<?php

declare(strict_types=1);

namespace Symplify\CodingStandard\Rules;

use Nette\Utils\Strings;
use PhpParser\Node;
use PhpParser\Node\Stmt;
use PhpParser\Node\Stmt\Class_;
use PhpParser\Node\Stmt\ClassConst;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Property;
use PHPStan\Analyser\Scope;

/**
 * @see \Symplify\CodingStandard\Tests\Rules\ExcessivePublicCountRule\ExcessivePublicCountRuleTest
 */
final class ExcessivePublicCountRule extends AbstractSymplifyRule
{
    /**
     * @var string
     */
    public const ERROR_MESSAGE = 'Too many public elements on class - %d. Try narrow it down under %d';

    /**
     * @var string
     * @see https://regex101.com/r/YnDoFR/1
     */
    private const VALUE_OBJECT_REGEX = '#\bValueObject\b#';

    /**
     * @var int
     */
    private $maxPublicClassElementCount;

    public function __construct(int $maxPublicClassElementCount)
    {
        $this->maxPublicClassElementCount = $maxPublicClassElementCount;
    }

    /**
     * @return string[]
     */
    public function getNodeTypes(): array
    {
        return [Class_::class];
    }

    /**
     * @param Class_ $node
     * @return string[]
     */
    public function process(Node $node, Scope $scope): array
    {
        $classPublicElementCount = $this->resolveClassPublicElementCount($node);
        if ($classPublicElementCount < $this->maxPublicClassElementCount) {
            return [];
        }

        $errorMessage = sprintf(self::ERROR_MESSAGE, $classPublicElementCount, $this->maxPublicClassElementCount);
        return [$errorMessage];
    }

    private function resolveClassPublicElementCount(Class_ $class): int
    {
        $publicElementCount = 0;

        $className = (string) $class->namespacedName;

        foreach ($class->stmts as $classStmt) {
            if ($this->shouldSkipClassStmt($classStmt, $className)) {
                continue;
            }

            ++$publicElementCount;
        }

        return $publicElementCount;
    }

    private function shouldSkipClassStmt(Stmt $classStmt, string $className): bool
    {
        if (! $classStmt instanceof Property && ! $classStmt instanceof ClassMethod && ! $classStmt instanceof ClassConst) {
            return true;
        }

        if (! $classStmt->isPublic()) {
            return true;
        }

        if (Strings::match($className, self::VALUE_OBJECT_REGEX) && $classStmt instanceof ClassConst) {
            return true;
        }

        if ($classStmt instanceof ClassMethod) {
            $methodName = (string) $classStmt->name;
            return Strings::startsWith($methodName, '__');
        }

        return false;
    }
}