"""Restaurant DB operations — save extracted data, link to videos."""

from __future__ import annotations

import json

import oracledb

from core.db import conn


def find_by_name(name: str) -> dict | None:
    """Find a restaurant by exact name match."""
    sql = "SELECT id, name, address, region, latitude, longitude FROM restaurants WHERE name = :n"
    with conn() as c:
        cur = c.cursor()
        cur.execute(sql, {"n": name})
        r = cur.fetchone()
        if r:
            return {
                "id": r[0], "name": r[1], "address": r[2],
                "region": r[3], "latitude": r[4], "longitude": r[5],
            }
    return None


def upsert(
    name: str,
    address: str | None = None,
    region: str | None = None,
    latitude: float | None = None,
    longitude: float | None = None,
    cuisine_type: str | None = None,
    price_range: str | None = None,
    google_place_id: str | None = None,
) -> str:
    """Insert or update a restaurant. Returns row id."""
    existing = find_by_name(name)
    if existing:
        sql = """
            UPDATE restaurants
            SET address = COALESCE(:addr, address),
                region = COALESCE(:reg, region),
                latitude = COALESCE(:lat, latitude),
                longitude = COALESCE(:lng, longitude),
                cuisine_type = COALESCE(:cuisine, cuisine_type),
                price_range = COALESCE(:price, price_range),
                google_place_id = COALESCE(:gid, google_place_id),
                updated_at = SYSTIMESTAMP
            WHERE id = :id
        """
        with conn() as c:
            c.cursor().execute(sql, {
                "addr": address, "reg": region,
                "lat": latitude, "lng": longitude,
                "cuisine": cuisine_type, "price": price_range,
                "gid": google_place_id, "id": existing["id"],
            })
        return existing["id"]

    sql = """
        INSERT INTO restaurants (name, address, region, latitude, longitude,
                                 cuisine_type, price_range, google_place_id)
        VALUES (:name, :addr, :reg, :lat, :lng, :cuisine, :price, :gid)
        RETURNING id INTO :out_id
    """
    with conn() as c:
        cur = c.cursor()
        out_id = cur.var(oracledb.STRING)
        cur.execute(sql, {
            "name": name, "addr": address, "reg": region,
            "lat": latitude, "lng": longitude,
            "cuisine": cuisine_type, "price": price_range,
            "gid": google_place_id, "out_id": out_id,
        })
        return out_id.getvalue()[0]


def link_video_restaurant(
    video_db_id: str,
    restaurant_id: str,
    foods: list[str] | None = None,
    evaluation: str | None = None,
    guests: list[str] | None = None,
    citation: str | None = None,
) -> str | None:
    """Create video-restaurant mapping. Returns row id or None if duplicate."""
    sql = """
        INSERT INTO video_restaurants
            (video_id, restaurant_id, foods_mentioned, evaluation, guests, citation_text)
        VALUES (:vid, :rid, :foods, :eval, :guests, :cite)
        RETURNING id INTO :out_id
    """
    with conn() as c:
        cur = c.cursor()
        out_id = cur.var(oracledb.STRING)
        try:
            cur.execute(sql, {
                "vid": video_db_id,
                "rid": restaurant_id,
                "foods": json.dumps(foods or [], ensure_ascii=False),
                "eval": json.dumps({"text": evaluation} if evaluation else {}, ensure_ascii=False),
                "guests": json.dumps(guests or [], ensure_ascii=False),
                "cite": citation,
                "out_id": out_id,
            })
            return out_id.getvalue()[0]
        except Exception as e:
            if "UQ_VR_VIDEO_REST" in str(e).upper():
                return None
            raise


def get_all(
    limit: int = 100,
    offset: int = 0,
    cuisine: str | None = None,
    region: str | None = None,
) -> list[dict]:
    """List restaurants with optional filters."""
    conditions = ["latitude IS NOT NULL"]
    params: dict = {"lim": limit, "off": offset}

    if cuisine:
        conditions.append("cuisine_type = :cuisine")
        params["cuisine"] = cuisine
    if region:
        conditions.append("region LIKE :region")
        params["region"] = f"%{region}%"

    where = " AND ".join(conditions)
    sql = f"""
        SELECT id, name, address, region, latitude, longitude,
               cuisine_type, price_range, google_place_id
        FROM restaurants
        WHERE {where}
        ORDER BY updated_at DESC
        OFFSET :off ROWS FETCH NEXT :lim ROWS ONLY
    """
    with conn() as c:
        cur = c.cursor()
        cur.execute(sql, params)
        cols = [d[0].lower() for d in cur.description]
        return [dict(zip(cols, row)) for row in cur.fetchall()]


def get_by_id(restaurant_id: str) -> dict | None:
    sql = """
        SELECT r.id, r.name, r.address, r.region, r.latitude, r.longitude,
               r.cuisine_type, r.price_range, r.phone, r.website, r.google_place_id
        FROM restaurants r
        WHERE r.id = :id
    """
    with conn() as c:
        cur = c.cursor()
        cur.execute(sql, {"id": restaurant_id})
        row = cur.fetchone()
        if not row:
            return None
        cols = [d[0].lower() for d in cur.description]
        return dict(zip(cols, row))


def get_video_links(restaurant_id: str) -> list[dict]:
    """Get all video appearances for a restaurant."""
    sql = """
        SELECT v.video_id, v.title, v.url, v.published_at,
               vr.foods_mentioned, vr.evaluation, vr.guests
        FROM video_restaurants vr
        JOIN videos v ON v.id = vr.video_id
        WHERE vr.restaurant_id = :rid
        ORDER BY v.published_at DESC
    """
    with conn() as c:
        cur = c.cursor()
        cur.execute(sql, {"rid": restaurant_id})
        results = []
        for r in cur.fetchall():
            foods_raw = r[4].read() if hasattr(r[4], "read") else r[4]
            eval_raw = r[5].read() if hasattr(r[5], "read") else r[5]
            guests_raw = r[6].read() if hasattr(r[6], "read") else r[6]
            results.append({
                "video_id": r[0],
                "title": r[1],
                "url": r[2],
                "published_at": r[3].isoformat() if r[3] else None,
                "foods_mentioned": _parse_json_field(foods_raw, []),
                "evaluation": _parse_json_field(eval_raw, {}),
                "guests": _parse_json_field(guests_raw, []),
            })
        return results


def _parse_json_field(val, default):
    """Parse a JSON field that may be a string, already-parsed object, or None."""
    if val is None:
        return default
    if isinstance(val, (list, dict)):
        return val
    if isinstance(val, str):
        try:
            return json.loads(val)
        except (json.JSONDecodeError, ValueError):
            return default
    return default