<?php

namespace Psalm\Internal\Type\Comparator;

use Psalm\Internal\Analyzer\StatementsAnalyzer;
use Psalm\Codebase;
use Psalm\Internal\Codebase\InternalCallMapHandler;
use Psalm\Type;
use Psalm\Type\Atomic\ObjectLike;
use Psalm\Type\Atomic\TArray;
use Psalm\Type\Atomic\TCallable;
use Psalm\Type\Atomic\TFn;
use Psalm\Type\Atomic\TList;
use Psalm\Type\Atomic\TLiteralString;
use Psalm\Type\Atomic\TNamedObject;
use function strtolower;
use function end;

/**
 * @internal
 */
class CallableTypeComparator
{
    /**
     * @param  TCallable|Type\Atomic\TFn   $input_type_part
     * @param  TCallable|Type\Atomic\TFn   $container_type_part
     */
    public static function isContainedBy(
        Codebase $codebase,
        Type\Atomic $input_type_part,
        Type\Atomic $container_type_part,
        ?TypeComparisonResult $atomic_comparison_result
    ) : bool {
        if ($container_type_part->is_pure && !$input_type_part->is_pure) {
            if ($atomic_comparison_result) {
                $atomic_comparison_result->type_coerced = $input_type_part->is_pure === null;
            }

            return false;
        }

        if ($container_type_part->params !== null && $input_type_part->params === null) {
            if ($atomic_comparison_result) {
                $atomic_comparison_result->type_coerced = true;
                $atomic_comparison_result->type_coerced_from_mixed = true;
            }

            return false;
        }

        if ($input_type_part->params !== null && $container_type_part->params !== null) {
            foreach ($input_type_part->params as $i => $input_param) {
                $container_param = null;

                if (isset($container_type_part->params[$i])) {
                    $container_param = $container_type_part->params[$i];
                } elseif ($container_type_part->params) {
                    $last_param = end($container_type_part->params);

                    if ($last_param->is_variadic) {
                        $container_param = $last_param;
                    }
                }

                if (!$container_param) {
                    if ($input_param->is_optional) {
                        break;
                    }

                    return false;
                }

                if ($container_param->type
                    && !$container_param->type->hasMixed()
                    && !UnionTypeComparator::isContainedBy(
                        $codebase,
                        $container_param->type,
                        $input_param->type ?: Type::getMixed(),
                        false,
                        false,
                        $atomic_comparison_result
                    )
                ) {
                    return false;
                }
            }
        }

        if (isset($container_type_part->return_type)) {
            if (!isset($input_type_part->return_type)) {
                if ($atomic_comparison_result) {
                    $atomic_comparison_result->type_coerced = true;
                    $atomic_comparison_result->type_coerced_from_mixed = true;
                }

                return false;
            }

            $input_return = $input_type_part->return_type;

            if ($input_return->isVoid() && $container_type_part->return_type->isNullable()) {
                return true;
            }

            if (!$container_type_part->return_type->isVoid()
                && !UnionTypeComparator::isContainedBy(
                    $codebase,
                    $input_return,
                    $container_type_part->return_type,
                    false,
                    false,
                    $atomic_comparison_result
                )
            ) {
                return false;
            }
        }

        return true;
    }

    public static function isNotExplicitlyCallableTypeCallable(
        Codebase $codebase,
        Type\Atomic $input_type_part,
        TCallable $container_type_part,
        ?TypeComparisonResult $atomic_comparison_result
    ) : bool {
        if ($input_type_part instanceof TList) {
            if ($input_type_part->type_param->isMixed()
                || $input_type_part->type_param->hasScalar()
            ) {
                if ($atomic_comparison_result) {
                    $atomic_comparison_result->type_coerced_from_mixed = true;
                    $atomic_comparison_result->type_coerced = true;
                }

                return false;
            }

            if (!$input_type_part->type_param->hasString()) {
                return false;
            }

            if (!$input_type_part instanceof Type\Atomic\TCallableList) {
                if ($atomic_comparison_result) {
                    $atomic_comparison_result->type_coerced_from_mixed = true;
                    $atomic_comparison_result->type_coerced = true;
                }

