7_final.py

from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from dotenv import load_dotenv
import uuid
import os
import json
from database import SessionLocal, Interview
from llm import generate_response

load_dotenv()

app = FastAPI(
    title="InterviewAI API",
    description="AI-powered mock interview system with feedback",
    version="1.0.0"
)

sessions = {}

class InterviewSetup(BaseModel):
    name: str
    experience: str
    skills: str
    level: str
    position: str
    company: str
    provider: str = "openai"   # default provider

class UserMessage(BaseModel):
    message: str

@app.get("/")
def health_check():
    return {"status": "running", "active_sessions": len(sessions)}

@app.post("/start-interview")
def start_interview(setup: InterviewSetup):
    session_id = str(uuid.uuid4())

    system_prompt = (
        f"You are an HR executive interviewing {setup.name} "
        f"who has experience: {setup.experience} and skills: {setup.skills}. "
        f"Interview them for the position of {setup.level} {setup.position} "
        f"at {setup.company}. "
        f"Ask one question at a time. Be professional but friendly. "
        f"Start by greeting them and asking them to introduce themselves."
    )

    sessions[session_id] = {
        "setup": setup.model_dump(),
        "provider": setup.provider,
        "messages": [{"role": "system", "content": system_prompt}],
        "message_count": 0,
        "max_messages": 5,
    }

    assistant_msg = generate_response(
        sessions[session_id]["messages"],
        provider=sessions[session_id]["provider"]
    )

    sessions[session_id]["messages"].append(
        {"role": "assistant", "content": assistant_msg}
    )

    db = SessionLocal()
    db_interview = Interview(
        id=session_id,
        name=setup.name,
        position=setup.position,
        company=setup.company,
        level=setup.level,
        messages=json.dumps(sessions[session_id]["messages"])
    )
    db.add(db_interview)
    db.commit()
    db.close()

    return {
        "session_id": session_id,
        "message": assistant_msg,
        "messages_remaining": 5,
    }

@app.post("/chat/{session_id}")
def chat(session_id: str, user_msg: UserMessage):
    if session_id not in sessions:
        raise HTTPException(status_code=404, detail="Session not found")

    session = sessions[session_id]

    if session["message_count"] >= session["max_messages"]:
        raise HTTPException(status_code=400, detail="Interview complete. Get feedback.")

    session["messages"].append({"role": "user", "content": user_msg.message})
    session["message_count"] += 1

    assistant_msg = ""
    if session["message_count"] < session["max_messages"]:
        assistant_msg = generate_response(
            session["messages"],
            provider=session["provider"]
        )
        session["messages"].append({"role": "assistant", "content": assistant_msg})

    remaining = session["max_messages"] - session["message_count"]

    return {
        "message": assistant_msg if assistant_msg else "Interview complete! Get your feedback.",
        "messages_remaining": remaining,
        "interview_complete": remaining == 0,
    }

@app.get("/feedback/{session_id}")
def get_feedback(session_id: str):
    if session_id not in sessions:
        raise HTTPException(status_code=404, detail="Session not found")

    session = sessions[session_id]

    conversation = "\n".join(
        f"{m['role']}: {m['content']}"
        for m in session["messages"]
        if m["role"] != "system"
    )

    feedback_messages = [
        {
            "role": "system",
            "content": """You are a helpful tool that provides
feedback on an interviewee's performance.
Follow this format:
Overall Score: [1-10]
Strengths: [list strengths]
Areas for Improvement: [list improvements]
Detailed Feedback: [your feedback]
Give only the feedback, do not ask questions."""
        },
        {
            "role": "user",
            "content": f"Evaluate this interview:\n{conversation}"
        }
    ]

    feedback = generate_response(
        feedback_messages,
        provider=session["provider"]
    )

    return {
        "session_id": session_id,
        "candidate": session["setup"]["name"],
        "position": f"{session['setup']['level']} {session['setup']['position']}",
        "company": session["setup"]["company"],
        "feedback": feedback,
    }

@app.get("/interviews")
def list_interviews():
    db = SessionLocal()
    interviews = db.query(Interview).order_by(Interview.created_at.desc()).all()
    db.close()

    return [
        {
            "id": i.id,
            "name": i.name,
            "position": f"{i.level} {i.position}",
            "company": i.company,
            "has_feedback": i.feedback is not None,
            "created_at": str(i.created_at),
        }
        for i in interviews
    ]