import json
from pathlib import Path


def load_single_bid_json_matrix(json_path):

    data_file = Path(json_path)
    if not data_file.exists():
        raise FileNotFoundError(f"JSON input file not found: {data_file}")

    with data_file.open("r", encoding="utf-8") as file:
        payload = json.load(file)

    if "matrix" in payload:
        matrix = [[_to_text(value) for value in row] for row in payload["matrix"]]
    elif "slot_range" in payload:
        matrix = _build_range_matrix(payload)
    else:
        price_row = [_to_text(value) for value in payload["price_row"]]
        slot_rows = [
            [_to_text(value) for value in slot["orders"]]
            for slot in payload.get("slots", [])
        ]
        matrix = [price_row, *slot_rows]

    if not matrix or not matrix[0]:
        raise ValueError(f"No bidding data found in {data_file}.")

    tsv = "\n".join("\t".join(row) for row in matrix)
    return {
        "matrix": matrix,
        "tsv": tsv,
        "row_count": len(matrix),
        "column_count": len(matrix[0]),
        "first_value": matrix[0][0],
    }


def _build_range_matrix(payload):

    price_row = [_to_text(value) for value in payload["price_row"]]
    slot_range = payload["slot_range"]
    from_slot = int(slot_range["from_slot"])
    to_slot = int(slot_range["to_slot"])
    orders = payload.get("orders", [])

    if from_slot < 1 or to_slot < from_slot:
        raise ValueError(f"Invalid slot_range: from_slot={from_slot}, to_slot={to_slot}")

    expected_row_count = to_slot - from_slot + 1
    if len(orders) != expected_row_count:
        raise ValueError(
            "Order row count does not match slot range: "
            f"expected {expected_row_count}, found {len(orders)}"
        )

    column_count = len(price_row)
    blank_row = [""] * column_count

    slot_rows = []
    for _ in range(from_slot - 1):
        slot_rows.append(blank_row.copy())

    for order_row in orders:
        normalized_row = [_to_text(value) for value in order_row]
        if len(normalized_row) != column_count:
            raise ValueError(
                "Each order row must have the same number of values as price_row: "
                f"expected {column_count}, found {len(normalized_row)}"
            )
        slot_rows.append(normalized_row)

    return [price_row, *slot_rows]


def _to_text(value):

    if value is None:
        return ""
    return str(value)