<?php

declare(strict_types=1);

namespace ProxyManager\ProxyGenerator\Util;

use ReflectionClass;
use ReflectionProperty;
use ReflectionType;

use function array_filter;
use function array_flip;
use function array_key_exists;
use function array_keys;
use function array_map;
use function array_merge;
use function array_values;
use function assert;

/**
 * DTO containing the list of all non-static proxy properties and utility methods to access them
 * in various formats/collections
 */
final class Properties
{
    /** @var ReflectionProperty[] */
    private $properties;

    /**
     * @param ReflectionProperty[] $properties
     */
    private function __construct(array $properties)
    {
        $this->properties = $properties;
    }

    public static function fromReflectionClass(ReflectionClass $reflection): self
    {
        $class         = $reflection;
        $parentClasses = [];

        do {
            $parentClasses[] = $class;

            $class = $class->getParentClass();
        } while ($class);

        return new self(array_merge(
            ...array_map(static function (ReflectionClass $class): array {
                return array_values(array_filter(
                    $class->getProperties(),
                    static function (ReflectionProperty $property) use ($class): bool {
                        return $class->getName() === $property->getDeclaringClass()->getName()
                            && ! $property->isStatic();
                    }
                ));
            }, $parentClasses)
        ));
    }

    /**
     * @param array<int, string> $excludedProperties
     */
    public function filter(array $excludedProperties): self
    {
        $properties = $this->getInstanceProperties();

        foreach ($excludedProperties as $propertyName) {
            unset($properties[$propertyName]);
        }

        return new self($properties);
    }

    public function onlyNonReferenceableProperties(): self
    {
        return new self(array_filter($this->properties, static function (ReflectionProperty $property): bool {
            if (\PHP_VERSION_ID < 70400 || ! $property->hasType()) {
                return false;
            }

            if (\PHP_VERSION_ID >= 80100 && $property->isReadOnly()) {
                return true;
            }

            $type = $property->getType();
            assert($type instanceof ReflectionType);

            if ($type->allowsNull()) {
                return false;
            }

            return ! array_key_exists(
                $property->getName(),
                // https://bugs.php.net/bug.php?id=77673
                array_flip(array_keys($property->getDeclaringClass()->getDefaultProperties()))
            );
        }));
    }

    /** @deprecated Since PHP 7.4.1, all properties can be unset, regardless if typed or not */
    public function onlyPropertiesThatCanBeUnset(): self
    {
        return $this;
    }

    /**
     * Properties that cannot be referenced are non-nullable typed properties that aren't initialised
     */
    public function withoutNonReferenceableProperties(): self
    {
        return new self(array_filter($this->properties, static function (ReflectionProperty $property): bool {
            if (\PHP_VERSION_ID < 70400 || ! $property->hasType()) {
                return true;
            }

            if (\PHP_VERSION_ID >= 80100 && $property->isReadOnly()) {
                return false;
            }

            $type = $property->getType();
            assert($type instanceof ReflectionType);

            if ($type->allowsNull()) {
                return true;
            }

            return array_key_exists(
                $property->getName(),
                // https://bugs.php.net/bug.php?id=77673
                array_flip(array_keys($property->getDeclaringClass()->getDefaultProperties()))
            );
        }));
    }

    public function onlyNullableProperties(): self
    {
        return new self(array_filter(
            $this->properties,
            static function (ReflectionProperty $property): bool {
                if (\PHP_VERSION_ID < 70400 || ! $property->hasType()) {
                    return true;
                }

                $type = $property->getType();

                return $type === null || $type->allowsNull();
            }
        ));
    }

    public function onlyInstanceProperties(): self
    {
        return new self(array_values(array_merge($this->getAccessibleProperties(), $this->getPrivateProperties())));
    }

    public function empty(): bool
    {
        return $this->properties === [];
    }

    /**
     * @return array<string, ReflectionProperty> indexed by the property internal visibility-aware name
     */
    public function getPublicProperties(): array
    {
        $publicProperties = [];

        foreach ($this->properties as $property) {
            if (! $property->isPublic()) {
                continue;
            }

            $publicProperties[$property->getName()] = $property;
        }

        return $publicProperties;
    }

    /**
     * @return array<string, ReflectionProperty> indexed by the property internal visibility-aware name (\0*\0propertyName)
     */
    public function getProtectedProperties(): array
    {
        $protectedProperties = [];

        foreach ($this->properties as $property) {
            if (! $property->isProtected()) {
                continue;
            }

            $protectedProperties["\0*\0" . $property->getName()] = $property;
        }

        return $protectedProperties;
    }

    /**
     * @return array<string, ReflectionProperty> indexed by the property internal visibility-aware name (\0ClassName\0propertyName)
     */
    public function getPrivateProperties(): array
    {
        $privateProperties = [];

        foreach ($this->properties as $property) {
            if (! $property->isPrivate()) {
                continue;
            }

            $declaringClass = $property->getDeclaringClass()->getName();

            $privateProperties["\0" . $declaringClass . "\0" . $property->getName()] = $property;
        }

        return $privateProperties;
    }

    /**
     * @return array<string, ReflectionProperty> indexed by the property internal visibility-aware name (\0*\0propertyName)
     */
    public function getAccessibleProperties(): array
    {
        return array_merge($this->getPublicProperties(), $this->getProtectedProperties());
    }

    /**
     * @return array<class-string, array<string, ReflectionProperty>> indexed by class name and property name
     */
    public function getGroupedPrivateProperties(): array
    {
        $propertiesMap = [];

        foreach ($this->getPrivateProperties() as $property) {
            $propertiesMap[$property->getDeclaringClass()->getName()][$property->getName()] = $property;
        }

        return $propertiesMap;
    }

    /**
     * @return array<string, ReflectionProperty> indexed by the property internal visibility-aware name (\0*\0propertyName)
     */
    public function getInstanceProperties(): array
    {
        return array_merge($this->getAccessibleProperties(), $this->getPrivateProperties());
    }
}