Files
gf-lt/pngmeta/metareader.go
2025-08-07 06:43:02 +03:00

148 lines
3.2 KiB
Go

package pngmeta
import (
"bytes"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"gf-lt/models"
"io"
"log/slog"
"os"
"path"
"strings"
)
const (
embType = "tEXt"
cKey = "chara"
IEND = "IEND"
header = "\x89PNG\r\n\x1a\n"
writeHeader = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"
)
type PngEmbed struct {
Key string
Value string
}
func (c PngEmbed) GetDecodedValue() (*models.CharCardSpec, error) {
data, err := base64.StdEncoding.DecodeString(c.Value)
if err != nil {
return nil, err
}
card := &models.CharCardSpec{}
if err := json.Unmarshal(data, &card); err != nil {
return nil, err
}
specWrap := &models.Spec2Wrapper{}
if card.Name == "" {
if err := json.Unmarshal(data, &specWrap); err != nil {
return nil, err
}
return &specWrap.Data, nil
}
return card, nil
}
func extractChar(fname string) (*PngEmbed, error) {
data, err := os.ReadFile(fname)
if err != nil {
return nil, err
}
reader := bytes.NewReader(data)
pr, err := NewPNGStepReader(reader)
if err != nil {
return nil, err
}
for {
step, err := pr.Next()
if err != nil {
if errors.Is(err, io.EOF) {
break
}
}
if step.Type() != embType {
if _, err := io.Copy(io.Discard, step); err != nil {
return nil, err
}
} else {
buf, err := io.ReadAll(step)
if err != nil {
return nil, err
}
dataInstep := string(buf)
values := strings.Split(dataInstep, "\x00")
if len(values) == 2 {
return &PngEmbed{Key: values[0], Value: values[1]}, nil
}
}
if err := step.Close(); err != nil {
return nil, err
}
}
return nil, errors.New("failed to find embedded char in png: " + fname)
}
func ReadCard(fname, uname string) (*models.CharCard, error) {
pe, err := extractChar(fname)
if err != nil {
return nil, err
}
charSpec, err := pe.GetDecodedValue()
if err != nil {
return nil, err
}
if charSpec.Name == "" {
return nil, fmt.Errorf("failed to find role; fname %s", fname)
}
return charSpec.Simplify(uname, fname), nil
}
func ReadCardJson(fname string) (*models.CharCard, error) {
data, err := os.ReadFile(fname)
if err != nil {
return nil, err
}
card := models.CharCard{}
if err := json.Unmarshal(data, &card); err != nil {
return nil, err
}
return &card, nil
}
func ReadDirCards(dirname, uname string, log *slog.Logger) ([]*models.CharCard, error) {
files, err := os.ReadDir(dirname)
if err != nil {
return nil, err
}
resp := []*models.CharCard{}
for _, f := range files {
if f.IsDir() {
continue
}
if strings.HasSuffix(f.Name(), ".png") {
fpath := path.Join(dirname, f.Name())
cc, err := ReadCard(fpath, uname)
if err != nil {
log.Warn("failed to load card", "error", err, "card", fpath)
continue
}
resp = append(resp, cc)
}
if strings.HasSuffix(f.Name(), ".json") {
fpath := path.Join(dirname, f.Name())
cc, err := ReadCardJson(fpath)
if err != nil {
log.Warn("failed to load card", "error", err, "card", fpath)
continue
}
cc.FirstMsg = strings.ReplaceAll(strings.ReplaceAll(cc.FirstMsg, "{{char}}", cc.Role), "{{user}}", uname)
cc.SysPrompt = strings.ReplaceAll(strings.ReplaceAll(cc.SysPrompt, "{{char}}", cc.Role), "{{user}}", uname)
resp = append(resp, cc)
}
}
return resp, nil
}