import os
import httpx
import trafilatura
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import asyncpg
import asyncio
from contextlib import asynccontextmanager

DB_DSN = "postgresql://{user}:{password}@{host}:{port}/{dbname}".format(
    user=os.environ["DB_USER"],
    password=os.environ["DB_PASSWORD"],
    host=os.environ["DB_HOST"],
    port=os.environ.get("DB_PORT", "5432"),
    dbname=os.environ["DB_NAME"],
)
SUMMARIZER_URL = os.environ.get("SUMMARIZER_URL", "http://summarizer:8000")

pool = None


@asynccontextmanager
async def lifespan(app: FastAPI):
    global pool
    pool = await asyncpg.create_pool(DB_DSN)
    await pool.execute("""
        CREATE TABLE IF NOT EXISTS articles (
            id SERIAL PRIMARY KEY,
            url TEXT NOT NULL,
            title TEXT DEFAULT '',
            full_text TEXT DEFAULT '',
            summary TEXT DEFAULT '',
            created_at TIMESTAMPTZ DEFAULT NOW()
        )
    """)
    yield
    await pool.close()


app = FastAPI(lifespan=lifespan)


class URLRequest(BaseModel):
    url: str


@app.get("/api/health")
async def health():
    return {"status": "ok"}


@app.get("/api/articles")
async def list_articles():
    rows = await pool.fetch(
        "SELECT id, url, title, summary, created_at "
        "FROM articles ORDER BY created_at DESC LIMIT 50"
    )
    return [dict(r) for r in rows]



@app.post("/api/articles")
async def create_article(req: URLRequest):
    downloaded = await asyncio.to_thread(trafilatura.fetch_url, req.url)
    if not downloaded:
        raise HTTPException(400, "Failed to fetch URL")

    result = await asyncio.to_thread(trafilatura.bare_extraction, downloaded, include_comments=False)
    if not result or not result.get("text"):
        raise HTTPException(400, "Failed to extract text")

    text = result["text"]
    title = result.get("title", "")

    async with httpx.AsyncClient(timeout=120.0) as client:
        resp = await client.post(
            f"{SUMMARIZER_URL}/summarize", json={"text": text}
        )
        if resp.status_code != 200:
            raise HTTPException(502, "Summarizer service unavailable")
        summary = resp.json()["summary"]

    row = await pool.fetchrow(
        "INSERT INTO articles (url, title, full_text, summary) "
        "VALUES ($1, $2, $3, $4) "
        "RETURNING id, url, title, summary, created_at",
        req.url, title, text, summary,
    )
    return dict(row)