From af2aa5e5efa82d3bc7cf5530e0a1eee72ba99244 Mon Sep 17 00:00:00 2001
From: Paul Buetow <paul@buetow.org>
Date: Mon, 20 Apr 2026 08:01:01 +0300
Subject: Fix task 25 follow-up: stop PNG prompt leaks and keep comics
 consistent

---
 internal/comic/image_validation.go | 68 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 internal/comic/image_validation.go

(limited to 'internal/comic/image_validation.go')

diff --git a/internal/comic/image_validation.go b/internal/comic/image_validation.go
new file mode 100644
index 0000000..475cb96
--- /dev/null
+++ b/internal/comic/image_validation.go
@@ -0,0 +1,68 @@
+package comic
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+var imageLeakMarkers = []string{
+	"mandatory language rule",
+	"this is a bulgarian comic book",
+	"bulgarian comic book",
+	"mandatory panel layout",
+	"mandatory speech bubbles",
+	"ultra-realistic rendering",
+	"final lock",
+	"photorealism",
+	"character & setting reference",
+	"this is a text-free character gallery page",
+	"story page",
+	"gallery page",
+	"back cover",
+	"cover lines",
+	"story teaser",
+	"story ending hint",
+	"art style:",
+	"no panel grid",
+	"no speech bubbles",
+	"no text of any kind",
+}
+
+var validateImagePromptLeakageFn = validateImagePromptLeakage
+
+func validateImagePromptLeakage(ctx context.Context, outputFile, label string) error {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	tesseractPath, err := exec.LookPath("tesseract")
+	if err != nil {
+		return nil
+	}
+
+	cmd := exec.CommandContext(ctx, tesseractPath, outputFile, "stdout", "-l", "eng", "--psm", "11")
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &bytes.Buffer{}
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("%s OCR failed: %w", label, err)
+	}
+
+	ocr := strings.ToLower(out.String())
+	if marker, ok := findImageLeakMarker(ocr); ok {
+		return fmt.Errorf("%s contains prompt leakage marker %q", label, marker)
+	}
+	return nil
+}
+
+func findImageLeakMarker(text string) (string, bool) {
+	for _, marker := range imageLeakMarkers {
+		if strings.Contains(text, marker) {
+			return marker, true
+		}
+	}
+	return "", false
+}
-- 
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