<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

namespace ExpressionEngine\Service\Consent;

use ExpressionEngine\Service\Model\Facade as ModelFacade;
use ExpressionEngine\Model\Member\Member;
use ExpressionEngine\Model\Consent\ConsentRequest;
use ExpressionEngine\Service\Model\Collection;
use InvalidArgumentException;

/**
 * Consent Service
 */
class Consent
{
    const COOKIE_NAME = 'visitor_consents';

    /**
     * @var array Cookie data, for visitors
     */
    protected $cookie = [];

    /**
     * @var int $member_id The Member ID the consent relates to
     */
    protected $member_id;

    /**
     * @var array $actor_userdata Injected ee()->session->userdata for the actor, usually the member being acted upon, but may be a super admin.
     */
    protected $actor_userdata;

    /**
     * @var string The addon prefix, if any, e.g. (addon_name:)
     */
    private $addon_prefix = '';

    /**
     * @var object Collection of granted consents for this Member
     */
    private $cached_consents;

    /**
     * @var object $model_delegate An injected `ee('Model')` object
     */
    protected $model_delegate;

    /**
     * @var object $input_delegate An injected `ee()->input` object
     */
    protected $input_delegate;

    /**
     * @var object $session_delegate An injected `ee()->session` object
     */
    protected $session_delegate;

    /**
     * @var int $now The current timestamp
     */
    protected $now;

    public function __construct(ModelFacade $model_delegate, $input_delegate, $session_delegate, $member_id, $actor_userdata, $now)
    {
        $this->model_delegate = $model_delegate;
        $this->input_delegate = $input_delegate;
        $this->session_delegate = $session_delegate;
        $this->member_id = $member_id;
        $this->actor_userdata = $actor_userdata;
        $this->now = $now;

        // load up the member's consent grants if we haven't yet
        if (($this->cached_consents = $this->session_delegate->cache(__CLASS__, 'cached_consents_' . $member_id)) === false) {
            $this->cached_consents = $this->getConsents();
            $this->session_delegate->set_cache(__CLASS__, 'cached_consents_' . $member_id, $this->cached_consents);
        }

        // keep persistent cookie data, otherwise subsequent reads will not reflect changes made before new cookie headers are sent
        if ($this->isAnonymous()) {
            if (($this->cookie = $this->session_delegate->cache(__CLASS__, 'cookie_data_' . $member_id)) === false) {
                $this->cookie = $this->getConsentCookie();
                $this->session_delegate->set_cache(__CLASS__, 'cookie_data_' . $member_id, $this->cookie);
            }
        }
    }

    /**
     * Creates/updates a consent record for the member for the given consent request
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @param string $via How the consent was granted
     * @throws InvalidArgumentException
     * @return NULL
     */
    public function grant($request_ref, $via = 'online_form')
    {
        try {
            $request = $this->getConsentRequest($request_ref);
        } catch (InvalidArgumentException $e) {
            // bubble up any exceptions so they are able to be handled by the caller
            throw $e;
        }

        // Can't consent to an empty consent request
        if (! $request->consent_request_version_id) {
            return;
        }

        if (! $this->callerHasPermission($request)) {
            throw new \Exception("Invalid Consent access, {$this->addon_prefix} cannot grant: '{$request_ref}'");
        }

        if ($this->isAnonymous()) {
            $this->cookie[$request->getId()] = ['has_granted' => true, 'timestamp' => $this->now];
            $this->saveConsentCookie($this->cookie);
            $request->log(sprintf(lang('consent_granted_log_msg'), lang($via)));
            $this->updateConsentCache($request);
        } else {
            $consent = $this->getOrMakeConsent($request);
            $consent->consent_given = true;
            $consent->ConsentRequestVersion = $request->CurrentVersion;
            $consent->response_date = $this->now;
            $consent->consent_given_via = $via;
            $consent->request_copy = $request->CurrentVersion->request;
            $consent->request_format = $request->CurrentVersion->request_format;

            $consent->save();

            if ($this->memberIsActor()) {
                $consent->log(sprintf(lang('consent_granted_log_msg'), lang($via)));
            } else {
                $consent->log(sprintf(lang('consent_granted_by_log_msg'), $this->getActorName(), lang($via)));
            }

