import { bigIntToVmNumber, utf8ToBin } from '@bitauth/libauth';
import { CashAssemblyNumberNotSafeIntegerError, CashAssemblyUnsupportedValueTypeError } from './errors.ts';

/**
 * Converts a value into bytes representation.
 *
 * @param {unknown} value - Value to encode, should be one of: Uint8Array, bigint, boolean, string, or a safe integer number.
 * @param {string} valueIdentifier - Identifier used in error messages.
 * @returns {Uint8Array} Bytes representation of the value.
 * @throws {@link CashAssemblyNumberNotSafeIntegerError} When a number is not a safe integer.
 * @throws {@link CashAssemblyUnsupportedValueTypeError} When the value type cannot be resolved.
 */
export const convertValueToBytes = (value: unknown, valueIdentifier: string): Uint8Array => {
    if (value instanceof Uint8Array) {
        return value;
    }

    if (typeof value === 'bigint') {
        return bigIntToVmNumber(value);
    }

    if (typeof value === 'boolean') {
        // The BCH VM treats an empty byte array as false and any nonempty byte array as true.
        return new Uint8Array(value ? [ 1 ] : []);
    }

    if (typeof value === 'string') {
        return utf8ToBin(value);
    }

    if (typeof value === 'number') {
        if (Number.isSafeInteger(value) === true) {
            return bigIntToVmNumber(BigInt(value));
        }

        throw new CashAssemblyNumberNotSafeIntegerError(valueIdentifier, value);
    }

    throw new CashAssemblyUnsupportedValueTypeError(valueIdentifier, typeof value);
};