<?php

declare(strict_types=1);

namespace Abovault\Retention;

use Abovault\Email\LifecycleMailer;
use Abovault\Model\Subscription;

defined('ABSPATH') || exit;

// Data-access on the plugin's own custom tables (internal identifiers only; values are
// prepared). Direct queries + no object cache are inherent to live subscription state.
// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery.SchemaChange, PluginCheck.Security.DirectDB.UnescapedDBParameter, WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedVariableFound

/**
 * Executes due enrollment steps — port of famos.fans ReEngagementExecutionService.
 * An Action Scheduler recurring job (every 5 min) walks active enrollments whose
 * next_run_at is due, runs the SequenceLibrary step, advances or completes.
 *
 * A daily sweep evaluates time-based triggers (renewal reminders, anniversaries).
 */
final class ExecutionService
{
    private const HOOK = 'abovault_process_enrollments';
    private const HOOK_DAILY = 'abovault_evaluate_triggers';
    private const GROUP = 'abovault';

    public function register(): void
    {
        add_action(self::HOOK, [$this, 'processDue']);
        add_action(self::HOOK_DAILY, [$this, 'evaluateScheduledTriggers']);

        add_action('init', static function (): void {
            if (!function_exists('as_has_scheduled_action')) {
                return;
            }
            if (!as_has_scheduled_action(self::HOOK, [], self::GROUP)) {
                as_schedule_recurring_action(time() + 60, 5 * MINUTE_IN_SECONDS, self::HOOK, [], self::GROUP);
            }
            if (!as_has_scheduled_action(self::HOOK_DAILY, [], self::GROUP)) {
                as_schedule_recurring_action(time() + 120, DAY_IN_SECONDS, self::HOOK_DAILY, [], self::GROUP);
            }
        });
    }

    public function processDue(): void
    {
        if (get_option('abovault_retention_enabled', 'yes') !== 'yes') {
            return;
        }
        global $wpdb;
        $table = EnrollmentService::table();
        $now = current_time('mysql', true);

        $due = $wpdb->get_results($wpdb->prepare(
            "SELECT * FROM {$table} WHERE status = 'active' AND next_run_at <= %s ORDER BY next_run_at ASC LIMIT 200",
            $now
        ), ARRAY_A);

        foreach ($due as $enrollment) {
            $this->runStep($enrollment);
        }
    }

    /** @param array<string, mixed> $enrollment */
    private function runStep(array $enrollment): void
    {
        global $wpdb;
        $table = EnrollmentService::table();

        $sequence  = (string) $enrollment['sequence'];
        $stepIndex = (int) $enrollment['step_index'];
        $subId     = (int) $enrollment['subscription_id'];
        $steps     = SequenceLibrary::steps($sequence);

        // Guard: sequence emptied or index out of range → complete.
        if (!isset($steps[$stepIndex])) {
            $this->complete($enrollment);
            return;
        }

        $this->dispatch($steps[$stepIndex], $subId, $sequence, $stepIndex);

        $next = $stepIndex + 1;
        if (isset($steps[$next])) {
            $created = strtotime((string) $enrollment['created_at']) ?: time();
            $wpdb->update($table, [
                'step_index'  => $next,
                'next_run_at' => gmdate('Y-m-d H:i:s', $created + (int) $steps[$next]['offset_hours'] * HOUR_IN_SECONDS),
            ], ['id' => (int) $enrollment['id']]);
        } else {
            $this->complete($enrollment);
        }
    }

    /**
     * @param array{action:string, template:string, meta?:array<string,mixed>} $step
     */
    private function dispatch(array $step, int $subId, string $sequence, int $stepIndex): void
    {
        switch ($step['action']) {
            case 'coupon_email':
                $code = $this->createRetentionCoupon($subId, (array) ($step['meta'] ?? []));
                LifecycleMailer::send($subId, $step['template'], ['coupon_code' => $code]);
                break;

            case 'pause_offer':
            case 'email':
            default:
                LifecycleMailer::send($subId, $step['template']);
                break;
        }
        do_action('abovault_sequence_step_ran', $subId, $sequence, $stepIndex, $step);
    }

    private function complete(array $enrollment): void
    {
        global $wpdb;
        $wpdb->update(
            EnrollmentService::table(),
            ['status' => 'completed', 'next_run_at' => null],
            ['id' => (int) $enrollment['id']]
        );
        do_action('abovault_sequence_completed', (int) $enrollment['subscription_id'], (string) $enrollment['sequence']);
    }

    /**
     * Time-based triggers (daily): renewal reminders (period ending soon) + anniversaries.
     */
    public function evaluateScheduledTriggers(): void
    {
        if (get_option('abovault_retention_enabled', 'yes') !== 'yes') {
            return;
        }
        global $wpdb;
        $t = Subscription::table();
        $now = current_time('mysql', true);

        // Renewal reminders: active, not cancelling, period ends within reminder window.
        $windowDays = (int) apply_filters('abovault_renewal_reminder_days', 3);
        $soon = gmdate('Y-m-d H:i:s', strtotime($now) + $windowDays * DAY_IN_SECONDS);
        $ids = $wpdb->get_col($wpdb->prepare(
            "SELECT id FROM {$t}
             WHERE status = %s AND cancel_at_period_end = 0
               AND current_period_end BETWEEN %s AND %s",
            Subscription::STATUS_ACTIVE,
            $now,
            $soon
        ));
        foreach ($ids as $id) {
            EnrollmentService::enroll((int) $id, 'renewal_reminder', 'period_ending');
        }

        // Anniversaries: created ~N*365 days ago (same calendar day).
        $anniv = $wpdb->get_col($wpdb->prepare(
            "SELECT id FROM {$t}
             WHERE status IN (%s, %s)
               AND DATEDIFF(%s, created_at) > 0
               AND MOD(DATEDIFF(%s, created_at), 365) = 0",
            Subscription::STATUS_ACTIVE,
            Subscription::STATUS_TRIALING,
            $now,
            $now
        ));
        foreach ($anniv as $id) {
            EnrollmentService::enroll((int) $id, 'loyalty', 'anniversary');
        }
    }

    /**
     * Create a single-use % coupon for a subscriber. @return string coupon code
     */
    private function createRetentionCoupon(int $subId, array $meta): string
    {
        if (!class_exists('WC_Coupon')) {
            return '';
        }
        $percent = (int) ($meta['percent'] ?? 15);
        $days    = (int) ($meta['days_valid'] ?? 30);
        $code = 'ABOVAULT-' . strtoupper(wp_generate_password(6, false));

        $coupon = new \WC_Coupon();
        $coupon->set_code($code);
        $coupon->set_discount_type('percent');
        $coupon->set_amount($percent);
        $coupon->set_individual_use(true);
        $coupon->set_usage_limit(1);
        $coupon->set_date_expires(time() + $days * DAY_IN_SECONDS);
        $coupon->save();

        return $code;
    }
}