<?php

declare (strict_types=1);
namespace Rector\TypeDeclaration\Rector\ClassMethod;

use PhpParser\Node;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Assign;
use PhpParser\Node\Expr\AssignOp\Concat;
use PhpParser\Node\Expr\Closure;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\FunctionLike;
use PhpParser\Node\Identifier;
use PhpParser\Node\NullableType;
use PhpParser\Node\Param;
use PhpParser\Node\Stmt\Class_;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Function_;
use PhpParser\NodeTraverser;
use PHPStan\Type\MixedType;
use PHPStan\Type\Type;
use PHPStan\Type\TypeCombinator;
use Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfoFactory;
use Rector\Rector\AbstractRector;
use Rector\VendorLocker\ParentClassMethodTypeOverrideGuard;
use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
/**
 * @see \Rector\Tests\TypeDeclaration\Rector\ClassMethod\StrictStringParamConcatRector\StrictStringParamConcatRectorTest
 */
final class StrictStringParamConcatRector extends AbstractRector
{
    /**
     * @readonly
     * @var \Rector\VendorLocker\ParentClassMethodTypeOverrideGuard
     */
    private $parentClassMethodTypeOverrideGuard;
    /**
     * @readonly
     * @var \Rector\BetterPhpDocParser\PhpDocInfo\PhpDocInfoFactory
     */
    private $phpDocInfoFactory;
    public function __construct(ParentClassMethodTypeOverrideGuard $parentClassMethodTypeOverrideGuard, PhpDocInfoFactory $phpDocInfoFactory)
    {
        $this->parentClassMethodTypeOverrideGuard = $parentClassMethodTypeOverrideGuard;
        $this->phpDocInfoFactory = $phpDocInfoFactory;
    }
    public function getRuleDefinition() : RuleDefinition
    {
        return new RuleDefinition('Add string type based on concat use', [new CodeSample(<<<'CODE_SAMPLE'
class SomeClass
{
    public function resolve($item)
    {
        return $item . ' world';
    }
}
CODE_SAMPLE
, <<<'CODE_SAMPLE'
class SomeClass
{
    public function resolve(string $item)
    {
        return $item . ' world';
    }
}
CODE_SAMPLE
)]);
    }
    /**
     * @return array<class-string<Node>>
     */
    public function getNodeTypes() : array
    {
        return [ClassMethod::class, Function_::class, Closure::class];
    }
    /**
     * @param ClassMethod|Function_|Closure $node
     */
    public function refactor(Node $node) : ?Node
    {
        if ($node instanceof ClassMethod && $this->parentClassMethodTypeOverrideGuard->hasParentClassMethod($node)) {
            return null;
        }
        $hasChanged = \false;
        $phpDocInfo = $this->phpDocInfoFactory->createFromNodeOrEmpty($node);
        foreach ($node->getParams() as $param) {
            if ($param->type instanceof Node) {
                continue;
            }
            $variableConcattedFromParam = $this->resolveVariableConcattedFromParam($param, $node);
            if (!$variableConcattedFromParam instanceof Variable) {
                continue;
            }
            $paramDocType = $phpDocInfo->getParamType($this->getName($param));
            if (!$paramDocType instanceof MixedType && !$paramDocType->isString()->yes()) {
                continue;
            }
            $nativeType = $this->nodeTypeResolver->getNativeType($variableConcattedFromParam);
            if (!$nativeType instanceof MixedType) {
                continue;
            }
            $subtractedType = $nativeType->getSubtractedType();
            if (!$subtractedType instanceof Type) {
                $param->type = new Identifier('string');
                $hasChanged = \true;
                continue;
            }
            if (TypeCombinator::containsNull($subtractedType)) {
                $param->type = new NullableType(new Identifier('string'));
                $hasChanged = \true;
            }
        }
        if ($hasChanged) {
            return $node;
        }
        return null;
    }
    /**
     * @param \PhpParser\Node\Stmt\ClassMethod|\PhpParser\Node\Stmt\Function_|\PhpParser\Node\Expr\Closure $functionLike
     */
    private function resolveVariableConcattedFromParam(Param $param, $functionLike) : ?Variable
    {
        if ($functionLike->stmts === null) {
            return null;
        }
        if ($param->default instanceof Expr && !$this->getType($param->default)->isString()->yes()) {
            return null;
        }
        $paramName = $this->getName($param);
        $variableConcatted = null;
        $this->traverseNodesWithCallable($functionLike->stmts, function (Node $node) use($paramName, &$variableConcatted) : ?int {
            // skip nested class and function nodes
            if ($node instanceof FunctionLike || $node instanceof Class_) {
                return NodeTraverser::DONT_TRAVERSE_CURRENT_AND_CHILDREN;
            }
            if ($node instanceof Assign && $node->var instanceof Variable && $this->isName($node->var, $paramName)) {
                $variableConcatted = null;
                return NodeTraverser::STOP_TRAVERSAL;
            }
            $expr = $this->resolveAssignConcatVariable($node, $paramName);
            if ($expr instanceof Variable) {
                $variableConcatted = $expr;
            }
            $variableBinaryConcat = $this->resolveBinaryConcatVariable($node, $paramName);
            if ($variableBinaryConcat instanceof Variable) {
                $variableConcatted = $variableBinaryConcat;
            }
            return null;
        });
        return $variableConcatted;
    }
    private function isVariableWithSameParam(Expr $expr, string $paramName) : bool
    {
        if (!$expr instanceof Variable) {
            return \false;
        }
        return $this->isName($expr, $paramName);
    }
    private function resolveAssignConcatVariable(Node $node, string $paramName) : ?Expr
    {
        if (!$node instanceof Concat) {
            return null;
        }
        if ($this->isVariableWithSameParam($node->var, $paramName)) {
            return $node->var;
        }
        if ($this->isVariableWithSameParam($node->expr, $paramName)) {
            return $node->expr;
        }
        return null;
    }
    private function resolveBinaryConcatVariable(Node $node, string $paramName) : ?Expr
    {
        if (!$node instanceof Expr\BinaryOp\Concat) {
            return null;
        }
        if ($this->isVariableWithSameParam($node->left, $paramName)) {
            return $node->left;
        }
        if ($this->isVariableWithSameParam($node->right, $paramName)) {
            return $node->right;
        }
        return null;
    }
}
