/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the Source EULA. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import { BugIndicatingError, onUnexpectedError } from 'vs/base/common/errors';

/**
 * Throws an error with the provided message if the provided value does not evaluate to a true Javascript value.
 *
 * @deprecated Use `assert(...)` instead.
 * This method is usually used like this:
 * ```ts
 * import * as assert from 'vs/base/common/assert';
 * assert.ok(...);
 * ```
 *
 * However, `assert` in that example is a user chosen name.
 * There is no tooling for generating such an import statement.
 * Thus, the `assert(...)` function should be used instead.
 */
export function ok(value?: unknown, message?: string) {
	if (!value) {
		throw new Error(message ? `Assertion failed (${message})` : 'Assertion Failed');
	}
}

export function assertNever(value: never, message = 'Unreachable'): never {
	throw new Error(message);
}

export function assert(condition: boolean): void {
	if (!condition) {
		throw new BugIndicatingError('Assertion Failed');
	}
}

/**
 * condition must be side-effect free!
 */
export function assertFn(condition: () => boolean): void {
	if (!condition()) {
		// eslint-disable-next-line no-debugger
		debugger;
		// Reevaluate `condition` again to make debugging easier
		condition();
		onUnexpectedError(new BugIndicatingError('Assertion Failed'));
	}
}

export function checkAdjacentItems<T>(items: readonly T[], predicate: (item1: T, item2: T) => boolean): boolean {
	let i = 0;
	while (i < items.length - 1) {
		const a = items[i];
		const b = items[i + 1];
		if (!predicate(a, b)) {
			return false;
		}
		i++;
	}
	return true;
}