                return false;
            }
        }

        if ($input_type_part instanceof TArray) {
            if ($input_type_part->type_params[1]->isMixed()
                || $input_type_part->type_params[1]->hasScalar()
            ) {
                if ($atomic_comparison_result) {
                    $atomic_comparison_result->type_coerced_from_mixed = true;
                    $atomic_comparison_result->type_coerced = true;
                }

                return false;
            }

            if (!$input_type_part->type_params[1]->hasString()) {
                return false;
            }

            if (!$input_type_part instanceof Type\Atomic\TCallableArray) {
                if ($atomic_comparison_result) {
                    $atomic_comparison_result->type_coerced_from_mixed = true;
                    $atomic_comparison_result->type_coerced = true;
                }

                return false;
            }
        } elseif ($input_type_part instanceof ObjectLike) {
            $method_id = self::getCallableMethodIdFromObjectLike($input_type_part);

            if ($method_id === 'not-callable') {
                return false;
            }

            if (!$method_id) {
                return true;
            }

            try {
                $method_id = $codebase->methods->getDeclaringMethodId($method_id);

                if (!$method_id) {
                    return false;
                }

                $codebase->methods->getStorage($method_id);
            } catch (\Exception $e) {
                return false;
            }
        }

        $input_callable = self::getCallableFromAtomic($codebase, $input_type_part, $container_type_part);

        if ($input_callable) {
            if (self::isContainedBy(
                $codebase,
                $input_callable,
                $container_type_part,
                $atomic_comparison_result
            ) === false
            ) {
                return false;
            }
        }

        return true;
    }

    /**
     * @return TCallable|TFn|null
     */
    public static function getCallableFromAtomic(
        Codebase $codebase,
        Type\Atomic $input_type_part,
        ?TCallable $container_type_part = null,
        ?StatementsAnalyzer $statements_analyzer = null
    ) {
        if ($input_type_part instanceof TCallable || $input_type_part instanceof TFn) {
            return $input_type_part;
        }

        if ($input_type_part instanceof TLiteralString && $input_type_part->value) {
            try {
                $function_storage = $codebase->functions->getStorage(
                    $statements_analyzer,
                    strtolower($input_type_part->value)
                );

                return new TCallable(
                    'callable',
                    $function_storage->params,
                    $function_storage->return_type,
                    $function_storage->pure
                );
            } catch (\UnexpectedValueException $e) {
                if (InternalCallMapHandler::inCallMap($input_type_part->value)) {
                    $args = [];

                    $nodes = new \Psalm\Internal\Provider\NodeDataProvider();

                    if ($container_type_part && $container_type_part->params) {
                        foreach ($container_type_part->params as $i => $param) {
                            $arg = new \PhpParser\Node\Arg(
                                new \PhpParser\Node\Expr\Variable('_' . $i)
                            );

                            if ($param->type) {
                                $nodes->setType($arg->value, $param->type);
                            }

                            $args[] = $arg;
                        }
                    }

                    $matching_callable = \Psalm\Internal\Codebase\InternalCallMapHandler::getCallableFromCallMapById(
                        $codebase,
                        $input_type_part->value,
                        $args,
                        $nodes
                    );

                    $must_use = false;

                    $matching_callable->is_pure = $codebase->functions->isCallMapFunctionPure(
                        $codebase,
                        $statements_analyzer ? $statements_analyzer->node_data : null,
                        $input_type_part->value,
                        null,
                        $must_use
                    );

                    return $matching_callable;
                }
            }
        } elseif ($input_type_part instanceof ObjectLike) {
            $method_id = self::getCallableMethodIdFromObjectLike($input_type_part);
            if ($method_id && $method_id !== 'not-callable') {
                try {
                    $method_storage = $codebase->methods->getStorage($method_id);
                    $method_fqcln = $method_id->fq_class_name;

