import logging
from typing import List, Optional

from fastapi import APIRouter, Depends, HTTPException, Query, Request
from fastapi.responses import Response

from app.ratelimit import limiter
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.models import Post, iso_utc
from app.schemas import PriceImpact, TrumpPost

router = APIRouter()
logger = logging.getLogger(__name__)


def _direction_correct(signal: Optional[str], pct: Optional[float]) -> Optional[bool]:
    if pct is None or signal is None:
        return None
    if signal == "buy":
        return pct > 0
    if signal in ("short", "sell"):
        return pct < 0
    return None  # hold has no direction


def _post_to_schema(post: Post) -> TrumpPost:
    price_impact: Optional[PriceImpact] = None
    if post.price_impact_asset and post.price_at_post is not None:
        # Overlay live rolling peaks for windows that haven't closed yet
        from app.services.price_impact_monitor import get_live_impact
        live = get_live_impact(post.id) or {}

        m5  = live.get("price_impact_m5",  post.price_impact_m5)
        m15 = live.get("price_impact_m15", post.price_impact_m15)
        m1h = live.get("price_impact_m1h", post.price_impact_m1h)

        price_impact = PriceImpact(
            asset=post.price_impact_asset,
            m5=m5,
            m15=m15,
            m1h=m1h,
            price_at_post=post.price_at_post,
            correct_m5=_direction_correct(post.signal, m5),
            correct_m15=_direction_correct(post.signal, m15),
            correct_m1h=_direction_correct(post.signal, m1h),
        )
    return TrumpPost(
        id=post.id,
        text=post.text,
        source=post.source,
        published_at=iso_utc(post.published_at),
        sentiment=post.sentiment,
        signal=post.signal,
        ai_confidence=post.ai_confidence,
        ai_reasoning=post.ai_reasoning,
        prefilter_reason=post.prefilter_reason,
        analysis_version=post.analysis_version,
        relevant=post.relevant,
        price_impact=price_impact,
        # v5 routing fields — null for pre-v5 posts
        target_asset=post.target_asset,
        category=post.category,
        expected_move_pct=post.expected_move_pct,
        invalidation_price=post.invalidation_price,
    )


@router.get("/posts", response_model=List[TrumpPost])
@limiter.limit("60/minute")
async def get_posts(
    request: Request,
    limit: int = Query(default=20, ge=1, le=500),
    page: int = Query(default=1, ge=1),
    source: Optional[str] = Query(
        default=None,
        description="Filter to a single source (e.g. 'btc_bottom_reversal', "
                    "'funding_reversal', 'truth'). Without it, rare-source "
                    "signals can be pushed off the latest-N page by Trump posts.",
    ),
    db: AsyncSession = Depends(get_db),
    response: Response = None,
):
    offset = (page - 1) * limit
    stmt = select(Post)
    if source:
        stmt = stmt.where(Post.source == source)
    stmt = stmt.order_by(Post.published_at.desc()).offset(offset).limit(limit)
    result = await db.execute(stmt)
    posts = result.scalars().all()
    # Posts are scraped every 5s but rarely change once written — allow CDN/browser
    # to cache for 30s. stale-while-revalidate=60 means stale content is served
    # while a fresh fetch happens in the background (no loading flash).
    if response is not None:
        response.headers["Cache-Control"] = "public, max-age=30, stale-while-revalidate=60"
    return [_post_to_schema(p) for p in posts]


@router.get("/signals/accuracy")
async def signal_accuracy(db: AsyncSession = Depends(get_db)):
    """Aggregate accuracy of directional signals (buy/sell/short) against realised price moves."""
    result = await db.execute(
        select(Post).where(Post.signal.in_(["buy", "sell", "short"]))
    )
    posts = result.scalars().all()

    def bucket():
        return {"checked": 0, "correct": 0}

    stats = {"m5": bucket(), "m15": bucket(), "m1h": bucket()}
    by_signal: dict[str, dict] = {}

    for p in posts:
        sig = p.signal
        if sig not in by_signal:
            by_signal[sig] = {"m5": bucket(), "m15": bucket(), "m1h": bucket(), "count": 0}
        by_signal[sig]["count"] += 1
        for win, val in (("m5", p.price_impact_m5), ("m15", p.price_impact_m15), ("m1h", p.price_impact_m1h)):
            ok = _direction_correct(sig, val)
            if ok is None:
                continue
            stats[win]["checked"] += 1
            stats[win]["correct"] += int(ok)
            by_signal[sig][win]["checked"] += 1
            by_signal[sig][win]["correct"] += int(ok)

    def pct(b): return round(b["correct"] / b["checked"] * 100, 1) if b["checked"] else None

    return {
        "overall": {k: {**v, "accuracy_pct": pct(v)} for k, v in stats.items()},
        "by_signal": {
            s: {
                "count": d["count"],
                "m5": {**d["m5"], "accuracy_pct": pct(d["m5"])},
                "m15": {**d["m15"], "accuracy_pct": pct(d["m15"])},
                "m1h": {**d["m1h"], "accuracy_pct": pct(d["m1h"])},
            }
            for s, d in by_signal.items()
        },
        "total_directional_signals": len(posts),
    }


@router.get("/posts/{post_id}", response_model=TrumpPost)
async def get_post(post_id: int, db: AsyncSession = Depends(get_db)):
    result = await db.execute(select(Post).where(Post.id == post_id))
    post = result.scalar_one_or_none()
    if post is None:
        raise HTTPException(status_code=404, detail="Post not found")
    return _post_to_schema(post)