/**
 * Copyright (c) Whales Corp.
 * All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

export function bitsForNumber(
    src: bigint | number,
    mode: "int" | "uint",
): number {
    let v = BigInt(src);

    // Handle negative values
    if (mode === "int") {
        // Corner case for zero or -1 value
        if (v === 0n || v === -1n) {
            return 1;
        }

        let v2 = v > 0 ? v : -v;
        return v2.toString(2).length + 1 /* Sign bit */;
    } else if (mode === "uint") {
        if (v < 0) {
            throw Error(`value is negative. Got ${src}`);
        }
        return v.toString(2).length;
    } else {
        throw Error(`invalid mode. Got ${mode}`);
    }
}