import os
from typing import Dict, Optional

import psycopg2
from psycopg2.extras import RealDictCursor


def _env_str(name: str, default: str) -> str:
    return os.environ.get(name, default)


def _env_int(name: str, default: int) -> int:
    try:
        return int(os.environ.get(name, default))
    except ValueError:
        return default


def get_connection():
    return psycopg2.connect(
        host=_env_str("PW_DB_HOST", "localhost"),
        port=_env_int("PW_DB_PORT", 5432),
        dbname=_env_str("PW_DB_NAME", "pricewatch"),
        user=_env_str("PW_DB_USER", "pricewatch"),
        password=_env_str("PW_DB_PASSWORD", "pricewatch"),
    )


def gather(limit: Optional[int] = None):
    query = """
    SELECT
        COALESCE(p.source, 'unknown') AS source,
        p.id,
        p.reference,
        p.title,
        p.description,
        p.category,
        p.msrp,
        EXISTS (
            SELECT 1 FROM product_images WHERE product_id = p.id LIMIT 1
        ) AS has_image,
        EXISTS (
            SELECT 1 FROM product_specs WHERE product_id = p.id LIMIT 1
        ) AS has_specs,
        ph.price,
        ph.stock_status
    FROM products p
    LEFT JOIN LATERAL (
        SELECT price, stock_status
        FROM price_history
        WHERE product_id = p.id
        ORDER BY fetched_at DESC
        LIMIT 1
    ) ph ON TRUE
    ORDER BY p.last_updated_at DESC
    """
    if limit:
        query += f" LIMIT {limit}"

    with get_connection() as conn:
        with conn.cursor(cursor_factory=RealDictCursor) as cur:
            cur.execute(query)
            return cur.fetchall()


def summarize(rows):
    stores: Dict[str, Dict[str, object]] = {}
    fields = [
        ("price", "Prix absent"),
        ("stock_status", "Statut stock manquant"),
        ("description", "Description manquante"),
        ("category", "Catégorie manquante"),
        ("msrp", "Prix conseillé absent"),
        ("has_image", "Images absentes"),
        ("has_specs", "Caractéristiques absentes"),
    ]
    for row in rows:
        store = row["source"] or "unknown"
        entry = stores.setdefault(
            store,
            {
                "total": 0,
                "details": {field: [] for field, _ in fields},
            },
        )
        entry["total"] += 1
        for field, label in fields:
            value = row.get(field)
            if field in ("has_image", "has_specs"):
                missing = not value
            else:
                missing = value in (None, "", [])
            if missing:
                entry["details"][field].append(
                    {
                        "id": row["id"],
                        "reference": row["reference"],
                        "title": row["title"] or "Sans titre",
                    }
                )
    return fields, stores


def pretty_print(fields, stores):
    for store, data in stores.items():
        print(f"\n=== Store: {store} ({data['total']} produits) ===")
        for field, label in fields:
            unit = len(data["details"][field])
            print(f"  {label}: {unit}")
            for item in data["details"][field][:5]:
                print(f"    - [{item['id']}] {item['reference']} · {item['title']}")


def main():
    rows = gather(limit=1000)
    fields, stores = summarize(rows)
    pretty_print(fields, stores)


if __name__ == "__main__":
    main()