Add API to get the status of topic subscriptions on a page

(Split off from Ic0fabda0de4ebbc5e424f49641e6b03ebb4b7e6a)

Bug: T290185
Change-Id: Iacc0f92bedfcb49e8a05d98af4d8170d08b1c8de

extension.json

@@ -375,6 +375,13 @@
 				"DiscussionTools.SubscriptionStore",
 				"ConfigFactory"
 			]
+		},
+		"discussiontoolsgetsubscriptions": {
+			"class": "MediaWiki\\Extension\\DiscussionTools\\ApiDiscussionToolsGetSubscriptions",
+			"services": [
+				"DiscussionTools.SubscriptionStore",
+				"ConfigFactory"
+			]
 		}
 	},
 	"Hooks": {

i18n/api/en.json

@@ -18,6 +18,8 @@
 	"apihelp-discussiontoolsedit-paramvalue-paction-addcomment": "Add a new comment as a reply to an existing comment.",
 	"apihelp-discussiontoolsedit-paramvalue-paction-addtopic": "Add a new discussion section and the first comment in it.",
 	"apihelp-discussiontoolsedit-summary": "Post a message on a discussion page.",
+	"apihelp-discussiontoolsgetsubscriptions-param-commentname": "Names of the topics to check",
+	"apihelp-discussiontoolsgetsubscriptions-summary": "Get the subscription statuses of given topics.",
 	"apihelp-discussiontoolssubscribe-param-page": "A page on which the topic appears",
 	"apihelp-discussiontoolssubscribe-param-commentname": "Name of the topic to subscribe to (or unsubscribe from)",
 	"apihelp-discussiontoolssubscribe-param-subscribe": "True to subscribe, false to unsubscribe",

i18n/api/qqq.json

@@ -20,6 +20,8 @@
 	"apihelp-discussiontoolsedit-paramvalue-paction-addcomment": "{{doc-apihelp-paramvalue|discussiontoolsedit|paction|addcomment}}",
 	"apihelp-discussiontoolsedit-paramvalue-paction-addtopic": "{{doc-apihelp-paramvalue|discussiontoolsedit|paction|addtopic}}",
 	"apihelp-discussiontoolsedit-summary": "{{doc-apihelp-summary|discussiontoolsedit}}",
+	"apihelp-discussiontoolsgetsubscriptions-param-commentname": "{{doc-apihelp-param|discussiontoolsgetsubscriptions|commentname}}",
+	"apihelp-discussiontoolsgetsubscriptions-summary": "{{doc-apihelp-summary|discussiontoolsgetsubscriptions}}",
 	"apihelp-discussiontoolssubscribe-param-page": "{{doc-apihelp-param|discussiontoolssubscribe|page}}",
 	"apihelp-discussiontoolssubscribe-param-commentname": "{{doc-apihelp-param|discussiontoolssubscribe|commentname}}",
 	"apihelp-discussiontoolssubscribe-param-subscribe": "{{doc-apihelp-param|discussiontoolssubscribe|subscribe}}",

includes/ApiDiscussionToolsGetSubscriptions.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace MediaWiki\Extension\DiscussionTools;
+
+use ApiBase;
+use ApiMain;
+use ConfigFactory;
+use Wikimedia\ParamValidator\ParamValidator;
+
+class ApiDiscussionToolsGetSubscriptions extends ApiBase {
+
+	/** @var SubscriptionStore */
+	private $subscriptionStore;
+
+	/** @var ConfigFactory */
+	private $configFactory;
+
+	/**
+	 * @param ApiMain $main
+	 * @param string $name
+	 * @param SubscriptionStore $subscriptionStore
+	 * @param ConfigFactory $configFactory
+	 */
+	public function __construct(
+		ApiMain $main,
+		$name,
+		SubscriptionStore $subscriptionStore,
+		ConfigFactory $configFactory
+	) {
+		parent::__construct( $main, $name );
+		$this->subscriptionStore = $subscriptionStore;
+		$this->configFactory = $configFactory;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function execute() {
+		$dtConfig = $this->configFactory->makeConfig( 'discussiontools' );
+		if ( !$dtConfig->get( 'DiscussionToolsEnableTopicSubscriptionBackend' ) ) {
+			$this->dieWithError( [ 'apierror-moduledisabled', $this->getModuleName() ] );
+		}
+
+		$user = $this->getUser();
+		if ( !$user->isRegistered() ) {
+			$this->dieWithError( 'apierror-mustbeloggedin-generic', 'notloggedin' );
+		}
+
+		$params = $this->extractRequestParams();
+		$itemNames = $params['commentname'];
+		$items = $this->subscriptionStore->getSubscriptionItemsForUser(
+			$user,
+			$itemNames
+		);
+
+		// Ensure consistent formatting in JSON and XML formats
+		$this->getResult()->addIndexedTagName( 'subscriptions', 'subscription' );
+		$this->getResult()->addArrayType( 'subscriptions', 'kvp', 'name' );
+
+		foreach ( $items as $item ) {
+			$this->getResult()->addValue( 'subscriptions', $item->getItemName(), $item->getState() );
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getAllowedParams() {
+		return [
+			'commentname' => [
+				ParamValidator::PARAM_REQUIRED => true,
+				ApiBase::PARAM_ISMULTI => true,
+			],
+		];
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function isInternal() {
+		return true;
+	}
+}

includes/SubscriptionItem.php

@@ -80,6 +80,15 @@ class SubscriptionItem {
 		return $this->notifiedTimestamp;
 	}
 
+	/**
+	 * Get the subscription status of this entry.
+	 *
+	 * @return int One of SubscriptionStore::STATE_* constants
+	 */
+	public function getState(): int {
+		return $this->state;
+	}
+
 	/**
 	 * Check if the notification is muted
 	 *