agent.py

"""
CodeLens – conversational agent (interactive CLI mode).

Fixes vs original:
- Correct import: langgraph.prebuilt.create_react_agent
- Env loading delegated to python-dotenv
- API key validation with friendly error message
- Config imported from config.py
"""
import os
import sys
from dotenv import load_dotenv
from langchain_groq import ChatGroq
from langgraph.prebuilt import create_react_agent

from config import LLM_MODEL
from tools import ALL_TOOLS

load_dotenv()

SYSTEM_PROMPT = (
    "You are CodeLens, an expert software engineering agent.\n"
    "You have full access to a codebase through the tools provided.\n\n"
    "STRATEGY:\n"
    "1. EXPLORE  — Start with get_directory_tree to understand the project structure.\n"
    "2. SEARCH   — Use grep_search for specific identifiers; codebase_search for concepts.\n"
    "3. UNDERSTAND — Use get_file_outline before reading a full file.\n"
    "4. PLAN     — Explain your findings and intended changes before writing anything.\n"
    "5. EXECUTE  — Use write_file for edits; run_terminal_command for tests/linting.\n\n"
    "Always verify your work after making changes."
)


def build_agent():
    """Construct and return the CodeLens LangGraph agent."""
    api_key = os.getenv("GROQ_API_KEY")
    if not api_key:
        print("Error: GROQ_API_KEY not set. Add it to your .env file.")
        sys.exit(1)

    llm = ChatGroq(model_name=LLM_MODEL, groq_api_key=api_key, temperature=0)
    return create_react_agent(model=llm, tools=ALL_TOOLS, prompt=SYSTEM_PROMPT)


def main():
    agent = build_agent()
    print("\n🔍 CodeLens Agent online! (type 'exit' to quit)\n")

    while True:
        try:
            query = input("Your request: ").strip()
        except (EOFError, KeyboardInterrupt):
            print("\nGoodbye!")
            break

        if query.lower() in ("exit", "quit", "q"):
            print("Goodbye!")
            break

        if not query:
            continue

        print("Thinking...\n")
        try:
            result = agent.invoke({"messages": [{"role": "user", "content": query}]})
            answer = result["messages"][-1].content
            print(f"Response:\n{answer}\n")
        except Exception as exc:
            print(f"Error: {exc}\n")


if __name__ == "__main__":
    main()