<?php

namespace Kaliop\eZMigrationBundle\Core\Executor;

use eZ\Publish\API\Repository\Repository;
use eZ\Publish\API\Repository\Values\User\UserReference;
use eZ\Publish\Core\MVC\ConfigResolverInterface;
use Kaliop\eZMigrationBundle\API\Collection\AbstractCollection;
use Kaliop\eZMigrationBundle\API\ReferenceResolverBagInterface;
use Kaliop\eZMigrationBundle\API\Value\MigrationStep;
use Kaliop\eZMigrationBundle\Core\AuthenticatedUserSetterTrait;

/**
 * The core manager class that all migration action managers inherit from.
 */
abstract class RepositoryExecutor extends AbstractExecutor
{
    use AuthenticatedUserSetterTrait;
    use IgnorableStepExecutorTrait;

    /**
     * Constant defining the default language code (used if not specified by the migration or on the command line)
     */
    const DEFAULT_LANGUAGE_CODE = 'eng-GB';

    /**
     * The default Admin user Id, used when no Admin user is specified
     */
    const ADMIN_USER_ID = 14;

    /**
     * The default Admin user login, used when no Admin user is specified
     */
    const ADMIN_USER_LOGIN = 'admin';

    /** Used if not specified by the migration */
    const USER_CONTENT_TYPE = 'user';
    /** Used if not specified by the migration */
    const USERGROUP_CONTENT_TYPE = 'user_group';

    const REFERENCE_TYPE_SCALAR = 'scalar';
    const REFERENCE_TYPE_ARRAY = 'array';

    /**
     * @var array $dsl The parsed DSL instruction array
     */
    //protected $dsl;

    /** @var array $context The context (configuration) for the execution of the current step */
    //protected $context;

    /**
     * The eZ Publish 5 API repository.
     *
     * @var \eZ\Publish\API\Repository\Repository
     */
    protected $repository;

    protected $configResolver;

    /** @var ReferenceResolverBagInterface $referenceResolver */
    protected $referenceResolver;

    // to redefine in subclasses if they don't support all methods, or if they support more...
    protected $supportedActions = array(
        'create', 'update', 'delete'
    );

    public function setRepository(Repository $repository)
    {
        $this->repository = $repository;
    }

    public function setConfigResolver(ConfigResolverInterface $configResolver)
    {
        $this->configResolver = $configResolver;
    }

    public function setReferenceResolver(ReferenceResolverBagInterface $referenceResolver)
    {
        $this->referenceResolver = $referenceResolver;
    }

    public function execute(MigrationStep $step)
    {
        // base checks
        parent::execute($step);

        if (!isset($step->dsl['mode'])) {
            throw new \Exception("Invalid step definition: missing 'mode'");
        }

        // q: should we convert snake_case to camelCase ?
        $action = $step->dsl['mode'];

        if (!in_array($action, $this->supportedActions)) {
            throw new \Exception("Invalid step definition: value '$action' is not allowed for 'mode'");
        }

        if (method_exists($this, $action)) {

            $this->skipStepIfNeeded($step);

            $currentUser = $this->authenticateUserByContext($step->context);
            try {
                $output = $this->$action($step);
            } finally {
                // reset the environment as much as possible as we had found it before the migration
                $this->authenticateUserByReference($currentUser);
            }

            return $output;
        } else {
            throw new \Exception("Invalid step definition: value '$action' is not a method of " . get_class($this));
        }
    }

    /**
     * Method that each executor (subclass) has to implement.
     *
     * It is used to get values for references based on the DSL instructions executed in the current step, for later steps to reuse.
     *
     * @throws \InvalidArgumentException when trying to set a reference to an unsupported attribute.
     * @param mixed $object a single element to extract reference values from
     * @param array $referencesDefinitions the definitions of the references to extract
     * @param MigrationStep $step
     * @return array key: the reference name (taken from $referencesDefinitions[n]['identifier'], value: the ref. value
     */
    abstract protected function getReferencesValues($object, array $referencesDefinitions, $step);

