<?php

declare(strict_types=1);

namespace Sarcio\WordPress\Assistant;

final class PluginAbilities
{
    /** @return array<int,Ability> */
    public static function abilities(): array
    {
        $slugSchema = ['maxLength' => 200, 'minLength' => 1, 'pattern' => '^[a-z0-9-]+$', 'type' => 'string'];
        return [
            new Ability(
                'sarcio/plugins-list',
                __('Look at the installed plugins', 'sarcio'),
                Ability::READ,
                'The plugins installed on this site: slug, file, name, version, whether it is active and whether an update is available.',
                ['properties' => [], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('activate_plugins'),
                static fn (array $args): array => self::list(),
            ),
            new Ability(
                'sarcio/plugin-install',
                __('Install a plugin from WordPress.org', 'sarcio'),
                Ability::WRITE,
                'Install a plugin from the WordPress.org directory by its slug (the last part of its wordpress.org/plugins/ URL). Only directory plugins; refused where the host forbids installs. Does not activate it; use plugin-activate after. Only when the owner asked for a plugin.',
                ['properties' => ['slug' => $slugSchema], 'required' => ['slug'], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('install_plugins') && SiteAbilities::fileModsAllowed(),
                static fn (array $args): array => self::install((string) $args['slug']),
                static fn (array $args): array => self::installPreview((string) $args['slug']),
                null,
                true,
            ),
            new Ability(
                'sarcio/plugin-activate',
                __('Turn a plugin on', 'sarcio'),
                Ability::WRITE,
                'Activate an installed plugin by its slug (from plugins-list or just installed).',
                ['properties' => ['slug' => $slugSchema], 'required' => ['slug'], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('activate_plugins'),
                static fn (array $args): array => self::activate((string) $args['slug']),
                static fn (array $args): array => self::togglePreview((string) $args['slug'], true),
                static fn (array $before, array $after): array => self::deactivate((string) $before['slug'], false),
                true,
            ),
            new Ability(
                'sarcio/plugin-deactivate',
                __('Turn a plugin off', 'sarcio'),
                Ability::WRITE,
                'Deactivate an active plugin by its slug. Its files and settings stay; the site just stops using it.',
                ['properties' => ['slug' => $slugSchema], 'required' => ['slug'], 'type' => 'object'],
                static fn (array $args): bool => current_user_can('activate_plugins'),
                static fn (array $args): array => self::deactivate((string) $args['slug']),
                static fn (array $args): array => self::togglePreview((string) $args['slug'], false),
                static fn (array $before, array $after): array => self::activate((string) $before['slug'], false),
            ),
        ];
    }

    private static function load(): void
    {
        if (!function_exists('get_plugins')) {
            require_once ABSPATH . 'wp-admin/includes/plugin.php';
        }
    }

    /** @return array{file:string,name:string,version:string}|null */
    private static function find(string $slug): ?array
    {
        self::load();
        foreach ((array) get_plugins() as $file => $data) {
            $folder = dirname((string) $file);
            $base = $folder === '.' ? basename((string) $file, '.php') : $folder;
            if ($base === $slug) {
                return ['file' => (string) $file, 'name' => (string) ($data['Name'] ?? $slug), 'version' => (string) ($data['Version'] ?? '')];
            }
        }
        return null;
    }

    private static function list(): array
    {
        self::load();
        $updates = get_site_transient('update_plugins');
        $available = is_object($updates) && isset($updates->response) && is_array($updates->response) ? $updates->response : [];
        $out = [];
        foreach ((array) get_plugins() as $file => $data) {
            $folder = dirname((string) $file);
            $out[] = [
                'active' => is_plugin_active((string) $file),
                'file' => (string) $file,
                'name' => (string) ($data['Name'] ?? ''),
                'slug' => $folder === '.' ? basename((string) $file, '.php') : $folder,
                'updateAvailable' => isset($available[$file]),
                'version' => (string) ($data['Version'] ?? ''),
            ];
        }
        return ['plugins' => $out];
    }

    /** @return array<string,mixed>|array{error:string} */
    public static function information(string $slug): array
    {
        if (!function_exists('plugins_api')) {
            require_once ABSPATH . 'wp-admin/includes/plugin-install.php';
        }
        $api = plugins_api('plugin_information', [
            'fields' => ['active_installs' => true, 'rating' => true, 'sections' => false, 'short_description' => true, 'versions' => false],
            'slug' => $slug,
        ]);
        if (is_wp_error($api) || !is_object($api)) {
            return ['error' => sprintf(
                /* translators: %s: the plugin slug. */
                __('WordPress.org has no plugin called “%s”.', 'sarcio'),
                $slug,
            )];
        }
        return [
            'activeInstalls' => (int) ($api->active_installs ?? 0),
            'author' => wp_strip_all_tags((string) ($api->author ?? '')),
            'downloadLink' => (string) ($api->download_link ?? ''),
            'name' => (string) ($api->name ?? $slug),
            'rating' => (float) ($api->rating ?? 0) / 20,
            'slug' => $slug,
            'summary' => wp_strip_all_tags((string) ($api->short_description ?? '')),
            'url' => 'https://wordpress.org/plugins/' . rawurlencode($slug) . '/',
            'version' => (string) ($api->version ?? ''),
        ];
    }

