from fastapi import FastAPI, Depends, HTTPException, BackgroundTasks
from pathlib import Path
import os
import requests
from dotenv import load_dotenv
from sqlalchemy.orm import Session
from database import Base, engine,SessionLocal
from models import User, Log, CtrReport
from schemas import SignupRequest, LoginRequest, LogRequest
from auth import hash_password, verify_password, create_token
from deps import get_db, get_current_user
from config import API_BASE_URL
from models import User, Log, CtrReport, Restaurant, Review
from utils import extract_points


app = FastAPI()
env_path = Path(__file__).resolve().parent / ".env"
load_dotenv(env_path)

Base.metadata.create_all(bind=engine)


def get_representatives(
    texts: list[str],
    eps: float,
    min_samples: int,
    error_label: str
) -> list[str]:
    if not texts:
        return []

    try:
        response = requests.post(
            f"{API_BASE_URL}/get_representatives",
            json={
                "texts": texts,
                "eps": eps,
                "min_samples": min_samples
            },
            timeout=60
        )
    except requests.RequestException as exc:
        raise HTTPException(
            502,
            f"{error_label} service failed: {exc}"
        )

    if response.status_code != 200:
        raise HTTPException(
            502,
            f"{error_label} service error"
        )

    payload = response.json()

    return payload.get("representatives", [])


def requesty_chat(prompt: str) -> str:
    api_key = os.getenv("REQUESTY_API_KEY")
    if not api_key:
        raise HTTPException(500, "Requesty API key not configured")

    base_url = os.getenv(
        "REQUESTY_API_URL",
        "https://router.requesty.ai/v1"
    ).rstrip("/")

    headers = {
        "Authorization": f"Bearer {api_key}",
    }

    referer = os.getenv("REQUESTY_HTTP_REFERER")
    title = os.getenv("REQUESTY_X_TITLE")
    if referer:
        headers["HTTP-Referer"] = referer
    if title:
        headers["X-Title"] = title

    try:
        response = requests.post(
            f"{base_url}/chat/completions",
            headers=headers,
            json={
                "model": "openai/gpt-4o",
                "temperature": 0.2,
                "max_tokens": 256,
                "messages": [
                    {
                        "role": "system",
                        "content": (
                            "You find correlations between insights and reviews. "
                            "Return 3-6 short numbered points, each under 20 words."
                        )
                    },
                    {"role": "user", "content": prompt}
                ]
            },
            timeout=60
        )
    except requests.RequestException as exc:
        raise HTTPException(502, f"Requesty service failed: {exc}")

    if response.status_code != 200:
        detail = response.text.strip()
        if detail:
            raise HTTPException(
                502,
                f"Requesty service error: {detail}"
            )
        raise HTTPException(502, "Requesty service error")

    payload = response.json()
    choices = payload.get("choices", [])
    if not choices:
        raise HTTPException(502, "Requesty service returned no choices")

    message = choices[0].get("message", {})
    content = message.get("content", "")

    return content.strip()


@app.post("/auth/signup")
def signup(data: SignupRequest, db: Session = Depends(get_db)):
    existing = db.query(User).filter(User.email == data.email).first()
    if existing:
        raise HTTPException(400, "Email already exists")

    user = User(
        email=data.email,
        password_hash=hash_password(data.password),
        name=data.name
    )
    db.add(user)
    db.commit()
    db.refresh(user)

    return {"message": "User created"}


@app.post("/auth/login")
def login(data: LoginRequest, db: Session = Depends(get_db)):
    user = db.query(User).filter(User.email == data.email).first()

    if not user or not verify_password(data.password, user.password_hash):
        raise HTTPException(401, "Invalid credentials")

    token = create_token({"user_id": user.id, "name": user.name, "email":user.email})

    return {"access_token": token}




def process_session_logs(user_id: int, session_id: str, db_session_factory):
    db = db_session_factory()

    try:
        session_logs = (
            db.query(Log)
            .filter(
                Log.user_id == user_id,
                Log.session_id == session_id
            )
            .order_by(Log.timestamp.asc())
            .all()
        )

        combined_logs = "\n".join(
            f"{entry.timestamp.isoformat()} : {entry.log}"
            for entry in session_logs
        )

        response = requests.post(
            f"{API_BASE_URL}/processed-logs",
            json={"logs": combined_logs},
            timeout=300   # allow long processing
        )

        if response.status_code != 200:
            print("Processing service error")
            return

        payload = response.json()

        report = CtrReport(
            user_id=user_id,
            session_id=session_id,
            report=payload.get("report", ""),
            insights=payload.get("insights", ""),
            state_flow=payload.get("state_flow", ""),
            suggestions=payload.get("suggestions", "")
        )

        db.add(report)
        db.commit()

    except Exception as e:
        print("Background processing failed:", e)

    finally:
        db.close()


