Added Flatpak PDFium library lookup (#834)

runtime/src/app_window.rs

@@ -24,7 +24,9 @@ use tokio::sync::broadcast;
 use tokio::time;
 use crate::api_token::APIToken;
 use crate::dotnet::{cleanup_dotnet_server, start_dotnet_server, stop_dotnet_server};
-use crate::environment::{is_prod, is_dev, CONFIG_DIRECTORY, DATA_DIRECTORY};
+use crate::environment::{
+    is_prod, is_dev, is_flatpak, CONFIG_DIRECTORY, DATA_DIRECTORY, FLATPAK_LIBRARY_DIRECTORY,
+};
 use crate::log::switch_to_file_logging;
 use crate::pdfium::PDFIUM_LIB_PATH;
 use crate::qdrant_edge_database::{start_qdrant_edge_database, stop_qdrant_edge_database};
@@ -974,7 +976,7 @@ fn set_pdfium_path<R: tauri::Runtime>(path_resolver: &PathResolver<R>) {
         }
     };
 
-    match select_pdfium_library_directory(&resource_dir) {
+    match select_pdfium_library_directory(&resource_dir, is_flatpak()) {
         Some(path) => {
             *PDFIUM_LIB_PATH.lock().unwrap() = Some(path.to_string_lossy().to_string());
         }
@@ -984,11 +986,23 @@ fn set_pdfium_path<R: tauri::Runtime>(path_resolver: &PathResolver<R>) {
     }
 }
 
-fn select_pdfium_library_directory(resource_dir: &Path) -> Option<PathBuf> {
-    let candidate_paths = [
-        resource_dir.join("resources").join("libraries"),
-        resource_dir.join("libraries"),
-    ];
+fn select_pdfium_library_directory(resource_dir: &Path, include_flatpak_library_directory: bool) -> Option<PathBuf> {
+    select_pdfium_library_directory_for(resource_dir, include_flatpak_library_directory, Path::new(FLATPAK_LIBRARY_DIRECTORY))
+}
+
+fn select_pdfium_library_directory_for(
+    resource_dir: &Path,
+    include_flatpak_library_directory: bool,
+    flatpak_library_directory: &Path,
+) -> Option<PathBuf> {
+    let mut candidate_paths = Vec::new();
+
+    if include_flatpak_library_directory {
+        candidate_paths.push(flatpak_library_directory.to_path_buf());
+    }
+
+    candidate_paths.push(resource_dir.join("resources").join("libraries"));
+    candidate_paths.push(resource_dir.join("libraries"));
 
     for path in candidate_paths {
         let pdfium_library_path = Pdfium::pdfium_platform_library_name_at_path(&path);
@@ -1022,7 +1036,7 @@ mod tests {
         create_pdfium_library_in(&libraries);
 
         assert_eq!(
-            select_pdfium_library_directory(temp_dir.path()),
+            select_pdfium_library_directory(temp_dir.path(), false),
             Some(resources_libraries)
         );
     }
@@ -1036,7 +1050,7 @@ mod tests {
         create_pdfium_library_in(&libraries);
 
         assert_eq!(
-            select_pdfium_library_directory(temp_dir.path()),
+            select_pdfium_library_directory(temp_dir.path(), false),
             Some(libraries)
         );
     }
@@ -1047,7 +1061,33 @@ mod tests {
         fs::create_dir_all(temp_dir.path().join("resources").join("libraries")).unwrap();
         fs::create_dir_all(temp_dir.path().join("libraries")).unwrap();
 
-        assert_eq!(select_pdfium_library_directory(temp_dir.path()), None);
+        assert_eq!(select_pdfium_library_directory(temp_dir.path(), false), None);
+    }
+
+    #[test]
+    fn pdfium_library_directory_prefers_flatpak_library_directory_when_flatpak() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let flatpak_library_directory = temp_dir.path().join("app").join("lib");
+        let resources_libraries = temp_dir.path().join("resources").join("libraries");
+        create_pdfium_library_in(&flatpak_library_directory);
+        create_pdfium_library_in(&resources_libraries);
+
+        assert_eq!(
+            select_pdfium_library_directory_for(temp_dir.path(), true, &flatpak_library_directory),
+            Some(flatpak_library_directory)
+        );
+    }
+
+    #[test]
+    fn pdfium_library_directory_skips_flatpak_library_directory_when_not_flatpak() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let flatpak_library_directory = temp_dir.path().join("app").join("lib");
+        create_pdfium_library_in(&flatpak_library_directory);
+
+        assert_eq!(
+            select_pdfium_library_directory_for(temp_dir.path(), false, &flatpak_library_directory),
+            None
+        );
     }
 
