Fixing path when processing embedded resources

Author: rupor-github

convert/kfx/generate.go

@@ -2,7 +2,10 @@ package kfx
 
 import (
 	"context"
+	"crypto/rand"
+	"crypto/sha256"
 	"fmt"
+	"math/big"
 	"os"
 	"sort"
 	"strings"
@@ -17,6 +20,7 @@ import (
 	"fbc/convert/kfx/ionutil"
 	"fbc/convert/kfx/model"
 	"fbc/convert/kfx/symbols"
+	"fbc/misc"
 )
 
 // Generate creates the KFX output file.
@@ -31,7 +35,7 @@ func Generate(ctx context.Context, c *content.Content, outputPath string, cfg *c
 
 	log.Info("Generating KFX", zap.String("output", outputPath))
 
-	containerID := "CR!" + c.Book.Description.DocumentInfo.ID
+	containerID := "CR!" + hashTo28Alphanumeric(c.Book.Description.DocumentInfo.ID)
 
 	// Minimal content fragment.
 	type contentFragment struct {
@@ -611,7 +615,7 @@ func Generate(ctx context.Context, c *content.Content, outputPath string, cfg *c
 
 	data, err := container.Pack(&container.PackParams{
 		ContainerID:              containerID,
-		KfxgenApplicationVersion: "kfxlib-20251012",
+		KfxgenApplicationVersion: misc.GetAppName() + "-" + misc.GetVersion(),
 		KfxgenPackageVersion:     "",
 		DocumentSymbols:          prolog.DocSymbols,
 		FormatCapabilities:       builders.BuildFormatCapabilities(),
@@ -628,3 +632,47 @@ func Generate(ctx context.Context, c *content.Content, outputPath string, cfg *c
 
 	return nil
 }
+
+const charsetCR = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+
+// randomAlphanumeric28 generates a random string of exactly 28 bytes
+// containing only uppercase Latin letters (A-Z) and digits (0-9).
+func randomAlphanumeric28() string {
+	const length = 28
+
+	result := make([]byte, length)
+	charsetLen := big.NewInt(int64(len(charsetCR)))
+
+	for i := range length {
+		num, err := rand.Int(rand.Reader, charsetLen)
+		if err != nil {
+			panic(err)
+		}
+		result[i] = charsetCR[num.Int64()]
+	}
+	return string(result)
+}
+
+// hashTo28Alphanumeric hashes the input string to produce exactly 28 bytes
+// containing only uppercase Latin letters (A-Z) and digits (0-9). It does this
+// deterministically - same input string will always produce the same output
+// string. If the input is empty, a random string is generated instead.
+func hashTo28Alphanumeric(input string) string {
+	if input == "" {
+		return randomAlphanumeric28()
+	}
+
+	// Use SHA-256 to hash the input
+	hash := sha256.Sum256([]byte(input))
+
+	// Map hash bytes to full alphanumeric charset (A-Z, 0-9)
+	result := make([]byte, 28)
+
+	for i := range 28 {
+		// Use hash bytes to deterministically select from charset
+		idx := hash[i] % byte(len(charsetCR))
+		result[i] = charsetCR[idx]
+	}
+
+	return string(result)
+}

fb2/stylesheet.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"path"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -260,7 +261,7 @@ func (fb *FictionBook) resolveStylesheetResource(ref cssExternalRef, binaryIndex
 	}
 
 	// Set full path with directory
-	resource.Filename = filepath.Join(dir, resource.Filename)
+	resource.Filename = path.Join(dir, resource.Filename)
 
 	log.Info("Loaded stylesheet resource from file",
 		zap.String("url", ref.URL),