<?php

declare(strict_types=1);

namespace Sarcio\WordPress\Assistant;

/**
 * Classic widget areas (sidebars, a classic theme's footer): what sits in
 * each, and the words in a text or block widget, changed in the preview
 * first and undone like any change.
 */
final class WidgetAbilities
{
    /** @return array<int,Ability> */
    public static function abilities(): array
    {
        return [
            new Ability(
                'sarcio/sidebars-list',
                __('Look at the widget areas', 'sarcio'),
                Ability::READ,
                'The theme’s widget areas (sidebars, footer columns) and the widgets in each: id, type and, for a text or block widget, its words. Block themes have none: their header and footer are template parts.',
                ['properties' => [], 'required' => [], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('edit_theme_options'),
                static fn (array $args): array => self::list(),
            ),
            new Ability(
                'sarcio/widget-text-update',
                __('Change the words in a widget', 'sarcio'),
                Ability::WRITE,
                'Replace the content of a text or block widget by its id from sidebars-list (such as block-3 or text-2). Previewed first; undo puts the old content back.',
                ['properties' => ['content' => ['maxLength' => 20000, 'type' => 'string'], 'title' => ['maxLength' => 200, 'type' => 'string'], 'widgetId' => ['maxLength' => 60, 'minLength' => 1, 'type' => 'string']], 'required' => ['content', 'widgetId'], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('edit_theme_options'),
                static fn (array $args): array => self::update($args),
                null,
                static fn (array $before, array $after): array => self::write((string) $before['widgetId'], (array) $before['instance']) + ['restored' => true],
                false,
                static fn (array $args, Overlay $overlay): array => self::stage($args, $overlay),
            ),
        ];
    }

    /** @return array{0:string,1:int}|null option name and instance number */
    private static function parse(string $widgetId): ?array
    {
        if (!preg_match('~^([a-z0-9_-]+?)-(\d+)$~', $widgetId, $m)) {
            return null;
        }
        return ['widget_' . $m[1], (int) $m[2]];
    }

    private static function list(): array
    {
        global $wp_registered_sidebars;
        $areas = [];
        $placed = (array) get_option('sidebars_widgets', []);
        foreach ((array) $wp_registered_sidebars as $id => $sidebar) {
            $widgets = [];
            foreach ((array) ($placed[$id] ?? []) as $widgetId) {
                $widgets[] = self::describe((string) $widgetId);
            }
            $areas[] = ['id' => (string) $id, 'name' => (string) ($sidebar['name'] ?? $id), 'widgets' => $widgets];
        }
        return ['areas' => $areas, 'inactive' => array_map([self::class, 'describe'], array_map('strval', (array) ($placed['wp_inactive_widgets'] ?? [])))];
    }

    private static function describe(string $widgetId, ?Overlay $overlay = null): array
    {
        $parsed = self::parse($widgetId);
        $out = ['id' => $widgetId, 'type' => $parsed !== null ? substr($parsed[0], 7) : $widgetId];
        if ($parsed === null) {
            return $out;
        }
        $instance = self::instance($widgetId, $overlay);
        if ($instance === null) {
            return $out;
        }
        if (isset($instance['content'])) {
            $out['content'] = (string) $instance['content'];
            $out['text'] = mb_substr(ContentAbilities::readable((string) $instance['content']), 0, 500);
        } elseif (isset($instance['text'])) {
            $out['content'] = (string) $instance['text'];
            $out['text'] = mb_substr(wp_strip_all_tags((string) $instance['text']), 0, 500);
        }
        if (isset($instance['title'])) {
            $out['title'] = (string) $instance['title'];
        }
        return $out;
    }

    /** @return array<string,mixed>|null */
    private static function instance(string $widgetId, ?Overlay $overlay = null): ?array
    {
        $parsed = self::parse($widgetId);
        if ($parsed === null) {
            return null;
        }
        $all = $overlay !== null ? $overlay->option($parsed[0], []) : get_option($parsed[0], []);
        $instance = is_array($all) ? ($all[$parsed[1]] ?? null) : null;
        return is_array($instance) ? $instance : null;
    }

    /** @param array<string,mixed> $args */
    private static function next(array $args, ?Overlay $overlay): array
    {
        $widgetId = (string) $args['widgetId'];
        $instance = self::instance($widgetId, $overlay);
        if ($instance === null) {
            return ['error' => __('There is no text or block widget with that id.', 'sarcio')];
        }
        if (!array_key_exists('content', $instance) && !array_key_exists('text', $instance)) {
            return ['error' => __('That widget has no words to change; only text and block widgets do.', 'sarcio')];
        }
        $after = $instance;
        $content = wp_kses_post((string) $args['content']);
        if (array_key_exists('content', $instance)) {
            $after['content'] = $content;
        } else {
            $after['text'] = $content;
        }
        if (array_key_exists('title', $args)) {
            $after['title'] = sanitize_text_field((string) $args['title']);
        }
        if ($after === $instance) {
            return ['error' => __('Nothing would change.', 'sarcio')];
        }
        return ['after' => $after, 'before' => $instance, 'widgetId' => $widgetId];
    }

    /** @param array<string,mixed> $args */
    private static function stage(array $args, Overlay $overlay): array
    {
        $next = self::next($args, $overlay);
        if (isset($next['error'])) {
            return $next;
        }
        [$option, $number] = self::parse($next['widgetId']);
        $all = $overlay->option($option, []);
        $all = is_array($all) ? $all : [];
        $all[$number] = $next['after'];
        $overlay->options[$option] = $all;
        return [
            'after' => (string) ($next['after']['content'] ?? $next['after']['text'] ?? ''),
            'before' => (string) ($next['before']['content'] ?? $next['before']['text'] ?? ''),
            'summary' => sprintf(
                /* translators: %s: the widget id. */
                __('Change the words in the widget %s', 'sarcio'),
                $next['widgetId'],
            ),
        ];
    }

    /** @param array<string,mixed> $args */
    private static function update(array $args): array
    {
        $next = self::next($args, null);
        if (isset($next['error'])) {
            return $next;
        }
        $written = self::write($next['widgetId'], $next['after']);
        if (isset($written['error'])) {
            return $written;
        }
        return [
            'journal' => [
                'after' => ['instance' => $next['after'], 'widgetId' => $next['widgetId']],
                'before' => ['instance' => $next['before'], 'widgetId' => $next['widgetId']],
                'summary' => sprintf(
                    /* translators: %s: the widget id. */
                    __('Changed the words in the widget %s', 'sarcio'),
                    $next['widgetId'],
                ),
                'target' => 'widget:' . $next['widgetId'],
            ],
            'widget' => self::describe($next['widgetId']),
        ];
    }

    /** @param array<string,mixed> $instance */
    private static function write(string $widgetId, array $instance): array
    {
        $parsed = self::parse($widgetId);
        if ($parsed === null) {
            return ['error' => __('There is no widget with that id.', 'sarcio')];
        }
        $all = get_option($parsed[0], []);
        $all = is_array($all) ? $all : [];
        $all[$parsed[1]] = $instance;
        update_option($parsed[0], $all);
        return ['widgetId' => $widgetId];
    }
}