<?php
/**
 * Adverships_Affiliate_Alerts
 *
 * In-WP sales alerts. A WP-Cron event polls the signed alerts.php read endpoint
 * every ~15 minutes, asking for confirmed sales newer than the largest sale id
 * it has already seen. New sales are surfaced two ways:
 *   - a dismissible admin notice in wp-admin, and
 *   - an email to the merchant via wp_mail() (their own site mailer — no inbound
 *     connection or open port required, which is the right model for self-hosted).
 *
 * The server is the source of truth for sales; this is purely a notify layer on
 * top of the existing read endpoint, so it works no matter which path recorded
 * the sale (thank-you page, status transition, or a future channel).
 *
 * NOTE on WP-Cron: on low-traffic stores WP-Cron only fires when the site gets a
 * visit, so alerts can lag on a quiet store. That trade-off is documented on the
 * Settings screen. A real system cron hitting wp-cron.php removes the lag.
 */

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

class Adverships_Affiliate_Alerts {

    /** Cron hook + custom schedule names. */
    const EVENT    = 'adverships_affiliate_poll_sales';
    const SCHEDULE = 'adverships_15min';

    /** Option holding the pending admin-notice payload (new sales to show once). */
    const NOTICE_OPTION = 'adverships_affiliate_alerts_notice';

    /** Nonce action for the "dismiss notice" link. */
    const DISMISS_NONCE = 'adverships_dismiss_alert';

    public function hooks() {
        // Custom 15-minute schedule (WP ships only hourly/twicedaily/daily).
        add_filter('cron_schedules', array($this, 'add_schedule'));

        // The cron worker.
        add_action(self::EVENT, array($this, 'poll'));

        // Keep the schedule in sync with the connection + toggle state on every
        // load (cheap: wp_next_scheduled is a single option read).
        $this->sync_schedule();

        // Admin notice for new sales + its dismiss handler.
        if (is_admin()) {
            add_action('admin_notices', array($this, 'render_notice'));
            add_action('admin_post_adverships_dismiss_alert', array($this, 'handle_dismiss'));
        }
    }

    /** Register the 15-minute interval used by the poll event. */
    public function add_schedule($schedules) {
        if (!isset($schedules[self::SCHEDULE])) {
            $schedules[self::SCHEDULE] = array(
                'interval' => 15 * MINUTE_IN_SECONDS,
                'display'  => __('Every 15 minutes (Adverships)', 'adverships-affiliate'),
            );
        }
        return $schedules;
    }

    /**
     * Schedule the poll when connected AND alerts are enabled; clear it
     * otherwise. Idempotent — safe to call on every request.
     */
    public function sync_schedule() {
        $s       = Adverships_Affiliate_Client::settings();
        $enabled = !empty($s['alerts_enabled']) && Adverships_Affiliate_Client::is_connected();
        $next    = wp_next_scheduled(self::EVENT);

        if ($enabled && !$next) {
            wp_schedule_event(time() + MINUTE_IN_SECONDS, self::SCHEDULE, self::EVENT);
        } elseif (!$enabled && $next) {
            wp_clear_scheduled_hook(self::EVENT);
        }
    }

    /** Remove the scheduled event (deactivation / disconnect). */
    public static function unschedule() {
        $ts = wp_next_scheduled(self::EVENT);
        while ($ts) {
            wp_unschedule_event($ts, self::EVENT);
            $ts = wp_next_scheduled(self::EVENT);
        }
    }

    /**
     * The cron worker: fetch sales newer than our cursor, notify, advance the
     * cursor. On the very first run (no cursor yet) we only SEED the cursor to
     * the current high-water mark so the merchant isn't emailed their entire
     * history the moment they enable alerts.
     */
    public function poll() {
        $s = Adverships_Affiliate_Client::settings();
        if (empty($s['alerts_enabled']) || !Adverships_Affiliate_Client::is_connected()) {
            return;
        }

        $lastSeen = isset($s['alerts_last_seen']) ? (int) $s['alerts_last_seen'] : 0;

        // No cursor yet → initialise it without notifying.
        if ($lastSeen <= 0) {
            $res = Adverships_Affiliate_Client::post_signed('/api/wordpress/alerts.php', array(), true);
            if (!is_wp_error($res) && !empty($res['data']['ok'])) {
                Adverships_Affiliate_Client::update_settings(array(
                    'alerts_last_seen' => (int) ($res['data']['max_id'] ?? 0),
                ));
            }
            return;
        }

        $res = Adverships_Affiliate_Client::post_signed(
            '/api/wordpress/alerts.php',
            array('since_id' => $lastSeen, 'limit' => 50),
            true
        );
        if (is_wp_error($res) || empty($res['data']['ok'])) {
            return; // transient failure — try again next tick, cursor unmoved.
        }

        $data  = $res['data'];
        $sales = isset($data['sales']) && is_array($data['sales']) ? $data['sales'] : array();
        $maxId = (int) ($data['max_id'] ?? $lastSeen);

        if (!empty($sales)) {
            $this->notify($sales);
            $this->queue_notice($sales);
        }

