Auto detect presence of external dependencies (LibreOffice etc) and disable/enable features dynamically (#2082)

* Create ExternalAppDepConfig.java

* Update EndpointConfiguration.java

* Hardening suggestions for Stirling-PDF / ExternalAppDepConfig (#2083)

Switch order of literals to prevent NullPointerException

Co-authored-by: pixeebot[bot] <104101892+pixeebot[bot]@users.noreply.github.com>

---------

Co-authored-by: pixeebot[bot] <104101892+pixeebot[bot]@users.noreply.github.com>

src/main/java/stirling/software/SPDF/config/EndpointConfiguration.java

@@ -5,6 +5,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -42,7 +43,7 @@ public class EndpointConfiguration {
 
     public void disableEndpoint(String endpoint) {
         if (!endpointStatuses.containsKey(endpoint) || endpointStatuses.get(endpoint) != false) {
-            logger.info("Disabling {}", endpoint);
+            logger.debug("Disabling {}", endpoint);
             endpointStatuses.put(endpoint, false);
         }
     }
@@ -76,6 +77,23 @@ public class EndpointConfiguration {
         }
     }
 
+    public void logDisabledEndpointsSummary() {
+        List<String> disabledList =
+                endpointStatuses.entrySet().stream()
+                        .filter(entry -> !entry.getValue()) // only get disabled endpoints (value
+                        // is false)
+                        .map(Map.Entry::getKey)
+                        .sorted()
+                        .collect(Collectors.toList());
+
+        if (!disabledList.isEmpty()) {
+            logger.info(
+                    "Total disabled endpoints: {}. Disabled endpoints: {}",
+                    disabledList.size(),
+                    String.join(", ", disabledList));
+        }
+    }
+
     public void init() {
         // Adding endpoints to "PageOps" group
         addEndpointToGroup("PageOps", "remove-pages");
@@ -163,14 +181,12 @@ public class EndpointConfiguration {
 
         // python
         addEndpointToGroup("Python", "extract-image-scans");
-        addEndpointToGroup("Python", REMOVE_BLANKS);
         addEndpointToGroup("Python", "html-to-pdf");
         addEndpointToGroup("Python", "url-to-pdf");
         addEndpointToGroup("Python", "pdf-to-img");
 
         // openCV
         addEndpointToGroup("OpenCV", "extract-image-scans");
-        addEndpointToGroup("OpenCV", REMOVE_BLANKS);
 
         // LibreOffice
         addEndpointToGroup("LibreOffice", "repair");
@@ -230,6 +246,17 @@ public class EndpointConfiguration {
         addEndpointToGroup("Javascript", "sign");
         addEndpointToGroup("Javascript", "compare");
         addEndpointToGroup("Javascript", "adjust-contrast");
+
+        // Ghostscript dependent endpoints
+        addEndpointToGroup("Ghostscript", "compress-pdf");
+        addEndpointToGroup("Ghostscript", "pdf-to-pdfa");
+
+        // Weasyprint dependent endpoints
+        addEndpointToGroup("Weasyprint", "html-to-pdf");
+        addEndpointToGroup("Weasyprint", "url-to-pdf");
+
+        // Pdftohtml dependent endpoints
+        addEndpointToGroup("Pdftohtml", "pdf-to-html");
     }
 
     private void processEnvironmentConfigs() {
@@ -251,5 +278,9 @@ public class EndpointConfiguration {
         }
     }
 
+    public Set<String> getEndpointsForGroup(String group) {
+        return endpointGroups.getOrDefault(group, new HashSet<>());
+    }
+
     private static final String REMOVE_BLANKS = "remove-blanks";
 }

