Refactor: pngmeta rewrite

1 files changed, 105 insertions, 109 deletions

diff --git a/pngmeta/partswriter.go b/pngmeta/partswriter.go
index 7c36daf..7282df6 100644
--- a/pngmeta/partswriter.go
+++ b/pngmeta/partswriter.go
@@ -1,116 +1,112 @@
 package pngmeta
 
-import (
-	"bytes"
-	"elefant/models"
-	"encoding/base64"
-	"encoding/binary"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"hash/crc32"
-	"io"
-	"os"
-)
+// import (
+// 	"bytes"
+// 	"encoding/binary"
+// 	"errors"
+// 	"fmt"
+// 	"hash/crc32"
+// 	"io"
+// )
 
-type Writer struct {
-	w io.Writer
-}
+// type Writer struct {
+// 	w io.Writer
+// }
 
-func NewPNGWriter(w io.Writer) (*Writer, error) {
-	if _, err := io.WriteString(w, writeHeader); err != nil {
-		return nil, err
-	}
-	return &Writer{w}, nil
-}
+// func NewPNGWriter(w io.Writer) (*Writer, error) {
+// 	if _, err := io.WriteString(w, writeHeader); err != nil {
+// 		return nil, err
+// 	}
+// 	return &Writer{w}, nil
+// }
 
-func (w *Writer) WriteChunk(length int32, typ string, r io.Reader) error {
-	if err := binary.Write(w.w, binary.BigEndian, length); err != nil {
-		return err
-	}
-	if _, err := w.w.Write([]byte(typ)); err != nil {
-		return err
-	}
-	checksummer := crc32.NewIEEE()
-	checksummer.Write([]byte(typ))
-	if _, err := io.CopyN(io.MultiWriter(w.w, checksummer), r, int64(length)); err != nil {
-		return err
-	}
-	if err := binary.Write(w.w, binary.BigEndian, checksummer.Sum32()); err != nil {
-		return err
-	}
-	return nil
-}
+// func (w *Writer) WriteChunk(length int32, typ string, r io.Reader) error {
+// 	if err := binary.Write(w.w, binary.BigEndian, length); err != nil {
+// 		return err
+// 	}
+// 	if _, err := w.w.Write([]byte(typ)); err != nil {
+// 		return err
+// 	}
+// 	checksummer := crc32.NewIEEE()
+// 	checksummer.Write([]byte(typ))
+// 	if _, err := io.CopyN(io.MultiWriter(w.w, checksummer), r, int64(length)); err != nil {
+// 		return err
+// 	}
+// 	if err := binary.Write(w.w, binary.BigEndian, checksummer.Sum32()); err != nil {
+// 		return err
+// 	}
+// 	return nil
+// }
 
-func WriteToPng(c *models.CharCardSpec, fpath, outfile string) error {
-	data, err := os.ReadFile(fpath)
-	if err != nil {
-		return err
-	}
-	jsonData, err := json.Marshal(c)
-	if err != nil {
-		return err
-	}
-	// Base64 encode the JSON data
-	base64Data := base64.StdEncoding.EncodeToString(jsonData)
-	pe := PngEmbed{
-		Key:   cKey,
-		Value: base64Data,
-	}
-	w, err := WritetEXtToPngBytes(data, pe)
-	if err != nil {
-		return err
-	}
-	return os.WriteFile(outfile, w.Bytes(), 0666)
-}
+// func WWriteToPngriteToPng(c *models.CharCardSpec, fpath, outfile string) error {
+// 	data, err := os.ReadFile(fpath)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	jsonData, err := json.Marshal(c)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	// Base64 encode the JSON data
+// 	base64Data := base64.StdEncoding.EncodeToString(jsonData)
+// 	pe := PngEmbed{
+// 		Key:   cKey,
+// 		Value: base64Data,
+// 	}
+// 	w, err := WritetEXtToPngBytes(data, pe)
+// 	if err != nil {
+// 		return err
+// 	}
+// 	return os.WriteFile(outfile, w.Bytes(), 0666)
+// }
 
