Infinite changes. Not working as I like, I can't make it flow as desired

app.py

@@ -1,21 +1,48 @@
 import gradio as gr
 from openai import OpenAI
-import os
-import json
+import tiktoken
+from os import getenv as os_getenv
+from json import loads as json_loads
+from pathlib import Path
+import fitz
 
-api_key = os.getenv("OPENAI_APIKEY")
+api_key = os_getenv("OPENAI_APIKEY")
 client = OpenAI(api_key=api_key)
 
-def chat(message, history):
+def get_prompt(books, question = None):
+    prompt = (
+        f"Read the following books.\n" +
+        f"Each book may have some pages at the beggining with data about the book, an index, or table of content, etc. " +
+        f"Pages may have a header and/or a footer. Consider all this maybe present." +
+        f"Please answer all below in the suggested format, in the language of the book:\n"+
+        f"**Title**: ...\n"
+        f"**Author**: ...\n"
+        f"**Chapter Names**: ...\n"
+        f"**Characters**: \n"
+        f"**Detailed Summary**: \n"
+    )
+    prompt += f"{books}\n" 
+
+    return prompt
+
+def chat(message, history, files):
     history_openai_format = []
-    for human, assistant in history:
-        if (assistant is not None) and (type(human) is str):
-            history_openai_format.append({"role": "user", "content": human })
-            history_openai_format.append({"role": "assistant", "content":assistant})
-        
-    history_openai_format.append({"role": "user", "content": message['text']})
-  
-    print(f"{history}\n----\n{message}\n----\n{history_openai_format}")
+
+    if len(history) == 0:
+        raise gr.Error("Primero hay que subir un libro")
+
+    if len(history) == 1:
+        if message:
+            raise gr.Error("First message must be empty")
+        message = history[0][0]
+    else:
+        for human, assistant in history:
+            if human:
+                history_openai_format.append({"role": "user", "content": human })
+            if assistant:
+                history_openai_format.append({"role": "assistant", "content":assistant})
+    
+    history_openai_format.append({"role": "user", "content": message})
 
     response = client.chat.completions.create(
         model='gpt-4-turbo',
@@ -29,12 +56,47 @@ def chat(message, history):
               partial_message = partial_message + chunk.choices[0].delta.content
               yield partial_message
 
-demo = gr.ChatInterface(
-    fn=chat,
-    # examples=[{"text": "hello"}, {"text": "hola"}, {"text": "merhaba"}],
-    title="Summarization and more",
-    multimodal=True)
+def get_text(filename):
+    answer = ""
+    suffix = Path(filename).suffix
+    if suffix in [".pdf"]:
+        for i,page in enumerate(fitz.open(filename)):
+            answer += f"\n### Page #{i+1}\n{page.get_text()}\n"
+    elif suffix in [".txt"]:
+        answer = open(filename).read()
+    return answer
+
+def files_ready(filenames):
+    encoder = encoding = tiktoken.encoding_for_model('gpt-4-turbo')
+    answer = ''
+    for i, name in enumerate(filenames):
+        answer += f"\n## Document #{i+1}\nName: {Path(name).name}\n"
+        answer += get_text(name)
+
+    return len(encoder.encode(answer)), [[get_prompt(answer), None]]
+
+def files_changed(filenames):
+    if not filenames:
+        return 0
+    
+with gr.Blocks(title="Book summarization and more") as demo:
+    with gr.Row():
+        files = gr.Files(file_types=["txt","doc","docx","pdf"] )
+        tokens = gr.Text("0", label="Tokens")
+
+    chat = gr.ChatInterface(
+        fn=chat,
+        title="Summarization and more",
+        additional_inputs=[files],
+        multimodal=False)
+    
+    other = gr.Button(interactive=False)
+    files.upload(files_ready, [files], [tokens, chat.chatbot_state])
+    files.change(files_changed, files, tokens)
+
+
+auth=os_getenv("APP_USERS", "null")
+auth=json_loads(auth)
 
-auth=os.environ.get("APP_USERS", "null")
-auth=json.loads(auth)
 demo.launch(auth=auth)
+