package packets

import (
	"bytes"
	"compress/zlib"
	"io"
)

type EQ2Compressor struct {
	level int
}

func NewEQ2Compressor() *EQ2Compressor {
	return &EQ2Compressor{level: zlib.DefaultCompression}
}

func (c *EQ2Compressor) Compress(data []byte) ([]byte, error) {
	if len(data) == 0 {
		return data, nil
	}

	var buf bytes.Buffer
	writer, err := zlib.NewWriterLevel(&buf, c.level)
	if err != nil {
		return nil, err
	}

	_, err = writer.Write(data)
	if err != nil {
		writer.Close()
		return nil, err
	}

	err = writer.Close()
	if err != nil {
		return nil, err
	}

	return buf.Bytes(), nil
}

func (c *EQ2Compressor) Decompress(data []byte) ([]byte, error) {
	if len(data) == 0 {
		return data, nil
	}

	reader, err := zlib.NewReader(bytes.NewReader(data))
	if err != nil {
		return nil, err
	}
	defer reader.Close()

	var buf bytes.Buffer
	_, err = io.Copy(&buf, reader)
	if err != nil {
		return nil, err
	}

	return buf.Bytes(), nil
}

func (c *EQ2Compressor) ShouldCompress(data []byte) bool {
	return len(data) > 100 // EQ2 compression threshold
}