            $this->updateConsentCache($consent);
        }
    }

    /**
     * Updates a consent record for the member for the given consent request to indicate
     * that consent has been withdrawn
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @throws InvalidArgumentException
     * @return NULL
     */
    public function withdraw($request_ref)
    {
        try {
            $request = $this->getConsentRequest($request_ref);
        } catch (InvalidArgumentException $e) {
            // bubble up any exceptions so they are able to be handled by the caller
            throw $e;
        }

        if (! $this->callerHasPermission($request)) {
            throw new \Exception("Invalid Consent access, {$this->addon_prefix} cannot withdraw: '{$request_ref}'");
        }

        if ($this->isAnonymous()) {
            $this->cookie[$request->getId()] = ['has_granted' => false, 'timestamp' => $this->now];
            $this->saveConsentCookie($this->cookie);
            $this->updateConsentCache($request);
        } else {
            $consent = $this->getOrMakeConsent($request);
            $consent->consent_given = false;
            $consent->response_date = $this->now;
            $consent->save();

            if ($this->memberIsActor()) {
                $consent->log(lang('consent_withdrawn_log_msg'));
            } else {
                $consent->log(sprintf(lang('consent_withdrawn_by_log_msg'), $this->getActorName()));
            }

            $this->updateConsentCache($consent);
        }
    }

    /**
     * Has the member granted consent for a given consent request?
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @throws InvalidArgumentException
     * @return bool TRUE if they have, FALSE if they have not
     */
    public function hasGranted($request_ref)
    {
        $column = (is_numeric($request_ref)) ? 'consent_request_id' : 'consent_name';

        if ($this->isAnonymous()) {
            $grants = $this->cached_consents->indexBy($column);
            if (isset($grants[$request_ref])) {
                $rid = $grants[$request_ref]->consent_request_id;

                return (isset($this->cookie[$rid]) && $this->cookie[$rid]['has_granted'] === true);
            }
        } else {
            $grants = $this->cached_consents->ConsentRequest->indexBy($column);

            if (isset($grants[$request_ref])) {
                $consents = $this->cached_consents->indexBy('consent_request_id');

                return $consents[$grants[$request_ref]->consent_request_id]->isGranted();
            }

            return false;
        }
    }

    /**
     * Has the member responded to a given consent request?
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @return bool TRUE if they have, FALSE if they have not
     */
    public function hasResponded($request_ref)
    {
        $column = (is_numeric($request_ref)) ? 'consent_request_id' : 'consent_name';

        if ($this->isAnonymous()) {
            $grants = $this->cached_consents->indexBy($column);
            if (isset($grants[$request_ref])) {
                $rid = $grants[$request_ref]->consent_request_id;

                return (isset($this->cookie[$rid]) && $this->cookie[$rid]['timestamp'] !== false);
            }
        } else {
            $grants = $this->cached_consents->ConsentRequest->indexBy($column);

            if (isset($grants[$request_ref])) {
                $rid = $grants[$request_ref]->consent_request_id;
                $consents = $this->cached_consents->indexBy('consent_request_id');

                return $consents[$rid]->response_date != false;
            }

            return false;
        }
    }

    /**
     * Gets all the consents the member (or anonymous visitor) has responded to.
     *
     * @return object A Collection of Consent objects (ConsentRequest for anonymous)
     */
    public function getConsents()
    {
        if ($this->isAnonymous()) {
            $request_ids = array_keys($this->getConsentCookie());

            if (empty($request_ids)) {
                return new Collection([]);
            }

            return $this->model_delegate->get('ConsentRequest')
                ->with('CurrentVersion')
                ->filter('consent_request_id', 'IN', $request_ids)
                ->all();
        }

