<?php

namespace WPZaraz\Admin;

if (!defined('ABSPATH')) {
    exit;
}

use WPZaraz\Cloudflare\ContainerBuilder;
use WPZaraz\Cloudflare\Recipes\RecipeRegistry;
use WPZaraz\Privacy\ConsentManager;
use WPZaraz\Support\Docs;
use WPZaraz\Support\Options;

/**
 * Checks the setup for the mistakes that stop tracking from working.
 * Each result is ['level' => 'ok'|'info'|'warning'|'error', 'title' => string, 'detail' => string,
 * 'docs' => string, 'action' => array]. The action is the fix the dashboard offers as a button:
 * ['type' => 'sync'|'export'|'field', 'label' => string, 'target' => field ID for 'field'], or [].
 */
class HealthCheck {

    public const CONTAINER_HASH_OPTION = 'last_container_hash';
    public const LAST_SYNC_OPTION = 'last_sync_at';

    /** Plugin files of consent plugins the CMP bridge listens to. */
    private const CONSENT_PLUGINS = [
        'complianz-gdpr/complianz-gpdr.php',
        'complianz-gdpr-premium/complianz-gpdr-premium.php',
        'cookiebot/cookiebot.php',
        'borlabs-cookie/borlabs-cookie.php',
        'cookie-law-info/cookie-law-info.php',
        'wp-consent-api/wp-consent-api.php',
    ];

    /** Hosts Zaraz calls for each tool, to name the tool behind a failed request. */
    private const TOOL_HOSTS = [
        'graph.facebook.com'       => 'Meta Conversions API',
        'business-api.tiktok.com'  => 'TikTok Events API',
        'api.pinterest.com'        => 'Pinterest Conversions API',
        'www.google-analytics.com' => 'Google Analytics 4',
        'region1.google-analytics.com' => 'Google Analytics 4',
        'googleads.g.doubleclick.net'  => 'Google Ads',
        'bat.bing.com'             => 'Microsoft Advertising (Bing)',
        'tr.snapchat.com'          => 'Snapchat',
        'ct.pinterest.com'         => 'Pinterest Tag',
        'px.ads.linkedin.com'      => 'LinkedIn',
    ];

    private bool $canSync;

    /**
     * @param bool|null $canSync Whether the container can be synced through the Cloudflare API
     *                           (Pro with an API token and zone ID). Detected when null.
     */
    public function __construct(?bool $canSync = null) {
        $this->canSync = $canSync ?? self::canSync();
    }

    /**
     * @return bool
     */
    public static function canSync(): bool {
        return class_exists('\WPZaraz\Licensing\LicenseManager') && \WPZaraz\Licensing\LicenseManager::isPro()
            && class_exists('\WPZaraz\Cloudflare\ApiClient')
            && Options::get('cf_api_token') && Options::get('cf_zone_id');
    }

    /**
     * Zaraz activity and the live Zaraz configuration, when the Cloudflare API can be used.
     * Rejected requests are counted from the last sync, so fixed problems disappear after syncing.
     *
     * @param bool $fresh Skip the cached copies
     * @return array ['activity' => array|null, 'live_config' => array|null]
     */
    public static function liveData(bool $fresh = false): array {
        $data = ['activity' => null, 'live_config' => null];
        if (!self::canSync()) {
            return $data;
        }
        $client = new \WPZaraz\Cloudflare\ApiClient();
        $data['activity'] = $client->getZarazActivity(24, self::lastSyncTime(), $fresh);

        $live = $fresh ? false : get_transient('wp_zaraz_live_config');
        if (!is_array($live)) {
            $response = $client->getConfig();
            $live = !empty($response['success']) ? (array) ($response['data']['result'] ?? []) : null;
            if ($live !== null) {
                set_transient('wp_zaraz_live_config', $live, 600);
            }
        }
        $data['live_config'] = $live;
        return $data;
    }

    /**
     * Fingerprint of a built container, stored after each export or sync.
     *
     * @param array $container
     * @return string
     */
    public static function containerHash(array $container): string {
        return md5((string) wp_json_encode($container));
    }

    /**
     * Records that the current container was exported or synced.
     *
     * @param array $container
     * @param bool $synced True when it was synced through the Cloudflare API
     */
    public static function recordContainer(array $container, bool $synced = false): void {
        Options::set(self::CONTAINER_HASH_OPTION, self::containerHash($container));
        if ($synced) {
            Options::set(self::LAST_SYNC_OPTION, time());
        }
    }

    /**
     * @return int Unix time of the last sync through the Cloudflare API, 0 if never
     */
    public static function lastSyncTime(): int {
        return (int) Options::get(self::LAST_SYNC_OPTION, 0);
    }