@app.post("/addLog")
def add_log(
    data: LogRequest,
    background_tasks: BackgroundTasks,
    user_id: int = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    log = Log(
        user_id=user_id,
        session_id=data.session_id,
        log=data.log,
        timestamp=data.timestamp
    )
    print(data.log)
    db.add(log)
    db.commit()

    # trigger async/background processing
    if "<END>" in data.log:

        background_tasks.add_task(
            process_session_logs,
            user_id,
            data.session_id,
            SessionLocal   # your DB session factory
        )

    return {"message": "Log stored"}


@app.get("/session-summary")
def get_session_summary(
    session_id: str,
    db: Session = Depends(get_db)
):

    logs = (
        db.query(Log)
        .filter(Log.session_id == session_id)
        .order_by(Log.timestamp.asc())
        .all()
    )

    report = (
        db.query(CtrReport)
        .filter(CtrReport.session_id == session_id)
        .order_by(CtrReport.id.desc())
        .first()
    )

    return {
        "session_id": session_id,
        "logs_count": len(logs),
        "logs": [
            {
                "id": entry.id,
                "log": entry.log,
                "timestamp": entry.timestamp
            }
            for entry in logs
        ],
        "report": report.report if report else "",
        "insights": report.insights if report else "",
        "suggestions": report.suggestions if report else "",
        "state_flow": report.state_flow if report else ""
    }


@app.get("/sessionid_list")
def get_sessionid_list(db: Session = Depends(get_db)):

    rows = (
        db.query(CtrReport.session_id)
        .distinct()
        .order_by(CtrReport.session_id.asc())
        .all()
    )

    session_ids = [row[0] for row in rows]

    return {
        "count": len(session_ids),
        "session_ids": session_ids
    }

@app.get("/restaurants")
def get_restaurants(db: Session = Depends(get_db)):

    restaurants = db.query(Restaurant).all()

    result = []

    for r in restaurants:
        result.append({
            "id": r.id,
            "name": r.name,
            "cuisine": r.cuisine,
            "location": r.location,
            "price_range": r.price_range,
            "avg_rating": r.avg_rating,
            "description": r.description
        })

    return {
        "count": len(result),
        "restaurants": result
    }


@app.get("/restaurants/{restaurant_id}/reviews")
def get_restaurant_reviews(
    restaurant_id: int,
    db: Session = Depends(get_db)
):

    restaurant = (
        db.query(Restaurant)
        .filter(Restaurant.id == restaurant_id)
        .first()
    )

    if not restaurant:
        raise HTTPException(404, "Restaurant not found")

    reviews = (
        db.query(Review)
        .filter(Review.restaurant_id == restaurant_id)
        .order_by(Review.created_at.desc())
        .all()
    )

    result = []

    for review in reviews:
        result.append({
            "id": review.id,
            "user_name": review.user_name,
            "rating": review.rating,
            "review": review.review,
            "created_at": review.created_at
        })

    return {
        "restaurant": {
            "id": restaurant.id,
            "name": restaurant.name,
            "cuisine": restaurant.cuisine,
            "location": restaurant.location,
            "avg_rating": restaurant.avg_rating
        },
        "total_reviews": len(result),
        "reviews": result
    }

@app.get("/restaurants/{restaurant_id}/get-few-reviews")
def get_few_reviews(
    restaurant_id: int,
    eps: float = 0.55,
    min_samples: int = 2,
    db: Session = Depends(get_db)
):

    restaurant = (
        db.query(Restaurant)
        .filter(Restaurant.id == restaurant_id)
        .first()
    )

    if not restaurant:
        raise HTTPException(404, "Restaurant not found")

    reviews = (
        db.query(Review)
        .filter(Review.restaurant_id == restaurant_id)
        .all()
    )

    if not reviews:
        return {
            "restaurant_id": restaurant_id,
            "restaurant_name": restaurant.name,
            "total_reviews": 0,
            "selected_reviews": []
        }

    review_texts = [r.review for r in reviews]

    try:
        response = requests.post(
            f"{API_BASE_URL}/get_representatives",
            json={
                "texts": review_texts,
                "eps": eps,
                "min_samples": min_samples
            },
            timeout=60
        )

    except requests.RequestException as exc:
        raise HTTPException(
            502,
            f"Representative review service failed: {exc}"
        )