    private static function installPreview(string $slug): array
    {
        if (self::find($slug) !== null) {
            return ['error' => __('That plugin is already installed. Turn it on instead.', 'sarcio')];
        }
        $info = self::information($slug);
        if (isset($info['error'])) {
            return $info;
        }
        return [
            'after' => $info['name'] . ' ' . $info['version'],
            'before' => '',
            'plugin' => $info,
            'summary' => sprintf(
                /* translators: 1: the plugin name, 2: its author. */
                __('Install %1$s by %2$s from WordPress.org', 'sarcio'),
                $info['name'],
                $info['author'],
            ),
        ];
    }

    private static function install(string $slug): array
    {
        if (self::find($slug) !== null) {
            return ['error' => __('That plugin is already installed. Turn it on instead.', 'sarcio')];
        }
        $info = self::information($slug);
        if (isset($info['error'])) {
            return $info;
        }
        require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';
        require_once ABSPATH . 'wp-admin/includes/file.php';
        require_once ABSPATH . 'wp-admin/includes/misc.php';
        $upgrader = new \Plugin_Upgrader(new \WP_Ajax_Upgrader_Skin());
        $result = $upgrader->install($info['downloadLink']);
        if (is_wp_error($result) || !$result) {
            return ['error' => __('WordPress could not install it. Your host may not allow plugin installs; ask them, or install it under Plugins → Add New.', 'sarcio')];
        }
        $installed = self::find($slug);
        return [
            'installed' => true,
            'journal' => [
                'after' => ['slug' => $slug, 'version' => $installed['version'] ?? $info['version']],
                'before' => [],
                'summary' => sprintf(
                    /* translators: %s: the plugin name. */
                    __('Installed %s', 'sarcio'),
                    $info['name'],
                ),
                'target' => 'plugin:' . $slug,
            ],
            'name' => $info['name'],
            'slug' => $slug,
        ];
    }

    private static function togglePreview(string $slug, bool $on): array
    {
        $plugin = self::find($slug);
        if ($plugin === null) {
            return ['error' => __('That plugin is not installed.', 'sarcio')];
        }
        $active = is_plugin_active($plugin['file']);
        if ($active === $on) {
            return ['error' => $on ? __('That plugin is already on.', 'sarcio') : __('That plugin is already off.', 'sarcio')];
        }
        return [
            'after' => $on ? __('On', 'sarcio') : __('Off', 'sarcio'),
            'before' => $on ? __('Off', 'sarcio') : __('On', 'sarcio'),
            'plugin' => ['name' => $plugin['name'], 'slug' => $slug, 'version' => $plugin['version']],
            'summary' => sprintf(
                $on
                    /* translators: %s: the plugin name. */
                    ? __('Turn on %s', 'sarcio')
                    /* translators: %s: the plugin name. */
                    : __('Turn off %s', 'sarcio'),
                $plugin['name'],
            ),
        ];
    }

    private static function activate(string $slug, bool $journal = true): array
    {
        $plugin = self::find($slug);
        if ($plugin === null) {
            return ['error' => __('That plugin is not installed.', 'sarcio')];
        }
        if (is_plugin_active($plugin['file'])) {
            return ['error' => __('That plugin is already on.', 'sarcio')];
        }
        $result = activate_plugin($plugin['file']);
        if (is_wp_error($result)) {
            return ['error' => sprintf(
                /* translators: 1: the plugin name, 2: WordPress’s reason. */
                __('%1$s could not be turned on: %2$s', 'sarcio'),
                $plugin['name'],
                wp_strip_all_tags((string) $result->get_error_message()),
            )];
        }
        $output = ['active' => true, 'name' => $plugin['name'], 'slug' => $slug];
        if ($journal) {
            $output['journal'] = [
                'after' => ['active' => true, 'slug' => $slug],
                'before' => ['active' => false, 'slug' => $slug],
                'summary' => sprintf(
                    /* translators: %s: the plugin name. */
                    __('Turned on %s', 'sarcio'),
                    $plugin['name'],
                ),
                'target' => 'plugin:' . $slug,
            ];
        }
        return $output;
    }

    private static function deactivate(string $slug, bool $journal = true): array
    {
        $plugin = self::find($slug);
        if ($plugin === null) {
            return ['error' => __('That plugin is not installed.', 'sarcio')];
        }
        if (!is_plugin_active($plugin['file'])) {
            return ['error' => __('That plugin is already off.', 'sarcio')];
        }
        if (str_starts_with($plugin['file'], 'sarcio/')) {
            return ['error' => __('Sarcio cannot turn itself off from here. Use the Plugins screen.', 'sarcio')];
        }
        deactivate_plugins($plugin['file']);
        $output = ['active' => false, 'name' => $plugin['name'], 'slug' => $slug];
        if ($journal) {
            $output['journal'] = [
                'after' => ['active' => false, 'slug' => $slug],
                'before' => ['active' => true, 'slug' => $slug],
                'summary' => sprintf(
                    /* translators: %s: the plugin name. */
                    __('Turned off %s', 'sarcio'),
                    $plugin['name'],
                ),
                'target' => 'plugin:' . $slug,
            ];
        }
        return $output;
    }
}