<?php

namespace PostLockdown;

class PostLockdown
{
    /** Plugin key for options and the option page. */
    public const KEY     = 'postlockdown';
    public const VERSION = '4.1.1';

    /** @var array List of post IDs which cannot be edited, trashed or deleted. */
    private $locked_post_ids = [];
    /** @var array List of post IDs which cannot be trashed or deleted. */
    private $protected_post_ids = [];
    /** @var bool */
    private $bulk_actions_enabled = false;
    /** @var string */
    public $plugin_path;
    /** @var string */
    public $plugin_url;
    /** @var string */
    public $db_version;

    public $registry = [];

    public function __construct($plugin_path, $plugin_url)
    {
        $this->plugin_path = $plugin_path;
        $this->plugin_url  = $plugin_url;

        $this->load_registry();
        $this->load_options();

        add_action('delete_post', [$this, '_remove_deleted_post']);
        add_filter('user_has_cap', [$this, '_filter_cap'], 10, 3);
        add_filter('wp_insert_post_data', [$this, '_prevent_status_change'], 10, 2);
    }

    /**
     * Returns an array of locked post IDs.
     *
     * @param bool $suppress_filters Whether to suppress filters and only return IDs
     *                               selected on the Post Lockdown options page.
     *
     * @return array
     */
    public function get_locked_post_ids($suppress_filters = false)
    {
        if ($suppress_filters) {
            return $this->locked_post_ids;
        }

        return apply_filters('postlockdown_locked_posts', $this->locked_post_ids);
    }

    /**
     * Returns an array of protected post IDs.
     *
     * @param bool $suppress_filters Whether to suppress filters and only return IDs
     *                               selected on the Post Lockdown options page.
     *
     * @return array
     */
    public function get_protected_post_ids($suppress_filters = false)
    {
        if ($suppress_filters) {
            return $this->protected_post_ids;
        }

        return apply_filters('postlockdown_protected_posts', $this->protected_post_ids);
    }

    /**
     * Returns whether there are any locked or protected posts set.
     *
     * @return bool
     */
    public function have_posts()
    {
        return (bool)($this->get_locked_post_ids() || $this->get_protected_post_ids());
    }

    /**
     * Returns whether a post is locked.
     *
     * @param int  $post_id          The ID of the post to check.
     * @param bool $suppress_filters
     *
     * @return bool
     */
    public function is_post_locked($post_id, $suppress_filters = false)
    {
        if ($suppress_filters) {
            return isset($this->locked_post_ids[$post_id]);
        }

        $locked_post_ids = $this->get_locked_post_ids();

        return isset($locked_post_ids[$post_id]);
    }

    /**
     * Returns whether a post is protected.
     *
     * @param int  $post_id          The ID of the post to check.
     * @param bool $suppress_filters
     *
     * @return bool
     */
    public function is_post_protected($post_id, $suppress_filters = false)
    {
        if ($suppress_filters) {
            return isset($this->protected_post_ids[$post_id]);
        }

        $protected_post_ids = $this->get_protected_post_ids();

        return isset($protected_post_ids[$post_id]);
    }

    /**
     * Adds the given post ID or post IDs to the list of locked posts.
     *
     * @param int ...$post_ids
     */
    public function add_locked_post(...$post_ids)
    {
        foreach ($post_ids as $post_id) {
            $this->locked_post_ids[$post_id] = $post_id;
        }

        $this->update_option();
    }

    /**
     * Removes the given post ID or post IDs from the list of locked posts.
     *
     * @param int ...$post_ids
     */
    public function remove_locked_post(...$post_ids)
    {
        foreach ($post_ids as $post_id) {
            unset($this->locked_post_ids[$post_id]);
        }

        $this->update_option();
    }

    /**
     * Adds the given post ID or post IDs to the list of protected posts.
     *
     * @param int ...$post_ids
     */
    public function add_protected_post(...$post_ids)
    {
        foreach ($post_ids as $post_id) {
            $this->protected_post_ids[$post_id] = $post_id;
        }

        $this->update_option();
    }

    /**
     * Removes the given post ID or post IDs to the list of protected posts.
     *
     * @param int ...$post_ids
     */
    public function remove_protected_post(...$post_ids)
    {
        foreach ($post_ids as $post_id) {
            unset($this->protected_post_ids[$post_id]);
        }

        $this->update_option();
    }

    /**
     * Convenience wrapper for get_posts().
     *
     * @param array $args Array of args to merge with defaults passed to get_posts().
     *
     * @return \WP_Post[] Array of post objects.
     */
    public function get_posts($args = [])
    {
        $defaults = [
            'post_type'              => $this->get_post_types(),
            'post_status'            => ['publish', 'pending', 'draft', 'future', 'private', 'inherit'],
            'update_post_meta_cache' => false,
            'update_post_term_cache' => false,
            'no_found_rows'          => true,
            'cache_results'          => false,
            'ignore_sticky_posts'    => true,
        ];

        $args = wp_parse_args($args, $defaults);

        $args = apply_filters('postlockdown_get_posts', $args);

        $query = new \WP_Query($args);

        return $query->posts;
    }

    /**
     * @return array
     */
    public function get_post_types()
    {
        $excluded_post_types = [];

        if (class_exists('WooCommerce')) {
            array_push($excluded_post_types, 'shop_order', 'shop_coupon');
        }

        $excluded_post_types = apply_filters('postlockdown_excluded_post_types', $excluded_post_types);

        $post_types = get_post_types([
            'show_ui' => true,
        ]);

