import logging
from .. import database

logger = logging.getLogger(__name__)

def check_orders_in_roa(min_date, conn) -> dict:
    """Check which orders already exist in Oracle COMENZI by date range.
    Returns: {comanda_externa: id_comanda} for all existing orders.
    Much faster than IN-clause batching — single query using date index.
    """
    if conn is None:
        return {}

    existing = {}
    try:
        with conn.cursor() as cur:
            cur.execute("""
                SELECT comanda_externa, id_comanda FROM COMENZI
                WHERE data_comanda >= :min_date
                  AND comanda_externa IS NOT NULL AND sters = 0
            """, {"min_date": min_date})
            for row in cur:
                existing[str(row[0])] = row[1]
    except Exception as e:
        logger.error(f"check_orders_in_roa failed: {e}")

    logger.info(f"ROA order check (since {min_date}): {len(existing)} existing orders found")
    return existing


def resolve_codmat_ids(codmats: set[str], id_gestiune: int = None, conn=None) -> dict[str, int]:
    """Resolve CODMATs to best id_articol: prefers article with stock, then MAX(id_articol).
    Filters: sters=0 AND inactiv=0.
    Returns: {codmat: id_articol}
    """
    if not codmats:
        return {}

    result = {}
    codmat_list = list(codmats)

    # Build stoc subquery dynamically for index optimization
    if id_gestiune is not None:
        stoc_filter = "AND s.id_gestiune = :id_gestiune"
    else:
        stoc_filter = ""

    own_conn = conn is None
    if own_conn:
        conn = database.get_oracle_connection()
    try:
        with conn.cursor() as cur:
            for i in range(0, len(codmat_list), 500):
                batch = codmat_list[i:i+500]
                placeholders = ",".join([f":c{j}" for j in range(len(batch))])
                params = {f"c{j}": cm for j, cm in enumerate(batch)}
                if id_gestiune is not None:
                    params["id_gestiune"] = id_gestiune

                cur.execute(f"""
                    SELECT codmat, id_articol FROM (
                        SELECT na.codmat, na.id_articol,
                               ROW_NUMBER() OVER (
                                   PARTITION BY na.codmat
                                   ORDER BY
                                       CASE WHEN EXISTS (
                                           SELECT 1 FROM stoc s
                                           WHERE s.id_articol = na.id_articol
                                             {stoc_filter}
                                             AND s.an = EXTRACT(YEAR FROM SYSDATE)
                                             AND s.luna = EXTRACT(MONTH FROM SYSDATE)
                                             AND s.cants + s.cant - s.cante > 0
                                       ) THEN 0 ELSE 1 END,
                                       na.id_articol DESC
                               ) AS rn
                          FROM nom_articole na
                         WHERE na.codmat IN ({placeholders})
                           AND na.sters = 0 AND na.inactiv = 0
                    ) WHERE rn = 1
                """, params)
                for row in cur:
                    result[row[0]] = row[1]
    finally:
        if own_conn:
            database.pool.release(conn)

    logger.info(f"resolve_codmat_ids: {len(result)}/{len(codmats)} resolved (gestiune={id_gestiune})")
    return result


def validate_skus(skus: set[str], conn=None, id_gestiune: int = None) -> dict:
    """Validate a set of SKUs against Oracle.
    Returns: {mapped: set, direct: set, missing: set, direct_id_map: {codmat: id_articol}}
    - mapped: found in ARTICOLE_TERTI (active)
    - direct: found in NOM_ARTICOLE by codmat (not in ARTICOLE_TERTI)
    - missing: not found anywhere
    - direct_id_map: {codmat: id_articol} for direct SKUs (saves a round-trip in validate_prices)
    """
    if not skus:
        return {"mapped": set(), "direct": set(), "missing": set(), "direct_id_map": {}}

    mapped = set()
    sku_list = list(skus)

    own_conn = conn is None
    if own_conn:
        conn = database.get_oracle_connection()
    try:
        with conn.cursor() as cur:
            # Check in batches of 500
            for i in range(0, len(sku_list), 500):
                batch = sku_list[i:i+500]
                placeholders = ",".join([f":s{j}" for j in range(len(batch))])
                params = {f"s{j}": sku for j, sku in enumerate(batch)}

                # Check ARTICOLE_TERTI
                cur.execute(f"""
                    SELECT DISTINCT sku FROM ARTICOLE_TERTI
                    WHERE sku IN ({placeholders}) AND activ = 1 AND sters = 0
                """, params)
                for row in cur:
                    mapped.add(row[0])

