api.py

from fastapi import FastAPI, HTTPException, Query
from fastapi.responses import PlainTextResponse
import os
from datetime import datetime
import logging

from main import graph_builder
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


app = FastAPI(
    title="Research Agent API",
    description="AI-powered research agent that generates comprehensive reports",
    version="1.0.0"
)

research_agent = None

@app.on_event("startup")
async def startup_event():
    global research_agent
    try:
        logger.info("initializing research agent...")
        research_agent = graph_builder()
        logger.info("research agent ready")
    except Exception as e:
        logger.error(f"failed to init agent: {e}")
        raise

@app.get("/")
async def root():
    return {
        "message": "research agent api running",
        "status": "healthy",
        "timestamp": datetime.now().isoformat()
    }

@app.get("/research", response_class=PlainTextResponse)
async def research_endpoint(q: str = Query(..., description="research query")):
    if not research_agent:
        raise HTTPException(status_code=503, detail="agent not ready")
    
    if not q.strip():
        raise HTTPException(status_code=400, detail="query cannot be empty")
    
    try:
        logger.info(f"processing: {q}")
        
        # Initialize state with defaults
        initial_state = {
            "user_input": q,
            "enhanced_query": "",
            "followup_questions": [],
            "selected_urls": [],
            "articles": [],
            "reddit_posts": [],
            "youtube_urls": [],
            "twitter_urls": [],
            "linkedin_urls": [],
            "platform_questions": [],
            "platform_content": "",
            "platform_summary": "",
            "platform_urls": {},
            "report_markdown": "",
            "errors": [],
            "messages": [],
            "step_info": "",
        }
        
        result = research_agent.invoke(initial_state)
        final_response = result.get("report_markdown", "<no report generated>")
        
        # If the report already has a header, use it as-is; otherwise add header
        if final_response.startswith("# "):
            markdown_report = final_response
        else:
            timestamp_str = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
            markdown_report = f"""# Research Report

**Generated:** {timestamp_str}  
**Query:** {q}

---

{final_response}

---

*Generated by Research Agent*
"""
        
        logger.info(f"completed: {q}")
        return markdown_report
        
    except Exception as e:
        logger.error(f"error: {e}")
        raise HTTPException(status_code=500, detail=f"server error: {str(e)}")

if __name__ == "__main__":
    import uvicorn
    print(" starting api...")
    print(" docs: http://localhost:8000/docs")
    print(" test: http://localhost:8000/research?q=your-query")
    uvicorn.run(app, host="0.0.0.0", port=8000)