<?php
/**
 * This file is part of the ramsey/uuid library
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @copyright Copyright (c) Ben Ramsey <ben@benramsey.com>
 * @license http://opensource.org/licenses/MIT MIT
 * @link https://benramsey.com/projects/ramsey-uuid/ Documentation
 * @link https://packagist.org/packages/ramsey/uuid Packagist
 * @link https://github.com/ramsey/uuid GitHub
 */

namespace Ramsey\Uuid;

use Ramsey\Uuid\Converter\TimeConverterInterface;
use Ramsey\Uuid\Generator\PeclUuidTimeGenerator;
use Ramsey\Uuid\Provider\Node\FallbackNodeProvider;
use Ramsey\Uuid\Provider\Node\RandomNodeProvider;
use Ramsey\Uuid\Provider\Node\SystemNodeProvider;
use Ramsey\Uuid\Converter\NumberConverterInterface;
use Ramsey\Uuid\Converter\Number\GmpConverter;
use Ramsey\Uuid\Converter\Number\BigNumberConverter;
use Ramsey\Uuid\Converter\Number\DegradedNumberConverter;
use Ramsey\Uuid\Converter\Time\GmpTimeConverter;
use Ramsey\Uuid\Converter\Time\BigNumberTimeConverter;
use Ramsey\Uuid\Converter\Time\DegradedTimeConverter;
use Ramsey\Uuid\Converter\Time\PhpTimeConverter;
use Ramsey\Uuid\Provider\Time\SystemTimeProvider;
use Ramsey\Uuid\Builder\UuidBuilderInterface;
use Ramsey\Uuid\Builder\DefaultUuidBuilder;
use Ramsey\Uuid\Codec\CodecInterface;
use Ramsey\Uuid\Codec\StringCodec;
use Ramsey\Uuid\Codec\GuidStringCodec;
use Ramsey\Uuid\Builder\DegradedUuidBuilder;
use Ramsey\Uuid\Generator\RandomGeneratorFactory;
use Ramsey\Uuid\Generator\RandomGeneratorInterface;
use Ramsey\Uuid\Generator\TimeGeneratorFactory;
use Ramsey\Uuid\Generator\TimeGeneratorInterface;
use Ramsey\Uuid\Provider\TimeProviderInterface;
use Ramsey\Uuid\Provider\NodeProviderInterface;

/**
 * FeatureSet detects and exposes available features in the current environment
 * (32- or 64-bit, available dependencies, etc.)
 */
class FeatureSet
{
    /**
     * @var bool
     */
    private $disableBigNumber = false;

    /**
     * @var bool
     */
    private $disableGmp = false;

    /**
     * @var bool
     */
    private $disable64Bit = false;

    /**
     * @var bool
     */
    private $ignoreSystemNode = false;

    /**
     * @var bool
     */
    private $enablePecl = false;

    /**
     * @var UuidBuilderInterface
     */
    private $builder;

    /**
     * @var CodecInterface
     */
    private $codec;

    /**
     * @var NodeProviderInterface
     */
    private $nodeProvider;

    /**
     * @var NumberConverterInterface
     */
    private $numberConverter;

    /**
     * The time converter to use for converting timestamps extracted from UUIDs to unix timestamps
     * @var TimeConverterInterface
     */
    protected $timeConverter;

    /**
     * @var RandomGeneratorInterface
     */
    private $randomGenerator;

    /**
     * @var TimeGeneratorInterface
     */
    private $timeGenerator;

    /**
     * Constructs a `FeatureSet` for use by a `UuidFactory` to determine or set
     * features available to the environment
     *
     * @param bool $useGuids Whether to build UUIDs using the `GuidStringCodec`
     * @param bool $force32Bit Whether to force the use of 32-bit functionality
     *     (primarily for testing purposes)
     * @param bool $forceNoBigNumber Whether to disable the use of moontoast/math
     *     `BigNumber` (primarily for testing purposes)
     * @param bool $ignoreSystemNode Whether to disable attempts to check for
     *     the system host ID (primarily for testing purposes)
     * @param bool $enablePecl Whether to enable the use of the `PeclUuidTimeGenerator`
     *     to generate version 1 UUIDs
     * @param bool $forceNoGmp Whether to disable the use of the GMP PHP-extension
     *     (primarily for testing purposes)
     */
    public function __construct(
        $useGuids = false,
        $force32Bit = false,
        $forceNoBigNumber = false,
        $ignoreSystemNode = false,
        $enablePecl = false,
        $forceNoGmp = false
    ) {
        $this->disableBigNumber = $forceNoBigNumber;
        $this->disableGmp = $forceNoGmp;
        $this->disable64Bit = $force32Bit;
        $this->ignoreSystemNode = $ignoreSystemNode;
        $this->enablePecl = $enablePecl;

        $this->numberConverter = $this->buildNumberConverter();
        $this->timeConverter = $this->buildTimeConverter();
        $this->builder = $this->buildUuidBuilder();
        $this->codec = $this->buildCodec($useGuids);
        $this->nodeProvider = $this->buildNodeProvider();
        $this->randomGenerator = $this->buildRandomGenerator();
        $this->setTimeProvider(new SystemTimeProvider());
    }