        # Resolve remaining SKUs via resolve_codmat_ids (consistent id_articol selection)
        all_remaining = [s for s in sku_list if s not in mapped]
        if all_remaining:
            direct_id_map = resolve_codmat_ids(set(all_remaining), id_gestiune, conn)
            direct = set(direct_id_map.keys())
        else:
            direct_id_map = {}
            direct = set()
    finally:
        if own_conn:
            database.pool.release(conn)

    missing = skus - mapped - direct

    logger.info(f"SKU validation: {len(mapped)} mapped, {len(direct)} direct, {len(missing)} missing")
    return {"mapped": mapped, "direct": direct, "missing": missing, "direct_id_map": direct_id_map}

def classify_orders(orders, validation_result):
    """Classify orders as importable or skipped based on SKU validation.
    Returns: (importable_orders, skipped_orders)
    Each skipped entry is a tuple of (order, list_of_missing_skus).
    """
    ok_skus = validation_result["mapped"] | validation_result["direct"]
    importable = []
    skipped = []

    for order in orders:
        order_skus = {item.sku for item in order.items if item.sku}
        order_missing = order_skus - ok_skus

        if order_missing:
            skipped.append((order, list(order_missing)))
        else:
            importable.append(order)

    return importable, skipped

def validate_prices(codmats: set[str], id_pol: int, conn=None, direct_id_map: dict=None) -> dict:
    """Check which CODMATs have a price entry in CRM_POLITICI_PRET_ART for the given policy.
    If direct_id_map is provided, skips the NOM_ARTICOLE lookup for those CODMATs.
    Returns: {"has_price": set_of_codmats, "missing_price": set_of_codmats}
    """
    if not codmats:
        return {"has_price": set(), "missing_price": set()}

    codmat_to_id = dict(direct_id_map) if direct_id_map else {}
    ids_with_price = set()

    own_conn = conn is None
    if own_conn:
        conn = database.get_oracle_connection()
    try:
        with conn.cursor() as cur:
            # Check which ID_ARTICOLs have a price in the policy
            id_list = list(codmat_to_id.values())
            for i in range(0, len(id_list), 500):
                batch = id_list[i:i+500]
                placeholders = ",".join([f":a{j}" for j in range(len(batch))])
                params = {f"a{j}": aid for j, aid in enumerate(batch)}
                params["id_pol"] = id_pol

                cur.execute(f"""
                    SELECT DISTINCT pa.ID_ARTICOL FROM CRM_POLITICI_PRET_ART pa
                    WHERE pa.ID_POL = :id_pol AND pa.ID_ARTICOL IN ({placeholders})
                """, params)
                for row in cur:
                    ids_with_price.add(row[0])
    finally:
        if own_conn:
            database.pool.release(conn)

    # Map back to CODMATs
    has_price = {cm for cm, aid in codmat_to_id.items() if aid in ids_with_price}
    missing_price = codmats - has_price

    logger.info(f"Price validation (policy {id_pol}): {len(has_price)} have price, {len(missing_price)} missing price")
    return {"has_price": has_price, "missing_price": missing_price}

def ensure_prices(codmats: set[str], id_pol: int, conn=None, direct_id_map: dict=None):
    """Insert price 0 entries for CODMATs missing from the given price policy.
    Uses batch executemany instead of individual INSERTs.
    Relies on TRG_CRM_POLITICI_PRET_ART trigger for ID_POL_ART sequence.
    """
    if not codmats:
        return

    own_conn = conn is None
    if own_conn:
        conn = database.get_oracle_connection()
    try:
        with conn.cursor() as cur:
            # Get ID_VALUTA for this policy
            cur.execute("""
                SELECT ID_VALUTA FROM CRM_POLITICI_PRETURI WHERE ID_POL = :id_pol
            """, {"id_pol": id_pol})
            row = cur.fetchone()
            if not row:
                logger.error(f"Price policy {id_pol} not found in CRM_POLITICI_PRETURI")
                return
            id_valuta = row[0]

            # Build batch params using direct_id_map (already resolved via resolve_codmat_ids)
            batch_params = []
            codmat_id_map = dict(direct_id_map) if direct_id_map else {}

            for codmat in codmats:
                id_articol = codmat_id_map.get(codmat)
                if not id_articol:
                    logger.warning(f"CODMAT {codmat} not found in NOM_ARTICOLE, skipping price insert")
                    continue
                batch_params.append({
                    "id_pol": id_pol,
                    "id_articol": id_articol,
                    "id_valuta": id_valuta
                })

            if batch_params:
                cur.executemany("""
                    INSERT INTO CRM_POLITICI_PRET_ART
                        (ID_POL, ID_ARTICOL, PRET, ID_VALUTA,
                         ID_UTIL, DATAORA, PROC_TVAV, PRETFTVA, PRETCTVA)
                    VALUES
                        (:id_pol, :id_articol, 0, :id_valuta,
                         -3, SYSDATE, 1.19, 0, 0)
                """, batch_params)
                logger.info(f"Batch inserted {len(batch_params)} price entries for policy {id_pol}")

            conn.commit()
    finally:
        if own_conn:
            database.pool.release(conn)

    logger.info(f"Ensure prices done: {len(codmats)} CODMATs processed for policy {id_pol}")