src/main/java/stirling/software/SPDF/config/ExternalAppDepConfig.java

@@ -0,0 +1,146 @@
+package stirling.software.SPDF.config;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+
+import jakarta.annotation.PostConstruct;
+import lombok.extern.slf4j.Slf4j;
+
+@Configuration
+@Slf4j
+public class ExternalAppDepConfig {
+    @Autowired private EndpointConfiguration endpointConfiguration;
+
+    private boolean isCommandAvailable(String command) {
+        try {
+            ProcessBuilder processBuilder = new ProcessBuilder();
+            if (System.getProperty("os.name").toLowerCase().contains("windows")) {
+                processBuilder.command("where", command);
+            } else {
+                processBuilder.command("which", command);
+            }
+            Process process = processBuilder.start();
+            int exitCode = process.waitFor();
+            return exitCode == 0;
+        } catch (Exception e) {
+            log.debug("Error checking for command {}: {}", command, e.getMessage());
+            return false;
+        }
+    }
+
+    private final Map<String, List<String>> commandToGroupMapping =
+            new HashMap<>() {
+                {
+                    put("gs", List.of("Ghostscript"));
+                    put("soffice", List.of("LibreOffice"));
+                    put("ocrmypdf", List.of("OCRmyPDF"));
+                    put("weasyprint", List.of("Weasyprint"));
+                    put("pdftohtml", List.of("Pdftohtml"));
+                }
+            };
+
+    private List<String> getAffectedFeatures(String group) {
+        return endpointConfiguration.getEndpointsForGroup(group).stream()
+                .map(endpoint -> formatEndpointAsFeature(endpoint))
+                .collect(Collectors.toList());
+    }
+
+    private String formatEndpointAsFeature(String endpoint) {
+        // First replace common terms
+        String feature = endpoint.replace("-", " ").replace("pdf", "PDF").replace("img", "image");
+
+        // Split into words and capitalize each word
+        return Arrays.stream(feature.split("\\s+"))
+                .map(word -> capitalizeWord(word))
+                .collect(Collectors.joining(" "));
+    }
+
+    private String capitalizeWord(String word) {
+        if (word.isEmpty()) {
+            return word;
+        }
+        if ("pdf".equalsIgnoreCase(word)) {
+            return "PDF";
+        }
+        return word.substring(0, 1).toUpperCase() + word.substring(1).toLowerCase();
+    }
+
+    private void checkDependencyAndDisableGroup(String command) {
+        boolean isAvailable = isCommandAvailable(command);
+        if (!isAvailable) {
+            List<String> affectedGroups = commandToGroupMapping.get(command);
+
+            if (affectedGroups != null) {
+                for (String group : affectedGroups) {
+                    List<String> affectedFeatures = getAffectedFeatures(group);
+                    endpointConfiguration.disableGroup(group);
+                    log.warn(
+                            "Missing dependency: {} - Disabling group: {} (Affected features: {})",
+                            command,
+                            group,
+                            affectedFeatures != null && !affectedFeatures.isEmpty()
+                                    ? String.join(", ", affectedFeatures)
+                                    : "unknown");
+                }
+            }
+        }
+    }
+
+    @PostConstruct
+    public void checkDependencies() {
+
+        // Check core dependencies
+        checkDependencyAndDisableGroup("gs");
+        checkDependencyAndDisableGroup("soffice");
+        checkDependencyAndDisableGroup("ocrmypdf");
+        checkDependencyAndDisableGroup("weasyprint");
+        checkDependencyAndDisableGroup("pdftohtml");
+
+        // Special handling for Python/OpenCV dependencies
+        boolean pythonAvailable = isCommandAvailable("python3") || isCommandAvailable("python");
+        if (!pythonAvailable) {
+            List<String> pythonFeatures = getAffectedFeatures("Python");
+            List<String> openCVFeatures = getAffectedFeatures("OpenCV");
+
+            endpointConfiguration.disableGroup("Python");
+            endpointConfiguration.disableGroup("OpenCV");
+            log.warn(
+                    "Missing dependency: Python - Disabling Python features: {} and OpenCV features: {}",
+                    String.join(", ", pythonFeatures),
+                    String.join(", ", openCVFeatures));
+        } else {
+            // If Python is available, check for OpenCV
+            try {
+                ProcessBuilder processBuilder = new ProcessBuilder();
+                if (System.getProperty("os.name").toLowerCase().contains("windows")) {
+                    processBuilder.command("python", "-c", "import cv2");
+                } else {
+                    processBuilder.command("python3", "-c", "import cv2");
+                }
+                Process process = processBuilder.start();
+                int exitCode = process.waitFor();
+                if (exitCode != 0) {
+                    List<String> openCVFeatures = getAffectedFeatures("OpenCV");
+                    endpointConfiguration.disableGroup("OpenCV");
+                    log.warn(
+                            "OpenCV not available in Python - Disabling OpenCV features: {}",
+                            String.join(", ", openCVFeatures));
+                }
+            } catch (Exception e) {
+                List<String> openCVFeatures = getAffectedFeatures("OpenCV");
+                endpointConfiguration.disableGroup("OpenCV");
+                log.warn(
+                        "Error checking OpenCV: {} - Disabling OpenCV features: {}",
+                        e.getMessage(),
+                        String.join(", ", openCVFeatures));
+            }
+        }
+        endpointConfiguration.logDisabledEndpointsSummary();
+    }
+}