<?php

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

function aismart_plugin_membership_sync_token() {
    if (defined('AISMART_SYNC_ENDPOINT_TOKEN') && trim((string) AISMART_SYNC_ENDPOINT_TOKEN) !== '') {
        return trim((string) AISMART_SYNC_ENDPOINT_TOKEN);
    }

    $option = get_option('aismart_sync_endpoint_token', '');
    if (is_string($option) && trim($option) !== '') {
        return trim($option);
    }

    return defined('AISMART_SSO_SECRET') ? trim((string) AISMART_SSO_SECRET) : '';
}

function aismart_plugin_membership_plan_map() {
    $saved = get_option('aismart_plan_map', []);
    if (!is_array($saved)) {
        return [];
    }

    $map = [];
    foreach ($saved as $main_plan_id => $level_id) {
        $main_plan_id = (int) $main_plan_id;
        $level_id = (int) $level_id;
        if ($main_plan_id > 0 && $level_id > 0) {
            $map[$main_plan_id] = $level_id;
        }
    }

    return $map;
}

function aismart_plugin_membership_user_by_email($email) {
    $email = sanitize_email((string) $email);
    if ($email === '') {
        return new WP_Error('aismart_invalid_email', 'A valid email address is required.');
    }

    $user = get_user_by('email', $email);
    if ($user instanceof WP_User) {
        return $user;
    }

    $username_base = sanitize_user(strstr($email, '@', true), true);
    $username_base = $username_base !== '' ? $username_base : 'aismart-user';
    $username = $username_base;
    while (username_exists($username)) {
        $username = $username_base . '-' . strtolower(wp_generate_password(6, false, false));
    }

    $user_id = wp_insert_user([
        'user_login' => $username,
        'user_email' => $email,
        'user_pass' => wp_generate_password(32, true, true),
        'display_name' => $username_base,
        'role' => 'subscriber',
    ]);

    return is_wp_error($user_id) ? $user_id : get_user_by('id', (int) $user_id);
}

function aismart_plugin_sync_membership_by_email($email, $main_plan_id) {
    global $wpdb;

    $main_plan_id = (int) $main_plan_id;
    $map = aismart_plugin_membership_plan_map();
    $target_level_id = isset($map[$main_plan_id]) ? (int) $map[$main_plan_id] : 0;
    if ($main_plan_id <= 0 || $target_level_id <= 0) {
        return new WP_Error('aismart_unmapped_plan', 'The Main plan does not have a WordPress membership mapping.');
    }
    if (!function_exists('pmpro_changeMembershipLevel')) {
        return new WP_Error('aismart_pmpro_unavailable', 'Paid Memberships Pro is unavailable.');
    }

    $level_exists = (int) $wpdb->get_var($wpdb->prepare(
        "SELECT id FROM {$wpdb->pmpro_membership_levels} WHERE id = %d LIMIT 1",
        $target_level_id
    ));
    if ($level_exists !== $target_level_id) {
        return new WP_Error('aismart_missing_level', 'The mapped WordPress membership level does not exist.');
    }

    $user = aismart_plugin_membership_user_by_email($email);
    if (is_wp_error($user)) {
        return $user;
    }

    $current = function_exists('pmpro_getMembershipLevelForUser')
        ? pmpro_getMembershipLevelForUser((int) $user->ID)
        : null;
    $current_level_id = isset($current->id) ? (int) $current->id : 0;
    if ($current_level_id === $target_level_id) {
        return [
            'wp_user_id' => (int) $user->ID,
            'main_plan_id' => $main_plan_id,
            'membership_level_id' => $target_level_id,
            'changed' => false,
        ];
    }

    if (!pmpro_changeMembershipLevel($target_level_id, (int) $user->ID)) {
        return new WP_Error('aismart_membership_sync_failed', 'WordPress membership synchronization failed.');
    }

    return [
        'wp_user_id' => (int) $user->ID,
        'main_plan_id' => $main_plan_id,
        'membership_level_id' => $target_level_id,
        'changed' => true,
    ];
}

function aismart_plugin_membership_sync_permission(WP_REST_Request $request) {
    $expected = aismart_plugin_membership_sync_token();
    $provided = trim((string) $request->get_header('X-Aismart-Sync-Token'));
    if ($expected === '' || $provided === '' || !hash_equals($expected, $provided)) {
        return new WP_Error('rest_forbidden', 'Invalid membership synchronization credentials.', ['status' => 403]);
    }

    return true;
}

function aismart_plugin_membership_sync_rest(WP_REST_Request $request) {
    $result = aismart_plugin_sync_membership_by_email(
        (string) $request->get_param('email'),
        (int) $request->get_param('main_plan_id')
    );
    if (is_wp_error($result)) {
        return new WP_REST_Response([
            'ok' => false,
            'message' => $result->get_error_message(),
        ], $result->get_error_code() === 'aismart_pmpro_unavailable' ? 503 : 422);
    }

    return new WP_REST_Response(['ok' => true, 'data' => $result], 200);
}

function aismart_plugin_register_membership_sync_route() {
    register_rest_route('aismart/v1', '/force-sync', [
        'methods' => WP_REST_Server::CREATABLE,
        'callback' => 'aismart_plugin_membership_sync_rest',
        'permission_callback' => 'aismart_plugin_membership_sync_permission',
        'args' => [
            'email' => [
                'required' => true,
                'type' => 'string',
                'format' => 'email',
                'sanitize_callback' => 'sanitize_email',
            ],
            'main_plan_id' => [
                'required' => true,
                'type' => 'integer',
                'minimum' => 1,
            ],
        ],
    ]);
}
add_action('rest_api_init', 'aismart_plugin_register_membership_sync_route');