        // Advance the cursor (never backwards).
        if ($maxId > $lastSeen) {
            Adverships_Affiliate_Client::update_settings(array('alerts_last_seen' => $maxId));
        }
    }

    // ---- notifications ----------------------------------------------------

    /** Email the merchant a summary of new sales. */
    private function notify(array $sales) {
        $s = Adverships_Affiliate_Client::settings();
        $to = !empty($s['alerts_email']) ? $s['alerts_email'] : get_bloginfo('admin_email');
        if (!is_email($to)) {
            return;
        }

        $site  = wp_specialchars_decode(get_bloginfo('name'), ENT_QUOTES);
        $count = count($sales);

        $subject = sprintf(
            /* translators: 1: number of sales, 2: site name */
            _n('%1$d new Adverships sale on %2$s', '%1$d new Adverships sales on %2$s', $count, 'adverships-affiliate'),
            $count,
            $site
        );

        $lines = array();
        $lines[] = sprintf(
            /* translators: %s: site name */
            __('New affiliate sales recorded on %s:', 'adverships-affiliate'),
            $site
        );
        $lines[] = '';
        foreach ($sales as $sale) {
            $lines[] = sprintf(
                '• %s — %s (%s) · %s',
                isset($sale['created_at']) ? $sale['created_at'] : '',
                $this->money($sale['amount'] ?? 0, $sale['currency'] ?? ''),
                isset($sale['creator']) ? $sale['creator'] : __('unknown creator', 'adverships-affiliate'),
                isset($sale['order_id']) ? ('#' . $sale['order_id']) : ''
            );
        }
        $lines[] = '';
        $lines[] = __('View your dashboard:', 'adverships-affiliate');
        $lines[] = admin_url('admin.php?page=adverships');

        wp_mail($to, $subject, implode("\n", $lines));
    }

    /** Stash new sales so the next admin pageload shows a dismissible notice. */
    private function queue_notice(array $sales) {
        $existing = get_option(self::NOTICE_OPTION, array());
        if (!is_array($existing)) {
            $existing = array();
        }
        // Keep the most recent 10 across ticks so the notice can't grow unbounded.
        $merged = array_merge($existing, $sales);
        if (count($merged) > 10) {
            $merged = array_slice($merged, -10);
        }
        update_option(self::NOTICE_OPTION, $merged, false);
    }

    /** Render the pending-sales admin notice (and a dismiss link). */
    public function render_notice() {
        if (!current_user_can($this->cap())) {
            return;
        }
        $sales = get_option(self::NOTICE_OPTION, array());
        if (empty($sales) || !is_array($sales)) {
            return;
        }

        $count    = count($sales);
        $dismiss  = wp_nonce_url(
            admin_url('admin-post.php?action=adverships_dismiss_alert'),
            self::DISMISS_NONCE
        );
        $dashboard = admin_url('admin.php?page=adverships');

        echo '<div class="notice notice-success is-dismissible adverships-alert-notice">';
        echo '<p><strong>' . esc_html__('Adverships', 'adverships-affiliate') . '</strong> — ';
        echo esc_html(sprintf(
            /* translators: %d: number of new sales */
            _n('%d new affiliate sale', '%d new affiliate sales', $count, 'adverships-affiliate'),
            $count
        ));
        echo '</p><ul style="margin:.25em 0 .5em 1.5em;list-style:disc;">';
        foreach (array_slice(array_reverse($sales), 0, 5) as $sale) {
            echo '<li>' . esc_html(sprintf(
                '%s — %s · %s',
                $this->money($sale['amount'] ?? 0, $sale['currency'] ?? ''),
                isset($sale['creator']) ? $sale['creator'] : '',
                isset($sale['order_id']) ? ('#' . $sale['order_id']) : ''
            )) . '</li>';
        }
        echo '</ul><p>';
        echo '<a class="button button-primary" href="' . esc_url($dashboard) . '">' . esc_html__('View dashboard', 'adverships-affiliate') . '</a> ';
        echo '<a class="button button-secondary" href="' . esc_url($dismiss) . '">' . esc_html__('Dismiss', 'adverships-affiliate') . '</a>';
        echo '</p></div>';
    }

    /** Clear the pending-notice payload. */
    public function handle_dismiss() {
        if (!current_user_can($this->cap())) {
            wp_die(esc_html__('You do not have permission to do this.', 'adverships-affiliate'));
        }
        check_admin_referer(self::DISMISS_NONCE);
        delete_option(self::NOTICE_OPTION);
        wp_safe_redirect(wp_get_referer() ?: admin_url('admin.php?page=adverships'));
        exit;
    }

    // ---- helpers ----------------------------------------------------------

    private function money($amount, $currency = '') {
        $amount = (float) $amount;
        if (function_exists('wc_price') && $currency !== '') {
            return wp_strip_all_tags(wc_price($amount, array('currency' => $currency)));
        }
        if (function_exists('wc_price')) {
            return wp_strip_all_tags(wc_price($amount));
        }
        return number_format_i18n($amount, 2);
    }

    private function cap() {
        return current_user_can('manage_woocommerce') ? 'manage_woocommerce' : 'manage_options';
    }
}