        $consents = $this->model_delegate->get('Consent')
            ->with('ConsentRequest')
            ->with(['ConsentRequest' => 'CurrentVersion'])
            ->with('ConsentRequestVersion')
            ->filter('member_id', $this->member_id)
            ->all();

        return $consents;
    }

    /**
     * Gets all the granted consents for a specific request
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @throws InvalidArgumentException
     * @return object A Collection of Consent objects
     */
    public function getGrantedConsentsFor($request_ref)
    {
        $request = $this->getConsentRequest($request_ref);

        return $this->model_delegate->get('Consent')
            ->with('ConsentRequest')
            ->with(['ConsentRequest' => 'CurrentVersion'])
            ->with('ConsentRequestVersion')
            ->filter('consent_id', $request_id)
            ->all()
            ->filter(function ($consent) {
                return $consent->isGranted();
            });
    }

    /**
     * Gets the values for a specific request and the member's consent
     *
     * @param int|string|array $request_refs The name or an array of names, or id or array of ids
     * @return object A Collection of associative arrays for each Consent Request
     */
    public function getConsentDataFor($request_refs)
    {
        if (empty($request_refs)) {
            return new Collection([]);
        }

        if (! is_array($request_refs)) {
            $request_refs = [$request_refs];
        }

        $data = [];
        $consents = ($this->isAnonymous()) ? $this->getConsentCookie() : $this->cached_consents->indexBy('consent_request_id');
        $requests = $this->model_delegate->get('ConsentRequest')->with('CurrentVersion');

        $numeric_refs = true;
        foreach ($request_refs as $ref) {
            if (! is_numeric($ref)) {
                $numeric_refs = false;

                break;
            }
        }

        if ($numeric_refs) {
            $requests->filter('consent_request_id', 'IN', $request_refs);
        } else {
            $requests->filter('consent_name', 'IN', $request_refs);
        }

        $requests = $requests->all();

        foreach ($requests as $request) {
            $key = $request->consent_name;
            $data[$key] = array_merge($request->getValues(), $request->CurrentVersion->getValues());
            $data[$key]['has_granted'] = false;
            $data[$key]['create_date'] = $request->CurrentVersion->create_date->format('U');

            if ($this->isAnonymous()) {
                $data[$key]['consent_given_via'] = 'online_form';
                $data[$key]['member_id'] = 0;

                if (isset($this->cookie[$request->getId()])) {
                    $data[$key]['has_granted'] = $this->cookie[$request->getId()]['has_granted'];
                    $data[$key]['response_date'] = $this->cookie[$request->getId()]['timestamp'];
                } else {
                    $data[$key]['has_granted'] = false;
                    $data[$key]['response_date'] = null;
                }
            } else {
                if (array_key_exists($request->getId(), $consents)) {
                    $consent = $consents[$request->getId()];
                    $data[$key] = array_merge($consent->getValues(), $data[$key]);
                    unset($data[$key]['consent_given']);

                    $data[$key]['has_granted'] = $consent->isGranted();

                    foreach (['expiration_date', 'response_date'] as $property) {
                        if (! is_null($data[$key][$property])) {
                            $data[$key][$property] = $data[$key][$property]->getTimestamp();
                        }
                    }
                }
            }

            // these keys may not be present if the user hasn't responded, but we want a consistent array
            foreach (['consent_given_via', 'consent_id', 'expiration_date', 'member_id', 'request_copy', 'response_date'] as $item) {
                if (! array_key_exists($item, $data[$key])) {
                    $data[$key][$item] = null;
                }
            }
        }

        return new Collection($data);
    }

    /**
     * Checks to make sure the caller has write access premission to a Consent Request
     *
     * @param  object $request ExpressionEngine\Model\Consent\ConsentRequest
     * @return bool whether or not the caller has permission to modify the user's consent
     */
    protected function callerHasPermission($request)
    {
        list($this_class, $caller) = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
        if (strpos($caller['file'], PATH_THIRD) === 0) {
            if (empty($this->addon_prefix)) {
                $relative_path = str_replace(PATH_THIRD, '', $caller['file']);
                list($addon_name, $extra_path) = explode('/', $relative_path, 2);

