Update app.py

app.py

@@ -1,77 +1,97 @@
-# app.py  ─  Streamlit + LangChain + Groq
-import os, asyncio, streamlit as st
-from dotenv import load_dotenv
-from langchain.schema import SystemMessage, HumanMessage, AIMessage
+import os, re, validators, streamlit as st
+from youtube_transcript_api import YouTubeTranscriptApi, TranscriptsDisabled, VideoUnavailable
+from langchain.prompts import PromptTemplate
+from langchain.chains.summarize import load_summarize_chain
 from langchain_groq import ChatGroq
+from langchain.schema import Document
+from langchain_community.document_loaders import UnstructuredURLLoader
+from langchain.document_loaders import PyPDFLoader
 
-# ─────────────────────────  bootstrap event‑loop  ─────────────────────
-try:
-    asyncio.get_running_loop()
-except RuntimeError:
-    asyncio.set_event_loop(asyncio.new_event_loop())
-if os.name == "nt":
-    import asyncio as _asyncio
-    asyncio.set_event_loop_policy(_asyncio.WindowsSelectorEventLoopPolicy())
-
-# ───────────────────────────  UI  /  SETTINGS  ────────────────────────
-st.set_page_config("Groq Chatbot", "🤖")
-st.title("🤖  Groq‑powered Advanced Chatbot")
-st.caption("DeepSeek‑R1‑Distill‑Llama‑70B • LangChain • Streamlit")
+# ─────────────────────────  STREAMLIT CONFIG  ──────────────────────────
+st.set_page_config(page_title="LangChain Summarizer", page_icon="🦜")
+st.title("🦜 LangChain: Summarize YT / Webpage / PDF")
 
+# ────────────────────────────  API KEY INPUT  ──────────────────────────
 with st.sidebar:
-    st.header("🔑  Groq API Key")
-    groq_key = st.text_input("Paste your key here", type="password")
-    st.divider()
-    temperature = st.slider("Temperature", 0.0, 1.2, 0.7, 0.1)
-    top_p       = st.slider("Top‑p",       0.0, 1.0, 1.0, 0.05)
-    st.markdown("*All values remain local to your browser.*")
+    st.header("API keys")
+    groq_api_key = st.text_input("Groq API Key", type="password")
+    if groq_api_key:
+        os.environ["GROQ_API_KEY"] = groq_api_key          # for libraries
+
+# ─────────────────────  PLACEHOLDERS / FILE & URL INPUT  ───────────────
+generic_url   = st.text_input("Paste a YouTube / web URL here:")
+uploaded_file = st.file_uploader("…or upload a PDF", type=["pdf"])
 
-user_q = st.chat_input("Type your message…")
+# ──────────────────────────  UTILITY FUNCTIONS  ────────────────────────
+def get_video_id(url: str) -> str | None:
+    m = re.search(r"(?:v=|\/)([0-9A-Za-z_-]{11})", url)
+    return m.group(1) if m else None
 
-# ──────────────────────────  LLM (lazy init)  ─────────────────────────
-MODEL_NAME = "deepseek-r1-distill-llama-70b"
+SUMMARY_PROMPT = PromptTemplate(
+    template="Provide a concise summary (~300 words):\n\nContent:\n{text}",
+    input_variables=["text"],
+)
 
-def get_llm():
+def build_llm() -> ChatGroq:
+    """Instantiate ChatGroq once and cache it in session_state."""
     if "llm" not in st.session_state:
-        key = groq_key or os.getenv("GROQ_API_KEY")
-        if not key:
-            raise ValueError("Add your Groq key in the sidebar.")
-        os.environ["GROQ_API_KEY"] = key                  # for the client
         st.session_state.llm = ChatGroq(
-            model        = MODEL_NAME,
-            groq_api_key = key,
-            temperature  = temperature,
-            top_p        = top_p,
+            model="llama3-70b-8192",
+            groq_api_key=os.environ["GROQ_API_KEY"],
         )
-    # refresh sampling params if the sliders changed
-    llm = st.session_state.llm
-    llm.temperature = temperature
-    llm.top_p       = top_p
-    return llm
+    return st.session_state.llm
 
-# ─────────────────────────  conversation memory  ──────────────────────
-if "history" not in st.session_state:
-    st.session_state.history = [
-        SystemMessage(content="You are an advanced, helpful assistant.")
-    ]
+def summarize(docs):
+    llm   = build_llm()
+    chain = load_summarize_chain(llm, chain_type="stuff", prompt=SUMMARY_PROMPT)
+    return chain({"input_documents": docs})["output_text"]
 
-# ────────────────────────────  main loop  ─────────────────────────────
-if user_q:
-    st.session_state.history.append(HumanMessage(content=user_q))
+# ────��────────────────────────  MAIN ACTION  ───────────────────────────
+if st.button("Summarize"):
+    if not groq_api_key:
+        st.error("Please enter your Groq API key in the sidebar.")
+    elif not generic_url and not uploaded_file:
+        st.error("Provide a URL or upload a PDF, then press Summarize.")
+    else:
+        try:
+            with st.spinner("Fetching and summarizing…"):
 
-    try:
-        with st.chat_message("assistant", avatar="🤖"):
-            with st.spinner("Thinking…"):
-                answer = get_llm().invoke(st.session_state.history).content
-            st.markdown(answer)
+                # ---------- PDF ----------
+                if uploaded_file:
+                    tmp_path = f"/tmp/{uploaded_file.name}"
+                    with open(tmp_path, "wb") as f:
+                        f.write(uploaded_file.read())
+                    docs = PyPDFLoader(tmp_path).load()
+                    st.success(summarize(docs))
+                    os.remove(tmp_path)
 
-        st.session_state.history.append(AIMessage(content=answer))
+                # ---------- YouTube ----------
+                elif "youtube" in generic_url or "youtu.be" in generic_url:
+                    vid = get_video_id(generic_url)
+                    if not vid:
+                        st.error("Couldn’t extract a YouTube video ID 🤔")
+                    else:
+                        transcript = YouTubeTranscriptApi.get_transcript(vid)
+                        text = " ".join(t["text"] for t in transcript)
+                        st.success(summarize([Document(page_content=text)]))
 
-    except Exception as err:
-        st.error(f"**Error:** {err}")
+                # ---------- Plain Webpage ----------
+                else:
+                    if not validators.url(generic_url):
+                        st.error("That doesn’t look like a valid URL.")
+                    else:
+                        docs = UnstructuredURLLoader(
+                            urls=[generic_url],
+                            ssl_verify=False,
+                            headers={
+                                "User-Agent":
+                                "Mozilla/5.0 (X11; Linux) AppleWebKit/537.36 "
+                                "(KHTML, like Gecko) Chrome/121.0 Safari/537.36"
+                            },
+                        ).load()
+                        st.success(summarize(docs))
 
-# ────────────────────────  display chat history  ──────────────────────
-for msg in st.session_state.history[1:]:              # skip system message
-    role = "user" if isinstance(msg, HumanMessage) else "assistant"
-    with st.chat_message(role):
-        st.markdown(msg.content)
+        except (TranscriptsDisabled, VideoUnavailable) as yt_err:
+            st.error(str(yt_err))
+        except Exception as e:
+            st.exception(e)