package meowlib

import (
	"bytes"
	"compress/gzip"
	"io"
	"os"

	"github.com/makiuchi-d/gozxing"
	"github.com/makiuchi-d/gozxing/qrcode"
	"google.golang.org/protobuf/proto"

	"image/png"
)

func (p *InvitationInitPayload) Serialize() ([]byte, error) {
	return proto.Marshal(p)
}

func (p *InvitationInitPayload) Compress() ([]byte, error) {
	out, err := p.Serialize()
	if err != nil {
		return nil, err
	}
	var b bytes.Buffer
	gz, err := gzip.NewWriterLevel(&b, gzip.BestCompression)
	if err != nil {
		return nil, err
	}
	if _, err := gz.Write(out); err != nil {
		return nil, err
	}
	if err := gz.Close(); err != nil {
		return nil, err
	}
	return b.Bytes(), nil
}

func NewInvitationInitPayloadFromCompressed(compressed []byte) (*InvitationInitPayload, error) {
	p := &InvitationInitPayload{}
	reader := bytes.NewReader(compressed)
	gzreader, err := gzip.NewReader(reader)
	if err != nil {
		return nil, err
	}
	output, err := io.ReadAll(gzreader)
	if err != nil {
		return nil, err
	}
	if err := proto.Unmarshal(output, p); err != nil {
		return nil, err
	}
	return p, nil
}

func (p *InvitationInitPayload) WriteCompressed(filename string) error {
	out, err := p.Compress()
	if err != nil {
		return err
	}
	return os.WriteFile(filename, out, 0600)
}

func (p *InvitationInitPayload) WriteQr(filename string) error {
	data, err := p.Compress()
	if err != nil {
		return err
	}
	qwriter := qrcode.NewQRCodeWriter()
	code, err := qwriter.Encode(string(data), gozxing.BarcodeFormat_QR_CODE, 512, 512, nil)
	if err != nil {
		return err
	}
	file, err := os.Create(filename)
	if err != nil {
		return err
	}
	defer file.Close()
	return png.Encode(file, code)
}