<?php

declare(strict_types=1);

namespace OCA\WorkflowDeckAutomation\Tests\Unit\Service;

use OCA\WorkflowDeckAutomation\Service\LoopDetector;
use PHPUnit\Framework\TestCase;

class LoopDetectorTest extends TestCase {
	public function testNoWorkflowsHaveNoLoop(): void {
		$this->assertSame([], LoopDetector::findLoopingWorkflows([]));
	}

	public function testSameSourceAndTargetIsALoop(): void {
		$this->assertSame([1], LoopDetector::findLoopingWorkflows([1 => [10, 10]]));
	}

	public function testTwoWorkflowsBackAndForthAreALoop(): void {
		$this->assertSame([1, 2], LoopDetector::findLoopingWorkflows([
			1 => [10, 20],
			2 => [20, 10],
		]));
	}

	public function testLongerCircleIsALoop(): void {
		$this->assertSame([1, 2, 3], LoopDetector::findLoopingWorkflows([
			1 => [10, 20],
			2 => [20, 30],
			3 => [30, 10],
		]));
	}

	public function testChainIsNoLoop(): void {
		$this->assertSame([], LoopDetector::findLoopingWorkflows([
			1 => [10, 20],
			2 => [20, 30],
		]));
	}

	public function testOnlyWorkflowsOnTheCircleAreReported(): void {
		// 1 feeds into the circle 2 → 3 → 2 and 4 leads out of it; neither
		// lies on it.
		$this->assertSame([2, 3], LoopDetector::findLoopingWorkflows([
			1 => [10, 20],
			2 => [20, 30],
			3 => [30, 20],
			4 => [30, 40],
		]));
	}

	public function testTwoWorkflowsFromTheSameSourceAreNoLoop(): void {
		$this->assertSame([], LoopDetector::findLoopingWorkflows([
			1 => [10, 20],
			2 => [10, 30],
		]));
	}

	public function testFindPathListsTheWorkflowsInOrder(): void {
		$edges = [
			7 => [30, 10],
			5 => [10, 20],
			6 => [20, 30],
		];
		$this->assertSame([5, 6], LoopDetector::findPath($edges, 10, 30));
		$this->assertSame([6, 7], LoopDetector::findPath($edges, 20, 10));
	}

	public function testFindPathWithoutConnectionIsNull(): void {
		$this->assertNull(LoopDetector::findPath([1 => [10, 20]], 20, 10));
	}

	public function testFindPathToItselfIsEmpty(): void {
		$this->assertSame([], LoopDetector::findPath([], 10, 10));
	}
}