app.py

###############################################################################
# app.py – Weather Umbrella Advisor (Streamlit + OpenWeatherMap + Claude 3)  #
###############################################################################
import os, json, requests, boto3, streamlit as st
from dotenv import load_dotenv

# --------------------------------------------------------------------------- #
# 1) Load env vars (local .env or HF Space “Secrets”)                         #
# --------------------------------------------------------------------------- #
load_dotenv()
OPENWEATHERMAP_API_KEY = os.getenv("OPENWEATHERMAP_API_KEY")
AWS_REGION            = os.getenv("AWS_REGION", "us-east-1")
AWS_ACCESS_KEY_ID     = os.getenv("AWS_ACCESS_KEY_ID")    # may be None
AWS_SECRET_ACCESS_KEY = os.getenv("AWS_SECRET_ACCESS_KEY")  # may be None

# --- Heuristic: auto-swap if ID looks like a secret (contains “/”) ----------
if AWS_ACCESS_KEY_ID and "/" in AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY and "/" not in AWS_SECRET_ACCESS_KEY:
    AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY = AWS_SECRET_ACCESS_KEY, AWS_ACCESS_KEY_ID

# --------------------------------------------------------------------------- #
# 2) Create Bedrock client, preferring explicit keys if they’re present        #
# --------------------------------------------------------------------------- #
if AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY:
    session = boto3.Session(
        aws_access_key_id     = AWS_ACCESS_KEY_ID,
        aws_secret_access_key = AWS_SECRET_ACCESS_KEY,
        region_name           = AWS_REGION,
    )
else:
    # Falls back to IAM role or default credentials chain
    session = boto3.Session(region_name=AWS_REGION)

bedrock = session.client("bedrock-runtime")

# Quick sanity-check – will raise if creds are still wrong
try:
    _ = bedrock.meta.region_name  # simple attribute access forces no call
except Exception as e:
    st.error(f"Credential problem: {e}")
    st.stop()

# --------------------------------------------------------------------------- #
# 3) Streamlit page style                                                     #
# --------------------------------------------------------------------------- #
st.set_page_config(page_title="🌤️ Umbrella Advisor", page_icon="☔", layout="centered")
st.markdown("""
<div style="text-align:center">
  <h1 style="color:#3c79f5;">☔ Weather Umbrella Advisor</h1>
  <p style="font-size:18px">Ask if you need an umbrella tomorrow – powered by <b>Claude 3</b> &amp; <b>OpenWeatherMap</b>.</p>
</div>
""", unsafe_allow_html=True)

# --------------------------------------------------------------------------- #
# 4) Conversation state                                                       #
# --------------------------------------------------------------------------- #
if "messages" not in st.session_state:
    st.session_state.messages = []

for m in st.session_state.messages:
    with st.chat_message(m["role"]):
        st.markdown(m["content"])

# --------------------------------------------------------------------------- #
# 5) Helper – get weather                                                     #
# --------------------------------------------------------------------------- #
def get_weather(city: str):
    if not city.strip():
        return {"error": "Please give me a city name."}

    geo = f"http://api.openweathermap.org/geo/1.0/direct?q={city}&limit=1&appid={OPENWEATHERMAP_API_KEY}"
    try:
        loc = requests.get(geo, timeout=10).json()
        if not loc:
            return {"error": f"City “{city}” not found."}
        lat, lon = loc[0]["lat"], loc[0]["lon"]
        wurl = f"http://api.openweathermap.org/data/2.5/forecast?lat={lat}&lon={lon}&appid={OPENWEATHERMAP_API_KEY}&units=metric"
        data = requests.get(wurl, timeout=10).json()
        if "list" not in data:
            return {"error": f"No forecast for “{city}”."}
        fc = [{
            "time": f["dt_txt"],
            "description": f["weather"][0]["description"].capitalize(),
            "rain_probability": round(f.get("pop", 0)*100, 1),
            "temp": f["main"]["temp"]
        } for f in data["list"][:8]]
        return {"location": city.title(), "forecast": fc}
    except Exception as e:
        return {"error": str(e)}

# --------------------------------------------------------------------------- #
# 6) Helper – talk to Claude (ReAct)                                          #
# --------------------------------------------------------------------------- #
SYSTEM_PROMPT = """You are a helpful umbrella advisor using ReAct:

1. Think about the question.
2. If needed, act with get_weather(location).
3. Observe results.
4. Reason and answer.

When you need weather data, respond EXACTLY:
{"thought":"…","action":"get_weather","action_input":{"location":"City"}}"""

def ask_claude(user, history=""):
    # First call
    body = {
        "anthropic_version": "bedrock-2023-05-31",
        "max_tokens": 1000,
        "temperature": 0.7,
        "top_p": 0.9,
        "messages": [{
            "role": "user",
            "content": f"{SYSTEM_PROMPT}\n\nHistory:\n{history}\n\nUser: {user}"
        }]
    }
    raw = bedrock.invoke_model(
        modelId="anthropic.claude-3-sonnet-20240229-v1:0",
        contentType="application/json",
        accept="application/json",
        body=json.dumps(body)
    )
    txt = json.loads(raw["body"].read())["content"][0]["text"].strip()

    # Try to parse ReAct JSON
    try:
        j = json.loads(txt)
        if j.get("action") == "get_weather":
            city = j["action_input"]["location"]
            wx = get_weather(city)
            if "error" in wx: return wx["error"]

            # Second call – reasoning
            reason_prompt = f"""Here is the forecast for {city}:

{json.dumps(wx, indent=2)}

Give a friendly answer: YES/NO umbrella, with reasoning."""
            body2 = {
                "anthropic_version": "bedrock-2023-05-31",
                "max_tokens": 500,
                "temperature": 0.7,
                "messages":[{"role":"user","content":reason_prompt}]
            }
            raw2 = bedrock.invoke_model(
                modelId="anthropic.claude-3-sonnet-20240229-v1:0",
                contentType="application/json",
                accept="application/json",
                body=json.dumps(body2)
            )
            return json.loads(raw2["body"].read())["content"][0]["text"].strip()
    except json.JSONDecodeError:
        pass
    return txt

# --------------------------------------------------------------------------- #
# 7) Chat input                                                               #
# --------------------------------------------------------------------------- #
def last_history(n=4):
    return "\n".join(f"{m['role'].capitalize()}: {m['content']}" for m in st.session_state.messages[-n:])

if prompt := st.chat_input("Ask: Do I need an umbrella tomorrow?"):
    st.session_state.messages.append({"role":"user","content":prompt})
    with st.chat_message("user"): st.markdown(prompt)

    with st.chat_message("assistant"):
        with st.spinner("Thinking…"):
            reply = ask_claude(prompt, last_history())
            st.markdown(reply)
    st.session_state.messages.append({"role":"assistant","content":reply})

# --------------------------------------------------------------------------- #
# 8) Sidebar                                                                  #
# --------------------------------------------------------------------------- #
with st.sidebar:
    st.image("https://img.icons8.com/clouds/100/umbrella.png", width=100)
    st.markdown("### About\nUses **Claude 3 Sonnet (Bedrock)** + **OpenWeatherMap**")