     fn create_pdfium_library_in(path: &Path) {

runtime/src/environment.rs

@@ -31,6 +31,8 @@ pub const DOTNET_ENV_CUSTOM_ROOT_CERTIFICATE_ALLOWED_HOSTS: &str = "AI_STUDIO_EX
 #[cfg(any(target_os = "linux", test))]
 const FLATPAK_ENTERPRISE_POLICY_DIRECTORY: &str = "/app/etc/MindWorkAI";
 
+pub(crate) const FLATPAK_LIBRARY_DIRECTORY: &str = "/app/lib";
+
 const ENTERPRISE_ENV_CONFIG_ID_PREFIX: &str = "MINDWORK_AI_STUDIO_ENTERPRISE_CONFIG_ID";
 const ENTERPRISE_ENV_CONFIG_SERVER_URL_PREFIX: &str = "MINDWORK_AI_STUDIO_ENTERPRISE_CONFIG_SERVER_URL";
 const ENTERPRISE_ENV_CONFIGS: &str = "MINDWORK_AI_STUDIO_ENTERPRISE_CONFIGS";

runtime/src/pdfium.rs

@@ -2,7 +2,7 @@ use std::error::Error;
 use std::sync::Mutex;
 use once_cell::sync::Lazy;
 use pdfium_render::prelude::Pdfium;
-use log::{error, warn};
+use log::{error, info, warn};
 
 pub static PDFIUM_LIB_PATH: Lazy<Mutex<Option<String>>> = Lazy::new(|| Mutex::new(None));
 static PDFIUM: Lazy<Mutex<Option<Pdfium>>> = Lazy::new(|| Mutex::new(None));
@@ -32,11 +32,22 @@ impl PdfiumInit for Pdfium {
 fn load_pdfium() -> Result<Pdfium, String> {
     let lib_path = PDFIUM_LIB_PATH.lock().unwrap().clone();
     if let Some(path) = lib_path.as_ref() {
-        return match Pdfium::bind_to_library(Pdfium::pdfium_platform_library_name_at_path(path)) {
-            Ok(binding) => Ok(Pdfium::new(binding)),
+        let pdfium_library_path = Pdfium::pdfium_platform_library_name_at_path(path);
+
+        return match Pdfium::bind_to_library(&pdfium_library_path) {
+            Ok(binding) => {
+                info!("Loaded PDFium from '{path}'.", path = pdfium_library_path.to_string_lossy());
+                Ok(Pdfium::new(binding))
+            },
             Err(library_error) => {
                 match Pdfium::bind_to_system_library() {
-                    Ok(binding) => Ok(Pdfium::new(binding)),
+                    Ok(binding) => {
+                        info!(
+                            "Loaded PDFium from the system library after failing to load '{path}'.",
+                            path = pdfium_library_path.to_string_lossy(),
+                        );
+                        Ok(Pdfium::new(binding))
+                    },
                     Err(system_error) => {
                         let error_message = format!(
                             "Failed to load PDFium from '{path}' and the system library. Developer action (from repo root): run the build script once to download the required PDFium version: `cd app/Build` and `dotnet run build`. Details: library error: '{library_error}'; system error: '{system_error}'."
@@ -52,7 +63,10 @@ fn load_pdfium() -> Result<Pdfium, String> {
 
     warn!("No custom PDFium library path set; trying to load PDFium from the system library.");
     match Pdfium::bind_to_system_library() {
-        Ok(binding) => Ok(Pdfium::new(binding)),
+        Ok(binding) => {
+            info!("Loaded PDFium from the system library.");
+            Ok(Pdfium::new(binding))
+        },
         Err(system_error) => {
             let error_message = format!(
                 "Failed to load PDFium from the system library. Developer action (from repo root): run the build script once to download the required PDFium version: `cd app/Build` and `dotnet run build`. Details: '{system_error}'."