    /**
     * @param MigrationStep $step
     * @return string
     */
    protected function getLanguageCode($step)
    {
        return isset($step->dsl['lang']) ? $step->dsl['lang'] : $this->getLanguageCodeFromContext($step->context);
    }

    /**
     * @param array|null $context
     * @return string
     */
    protected function getLanguageCodeFromContext($context)
    {
        if (is_array($context) && isset($context['defaultLanguageCode'])) {
            return $context['defaultLanguageCode'];
        }

        if ($this->configResolver) {
            $locales = $this->configResolver->getParameter('languages');
            return reset($locales);
        }

        return self::DEFAULT_LANGUAGE_CODE;
    }

    /**
     * @param MigrationStep $step
     * @return string
     */
    protected function getUserContentType($step)
    {
        return isset($step->dsl['user_content_type']) ? $this->referenceResolver->resolveReference($step->dsl['user_content_type']) : $this->getUserContentTypeFromContext($step->context);
    }

    /**
     * @param MigrationStep $step
     * @return string
     */
    protected function getUserGroupContentType($step)
    {
        return isset($step->dsl['usergroup_content_type']) ? $this->referenceResolver->resolveReference($step->dsl['usergroup_content_type']) : $this->getUserGroupContentTypeFromContext($step->context);
    }

    /**
     * @param array $context
     * @return string
     */
    protected function getUserContentTypeFromContext($context)
    {
        return isset($context['userContentType']) ? $context['userContentType'] : self::USER_CONTENT_TYPE;
    }

    /**
     * @param array $context
     * @return string
     */
    protected function getUserGroupContentTypeFromContext($context)
    {
        return isset($context['userGroupContentType']) ? $context['userGroupContentType'] : self::USERGROUP_CONTENT_TYPE;
    }

    /**
     * @param array $context
     *
     * @return \eZ\Publish\API\Repository\Values\User\UserReference previously logged-in user
     *
     * @throws \Kaliop\eZMigrationBundle\API\Exception\InvalidUserAccountException
     */
    protected function authenticateUserByContext(array $context): UserReference
    {
        $currentUser = $this->getCurrentUser();

        $userLogin = $context['adminUserLogin'] ?? self::ADMIN_USER_LOGIN;
        if (false !== $userLogin) {
            $this->authenticateUserByLogin($userLogin);
        }

        return $currentUser;
    }

    /**
     * Sets references to certain attributes of the items returned by steps.
     *
     * @param \Object|AbstractCollection $item
     * @param MigrationStep $step
     * @throws \InvalidArgumentException When trying to set a reference to an unsupported attribute
     * @return boolean
     * @todo should we allow to be passed in plain arrays as well as Collections?
     */
    protected function setReferences($item, $step)
    {
        if (!array_key_exists('references', $step->dsl)) {
            return false;
        }

        $referencesDefs = $this->setReferencesCommon($item, $step->dsl['references']);

        $this->insureEntityCountCompatibility($item, $referencesDefs, $step);

        $multivalued = ($this->getReferencesType($step) == self::REFERENCE_TYPE_ARRAY);

        if ($item instanceof AbstractCollection) {
            $items = $item;
        } else {
            $items = array($item);
        }

        $referencesValues = array();
        foreach ($items as $item) {
            $itemReferencesValues = $this->getReferencesValues($item, $referencesDefs, $step);
            if (!$multivalued) {
                $referencesValues = $itemReferencesValues;
            } else {
                foreach ($itemReferencesValues as $refName => $refValue) {
                    if (!isset($referencesValues[$refName])) {
                        $referencesValues[$refName] = array($refValue);
                    } else {
                        $referencesValues[$refName][] = $refValue;
                    }
                }
            }
        }

        foreach($referencesDefs as $reference) {
            $overwrite = false;
            if (isset($reference['overwrite'])) {
                $overwrite = $reference['overwrite'];
            }
            $this->referenceResolver->addReference($reference['identifier'], count($referencesValues) ? $referencesValues[$reference['identifier']] : array(), $overwrite);
        }