                $addon = ee('Addon')->get($addon_name);
                $this->addon_prefix = $addon->getPrefix();
            }

            return (strpos($request->consent_name, $this->addon_prefix . ':') === 0);
        }

        return true;
    }

    /**
     * Is the member we are checking anonymous?
     *
     * @return bool TRUE if they are, FALSE if not
     */
    protected function isAnonymous()
    {
        return ($this->member_id == 0);
    }

    /**
     * Is the member granting/withdrawing consent the member initiating the action (actor)?
     *
     * @return bool TRUE if they are, FALSE if not
     */
    protected function memberIsActor()
    {
        return ($this->member_id == $this->actor_userdata['member_id']);
    }

    /**
     * Gets the name and UID of the actor for logging purposes
     *
     * @return string The member name and UID.
     */
    protected function getActorName()
    {
        return $this->actor_userdata['screen_name'] . ' (' . $this->actor_userdata['screen_name'] . ', #' . $this->actor_userdata['member_id'] . ')';
    }

    /**
     * Gets the consent cookie
     *
     * @return array An associative array of granted consents
     */
    protected function getConsentCookie()
    {
        $cookie = $this->input_delegate->cookie(self::COOKIE_NAME);
        $cookie = ee('Encrypt/Cookie')->getVerifiedCookieData($cookie);

        if (! $cookie) {
            $cookie = [];
        }

        return $cookie;
    }

    /**
     * Encodes, signs, and saves the consent cookie
     *
     * @param array $consented_to An associative array of granted consents with the
     *   request's ID as the array key.
     */
    protected function saveConsentCookie(array $consented_to)
    {
        $payload = ee('Encrypt/Cookie')->signCookieData($consented_to);
        // 60 * 60 * 24 * 360 = 31104000; A (almost) year of seconds
        $this->input_delegate->set_cookie(self::COOKIE_NAME, $payload, 31104000);
        $this->session_delegate->set_cache(__CLASS__, 'cookie_data_' . $this->member_id, $consented_to);
    }

    /**
     * Gets a ConsentRequest entity
     *
     * @param int|string $request_ref The name or ID of a consent request
     * @return ConsentRequest|null The consent request entity or NULL if it's not found.
     */
    protected function getConsentRequest($request_ref)
    {
        $column = (is_numeric($request_ref)) ? 'consent_request_id' : 'consent_name';

        $request = $this->model_delegate->get('ConsentRequest')
            ->with('CurrentVersion')
            ->filter($column, $request_ref)
            ->first();

        if (! $request) {
            throw new InvalidArgumentException("No such consent: '{$request_ref}'");
        }

        return $request;
    }

    /**
     * Gets a Consent entity
     *
     * @param int $request_id The ID of a consent request
     * @return Consent|null The consent entity or NULL if it's not found.
     */
    protected function getConsent($request_id)
    {
        return $this->model_delegate->get('Consent')
            ->with('ConsentRequest')
            ->with(['ConsentRequest' => 'CurrentVersion'])
            ->with('ConsentRequestVersion')
            ->filter('member_id', $this->member_id)
            ->filter('consent_request_id', $request_id)
            ->first();
    }

    /**
     * Gets a Consent entity, and if one doesn't exist a new object is created
     *
     * @param ConsentRequest $request A ConsentRequest object
     * @return Consent The consent entity
     */
    protected function getOrMakeConsent(ConsentRequest $request)
    {
        $consent = $this->getConsent($request->getId());

        if (! $consent) {
            $consent = $this->model_delegate->make('Consent');
            $consent->ConsentRequest = $request;
            $consent->ConsentRequestVersion = $request->CurrentVersion;
            $consent->member_id = $this->member_id;
        }

        return $consent;
    }

    /**
     * Updates the cached consents for the affected member with the new consent
     *
     * @param  object $request ExpressionEngine\Model\Consent\Consent
     * @return void
     */
    protected function updateConsentCache($consent)
    {
        foreach ($this->cached_consents as $key => $cached) {
            if ($cached->consent_request_id == $consent->consent_request_id) {
                $this->cached_consents[$key] = $consent;
            }
        }

        $this->session_delegate->set_cache(__CLASS__, 'cached_consents_' . $this->member_id, $this->cached_consents);
    }
}
// END CLASS

// EOF
