
			if ra != nil {
				return ra(groups, a)
			} else {
				return a
			}
		}
	}
	return &MyJsonHandler{output: output, mu: sync.Mutex{}, jsonHandler: slog.NewJSONHandler(output, opts)}
}

func (s *MyJsonHandler) Enabled(ctx context.Context, level slog.Level) bool {
	return s.jsonHandler.Enabled(ctx, level)
}

func (s *MyJsonHandler) Handle(ctx context.Context, record slog.Record) error {
	err := s.jsonHandler.Handle(ctx, record)
	if err != nil {
		return err
	}
	select {
	case stack := <-stackChan:
		s.mu.Lock()
		defer s.mu.Unlock()
		_, err = s.output.Write([]byte(stack))
	default:
	}
	return err
}

func (s *MyJsonHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
	return s.jsonHandler.WithAttrs(attrs)
}

func (s *MyJsonHandler) WithGroup(name string) slog.Handler {
	return s.jsonHandler.WithGroup(name)
}