    /**
     * Runs every check.
     *
     * @param array|null $activity Zaraz activity from ApiClient::getZarazActivity(), when available
     * @param array|null $liveConfig Live Zaraz configuration from ApiClient::getConfig(), when available
     * @return array
     */
    public function run(?array $activity = null, ?array $liveConfig = null): array {
        $results = [];
        $credentials = Options::getAll();
        $registry = new RecipeRegistry();
        $activeToolIds = AjaxHandler::activeToolIds($registry, $credentials);

        // 1. Tools configured
        if (empty($activeToolIds)) {
            $results[] = $this->result('error', __('No tools configured', 'zbridge'), __('Enter at least one tool ID under Zaraz Recipes, such as your GA4 Measurement ID.', 'zbridge'), 'getting-started/quickstart/', [], 'tools');
            return $results;
        }

        // 2. Zaraz has the current container
        $built = (new ContainerBuilder($registry))->build($activeToolIds, $credentials);
        $stored = (string) Options::get(self::CONTAINER_HASH_OPTION, '');
        $sendAction = $this->canSync
            ? ['type' => 'sync', 'label' => __('Sync to Zaraz', 'zbridge')]
            : ['type' => 'export', 'label' => __('Download container', 'zbridge')];
        if ($stored === '') {
            $detail = $this->canSync
                ? __('Sync the container so Zaraz knows about your tools.', 'zbridge')
                : __('Download the container and import it in Cloudflare (Zaraz > Settings > Advanced > Import). Until then Zaraz does not know about your tools.', 'zbridge');
            $results[] = $this->result('warning', __('Container not sent to Zaraz yet', 'zbridge'), $detail, 'cloudflare/export/', $sendAction, 'container');
        } elseif ($stored !== self::containerHash($built)) {
            $detail = $this->canSync
                ? __('Your settings or the plugin changed since the container was last synced. Sync again so Zaraz gets the changes.', 'zbridge')
                : __('Your settings or the plugin changed since the container was last downloaded. Download it and import it in Cloudflare again so Zaraz gets the changes.', 'zbridge');
            $results[] = $this->result('warning', __('Zaraz has an older container', 'zbridge'), $detail, 'cloudflare/export/', $sendAction, 'container');
        } else {
            $results[] = $this->result('ok', __('Zaraz container is up to date', 'zbridge'), __('The last exported or synced container matches your current settings.', 'zbridge'), '', [], 'container');
        }

        // 3. Tools that need an access token to send anything
        $tokenTools = [
            'meta'   => ['recipes/meta/', 'meta_pixel_id', 'meta_capi_token', __('Meta needs a Conversions API access token', 'zbridge'), __('Zaraz sends Meta events from Cloudflare through the Conversions API, which rejects them without a token. Add it under Zaraz Recipes.', 'zbridge')],
            'tiktok' => ['recipes/tiktok/', 'tiktok_pixel_id', 'tiktok_access_token', __('TikTok needs an Events API access token', 'zbridge'), __('Zaraz sends TikTok events through the Events API, which rejects them without a token. Add it under Zaraz Recipes.', 'zbridge')],
        ];
        foreach ($tokenTools as $toolId => [$docsPath, $idKey, $tokenKey, $title, $detail]) {
            if (in_array($toolId, $activeToolIds, true) && !empty($credentials[$idKey]) && empty($credentials[$tokenKey])) {
                $results[] = $this->result('error', $title, $detail, $docsPath, ['type' => 'field', 'label' => __('Add the token', 'zbridge'), 'target' => $tokenKey]);
            }
        }

        // 4. Consent
        $bannerOn = (bool) Options::get('banner_enabled', false);
        $gateForCmp = (bool) Options::get('consent_gate_tools', false);
        if (!$bannerOn && $gateForCmp && !$this->consentPluginActive()) {
            $results[] = $this->result('error', __('Tools wait for consent nobody asks for', 'zbridge'), __('Tools are held until a consent plugin grants consent, but no supported consent plugin (Complianz, Cookiebot, CookieYes, Borlabs Cookie, WP Consent API) is active. Turn on the built-in banner or install a consent plugin.', 'zbridge'), 'consent/cmp-integrations/', [], 'consent');
        } elseif (!ConsentManager::isToolGatingEnabled()) {
            $results[] = $this->result('info', __('Tools run without asking for consent', 'zbridge'), __('Neither the cookie banner nor consent gating is on, so Zaraz loads your tools for every visitor. Turn on the banner if your visitors need to consent first.', 'zbridge'), 'consent/cookie-banner/', [], 'consent');
        } else {
            $results[] = $this->result('ok', __('Consent is collected', 'zbridge'), $bannerOn ? __('The built-in cookie banner collects consent and passes it to Zaraz.', 'zbridge') : __('Your consent plugin collects consent and WP Zbridge passes it to Zaraz.', 'zbridge'), '', [], 'consent');
        }