    /**
     * Returns the builder configured for this environment
     *
     * @return UuidBuilderInterface
     */
    public function getBuilder()
    {
        return $this->builder;
    }

    /**
     * Returns the UUID UUID coder-decoder configured for this environment
     *
     * @return CodecInterface
     */
    public function getCodec()
    {
        return $this->codec;
    }

    /**
     * Returns the system node ID provider configured for this environment
     *
     * @return NodeProviderInterface
     */
    public function getNodeProvider()
    {
        return $this->nodeProvider;
    }

    /**
     * Returns the number converter configured for this environment
     *
     * @return NumberConverterInterface
     */
    public function getNumberConverter()
    {
        return $this->numberConverter;
    }

    /**
     * Returns the random UUID generator configured for this environment
     *
     * @return RandomGeneratorInterface
     */
    public function getRandomGenerator()
    {
        return $this->randomGenerator;
    }

    /**
     * Returns the time-based UUID generator configured for this environment
     *
     * @return TimeGeneratorInterface
     */
    public function getTimeGenerator()
    {
        return $this->timeGenerator;
    }

    /**
     * Sets the time provider for use in this environment
     *
     * @param TimeProviderInterface $timeProvider
     */
    public function setTimeProvider(TimeProviderInterface $timeProvider)
    {
        $this->timeGenerator = $this->buildTimeGenerator($timeProvider);
    }

    /**
     * Determines which UUID coder-decoder to use and returns the configured
     * codec for this environment
     *
     * @param bool $useGuids Whether to build UUIDs using the `GuidStringCodec`
     * @return CodecInterface
     */
    protected function buildCodec($useGuids = false)
    {
        if ($useGuids) {
            return new GuidStringCodec($this->builder);
        }

        return new StringCodec($this->builder);
    }

    /**
     * Determines which system node ID provider to use and returns the configured
     * system node ID provider for this environment
     *
     * @return NodeProviderInterface
     */
    protected function buildNodeProvider()
    {
        if ($this->ignoreSystemNode) {
            return new RandomNodeProvider();
        }

        return new FallbackNodeProvider([
            new SystemNodeProvider(),
            new RandomNodeProvider()
        ]);
    }

    /**
     * Determines which number converter to use and returns the configured
     * number converter for this environment
     *
     * @return NumberConverterInterface
     */
    protected function buildNumberConverter()
    {
        if ($this->hasGmp()) {
            return new GmpConverter();
        } elseif ($this->hasBigNumber()) {
            return new BigNumberConverter();
        }

        return new DegradedNumberConverter();
    }

    /**
     * Determines which random UUID generator to use and returns the configured
     * random UUID generator for this environment
     *
     * @return RandomGeneratorInterface
     */
    protected function buildRandomGenerator()
    {
        return (new RandomGeneratorFactory())->getGenerator();
    }

    /**
     * Determines which time-based UUID generator to use and returns the configured
     * time-based UUID generator for this environment
     *
     * @param TimeProviderInterface $timeProvider
     * @return TimeGeneratorInterface
     */
    protected function buildTimeGenerator(TimeProviderInterface $timeProvider)
    {
        if ($this->enablePecl) {
            return new PeclUuidTimeGenerator();
        }

        return (new TimeGeneratorFactory(
            $this->nodeProvider,
            $this->timeConverter,
            $timeProvider
        ))->getGenerator();
    }

    /**
     * Determines which time converter to use and returns the configured
     * time converter for this environment
     *
     * @return TimeConverterInterface
     */
    protected function buildTimeConverter()
    {
        if ($this->is64BitSystem()) {
            return new PhpTimeConverter();
        } elseif ($this->hasGmp()) {
            return new GmpTimeConverter();
        } elseif ($this->hasBigNumber()) {
            return new BigNumberTimeConverter();
        }

        return new DegradedTimeConverter();
    }

    /**
     * Determines which UUID builder to use and returns the configured UUID
     * builder for this environment
     *
     * @return UuidBuilderInterface
     */
    protected function buildUuidBuilder()
    {
        if ($this->is64BitSystem()) {
            return new DefaultUuidBuilder($this->numberConverter, $this->timeConverter);
        }

        return new DegradedUuidBuilder($this->numberConverter, $this->timeConverter);
    }

    /**
     * Returns true if the system has `Moontoast\Math\BigNumber`
     *
     * @return bool
     */
    protected function hasBigNumber()
    {
        return class_exists('Moontoast\Math\BigNumber') && !$this->disableBigNumber;
    }

    /**
     * Returns true if the system has the GMP PHP-extension
     *
     * @return bool
     */
    protected function hasGmp()
    {
        return extension_loaded('gmp') && !$this->disableGmp;
    }

    /**
     * Returns true if the system is 64-bit, false otherwise
     *
     * @return bool
     */
    protected function is64BitSystem()
    {
        return PHP_INT_SIZE == 8 && !$this->disable64Bit;
    }
}
