<?php
/**
 * Bootstraps collaborative editing.
 *
 * @package WordPress
 * @since 7.0.0
 */

/**
 * Determines whether real-time collaboration is enabled.
 *
 * If the WP_ALLOW_COLLABORATION constant is false,
 * collaboration is always disabled regardless of the database option.
 * Otherwise, falls back to the 'wp_collaboration_enabled' option.
 *
 * @since 7.0.0
 *
 * @return bool Whether real-time collaboration is enabled.
 */
function wp_is_collaboration_enabled() {
    return (
        wp_is_collaboration_allowed() &&
        (bool) get_option( 'wp_collaboration_enabled' )
    );
}

/**
 * Determines whether real-time collaboration is allowed.
 *
 * If the WP_ALLOW_COLLABORATION constant is false,
 * collaboration is not allowed and cannot be enabled.
 * The constant defaults to true, unless the WP_ALLOW_COLLABORATION
 * environment variable is set to string "false".
 *
 * @since 7.0.0
 *
 * @return bool Whether real-time collaboration is enabled.
 */
function wp_is_collaboration_allowed() {
    if ( ! defined( 'WP_ALLOW_COLLABORATION' ) ) {
        $env_value = getenv( 'WP_ALLOW_COLLABORATION' );
        if ( false === $env_value ) {
            // Environment variable is not defined, default to allowing collaboration.
            define( 'WP_ALLOW_COLLABORATION', true );
        } else {
            /*
             * Environment variable is defined, let's confirm it is actually set to
             * "true" as it may still have a string value "false" – the preceeding
             * `if` branch only tests for the boolean `false`.
             */
            define( 'WP_ALLOW_COLLABORATION', 'true' === $env_value );
        }
    }

    return WP_ALLOW_COLLABORATION;
}

/**
 * Injects the real-time collaboration setting into a global variable.
 *
 * @since 7.0.0
 *
 * @access private
 *
 * @global string $pagenow The filename of the current screen.
 */
function wp_collaboration_inject_setting() {
    global $pagenow;

    if ( ! wp_is_collaboration_enabled() ) {
        return;
    }

    // Disable real-time collaboration on the site editor.
    $enabled = true;
    if ( 'site-editor.php' === $pagenow ) {
        $enabled = false;
    }

    wp_add_inline_script(
        'wp-core-data',
        'window._wpCollaborationEnabled = ' . wp_json_encode( $enabled ) . ';',
        'after'
    );
}