import os
import time

from dotenv import load_dotenv
from fastapi import FastAPI, HTTPException, Request
from fastapi.responses import FileResponse, RedirectResponse
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel
from starlette.middleware.sessions import SessionMiddleware

from tmdb import TMDBClient
from trakt import TraktClient

load_dotenv()

app = FastAPI()
app.add_middleware(
    SessionMiddleware,
    secret_key=os.getenv("SECRET_KEY", "change-me"),
    max_age=86400 * 30,
)

TRAKT_CLIENT_ID = os.getenv("TRAKT_CLIENT_ID", "")
TRAKT_CLIENT_SECRET = os.getenv("TRAKT_CLIENT_SECRET", "")
TRAKT_REDIRECT_URI = os.getenv("TRAKT_REDIRECT_URI", "http://localhost:8000/auth/callback")
TMDB_API_KEY = os.getenv("TMDB_API_KEY", "")

# Simple in-memory cache (per user token)
_cache: dict = {}
CACHE_TTL = 300  # 5 minutes


def cache_get(key: str):
    if key in _cache:
        data, ts = _cache[key]
        if time.time() - ts < CACHE_TTL:
            return data
        del _cache[key]
    return None


def cache_set(key: str, data):
    _cache[key] = (data, time.time())


def cache_del(key: str):
    _cache.pop(key, None)


@app.get("/")
async def root():
    return FileResponse("static/index.html")


@app.get("/api/auth/status")
async def auth_status(request: Request):
    return {"authenticated": bool(request.session.get("access_token"))}


@app.get("/auth/login")
async def auth_login():
    url = (
        f"https://trakt.tv/oauth/authorize"
        f"?response_type=code"
        f"&client_id={TRAKT_CLIENT_ID}"
        f"&redirect_uri={TRAKT_REDIRECT_URI}"
    )
    return RedirectResponse(url)


@app.get("/auth/callback")
async def auth_callback(request: Request, code: str):
    import httpx

    async with httpx.AsyncClient() as client:
        resp = await client.post(
            "https://api.trakt.tv/oauth/token",
            json={
                "code": code,
                "client_id": TRAKT_CLIENT_ID,
                "client_secret": TRAKT_CLIENT_SECRET,
                "redirect_uri": TRAKT_REDIRECT_URI,
                "grant_type": "authorization_code",
            },
        )
    data = resp.json()
    if "access_token" not in data:
        raise HTTPException(400, f"OAuth failed: {data}")
    request.session["access_token"] = data["access_token"]
    return RedirectResponse("/")


@app.get("/auth/logout")
async def auth_logout(request: Request):
    request.session.clear()
    return RedirectResponse("/")


@app.get("/api/movies")
async def get_movies(
    request: Request,
    page: int = 1,
    per_page: int = 20,
    sort: str = "watched_at",
    filter_type: str = "all",
    exclude: str = "",  # comma-separated trakt IDs to skip client-side
):
    token = request.session.get("access_token")
    if not token:
        raise HTTPException(401, "Not authenticated")

    cache_key = f"movies_{token[:16]}"
    all_movies = cache_get(cache_key)

    if all_movies is None:
        trakt = TraktClient(TRAKT_CLIENT_ID, token)
        watched, ratings = await trakt.get_watched_and_ratings()
        rating_map = {r["movie"]["ids"]["trakt"]: r["rating"] for r in ratings}

        all_movies = []
        for w in watched:
            m = w["movie"]
            tid = m["ids"]["trakt"]
            r = rating_map.get(tid)
            if r is None or r == 10:
                all_movies.append({
                    "trakt_id": tid,
                    "imdb_id": m["ids"].get("imdb"),
                    "tmdb_id": m["ids"].get("tmdb"),
                    "title": m["title"],
                    "year": m.get("year"),
                    "watched_at": w.get("last_watched_at"),
                    "plays": w.get("plays", 1),
                    "current_rating": r,
                })
        cache_set(cache_key, all_movies)

    # Exclude skipped IDs (sent by client from localStorage)
    excluded = {int(x) for x in exclude.split(",") if x.strip().lstrip("-").isdigit()}

    # Filter
    movies = [m for m in all_movies if m["trakt_id"] not in excluded]
    if filter_type == "unrated":
        movies = [m for m in movies if m["current_rating"] is None]
    elif filter_type == "10":
        movies = [m for m in movies if m["current_rating"] == 10]

    # Sort
    if sort == "watched_at":
        movies = sorted(movies, key=lambda x: x["watched_at"] or "", reverse=True)
    elif sort == "title":
        movies = sorted(movies, key=lambda x: x["title"].lower())
    elif sort == "year":
        movies = sorted(movies, key=lambda x: x["year"] or 0, reverse=True)

    total = len(movies)
    start = (page - 1) * per_page
    page_movies = movies[start: start + per_page]

    tmdb = TMDBClient(TMDB_API_KEY)
    enriched = await tmdb.enrich_movies(page_movies)

    return {
        "movies": enriched,
        "total": total,
        "page": page,
        "per_page": per_page,
        "total_pages": max(1, (total + per_page - 1) // per_page),
    }


class RateBody(BaseModel):
    rating: int


@app.post("/api/rate/{trakt_id}")
async def rate_movie(request: Request, trakt_id: int, body: RateBody):
    token = request.session.get("access_token")
    if not token:
        raise HTTPException(401, "Not authenticated")
    if not (1 <= body.rating <= 10):
        raise HTTPException(400, "Rating must be between 1 and 10")

    trakt = TraktClient(TRAKT_CLIENT_ID, token)
    await trakt.rate_movie(trakt_id, body.rating)
    cache_del(f"movies_{token[:16]}")
    return {"success": True}


@app.delete("/api/rate/{trakt_id}")
async def remove_rating(request: Request, trakt_id: int):
    token = request.session.get("access_token")
    if not token:
        raise HTTPException(401, "Not authenticated")

    trakt = TraktClient(TRAKT_CLIENT_ID, token)
    await trakt.remove_rating(trakt_id)
    cache_del(f"movies_{token[:16]}")
    return {"success": True}


app.mount("/static", StaticFiles(directory="static"), name="static")