DowngradeArrayKeyFirstLastRector.php

<?php

declare(strict_types=1);

namespace Rector\DowngradePhp73\Rector\FuncCall;

use PhpParser\Node;
use PhpParser\Node\Arg;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\BinaryOp\BooleanOr;
use PhpParser\Node\Expr\CallLike;
use PhpParser\Node\Expr\Cast\Array_;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\New_;
use PhpParser\Node\Expr\NullsafeMethodCall;
use PhpParser\Node\Expr\StaticCall;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Name;
use PhpParser\Node\Stmt;
use PhpParser\Node\Stmt\Echo_;
use PhpParser\Node\Stmt\Expression;
use PhpParser\Node\Stmt\If_;
use PhpParser\Node\Stmt\Return_;
use PhpParser\Node\Stmt\Switch_;
use PHPStan\Analyser\Scope;
use Rector\Naming\Naming\VariableNaming;
use Rector\NodeAnalyzer\ExprInTopStmtMatcher;
use Rector\NodeTypeResolver\Node\AttributeKey;
use Rector\PhpParser\Enum\NodeGroup;
use Rector\Rector\AbstractRector;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;

/**
 * @changelog https://wiki.php.net/rfc/array_key_first_last
 *
 * @see \Rector\Tests\DowngradePhp73\Rector\FuncCall\DowngradeArrayKeyFirstLastRector\DowngradeArrayKeyFirstLastRectorTest
 */
final class DowngradeArrayKeyFirstLastRector extends AbstractRector
{
    public function __construct(
        private readonly VariableNaming $variableNaming,
        private readonly ExprInTopStmtMatcher $exprInTopStmtMatcher
    ) {
    }

    public function getRuleDefinition(): RuleDefinition
    {
        return new RuleDefinition('Downgrade array_key_first() and array_key_last() functions', [
            new CodeSample(
                <<<'CODE_SAMPLE'
class SomeClass
{
    public function run($items)
    {
        $firstItemKey = array_key_first($items);
    }
}
CODE_SAMPLE

                ,
                <<<'CODE_SAMPLE'
class SomeClass
{
    public function run($items)
    {
        reset($items);
        $firstItemKey = key($items);
    }
}
CODE_SAMPLE
            ),
        ]);
    }

    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes(): array
    {
        return [...NodeGroup::STMTS_AWARE, Switch_::class, Return_::class, Expression::class, Echo_::class];
    }

    /**
     * @param StmtsAware|Switch_|Return_|Expression|Echo_ $node
     * @return Node[]|null
     */
    public function refactor(Node $node): ?array
    {
        $exprArrayKeyFirst = $this->exprInTopStmtMatcher->match(
            $node,
            function (Node $subNode): bool {
                if (! $subNode instanceof FuncCall) {
                    return false;
                }

                return $this->isName($subNode, 'array_key_first');
            }
        );

        if ($exprArrayKeyFirst instanceof FuncCall) {
            return $this->refactorArrayKeyFirst($exprArrayKeyFirst, $node);
        }

        $exprArrayKeyLast = $this->exprInTopStmtMatcher->match(
            $node,
            function (Node $subNode): bool {
                if (! $subNode instanceof FuncCall) {
                    return false;
                }

                return $this->isName($subNode, 'array_key_last');
            }
        );

        if ($exprArrayKeyLast instanceof FuncCall) {
            return $this->refactorArrayKeyLast($exprArrayKeyLast, $node);
        }

        return null;
    }

    private function resolveVariableFromCallLikeScope(CallLike $callLike, ?Scope $scope): Variable
    {
        /** @var MethodCall|FuncCall|StaticCall|New_|NullsafeMethodCall $callLike */
        if ($callLike instanceof New_) {
            $variableName = (string) $this->getName($callLike->class);
        } else {
            $variableName = (string) $this->getName($callLike->name);
        }

        if ($variableName === '') {
            $variableName = 'array';
        }

        return new Variable($this->variableNaming->createCountedValueName($variableName, $scope));
    }

    /**
     * @return Node[]|null
     */
    private function refactorArrayKeyFirst(
        FuncCall $funcCall,
        Node|Switch_|Return_|Expression|Echo_ $stmt
    ): null|array {
        $args = $funcCall->getArgs();
        if (! isset($args[0])) {
            return null;
        }

        $originalArray = $args[0]->value;
        $array = $this->resolveCastedArray($originalArray);
        $newStmts = [];

        if ($originalArray instanceof CallLike) {
            $scope = $originalArray->getAttribute(AttributeKey::SCOPE);
            $array = $this->resolveVariableFromCallLikeScope($originalArray, $scope);
        }

        if ($originalArray !== $array) {
            $newStmts[] = new Expression(new Assign($array, $originalArray));
        }

        $resetFuncCall = $this->nodeFactory->createFuncCall('reset', [$array]);
        $newStmts[] = $this->resolvePrependNewStmt($array, $resetFuncCall, $stmt);

        $funcCall->name = new Name('key');
        if ($originalArray !== $array) {
            $firstArg = $args[0];
            $firstArg->value = $array;
        }

        $newStmts[] = $stmt;

        return $newStmts;
    }

    /**
     * @return Node[]|null
     */
    private function refactorArrayKeyLast(
        FuncCall $funcCall,
        Node|Switch_|Return_|Expression|Echo_ $stmt
    ): null|array {
        $args = $funcCall->getArgs();
        $firstArg = $args[0] ?? null;
        if (! $firstArg instanceof Arg) {
            return null;
        }

        $originalArray = $firstArg->value;
        $array = $this->resolveCastedArray($originalArray);

        $newStmts = [];

        if ($originalArray instanceof CallLike) {
            $scope = $originalArray->getAttribute(AttributeKey::SCOPE);
            $array = $this->resolveVariableFromCallLikeScope($originalArray, $scope);
        }

        if ($originalArray !== $array) {
            $newStmts[] = new Expression(new Assign($array, $originalArray));
        }

        $endFuncCall = $this->nodeFactory->createFuncCall('end', [$array]);
        $newStmts[] = $this->resolvePrependNewStmt($array, $endFuncCall, $stmt);

        $funcCall->name = new Name('key');
        if ($originalArray !== $array) {
            $firstArg->value = $array;
        }

        $newStmts[] = $stmt;

        $resetExpression = new Expression($this->nodeFactory->createFuncCall('reset', [$array]));

        if (property_exists($stmt, 'stmts')) {
            $stmt->stmts = array_merge([$resetExpression], $stmt->stmts);
        } elseif (! $stmt instanceof Return_) {
            $newStmts[] = $resetExpression;
        }

        return $newStmts;
    }

    private function resolvePrependNewStmt(
        Expr|Variable $array,
        FuncCall $funcCall,
        Stmt|Node $stmt
    ): Expression|If_ {
        if (! $stmt instanceof If_ || $stmt->cond instanceof FuncCall || ! $stmt->cond instanceof BooleanOr) {
            return new Expression($funcCall);
        }

        $if = new If_($this->nodeFactory->createFuncCall('is_array', [$array]));
        $if->stmts[] = new Expression($funcCall);

        return $if;
    }

    private function resolveCastedArray(Expr $expr): Expr|Variable
    {
        if (! $expr instanceof Array_) {
            return $expr;
        }

        if ($expr->expr instanceof Array_) {
            return $this->resolveCastedArray($expr->expr);
        }

        $scope = $expr->getAttribute(AttributeKey::SCOPE);

        $variableName = $this->variableNaming->createCountedValueName(
            (string) $this->getName($expr->expr),
            $scope
        );

        return new Variable($variableName);
    }
}