"""Search API routes — keyword + semantic search."""

from fastapi import APIRouter, Query

from core import restaurant, vector
from core.db import conn

router = APIRouter()


@router.get("")
def search_restaurants(
    q: str = Query(..., min_length=1),
    mode: str = Query("keyword", pattern="^(keyword|semantic|hybrid)$"),
    limit: int = Query(20, le=100),
):
    """Search restaurants by keyword, semantic similarity, or hybrid."""
    if mode == "semantic":
        return _semantic_search(q, limit)
    elif mode == "hybrid":
        kw = _keyword_search(q, limit)
        sem = _semantic_search(q, limit)
        # merge: keyword results first, then semantic results not already in keyword
        seen = {r["id"] for r in kw}
        merged = list(kw)
        for r in sem:
            if r["id"] not in seen:
                merged.append(r)
                seen.add(r["id"])
        return merged[:limit]
    else:
        return _keyword_search(q, limit)


def _keyword_search(q: str, limit: int) -> list[dict]:
    sql = """
        SELECT id, name, address, region, latitude, longitude,
               cuisine_type, price_range
        FROM restaurants
        WHERE latitude IS NOT NULL
          AND (UPPER(name) LIKE UPPER(:q)
               OR UPPER(address) LIKE UPPER(:q)
               OR UPPER(region) LIKE UPPER(:q)
               OR UPPER(cuisine_type) LIKE UPPER(:q))
        FETCH FIRST :lim ROWS ONLY
    """
    pattern = f"%{q}%"
    with conn() as c:
        cur = c.cursor()
        cur.execute(sql, {"q": pattern, "lim": limit})
        cols = [d[0].lower() for d in cur.description]
        return [dict(zip(cols, row)) for row in cur.fetchall()]


def _semantic_search(q: str, limit: int) -> list[dict]:
    similar = vector.search_similar(q, top_k=limit)
    if not similar:
        return []

    rest_ids = list({s["restaurant_id"] for s in similar})
    results = []
    for rid in rest_ids[:limit]:
        r = restaurant.get_by_id(rid)
        if r and r.get("latitude"):
            results.append(r)
    return results