<?php declare(strict_types=1);

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\Repository;

use Composer\Package\AliasPackage;
use Composer\Package\BasePackage;
use Composer\Package\CompleteAliasPackage;
use Composer\Package\CompletePackage;
use Composer\Package\PackageInterface;
use Composer\Package\CompletePackageInterface;
use Composer\Package\Version\VersionParser;
use Composer\Package\Version\StabilityFilter;
use Composer\Pcre\Preg;
use Composer\Semver\Constraint\ConstraintInterface;
use Composer\Semver\Constraint\Constraint;

/**
 * A repository implementation that simply stores packages in an array
 *
 * @author Nils Adermann <naderman@naderman.de>
 */
class ArrayRepository implements RepositoryInterface
{
    /** @var ?array<BasePackage> */
    protected $packages = null;

    /**
     * @var ?array<BasePackage> indexed by package unique name and used to cache hasPackage calls
     */
    protected $packageMap = null;

    /**
     * @param array<PackageInterface> $packages
     */
    public function __construct(array $packages = array())
    {
        foreach ($packages as $package) {
            $this->addPackage($package);
        }
    }

    public function getRepoName()
    {
        return 'array repo (defining '.$this->count().' package'.($this->count() > 1 ? 's' : '').')';
    }

    /**
     * @inheritDoc
     */
    public function loadPackages(array $packageNameMap, array $acceptableStabilities, array $stabilityFlags, array $alreadyLoaded = array())
    {
        $packages = $this->getPackages();

        $result = array();
        $namesFound = array();
        foreach ($packages as $package) {
            if (array_key_exists($package->getName(), $packageNameMap)) {
                if (
                    (!$packageNameMap[$package->getName()] || $packageNameMap[$package->getName()]->matches(new Constraint('==', $package->getVersion())))
                    && StabilityFilter::isPackageAcceptable($acceptableStabilities, $stabilityFlags, $package->getNames(), $package->getStability())
                    && !isset($alreadyLoaded[$package->getName()][$package->getVersion()])
                ) {
                    // add selected packages which match stability requirements
                    $result[spl_object_hash($package)] = $package;
                    // add the aliased package for packages where the alias matches
                    if ($package instanceof AliasPackage && !isset($result[spl_object_hash($package->getAliasOf())])) {
                        $result[spl_object_hash($package->getAliasOf())] = $package->getAliasOf();
                    }
                }

                $namesFound[$package->getName()] = true;
            }
        }

        // add aliases of packages that were selected, even if the aliases did not match
        foreach ($packages as $package) {
            if ($package instanceof AliasPackage) {
                if (isset($result[spl_object_hash($package->getAliasOf())])) {
                    $result[spl_object_hash($package)] = $package;
                }
            }
        }

        return array('namesFound' => array_keys($namesFound), 'packages' => $result);
    }

    /**
     * @inheritDoc
     */
    public function findPackage(string $name, $constraint)
    {
        $name = strtolower($name);

        if (!$constraint instanceof ConstraintInterface) {
            $versionParser = new VersionParser();
            $constraint = $versionParser->parseConstraints($constraint);
        }

        foreach ($this->getPackages() as $package) {
            if ($name === $package->getName()) {
                $pkgConstraint = new Constraint('==', $package->getVersion());
                if ($constraint->matches($pkgConstraint)) {
                    return $package;
                }
            }
        }

        return null;
    }

    /**
     * @inheritDoc
     */
    public function findPackages(string $name, $constraint = null)
    {
        // normalize name
        $name = strtolower($name);
        $packages = array();

        if (null !== $constraint && !$constraint instanceof ConstraintInterface) {
            $versionParser = new VersionParser();
            $constraint = $versionParser->parseConstraints($constraint);
        }

        foreach ($this->getPackages() as $package) {
            if ($name === $package->getName()) {
                if (null === $constraint || $constraint->matches(new Constraint('==', $package->getVersion()))) {
                    $packages[] = $package;
                }
            }
        }

        return $packages;
    }

    /**
     * @inheritDoc
     */
    public function search(string $query, int $mode = 0, ?string $type = null)
    {
        if ($mode === self::SEARCH_FULLTEXT) {
            $regex = '{(?:'.implode('|', Preg::split('{\s+}', preg_quote($query))).')}i';
        } else {
            // vendor/name searches expect the caller to have preg_quoted the query
            $regex = '{(?:'.implode('|', Preg::split('{\s+}', $query)).')}i';
        }