-func WritetEXtToPngBytes(inputBytes []byte, pe PngEmbed) (outputBytes bytes.Buffer, err error) {
-	if !(string(inputBytes[:8]) == header) {
-		return outputBytes, errors.New("wrong file format")
-	}
-	reader := bytes.NewReader(inputBytes)
-	pngr, err := NewPNGStepReader(reader)
-	if err != nil {
-		return outputBytes, fmt.Errorf("NewReader(): %s", err)
-	}
-	pngw, err := NewPNGWriter(&outputBytes)
-	if err != nil {
-		return outputBytes, fmt.Errorf("NewWriter(): %s", err)
-	}
-	for {
-		chunk, err := pngr.Next()
-		if err != nil {
-			if errors.Is(err, io.EOF) {
-				break
-			}
-			return outputBytes, fmt.Errorf("NextChunk(): %s", err)
-		}
-		if chunk.Type() != embType {
-			// IENDChunkType will only appear on the final iteration of a valid PNG
-			if chunk.Type() == IEND {
-				// This is where we inject tEXtChunkType as the penultimate chunk with the new value
-				newtEXtChunk := []byte(fmt.Sprintf(tEXtChunkDataSpecification, pe.Key, pe.Value))
-				if err := pngw.WriteChunk(int32(len(newtEXtChunk)), embType, bytes.NewBuffer(newtEXtChunk)); err != nil {
-					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
-				}
-				// Now we end the buffer with IENDChunkType chunk
-				if err := pngw.WriteChunk(chunk.length, chunk.Type(), chunk); err != nil {
-					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
-				}
-			} else {
-				// writes back original chunk to buffer
-				if err := pngw.WriteChunk(chunk.length, chunk.Type(), chunk); err != nil {
-					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
-				}
-			}
-		} else {
-			if _, err := io.Copy(io.Discard, chunk); err != nil {
-				return outputBytes, fmt.Errorf("io.Copy(io.Discard, chunk): %s", err)
-			}
-		}
-		if err := chunk.Close(); err != nil {
-			return outputBytes, fmt.Errorf("chunk.Close(): %s", err)
-		}
-	}
-	return outputBytes, nil
-}
+// func WritetEXtToPngBytes(inputBytes []byte, pe PngEmbed) (outputBytes bytes.Buffer, err error) {
+// 	if !(string(inputBytes[:8]) == header) {
+// 		return outputBytes, errors.New("wrong file format")
+// 	}
+// 	reader := bytes.NewReader(inputBytes)
+// 	pngr, err := NewPNGStepReader(reader)
+// 	if err != nil {
+// 		return outputBytes, fmt.Errorf("NewReader(): %s", err)
+// 	}
+// 	pngw, err := NewPNGWriter(&outputBytes)
+// 	if err != nil {
+// 		return outputBytes, fmt.Errorf("NewWriter(): %s", err)
+// 	}
+// 	for {
+// 		chunk, err := pngr.Next()
+// 		if err != nil {
+// 			if errors.Is(err, io.EOF) {
+// 				break
+// 			}
+// 			return outputBytes, fmt.Errorf("NextChunk(): %s", err)
+// 		}
+// 		if chunk.Type() != embType {
+// 			// IENDChunkType will only appear on the final iteration of a valid PNG
+// 			if chunk.Type() == IEND {
+// 				// This is where we inject tEXtChunkType as the penultimate chunk with the new value
+// 				newtEXtChunk := []byte(fmt.Sprintf(tEXtChunkDataSpecification, pe.Key, pe.Value))
+// 				if err := pngw.WriteChunk(int32(len(newtEXtChunk)), embType, bytes.NewBuffer(newtEXtChunk)); err != nil {
+// 					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
+// 				}
+// 				// Now we end the buffer with IENDChunkType chunk
+// 				if err := pngw.WriteChunk(chunk.length, chunk.Type(), chunk); err != nil {
+// 					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
+// 				}
+// 			} else {
+// 				// writes back original chunk to buffer
+// 				if err := pngw.WriteChunk(chunk.length, chunk.Type(), chunk); err != nil {
+// 					return outputBytes, fmt.Errorf("WriteChunk(): %s", err)
+// 				}
+// 			}
+// 		} else {
+// 			if _, err := io.Copy(io.Discard, chunk); err != nil {
+// 				return outputBytes, fmt.Errorf("io.Copy(io.Discard, chunk): %s", err)
+// 			}
+// 		}
+// 		if err := chunk.Close(); err != nil {
+// 			return outputBytes, fmt.Errorf("chunk.Close(): %s", err)
+// 		}
+// 	}
+// 	return outputBytes, nil
+// }