        return true;
    }

    /**
     * @param mixed $entity
     * @param array $referencesDefinition
     * @return array the same as $referencesDefinition, with the references already treated having been removed
     */
    protected function setReferencesCommon($entity, $referencesDefinition)
    {
        // allow setting *some* refs even when we have 0 or N matches
        foreach ($referencesDefinition as $key => $reference) {
            switch($reference['attribute']) {

                case 'count':
                    $value = count($entity);
                    $overwrite = false;
                    if (isset($reference['overwrite'])) {
                        $overwrite = $reference['overwrite'];
                    }
                    $this->referenceResolver->addReference($reference['identifier'], $value, $overwrite);
                    unset($referencesDefinition[$key]);
                    break;

                default:
                    // do nothing
            }
        }

        return $referencesDefinition;
    }

    /**
     * Verifies compatibility between the definition of the refences to be set and the data set to extarct them from,
     * and returns a single entity
     *
     * @param AbstractCollection|mixed $entity
     * @param array $referencesDefinition
     * @param MigrationStep $step
     * @return AbstractCollection|mixed
     * @deprecated
     */
    protected function insureSingleEntity($entity, $referencesDefinition, $step)
    {
        $this->insureEntityCountCompatibility($entity, $referencesDefinition, $step);

        if ($entity instanceof AbstractCollection) {
            return reset($entity);
        }

        return $entity;
    }

    /**
     * Verifies compatibility between the definition of the references to be set and the data set to extract them from.
     * NB: for multivalued refs, we assume that the users always expect at least one value
     * @param AbstractCollection|mixed $entity
     * @param array $referencesDefinition
     * @param MigrationStep $step
     * @return void throws when incompatibility is found
     * @todo should we allow to be passed in plain arrays as well as Collections?
     */
    protected function insureEntityCountCompatibility($entity, $referencesDefinition, $step)
    {
        if ($entity instanceof AbstractCollection) {

            $minOneRef = count($referencesDefinition) > 0 && (!$this->allowEmptyReferences($step));
            $maxOneRef = count($referencesDefinition) > 0 && $this->getReferencesType($step) == self::REFERENCE_TYPE_SCALAR;

            if ($maxOneRef && count($entity) > 1) {
                throw new \InvalidArgumentException($this->getSelfName() . ' does not support setting references for multiple ' . $this->getCollectionName($entity) . 's');
            }
            if ($minOneRef && count($entity) == 0) {
                throw new \InvalidArgumentException($this->getSelfName() . ' does not support setting references for no ' . $this->getCollectionName($entity) . 's');
            }
        }
    }

    /**
     * @param array $step
     * @return string
     */
    protected function getReferencesType($step)
    {
        return isset($step->dsl['references_type']) ? $step->dsl['references_type'] : self::REFERENCE_TYPE_SCALAR;
    }

    /**
     * @param array $step
     * @return bool
     */
    protected function allowEmptyReferences($step)
    {
        if (isset($step->dsl['references_type']) && $step->dsl['references_type'] == self::REFERENCE_TYPE_ARRAY &&
            isset($step->dsl['references_allow_empty']) && $step->dsl['references_allow_empty'] == true
        )
            return true;
        return false;
    }

    protected function getSelfName()
    {
        $className = get_class($this);
        $array = explode('\\', $className);
        $className = end($array);
        // CamelCase to Camel Case using negative look-behind in regexp
        return preg_replace('/(?<!^)[A-Z]/', ' $0', $className);
    }

    protected function getCollectionName($collection)
    {
        $className = get_class($collection);
        $array = explode('\\', $className);
        $className = str_replace('Collection', '', end($array));
        // CamelCase to snake case using negative look-behind in regexp
        return strtolower(preg_replace('/(?<!^)[A-Z]/', ' $0', $className));
    }

    /**
     * Courtesy code to avoid reimplementing it in every subclass
     * @todo will be moved into the reference resolver classes
     */
    protected function resolveReferencesRecursively($match)
    {
        if (is_array($match)) {
            foreach ($match as $condition => $values) {
                $match[$condition] = $this->resolveReferencesRecursively($values);
            }
            return $match;
        } else {
            return $this->referenceResolver->resolveReference($match);
        }
    }
}