<?php declare(strict_types = 1);

namespace PHPStan\Rules\PHPUnit;

use PhpParser\Node;
use PHPStan\Analyser\Scope;
use PHPStan\PhpDocParser\Ast\PhpDoc\PhpDocTagNode;
use PHPStan\Rules\Rule;
use PHPStan\Rules\RuleErrorBuilder;
use PHPStan\Type\FileTypeMapper;
use PHPUnit\Framework\TestCase;
use function array_map;
use function array_merge;
use function array_shift;
use function count;
use function in_array;
use function sprintf;

/**
 * @implements Rule<Node\Stmt\ClassMethod>
 */
class ClassMethodCoversExistsRule implements Rule
{

	/**
	 * Covers helper.
	 *
	 * @var CoversHelper
	 */
	private $coversHelper;

	/**
	 * The file type mapper.
	 *
	 * @var FileTypeMapper
	 */
	private $fileTypeMapper;

	public function __construct(
		CoversHelper $coversHelper,
		FileTypeMapper $fileTypeMapper
	)
	{
		$this->coversHelper = $coversHelper;
		$this->fileTypeMapper = $fileTypeMapper;
	}

	public function getNodeType(): string
	{
		return Node\Stmt\ClassMethod::class;
	}

	public function processNode(Node $node, Scope $scope): array
	{
		$classReflection = $scope->getClassReflection();

		if ($classReflection === null) {
			return [];
		}

		if (!$classReflection->isSubclassOf(TestCase::class)) {
			return [];
		}

		$errors = [];
		$classPhpDoc = $classReflection->getResolvedPhpDoc();
		[$classCovers, $classCoversDefaultClasses] = $this->coversHelper->getCoverAnnotations($classPhpDoc);

		$classCoversStrings = array_map(static function (PhpDocTagNode $covers): string {
			return (string) $covers->value;
		}, $classCovers);

		$docComment = $node->getDocComment();
		if ($docComment === null) {
			return [];
		}

		$coversDefaultClass = count($classCoversDefaultClasses) === 1
			? array_shift($classCoversDefaultClasses)
			: null;

		$methodPhpDoc = $this->fileTypeMapper->getResolvedPhpDoc(
			$scope->getFile(),
			$classReflection->getName(),
			$scope->isInTrait() ? $scope->getTraitReflection()->getName() : null,
			$node->name->toString(),
			$docComment->getText()
		);

		[$methodCovers, $methodCoversDefaultClasses] = $this->coversHelper->getCoverAnnotations($methodPhpDoc);

		$errors = [];

		if (count($methodCoversDefaultClasses) > 0) {
			$errors[] = RuleErrorBuilder::message(sprintf(
				'@coversDefaultClass defined on class method %s.',
				$node->name
			))->build();
		}

		foreach ($methodCovers as $covers) {
			if (in_array((string) $covers->value, $classCoversStrings, true)) {
				$errors[] = RuleErrorBuilder::message(sprintf(
					'Class already @covers %s so the method @covers is redundant.',
					$covers->value
				))->build();
			}

			$errors = array_merge(
				$errors,
				$this->coversHelper->processCovers($node, $covers, $coversDefaultClass)
			);
		}

		return $errors;
	}

}