<?php

new WPCOM_JSON_API_Update_User_Endpoint( array(
	'description' => 'Deletes or removes a user of a site.',
	'group'       => 'users',
	'stat'        => 'users:delete',

	'method'      => 'POST',
	'path'        => '/sites/%s/users/%d/delete',
	'path_labels' => array(
		'$site'       => '(int|string) The site ID or domain.',
		'$user_ID'    => '(int) The user\'s ID'
	),

	'request_format' => array(
		'reassign' => '(int) An optional id of a user to reassign posts to.',
	),

	'response_format' => array(
		'success' => '(bool) Was the deletion of user successful?',
	),

	'example_request'      => 'https://public-api.wordpress.com/rest/v1/sites/82974409/users/1/delete',
	'example_request_data' => array(
		'headers' => array(
			'authorization' => 'Bearer YOUR_API_TOKEN'
		),
	),

	'example_response' => '
	{
		"success": true
	}'
) );

class WPCOM_JSON_API_Update_User_Endpoint extends WPCOM_JSON_API_Endpoint {

	function callback( $path = '', $blog_id = 0, $user_id = 0 ) {
		$blog_id = $this->api->switch_to_blog_and_validate_user( $this->api->get_blog_id( $blog_id ) );
		if ( is_wp_error( $blog_id ) ) {
			return $blog_id;
		}

		if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) {
			if ( wpcom_get_blog_owner( $blog_id ) == $user_id ) {
				return new WP_Error( 'forbidden', 'A site owner can not be removed through this endpoint.', 403 );
			}
		}

		if ( $this->api->ends_with( $path, '/delete' ) ) {
			return $this->delete_or_remove_user( $user_id );
		}

		return false;
	}

	/**
	 * Checks if a user exists by checking to see if a WP_User object exists for a user ID.
	 * @param  int $user_id
	 * @return bool
	 */
	function user_exists( $user_id ) {
		$user = get_user_by( 'id', $user_id );

		return false != $user && is_a( $user, 'WP_User' );
	}

	/**
	 * Return the domain name of a subscription
	 *
	 * @param  Store_Subscription $subscription
	 * @return string
	 */
	protected function get_subscription_domain_name( $subscription ) {
		return $subscription->meta;
	}

	/**
	 * Get a list of the domains owned by the given user.
	 *
	 * @param  int $user_id
	 * @return array
	 */
	protected function domain_subscriptions_for_site_owned_by_user( $user_id ) {
		$subscriptions = WPCOM_Store::get_subscriptions( get_current_blog_id(), $user_id, domains::get_domain_products() );

		$domains = array_unique( array_map( array( $this, 'get_subscription_domain_name' ), $subscriptions ) );

		return array_values( $domains );
	}

	/**
	 * Validates user input and then decides whether to remove or delete a user.
	 * @param  int $user_id
	 * @return array|WP_Error
	 */
	function delete_or_remove_user( $user_id ) {
		if ( 0 == $user_id ) {
			return new WP_Error( 'invalid_input', 'A valid user ID must be specified.', 400 );
		}

		if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) {
			$domains = $this->domain_subscriptions_for_site_owned_by_user( $user_id );
			if ( ! empty( $domains ) ) {
				$error = new WP_Error( 'user_owns_domain_subscription', join( ', ', $domains ) );
				$error->add_data( $domains, 'additional_data' );
				return $error;
			}

			$active_user_subscriptions = WPCOM_Store::get_user_subscriptions( $user_id, get_current_blog_id() );
			if ( ! empty( $active_user_subscriptions ) ) {
				$product_names = array_values( wp_list_pluck( $active_user_subscriptions, 'product_name' ) );
				$error         = new WP_Error( 'user_has_active_subscriptions', 'User has active subscriptions' );
				$error->add_data( $product_names, 'additional_data' );
				return $error;
			}
		}

    	if ( get_current_user_id() == $user_id ) {
			return new WP_Error( 'invalid_input', 'User can not remove or delete self through this endpoint.', 400 );
		}

		if ( ! $this->user_exists( $user_id ) ) {
			return new WP_Error( 'invalid_input', 'A user does not exist with that ID.', 400 );
		}

		return is_multisite() ? $this->remove_user( $user_id ) : $this->delete_user( $user_id );
	}

	/**
	 * Removes a user from the current site.
	 * @param  int $user_id
	 * @return array|WP_Error
	 */
	function remove_user( $user_id ) {
		if ( ! current_user_can( 'remove_users' ) ) {
			return new WP_Error( 'unauthorized', 'User cannot remove users for specified site.', 403 );
		}

		if ( ! is_user_member_of_blog( $user_id, get_current_blog_id() ) ) {
			return new WP_Error( 'invalid_input', 'User is not a member of the specified site.', 400 );
		}

		return array(
			'success' => remove_user_from_blog( $user_id, get_current_blog_id() )
		);
	}

	/**
	 * Deletes a user and optionally reassigns posts to another user.
	 * @param  int $user_id
	 * @return array|WP_Error
	 */
	function delete_user( $user_id ) {
		if ( ! current_user_can( 'delete_users' ) ) {
			return new WP_Error( 'unauthorized', 'User cannot delete users for specified site.', 403 );
		}

		$input = (array) $this->input();

		if ( isset( $input['reassign'] ) ) {
			if ( $user_id == $input['reassign'] ) {
				return new WP_Error( 'invalid_input', 'Can not reassign posts to user being deleted.', 400 );
			}

			if ( ! $this->user_exists( $input['reassign'] ) ) {
				return new WP_Error( 'invalid_input', 'User specified in reassign argument is not a member of the specified site.', 400 );
			}
		}

		return array(
			'success' => wp_delete_user( $user_id, (int) $input['reassign'] ),
		);
	}
}