        // 5. HTTP Events API path used by the server fallback (Pro, needs the live config)
        if ($liveConfig !== null) {
            $livePath = (string) ($liveConfig['settings']['eventsApiPath'] ?? '');
            if ($livePath !== Options::eventsApiPath()) {
                $results[] = $this->result('error', __('Server fallback cannot reach Zaraz', 'zbridge'), __('The HTTP Events API path in Zaraz does not match this site, so server-sent purchases are not received. Sync the container again.', 'zbridge'), 'woocommerce/deduplication/', $this->canSync ? ['type' => 'sync', 'label' => __('Sync to Zaraz', 'zbridge')] : []);
            }
        }

        // 6. Requests Zaraz sent that the tools rejected (Pro, Zaraz Monitoring API)
        if ($activity !== null && !empty($activity['success'])) {
            $since = (int) ($activity['since'] ?? 0);
            foreach ((array) ($activity['failures'] ?? []) as $failure) {
                $tool = self::TOOL_HOSTS[$failure['host']] ?? $failure['host'];
                $hint = in_array((int) $failure['status'], [401, 403], true) ? __('The access token is missing, wrong or expired.', 'zbridge') : __('Check the tool ID and token under Zaraz Recipes.', 'zbridge');
                $results[] = $this->result(
                    'warning',
                    /* translators: 1: tool name, 2: number of requests, 3: HTTP status code */
                    sprintf(__('%1$s rejected %2$d requests (HTTP %3$d)', 'zbridge'), $tool, (int) $failure['count'], (int) $failure['status']),
                    $since > 0
                        /* translators: 1: date and time of the last sync, 2: what to check */
                        ? sprintf(__('Since your last sync (%1$s). %2$s', 'zbridge'), self::formatTime($since), $hint)
                        /* translators: 1: number of hours, 2: what to check */
                        : sprintf(__('In the last %1$d hours. %2$s', 'zbridge'), (int) ($activity['hours'] ?? 24), $hint),
                    'diagnostics/recovery-dashboard/'
                );
            }
        }

        return $results;
    }

    /**
     * @return bool
     */
    private function consentPluginActive(): bool {
        if (function_exists('wp_has_consent')) {
            return true;
        }
        if (!function_exists('is_plugin_active') && defined('ABSPATH') && file_exists(ABSPATH . 'wp-admin/includes/plugin.php')) {
            require_once ABSPATH . 'wp-admin/includes/plugin.php';
        }
        if (function_exists('is_plugin_active')) {
            foreach (self::CONSENT_PLUGINS as $plugin) {
                if (is_plugin_active($plugin)) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * @param int $timestamp
     * @return string Date and time in the site's format and timezone
     */
    private static function formatTime(int $timestamp): string {
        $format = (function_exists('get_option') ? get_option('date_format', 'Y-m-d') . ' ' . get_option('time_format', 'H:i') : 'Y-m-d H:i');
        return function_exists('wp_date') ? (string) wp_date($format, $timestamp) : gmdate($format, $timestamp);
    }

    /**
     * @param string $level
     * @param string $title
     * @param string $detail
     * @param string $docsPath
     * @param array $action
     * @return array
     */
    private function result(string $level, string $title, string $detail, string $docsPath = '', array $action = [], string $id = ''): array {
        return ['id' => $id, 'level' => $level, 'title' => $title, 'detail' => $detail, 'docs' => $docsPath !== '' ? Docs::url($docsPath) : '', 'action' => $action];
    }

    /**
     * The three setup steps, read from Setup Health results: tool IDs entered, Zaraz has the
     * current container, consent decided (collected, or knowingly running without it).
     *
     * @param array $results From run()
     * @return array [['id' => string, 'label' => string, 'done' => bool], ...]
     */
    public static function setupSteps(array $results): array {
        $byId = [];
        foreach ($results as $result) {
            if (!empty($result['id'])) {
                $byId[$result['id']] = $result['level'];
            }
        }
        $toolsDone = !isset($byId['tools']);
        return [
            ['id' => 'tools', 'label' => __('Tool IDs entered', 'zbridge'), 'done' => $toolsDone],
            ['id' => 'container', 'label' => __('Container in Zaraz', 'zbridge'), 'done' => $toolsDone && ($byId['container'] ?? '') === 'ok'],
            ['id' => 'consent', 'label' => __('Consent set up', 'zbridge'), 'done' => $toolsDone && in_array($byId['consent'] ?? '', ['ok', 'info'], true)],
        ];
    }
}