Create PPTX file and allow to download

chat_app.py

@@ -1,5 +1,8 @@
 import logging
+import pathlib
 import random
+import tempfile
+from typing import List
 
 import json5
 import streamlit as st
@@ -10,8 +13,7 @@ from langchain_core.prompts import ChatPromptTemplate
 from langchain_core.runnables.history import RunnableWithMessageHistory
 
 from global_config import GlobalConfig
-from helpers import llm_helper
-
+from helpers import llm_helper, pptx_helper
 
 APP_TEXT = json5.loads(open(GlobalConfig.APP_STRINGS_FILE, 'r', encoding='utf-8').read())
 # langchain.debug = True
@@ -89,7 +91,8 @@ def set_up_chat_ui():
     )
 
     for msg in history.messages:
-        st.chat_message(msg.type).markdown(msg.content)
+        # st.chat_message(msg.type).markdown(msg.content)
+        st.chat_message(msg.type).code(msg.content, language='json')
 
     progress_bar.progress(100, text='Done!')
     progress_bar.empty()
@@ -101,11 +104,74 @@ def set_up_chat_ui():
         logger.debug('User input: %s', prompt)
         st.chat_message('user').write(prompt)
 
+        progress_bar_pptx = st.progress(0, 'Calling LLM...')
+
         # As usual, new messages are added to StreamlitChatMessageHistory when the Chain is called
         config = {'configurable': {'session_id': 'any'}}
-        response = chain_with_history.invoke({'question': prompt}, config)
+        response: str = chain_with_history.invoke({'question': prompt}, config)
         st.chat_message('ai').markdown('```json\n' + response)
 
+        # The content has been generated as JSON
+        # There maybe trailing ``` at the end of the response -- remove them
+        # To be careful: ``` may be part of the content as well when code is generated
+        str_len = len(response)
+        response_cleaned = response
+
+        progress_bar_pptx.progress(50, 'Analyzing response...')
+
+        try:
+            idx = response.rindex('```')
+            logger.debug('str_len: %d, idx of ```: %d', str_len, idx)
+
+            if idx + 3 == str_len:
+                # The response ends with ``` -- most likely the end of JSON response string
+                response_cleaned = response[:idx]
+            elif idx + 3 < str_len:
+                # Looks like there are some more content beyond the last ```
+                # In the best case, it would be some additional plain-text response from the LLM
+                # and is unlikely to contain } or ] that are present in JSON
+                if '}' not in response[idx + 3:]:  # the remainder of the text
+                    response_cleaned = response[:idx]
+        except ValueError:
+            # No ``` found
+            pass
+
+        # Now create the PPT file
+        progress_bar_pptx.progress(75, 'Creating the slide deck...give it a moment')
+        generate_slide_deck(response_cleaned, pptx_template='Blank')
+        progress_bar_pptx.progress(100, text='Done!')
+
+
+def generate_slide_deck(json_str: str, pptx_template: str) -> List:
+    """
+    Create a slide deck.
+
+    :param json_str: The content in *valid* JSON format.
+    :param pptx_template: The PPTX template name.
+    :return: A list of all slide headers and the title.
+    """
+
+    # # Get a unique name for the file to save -- use the session ID
+    # ctx = st_sr.get_script_run_ctx()
+    # session_id = ctx.session_id
+    # timestamp = time.time()
+    # output_file_name = f'{session_id}_{timestamp}.pptx'
+
+    temp = tempfile.NamedTemporaryFile(delete=False, suffix='.pptx')
+    path = pathlib.Path(temp.name)
+
+    logger.info('Creating PPTX file...')
+    all_headers = pptx_helper.generate_powerpoint_presentation(
+        json_str,
+        slides_template=pptx_template,
+        output_file_path=path
+    )
+
+    with open(path, 'rb') as f:
+        st.download_button('Download PPTX file ⇩', f, file_name='Presentation.pptx')
+
+    return all_headers
+
 
 def main():
     """