(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
	typeof define === 'function' && define.amd ? define(['exports'], factory) :
	(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.vlq = {}));
})(this, (function (exports) { 'use strict';

	/** @type {Record<string, number>} */
	let char_to_integer = {};

	/** @type {Record<number, string>} */
	let integer_to_char = {};

	'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
		.split('')
		.forEach(function (char, i) {
			char_to_integer[char] = i;
			integer_to_char[i] = char;
		});

	/** @param {string} string */
	function decode(string) {
		/** @type {number[]} */
		let result = [];

		let shift = 0;
		let value = 0;

		for (let i = 0; i < string.length; i += 1) {
			let integer = char_to_integer[string[i]];

			if (integer === undefined) {
				throw new Error('Invalid character (' + string[i] + ')');
			}

			const has_continuation_bit = integer & 32;

			integer &= 31;
			value += integer << shift;

			if (has_continuation_bit) {
				shift += 5;
			} else {
				const should_negate = value & 1;
				value >>>= 1;

				if (should_negate) {
					result.push(value === 0 ? -0x80000000 : -value);
				} else {
					result.push(value);
				}

				// reset
				value = shift = 0;
			}
		}

		return result;
	}

	/** @param {number | number[]} value */
	function encode(value) {
		if (typeof value === 'number') {
			return encode_integer(value);
		}

		let result = '';
		for (let i = 0; i < value.length; i += 1) {
			result += encode_integer(value[i]);
		}

		return result;
	}

	/** @param {number} num */
	function encode_integer(num) {
		let result = '';

		if (num < 0) {
			num = (-num << 1) | 1;
		} else {
			num <<= 1;
		}

		do {
			let clamped = num & 31;
			num >>>= 5;

			if (num > 0) {
				clamped |= 32;
			}

			result += integer_to_char[clamped];
		} while (num > 0);

		return result;
	}

	exports.decode = decode;
	exports.encode = encode;

	Object.defineProperty(exports, '__esModule', { value: true });

}));