        $post_types = array_diff($post_types, $excluded_post_types);

        return apply_filters('postlockdown_post_types', $post_types);
    }

    /**
     * Returns the required capability a user must have to bypass all
     * locked and protected post restrictions. Defaults to 'manage_options'.
     *
     * Also serves as a callback for the 'option_page_capability_{slug}' hook.
     *
     * @return string The required capability.
     */
    public function get_admin_cap()
    {
        return apply_filters('postlockdown_admin_capability', 'manage_options');
    }

    /**
     * @return bool
     */
    public function is_bulk_actions_enabled()
    {
        return $this->bulk_actions_enabled;
    }

    /**
     * Filter for the 'user_has_cap' hook.
     *
     * Sets the capability to false when current_user_can() has been called on
     * one of the capabilities we're interested in on a locked or protected post.
     *
     * @param array $allcaps All capabilities of the user.
     * @param array $cap     [0] Required capability.
     * @param array $args    [0] Requested capability.
     *                       [1] User ID.
     *                       [2] Post ID.
     *
     * @return array
     */
    public function _filter_cap($allcaps, $cap, $args)
    {
        /* If the user doesn't have the required capabilities to begin with we can return early
         * because we never want to give users more capabilities than they already have.
         * We only want to restrict capabilities based on whether the post is locked or protected.
         */
        foreach ($cap as $requiredCap) {
            if (empty($allcaps[$requiredCap])) {
                return $allcaps;
            }
        }

        /* If there are no locked or protected posts, or the user
         * has the required capability to bypass restrictions get out of here.
         */
        if (!$this->have_posts() || !empty($allcaps[$this->get_admin_cap()])) {
            return $allcaps;
        }

        $the_caps = apply_filters('postlockdown_capabilities', [
            'delete_post' => true,
            'edit_post'   => true,
        ]);

        // If it's not a capability we're interested in get out of here.
        if (!isset($the_caps[$args[0]])) {
            return $allcaps;
        }

        $post_id = $args[2];

        if (!$post_id) {
            return $allcaps;
        }

        $has_cap = true;

        if ($this->is_post_locked($post_id) || ('edit_post' !== $args[0] && $this->is_post_protected($post_id))) {
            $has_cap = false;
        }

        foreach ($cap as $requiredCap) {
            $allcaps[$requiredCap] = $has_cap;
        }

        return $allcaps;
    }

    /**
     * Filter for the 'wp_insert_post_data' hook.
     *
     * Reverts any changes made by a non-admin to a published protected post's status, privacy and password.
     * Also reverts any date changes if they're set to a future date. If anything is changed a filter for
     * the 'redirect_post_location' hook is added to display an admin notice letting the user know we reverted it.
     *
     * @param array $data    Sanitized post data.
     * @param array $postarr Raw post data. Contains post ID.
     *
     * @return array
     */
    public function _prevent_status_change($data, $postarr)
    {
        $post_id = $postarr['ID'];

        if ($post_id === 0) {
            // New post
            return $data;
        }

        $post    = get_post($post_id);

        /*
         * Only continue if the current user is a non-admin
         * and the post is both published and protected.
         */
        if (current_user_can($this->get_admin_cap()) || 'publish' !== $post->post_status || !$this->is_post_protected($post_id)) {
            return $data;
        }

        $changed = false;

        if ('publish' !== $data['post_status']) {
            $changed             = true;
            $data['post_status'] = $post->post_status;
        }

        if ($data['post_password'] !== $post->post_password) {
            $changed               = true;
            $data['post_password'] = $post->post_password;
        }

        // Revert the post date if it's set to a future date.
        if ($data['post_date'] !== $post->post_date && strtotime($data['post_date']) > time()) {
            $changed               = true;
            $data['post_date']     = $post->post_date;
            $data['post_date_gmt'] = $post->post_date_gmt;
        }

        if ($changed) {
            add_filter('redirect_post_location', [$this->registry['AdminNotice'], '_add_query_arg']);
            $this->registry['BlockEditorNotice']->flag_reverted($post_id);
        }

        return $data;
    }

    /**
     * Callback for the 'delete_post' hook.
     *
     * Removes the deleted post's ID from both locked and protected arrays.
     *
     * @param int $post_id Deleted post's ID.
     */
    public function _remove_deleted_post($post_id)
    {
        unset($this->locked_post_ids[$post_id], $this->protected_post_ids[$post_id]);

        $this->update_option();
    }

    public function update_option()
    {
        update_option(self::KEY, [
            'locked_post_ids'      => $this->locked_post_ids,
            'protected_post_ids'   => $this->protected_post_ids,
            'bulk_actions_enabled' => $this->bulk_actions_enabled,
        ]);
    }

    /**
     * Callback for register_uninstall_hook() function.
     *
     * Removes the plugin option from the database when it is uninstalled.
     */
    public static function _uninstall()
    {
        delete_option(self::KEY);
    }

    /**
     * Initialises class instances and adds them to our registry array.
     */
    private function load_registry()
    {
        $this->registry = [
            'AdminNotice'       => new AdminNotice($this->plugin_path),
            'BlockEditorNotice' => new BlockEditorNotice($this),
            'OptionsPage'       => new OptionsPage($this),
            'StatusColumn'      => new StatusColumn($this),
            'BulkActions'       => new BulkActions($this),
        ];
    }

    /**
     * Sets the arrays of locked and protected post IDs.
     */
    private function load_options()
    {
        $options = get_option(self::KEY, []);

        if (!empty($options['locked_post_ids']) && \is_array($options['locked_post_ids'])) {
            $this->locked_post_ids = $options['locked_post_ids'];
        }

        if (!empty($options['protected_post_ids']) && \is_array($options['protected_post_ids'])) {
            $this->protected_post_ids = $options['protected_post_ids'];
        }

        if (!empty($options['bulk_actions_enabled'])) {
            $this->bulk_actions_enabled = true;
        }
    }
}