app.py

import os
import json
import streamlit as st
from streamlit_ace import st_ace
from typing_extensions import TypedDict

from langchain.chat_models import ChatOpenAI
from langchain.schema import HumanMessage


# ------------------------------------------
# 1. Define a TypedDict for review state
# ------------------------------------------
class CodeReviewState(TypedDict):
    code_content: str
    review_outcome: str
    revised_code: str
    similar_examples: str


# ------------------------------------------
# 2. LLM Classes for Analyzing & Proposing
# ------------------------------------------
class LLMAnalyzer:
    """Analyzes Python code snippet: 'Approved' or 'NeedsRevision'."""
    def __init__(self, llm: ChatOpenAI) -> None:
        self.llm = llm

    def analyze(self, code_content: str) -> str:
        prompt_text = f"""You are a senior Python reviewer.

Analyze the following code:

{code_content}

Respond with:
- "Approved" if the code is correct or good enough.
- "NeedsRevision" if changes or improvements are needed.
"""
        # Use 'generate()' with a HumanMessage.
        response = self.llm.generate([[HumanMessage(content=prompt_text)]])
        outcome_text = response.generations[0][0].text.strip()
        return outcome_text


class LLMProposer:
    """Proposes an improved version of the code."""
    def __init__(self, llm: ChatOpenAI) -> None:
        self.llm = llm

    def propose(self, code_content: str) -> str:
        prompt_text = f"""You are a senior Python reviewer.

Review the following code and provide an improved version, with any necessary fixes or best practices:

{code_content}
"""
        response = self.llm.generate([[HumanMessage(content=prompt_text)]])
        return response.generations[0][0].text.strip()


class LLMExampleGenerator:
    """Generates similar example snippets for educational purposes."""
    def __init__(self, llm: ChatOpenAI) -> None:
        self.llm = llm

    def generate_examples(self, code_content: str) -> str:
        prompt_text = f"""You are a senior Python mentor.

The user learned this Python snippet:

{code_content}

Now provide a few similar Python code examples or patterns with short explanations.
Show best practices and different variations so the user can learn and improve.
"""
        response = self.llm.generate([[HumanMessage(content=prompt_text)]])
        return response.generations[0][0].text.strip()


# ------------------------------------------
# 3. Streamlit Page Layout
# ------------------------------------------
st.set_page_config(page_title="Code Reviewer with AI", layout="wide")

st.title("Code Reviewer with suggested Examples")

# ------------------------------------------
# 4. Check for OpenAI API Key
# ------------------------------------------
openai_api_key = os.getenv("OPENAI_API_KEY")
if not openai_api_key:
    st.error("Error: OPENAI_API_KEY not set. Please provide a valid API key.")
    st.stop()

# ------------------------------------------
# 5. Initialize ChatOpenAI
# ------------------------------------------
# Make sure to have a compatible version: langchain>=0.0.300, openai>=1.0.0
llm = ChatOpenAI(
    openai_api_key=openai_api_key,
    model_name="gpt-4o-mini",
    temperature=0.7
)

analyzer = LLMAnalyzer(llm)
proposer = LLMProposer(llm)
example_gen = LLMExampleGenerator(llm)

# ------------------------------------------
# 6. Initialize Session State
# ------------------------------------------
if "review_state" not in st.session_state:
    st.session_state["review_state"] = CodeReviewState(
        code_content="",
        review_outcome="",
        revised_code="",
        similar_examples=""
    )

# ------------------------------------------
# 7. ACE Editor for User Code
# ------------------------------------------
st.write("### Enter or modify your Python code:")
code_input = st_ace(
    language="python",
    #theme="monokai",
    auto_update=True,
    key="ace-editor",
    height=250,
    #value="def greet(name):\n    print(f'Hello, {name}!')"
)

# ------------------------------------------
# 8. On Submit: Analyze, Propose (if needed), & Provide Examples
# ------------------------------------------
if st.button("Submit for Review"):
    if not code_input.strip():
        st.error("Please enter some code.")
    else:
        outcome = analyzer.analyze(code_input)
        revised_snippet = ""

        if outcome == "NeedsRevision":
            revised_snippet = proposer.propose(code_input)

        examples = example_gen.generate_examples(code_input)

        # Update session state
        st.session_state["review_state"]["code_content"] = code_input
        st.session_state["review_state"]["review_outcome"] = outcome
        st.session_state["review_state"]["revised_code"] = revised_snippet
        st.session_state["review_state"]["similar_examples"] = examples

# ------------------------------------------
# 9. Display Output
# ------------------------------------------
review_state = st.session_state["review_state"]
if review_state["review_outcome"]:
    if review_state["review_outcome"] == "Approved":
        st.success("Your code is approved! Great job.")
    else:
        st.warning("Your code needs some revision based on best practices.")
        st.markdown("**Proposed Fixes / Improved Version:**")
        st.code(review_state["revised_code"], language="python")

    st.markdown("---")
    st.markdown("### Similar Examples to Learn & Improve")
    st.write(review_state["similar_examples"])