From 80c26a9550efd118dd2107bfd0509ac1d4c61ba8 Mon Sep 17 00:00:00 2001
From: Anthony Stirling <77850077+Frooodle@users.noreply.github.com>
Date: Sun, 30 Apr 2023 14:42:26 +0100
Subject: [PATCH] fix for OCR multi lang

---
 HowToUseOCR.md                                |  2 ++
 .../controller/api/other/OCRController.java   | 19 +++++++++++++++----
 .../resources/templates/other/ocr-pdf.html    |  4 ++--
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/HowToUseOCR.md b/HowToUseOCR.md
index 1b7d75f9..9a867cbb 100644
--- a/HowToUseOCR.md
+++ b/HowToUseOCR.md
@@ -20,6 +20,8 @@ Depending on your requirements, you can choose the appropriate language pack for
 1. Download the desired language pack(s) by selecting the `.traineddata` file(s) for the language(s) you need.
 2. Place the `.traineddata` files in the Tesseract tessdata directory: `/usr/share/tesseract-ocr/4.00/tessdata`
 
+# DO NOT REMOVE EXISTING ENG.TRAINEDDATA, ITS REQUIRED.
+
 #### Docker
 
 If you are using Docker, you need to expose the Tesseract tessdata directory as a volume in order to use the additional language packs. 
diff --git a/src/main/java/stirling/software/SPDF/controller/api/other/OCRController.java b/src/main/java/stirling/software/SPDF/controller/api/other/OCRController.java
index 9a9b527c..e7534b12 100644
--- a/src/main/java/stirling/software/SPDF/controller/api/other/OCRController.java
+++ b/src/main/java/stirling/software/SPDF/controller/api/other/OCRController.java
@@ -36,6 +36,15 @@ public class OCRController {
 
     private static final Logger logger = LoggerFactory.getLogger(OCRController.class);
 
+    public List<String> getAvailableTesseractLanguages() {
+        String tessdataDir = "/usr/share/tesseract-ocr/4.00/tessdata";
+        File[] files = new File(tessdataDir).listFiles();
+        if (files == null) {
+            return Collections.emptyList();
+        }
+        return Arrays.stream(files).filter(file -> file.getName().endsWith(".traineddata")).map(file -> file.getName().replace(".traineddata", ""))
+                .filter(lang -> !lang.equalsIgnoreCase("osd")).collect(Collectors.toList());
+    }
 
     @PostMapping(consumes = "multipart/form-data", value = "/ocr-pdf")
     public ResponseEntity<byte[]> processPdfWithOCR(@RequestPart(required = true, value = "fileInput") MultipartFile inputFile,
@@ -49,9 +58,11 @@ public class OCRController {
             throw new IOException("Please select at least one language.");
         }
 
-        // Validate and sanitize selected languages using regex
-        String languagePattern = "^[a-zA-Z]{3}$"; // Regex pattern for three-letter language codes
-        selectedLanguages = selectedLanguages.stream().filter(lang -> Pattern.matches(languagePattern, lang)).collect(Collectors.toList());
+        // Get available Tesseract languages
+        List<String> availableLanguages = getAvailableTesseractLanguages();
+
+        // Validate selected languages
+        selectedLanguages = selectedLanguages.stream().filter(availableLanguages::contains).collect(Collectors.toList());
 
         if (selectedLanguages.isEmpty()) {
             throw new IOException("None of the selected languages are valid.");
@@ -69,7 +80,7 @@ public class OCRController {
         // Run OCR Command
         String languageOption = String.join("+", selectedLanguages);
 
-        List<String> command = new ArrayList<>(Arrays.asList("ocrmypdf", "--verbose", "2", "--output-type", "pdf"));
+        List<String> command = new ArrayList<>(Arrays.asList("ocrmypdf", "--verbose", "2", "--output-type", "pdf", "--pdf-renderer" , "hocr"));
 
         if (sidecar != null && sidecar) {
             sidecarTextPath = Files.createTempFile("sidecar", ".txt");
diff --git a/src/main/resources/templates/other/ocr-pdf.html b/src/main/resources/templates/other/ocr-pdf.html
index a1470ac9..b63089e1 100644
--- a/src/main/resources/templates/other/ocr-pdf.html
+++ b/src/main/resources/templates/other/ocr-pdf.html
@@ -20,9 +20,9 @@
                                 <label for="languages" class="form-label" th:text="#{ocr.selectText.1}"></label>
                                 <hr>
                                 <div id="languages">
-                                    <div th:each="language, iterStat : ${languages}" >
+                                    <div th:each="language, iterStat : ${languages}">
                                         <input type="checkbox" class="form-check-input" th:name="languages" th:value="${language}" th:id="${'language-' + language}" />
-                                        <label class="form-check-label" th:for="${'language-' + language}" th:text="  ${language}"></label>
+                                        <label class="form-check-label" th:for="${'language-' + language}" th:text="${(language == 'eng') ? 'English' : language}"></label>
                                     </div>
                                 </div>
                                 <hr>