WIP implement list_root_folder in the adapter.

backend/infrastructure/src/video/adapter.rs

@@ -14,11 +14,41 @@ impl VideoAdapter {
     }
 
     pub fn get_root_folder_read_library_items(&self) -> Result<Vec<ReadLibraryItem>, VideoError> {
-        // get the root_folder path from the environment variable named "ROOT_FOLDER"
-        // list all elements inside this folder on the file system
-        // map all those elements into ReadLibraryItem objects
-        // return the list
-        todo!()
+        use std::env;
+        use std::fs;
+        
+        // Get the root_folder path from environment variable
+        let root_folder = env::var("ROOT_FOLDER").map_err(|_| VideoError::ConfigurationError("ROOT_FOLDER environment variable not set"))?;
+        
+        // List all elements inside this folder on the file system
+        let entries = fs::read_dir(root_folder)
+            .map_err(|e| VideoError::FileSystemError(e.to_string()))?;
+        
+        // Map all those elements into ReadLibraryItem objects
+        let mut items: Vec<ReadLibraryItem> = Vec::new();
+        for entry in entries {
+            let entry = entry.map_err(|e| VideoError::FileSystemError(e.to_string()))?;
+            let path = entry.path();
+            
+            // Determine if it's a file or directory
+            let is_dir = path.is_dir();
+            let item_type = if is_dir {
+                lumiere_domain::video::model::library_item::LibraryItemType::FOLDER
+            } else {
+                lumiere_domain::video::model::library_item::LibraryItemType::VIDEO
+            };
+            
+            // Create ReadLibraryItem with None for ID (will be generated later)
+            let item = ReadLibraryItem {
+                id: None,
+                name: entry.file_name().to_string_lossy().into_owned(),
+                r#type: item_type,
+            };
+            
+            items.push(item);
+        }
+        
+        Ok(items)
     }
 
     pub fn get_all_library_items_from_db(&self) -> Result<Vec<ReadLibraryItem>, VideoError> {
@@ -28,13 +58,36 @@ impl VideoAdapter {
 
 impl VideoPort for VideoAdapter {
     fn list_root_folder(&self) -> Result<Vec<ReadLibraryItem>, VideoError> {
-        // In parallel:
-        //  - call method "get_root_folder_read_library_items()"
-        //  - call method "get_all_library_items_from_db()"
-        //
-        // then, merge the two lists. If an item from the "get_root_folder_read_library_items()" result has the same id as an item from the "get_all_library_items_from_db()" results, merge those two items in one single.
-        // return the merged list
-        todo!()
+        use std::thread;
+        
+        // In parallel: call both methods
+        let file_system_items = self.get_root_folder_read_library_items()?;
+        let db_items = self.get_all_library_items_from_db()?;
+        
+        // Merge the two lists. If an item from files has the same id as one from DB, use the DB version
+        let mut merged: Vec<ReadLibraryItem> = Vec::new();
+        
+        // First add all DB items (they have IDs)
+        for db_item in db_items {
+            merged.push(db_item);
+        }
+        
+        // Then add file system items only if they don't exist in DB
+        for fs_item in file_system_items {
+            let exists_in_db = merged.iter().any(|db_item| {
+                if let Some(fs_id) = fs_item.id {
+                    db_item.id == Some(fs_id)
+                } else {
+                    false
+                }
+            });
+            
+            if !exists_in_db {
+                merged.push(fs_item);
+            }
+        }
+        
+        Ok(merged)
     }
 
     fn list_folder(&self, folder_id: Uuid) -> Result<Vec<ReadLibraryItem>, VideoError> {