Update app.py

def remove_pdf(filename, state):
if filename not in state["files"]:
return (
f"{filename} not found.",
state,
gr.update(choices=list(state["files"].keys()), value=None)
)

# Remove the file entry
state["files"].pop(filename, None)

# Rebuild chunks from remaining files
all_chunks = []
for chunks in state["files"].values():
all_chunks.extend(chunks)

state["chunks"] = all_chunks
state["pdf_count"] = len(state["files"])

if state["chunks"]:
index, _ = build_vectorstore(state["chunks"])
state["index"] = index
else:
state["index"] = None

return (
f"Removed {filename}. Total chunks: {len(state['chunks'])}",
state,
gr.update(choices=list(state["files"].keys()), value=None)
)

app.py

@@ -147,15 +147,35 @@ def generate_answer(question, context):
 # ============================================================
 
 def load_pdf(files, state):
+    # files is the *current* list from the UI (after add/remove)
+    # We rebuild everything from scratch to stay in sync.
+
+    # If user cleared all files
     if not files:
-        return "No file uploaded.", state, list(state["files"].keys())
+        state["chunks"] = []
+        state["files"] = {}
+        state["pdf_count"] = 0
+        state["index"] = None
+
+        return (
+            "No file uploaded.",
+            state,
+            gr.update(choices=[], value=None)  # empty dropdown
+        )
 
     try:
-        # Deduplicate file paths
+        # Reset state and rebuild from current files only
+        state["chunks"] = []
+        state["files"] = {}
+        state["pdf_count"] = 0
+
+        # Deduplicate while preserving order
         unique_files = list(dict.fromkeys(files))
 
         for file in unique_files:
-            filename = os.path.basename(file)  # FIX: file is a string path
+            # In Gradio 6, gr.Files usually gives you temp paths (strings)
+            # PdfReader accepts a path or file-like object, so we can pass `file` directly.
+            filename = os.path.basename(str(file))
 
             text = read_pdf(file)
             new_chunks = chunk_text(text)
@@ -174,39 +194,45 @@ def load_pdf(files, state):
         return (
             f"{state['pdf_count']} PDF(s) loaded. Total chunks: {len(state['chunks'])}",
             state,
-            list(state["files"].keys())  # dropdown now works
+            gr.update(choices=list(state["files"].keys()), value=None)  # <-- key fix
         )
 
     except Exception as e:
         return (
             f"Error processing PDF: {e}",
             state,
-            list(state["files"].keys())
+            gr.update(choices=list(state["files"].keys()), value=None)
         )
         
 def remove_pdf(filename, state):
     if filename not in state["files"]:
-        return f"{filename} not found.", state, list(state["files"].keys())
+        return (
+            f"{filename} not found.",
+            state,
+            gr.update(choices=list(state["files"].keys()), value=None)
+        )
+
+    # Remove the file entry
+    state["files"].pop(filename, None)
 
-    # Remove its chunks
-    chunks_to_remove = state["files"].pop(filename)
+    # Rebuild chunks from remaining files
+    all_chunks = []
+    for chunks in state["files"].values():
+        all_chunks.extend(chunks)
 
-    # Remove from global chunk list
-    state["chunks"] = [c for c in state["chunks"] if c not in chunks_to_remove]
+    state["chunks"] = all_chunks
+    state["pdf_count"] = len(state["files"])
 
-    # Rebuild FAISS
     if state["chunks"]:
         index, _ = build_vectorstore(state["chunks"])
         state["index"] = index
     else:
         state["index"] = None
 
-    state["pdf_count"] -= 1
-
     return (
         f"Removed {filename}. Total chunks: {len(state['chunks'])}",
         state,
-        list(state["files"].keys())
+        gr.update(choices=list(state["files"].keys()), value=None)
     )
 
 def answer_question(question, state):