        $matches = array();
        foreach ($this->getPackages() as $package) {
            $name = $package->getName();
            if ($mode === self::SEARCH_VENDOR) {
                list($name) = explode('/', $name);
            }
            if (isset($matches[$name])) {
                continue;
            }
            if (null !== $type && $package->getType() !== $type) {
                continue;
            }

            if (Preg::isMatch($regex, $name)
                || ($mode === self::SEARCH_FULLTEXT && $package instanceof CompletePackageInterface && Preg::isMatch($regex, implode(' ', (array) $package->getKeywords()) . ' ' . $package->getDescription()))
            ) {
                if ($mode === self::SEARCH_VENDOR) {
                    $matches[$name] = array(
                        'name' => $name,
                        'description' => null,
                    );
                } else {
                    $matches[$name] = array(
                        'name' => $package->getPrettyName(),
                        'description' => $package instanceof CompletePackageInterface ? $package->getDescription() : null,
                    );

                    if ($package instanceof CompletePackageInterface && $package->isAbandoned()) {
                        $matches[$name]['abandoned'] = $package->getReplacementPackage() ?: true;
                    }
                }
            }
        }

        return array_values($matches);
    }

    /**
     * @inheritDoc
     */
    public function hasPackage(PackageInterface $package)
    {
        if ($this->packageMap === null) {
            $this->packageMap = array();
            foreach ($this->getPackages() as $repoPackage) {
                $this->packageMap[$repoPackage->getUniqueName()] = $repoPackage;
            }
        }

        return isset($this->packageMap[$package->getUniqueName()]);
    }

    /**
     * Adds a new package to the repository
     *
     * @return void
     */
    public function addPackage(PackageInterface $package)
    {
        if (!$package instanceof BasePackage) {
            throw new \InvalidArgumentException('Only subclasses of BasePackage are supported');
        }
        if (null === $this->packages) {
            $this->initialize();
        }
        $package->setRepository($this);
        $this->packages[] = $package;

        if ($package instanceof AliasPackage) {
            $aliasedPackage = $package->getAliasOf();
            if (null === $aliasedPackage->getRepository()) {
                $this->addPackage($aliasedPackage);
            }
        }

        // invalidate package map cache
        $this->packageMap = null;
    }

    /**
     * @inheritDoc
     */
    public function getProviders(string $packageName)
    {
        $result = array();

        foreach ($this->getPackages() as $candidate) {
            if (isset($result[$candidate->getName()])) {
                continue;
            }
            foreach ($candidate->getProvides() as $link) {
                if ($packageName === $link->getTarget()) {
                    $result[$candidate->getName()] = array(
                        'name' => $candidate->getName(),
                        'description' => $candidate instanceof CompletePackageInterface ? $candidate->getDescription() : null,
                        'type' => $candidate->getType(),
                    );
                    continue 2;
                }
            }
        }

        return $result;
    }

    /**
     * @param string $alias
     * @param string $prettyAlias
     *
     * @return AliasPackage|CompleteAliasPackage
     */
    protected function createAliasPackage(BasePackage $package, string $alias, string $prettyAlias)
    {
        while ($package instanceof AliasPackage) {
            $package = $package->getAliasOf();
        }

        if ($package instanceof CompletePackage) {
            return new CompleteAliasPackage($package, $alias, $prettyAlias);
        }

        return new AliasPackage($package, $alias, $prettyAlias);
    }

    /**
     * Removes package from repository.
     *
     * @param PackageInterface $package package instance
     *
     * @return void
     */
    public function removePackage(PackageInterface $package)
    {
        $packageId = $package->getUniqueName();

        foreach ($this->getPackages() as $key => $repoPackage) {
            if ($packageId === $repoPackage->getUniqueName()) {
                array_splice($this->packages, $key, 1);

                // invalidate package map cache
                $this->packageMap = null;

                return;
            }
        }
    }

    /**
     * @inheritDoc
     */
    public function getPackages()
    {
        if (null === $this->packages) {
            $this->initialize();
        }

        if (null === $this->packages) {
            throw new \LogicException('initialize failed to initialize the packages array');
        }

        return $this->packages;
    }

    /**
     * Returns the number of packages in this repository
     *
     * @return 0|positive-int Number of packages
     */
    public function count(): int
    {
        if (null === $this->packages) {
            $this->initialize();
        }

        return count($this->packages);
    }

    /**
     * Initializes the packages array. Mostly meant as an extension point.
     *
     * @return void
     */
    protected function initialize()
    {
        $this->packages = array();
    }
}