/*
This file is part of web3.js.

web3.js is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

web3.js is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with web3.js.  If not, see <http://www.gnu.org/licenses/>.
*/

import { keccak256 } from 'ethereum-cryptography/keccak.js';
import { ValidInputTypes } from '../types.js';
import { codePointToInt, hexToUint8Array, padLeft, uint8ArrayToHexString } from '../utils.js';
import { isAddress } from './address.js';
import { isHexStrict } from './string.js';

/**
 * Returns true if the bloom is a valid bloom
 * https://github.com/joshstevens19/ethereum-bloom-filters/blob/fbeb47b70b46243c3963fe1c2988d7461ef17236/src/index.ts#L7
 */
export const isBloom = (bloom: ValidInputTypes): boolean => {
	if (typeof bloom !== 'string') {
		return false;
	}

	if (!/^(0x)?[0-9a-f]{512}$/i.test(bloom)) {
		return false;
	}

	if (/^(0x)?[0-9a-f]{512}$/.test(bloom) || /^(0x)?[0-9A-F]{512}$/.test(bloom)) {
		return true;
	}

	return false;
};

/**
 * Returns true if the value is part of the given bloom
 * note: false positives are possible.
 */
export const isInBloom = (bloom: string, value: string | Uint8Array): boolean => {
	if (typeof value === 'string' && !isHexStrict(value)) {
		return false;
	}

	if (!isBloom(bloom)) {
		return false;
	}

	const uint8Array = typeof value === 'string' ? hexToUint8Array(value) : value;

	const hash = uint8ArrayToHexString(keccak256(uint8Array)).slice(2);

	for (let i = 0; i < 12; i += 4) {
		// calculate bit position in bloom filter that must be active
		const bitpos =
			// eslint-disable-next-line no-bitwise
			((parseInt(hash.slice(i, i + 2), 16) << 8) + parseInt(hash.slice(i + 2, i + 4), 16)) &
			2047;

		// test if bitpos in bloom is active
		const code = codePointToInt(bloom.charCodeAt(bloom.length - 1 - Math.floor(bitpos / 4)));

		// eslint-disable-next-line no-bitwise
		const offset = 1 << bitpos % 4;

		// eslint-disable-next-line no-bitwise
		if ((code & offset) !== offset) {
			return false;
		}
	}

	return true;
};

/**
 * Returns true if the ethereum users address is part of the given bloom note: false positives are possible.
 */
export const isUserEthereumAddressInBloom = (bloom: string, ethereumAddress: string): boolean => {
	if (!isBloom(bloom)) {
		return false;
	}

	if (!isAddress(ethereumAddress)) {
		return false;
	}

	// you have to pad the ethereum address to 32 bytes
	// else the bloom filter does not work
	// this is only if your matching the USERS
	// ethereum address. Contract address do not need this
	// hence why we have 2 methods
	// (0x is not in the 2nd parameter of padleft so 64 chars is fine)

	const address = padLeft(ethereumAddress, 64);

	return isInBloom(bloom, address);
};

/**
 * Returns true if the contract address is part of the given bloom.
 * note: false positives are possible.
 */
export const isContractAddressInBloom = (bloom: string, contractAddress: string): boolean => {
	if (!isBloom(bloom)) {
		return false;
	}

	if (!isAddress(contractAddress)) {
		return false;
	}

	return isInBloom(bloom, contractAddress);
};