    if response.status_code != 200:
        raise HTTPException(
            502,
            "Representative review service error"
        )

    payload = response.json()

    representative_texts = payload.get("representatives", [])

    selected_reviews = []

    for text in representative_texts:

        matching_review = next(
            (r for r in reviews if r.review == text),
            None
        )

        if matching_review:
            selected_reviews.append({
                "id": matching_review.id,
                "user_name": matching_review.user_name,
                "rating": matching_review.rating,
                "review": matching_review.review,
                "created_at": matching_review.created_at
            })

    return {
        "restaurant_id": restaurant.id,
        "restaurant_name": restaurant.name,
        "total_reviews": len(reviews),
        "selected_count": len(selected_reviews),
        "selected_reviews": selected_reviews
    }


@app.get("/correlated-review-insights")
def correlated_review_insights(
    restaurant_id: int,
    eps: float = 0.41,
    min_samples: int = 2,
    db: Session = Depends(get_db)
):

    restaurant = (
        db.query(Restaurant)
        .filter(Restaurant.id == restaurant_id)
        .first()
    )

    if not restaurant:
        raise HTTPException(404, "Restaurant not found")

    reviews = (
        db.query(Review)
        .filter(Review.restaurant_id == restaurant_id)
        .all()
    )

    reports = (
        db.query(CtrReport)
        .order_by(CtrReport.id.desc())
        .all()
    )

    if not reviews or not reports:
        return {
            "restaurant_id": restaurant.id,
            "restaurant_name": restaurant.name,
            "correlation_points": []
        }

    review_texts = [r.review for r in reviews]

    all_points = []
    for report in reports:
        if not report.insights:
            continue
        all_points.extend(extract_points(report.insights))

    unique_points = list(dict.fromkeys(all_points))

    if not unique_points:
        return {
            "restaurant_id": restaurant.id,
            "restaurant_name": restaurant.name,
            "correlation_points": []
        }

    representative_reviews = get_representatives(
        review_texts,
        eps=eps,
        min_samples=min_samples,
        error_label="Representative review"
    )

    representative_insights = get_representatives(
        unique_points,
        eps=eps,
        min_samples=min_samples,
        error_label="Representative insight"
    )

    trimmed_reviews = representative_reviews[:25]
    trimmed_insights = representative_insights[:25]

    prompt = (
        "Insights:\n"
        + "\n".join(f"- {point}" for point in trimmed_insights)
        + "\n\nReviews:\n"
        + "\n".join(f"- {text}" for text in trimmed_reviews)
        + "\n\nCorrelate them in short numbered points."
    )

    content = requesty_chat(prompt)

    correlation_points = extract_points(content)

    if not correlation_points:
        correlation_points = [
            line.strip("- ").strip()
            for line in content.splitlines()
            if line.strip()
        ]

    if not correlation_points and content:
        correlation_points = [content]

    cleaned_points = []
    for point in correlation_points[:6]:
        cleaned = point.strip()
        if len(cleaned) > 200:
            cleaned = cleaned[:197].rstrip() + "..."
        cleaned_points.append(cleaned)

    return {
        "restaurant_id": restaurant.id,
        "restaurant_name": restaurant.name,
        "reviews_considered": len(trimmed_reviews),
        "insights_considered": len(trimmed_insights),
        "correlation_points": cleaned_points
    }



@app.get("/few-insights")
def get_all_insights(
    eps: float = 0.41,
    min_samples: int = 2,
    db: Session = Depends(get_db)
):

    reports = (
        db.query(CtrReport)
        .order_by(CtrReport.id.desc())
        .all()
    )

    if not reports:
        return {
            "count": 0,
            "insights": [],
            "selected_insights": []
        }

    # flatten all insight points
    all_points = []

    for report in reports:

        if not report.insights:
            continue

        extracted = extract_points(report.insights)

        all_points.extend(extracted)

    # remove duplicates while preserving order
    unique_points = list(dict.fromkeys(all_points))

    selected_insights = []

    if unique_points:

        try:
            response = requests.post(
                f"{API_BASE_URL}/get_representatives",
                json={
                    "texts": unique_points,
                    "eps": eps,
                    "min_samples": min_samples
                },
                timeout=60
            )

        except requests.RequestException as exc:
            raise HTTPException(
                502,
                f"Representative insight service failed: {exc}"
            )

        if response.status_code != 200:
            raise HTTPException(
                502,
                "Representative insight service error"
            )

        payload = response.json()

        selected_insights = payload.get(
            "representatives",
            []
        )

    return {
        "count": len(selected_insights),
        "selected_insights": selected_insights
    }