                    $converted_return_type = null;

                    if ($method_storage->return_type) {
                        $converted_return_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
                            $codebase,
                            $method_storage->return_type,
                            $method_fqcln,
                            $method_fqcln,
                            null
                        );
                    }

                    return new TCallable(
                        'callable',
                        $method_storage->params,
                        $converted_return_type,
                        $method_storage->pure
                    );
                } catch (\UnexpectedValueException $e) {
                    // do nothing
                }
            }
        } elseif ($input_type_part instanceof TNamedObject
            && $input_type_part->value === 'Closure'
        ) {
            return new TCallable();
        } elseif ($input_type_part instanceof TNamedObject
            && $codebase->classExists($input_type_part->value)
        ) {
            $invoke_id = new \Psalm\Internal\MethodIdentifier(
                $input_type_part->value,
                '__invoke'
            );

            if ($codebase->methods->methodExists($invoke_id)) {
                $declaring_method_id = $codebase->methods->getDeclaringMethodId($invoke_id);

                if ($declaring_method_id) {
                    $method_storage = $codebase->methods->getStorage($declaring_method_id);
                    $method_fqcln = $invoke_id->fq_class_name;
                    $converted_return_type = null;
                    if ($method_storage->return_type) {
                        $converted_return_type = \Psalm\Internal\Type\TypeExpander::expandUnion(
                            $codebase,
                            $method_storage->return_type,
                            $method_fqcln,
                            $method_fqcln,
                            null
                        );
                    }

                    return new TCallable(
                        'callable',
                        $method_storage->params,
                        $converted_return_type,
                        $method_storage->pure
                    );
                }
            }
        }

        return null;
    }

    /** @return null|'not-callable'|\Psalm\Internal\MethodIdentifier */
    public static function getCallableMethodIdFromObjectLike(
        ObjectLike $input_type_part,
        ?Codebase $codebase = null,
        ?string $calling_method_id = null,
        ?string $file_name = null
    ) {
        if (!isset($input_type_part->properties[0])
            || !isset($input_type_part->properties[1])
        ) {
            return 'not-callable';
        }

        [$lhs, $rhs] = $input_type_part->properties;

        $rhs_low_info = $rhs->hasMixed() || $rhs->hasScalar();

        if ($rhs_low_info || !$rhs->isSingleStringLiteral()) {
            if (!$rhs_low_info && !$rhs->hasString()) {
                return 'not-callable';
            }

            if ($codebase && ($calling_method_id || $file_name)) {
                foreach ($lhs->getAtomicTypes() as $lhs_atomic_type) {
                    if ($lhs_atomic_type instanceof TNamedObject) {
                        $codebase->analyzer->addMixedMemberName(
                            strtolower($lhs_atomic_type->value) . '::',
                            $calling_method_id ?: $file_name
                        );
                    }
                }
            }

            return null;
        }

        $method_name = $rhs->getSingleStringLiteral()->value;

        $class_name = null;

        if ($lhs->isSingleStringLiteral()) {
            $class_name = $lhs->getSingleStringLiteral()->value;
            if ($class_name[0] === '\\') {
                $class_name = \substr($class_name, 1);
            }
        } elseif ($lhs->isSingle()) {
            foreach ($lhs->getAtomicTypes() as $lhs_atomic_type) {
                if ($lhs_atomic_type instanceof TNamedObject) {
                    $class_name = $lhs_atomic_type->value;
                } elseif ($lhs_atomic_type instanceof Type\Atomic\TClassString
                    && $lhs_atomic_type->as
                ) {
                    $class_name = $lhs_atomic_type->as;
                }
            }
        }

        if ($class_name === 'self'
            || $class_name === 'static'
            || $class_name === 'parent'
        ) {
            return null;
        }

        if (!$class_name) {
            if ($codebase && ($calling_method_id || $file_name)) {
                $codebase->analyzer->addMixedMemberName(
                    strtolower($method_name),
                    $calling_method_id ?: $file_name
                );
            }

            return null;
        }

        return new \Psalm\Internal\MethodIdentifier(
            $class_name,
            strtolower($method_name)
        );
    }
}
