package file

import (
	"errors"
	"os"

	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/agent/internal/logsource"
	"github.com/hpcloud/tail"
)

var _ logsource.LogSource = new(FileLogSource)

type FileLogSource struct {
	*tail.Tail
}

func New(filepath string) (fls *FileLogSource, err error) {
	if _, err := os.Stat(filepath); os.IsNotExist(err) {
		if err := os.WriteFile(filepath, []byte{}, 0600); err != nil {
			return nil, err
		}
	}
	t, err := tail.TailFile(filepath, tail.Config{
		Follow: true,
		Location: &tail.SeekInfo{
			Offset: 100,
			Whence: 2,
		},
	})
	if err != nil {
		return
	}
	return &FileLogSource{t}, nil
}
func (f *FileLogSource) ReadLine() (string, error) {
	select {
	case <-f.Dead():
		return "", errors.Join(logsource.ErrDead, f.Err())
	case line := <-f.Lines:
		return line.Text, line.Err
	}
}
func (f *FileLogSource) Close() error {
	return f.Stop()
}