WordPress│自作プラグインにGumroadライセンス認証を実装する方法

curl -X POST https://api.gumroad.com/v2/licenses/verify \
  -d "product_id=xxxxxxxxxxxxxxxxxxx-X==" \
  -d "license_key=XXXX-XXXX-XXXX-XXXX" \
  -d "increment_uses_count=false"

/wp-content/plugins/My-license-server/
    └── My-license-server.php

wp option update mls_product_id "YOUR_PRODUCT_ID" --url="https://api.example.com"

SELECT option_name, option_value FROM wp_options
WHERE option_name = 'mls_product_id';

curl -X POST https://api.example.com/wp-json/mls/v1/license -H "Content-Type: application/json" -d "{\"action\":\"activate\",\"license_key\":\"XXXX-XXXX-XXXX-XXXX\",\"site_url\":\"https://test.example.com\",\"product_id\":\"xxxxxxxxxxxxxxxxxxx-X==\",\"plugin_version\":\"1.0.0\"}"

{
  "ok": true,
  "status": "active",
  "message": "activated",
  "site_count": 1,
  "max_sites": 3,
  "domain": "test.example.com"
}

curl -X POST https://api.example.com/wp-json/mls/v1/license \
  -H "Content-Type: application/json" \
  -d '{
    "action": "activate",
    "license_key": "XXXX-XXXX-XXXX-XXXX",
    "site_url": "https://test.example.com",
    "product_id": "xxxxxxxxxxxxxxxxxxx-X==",
    "plugin_version": "1.0.0"
  }'

// 変更前
value="<?php echo esc_attr((string) ($settings['license_api_url'] ?? '')); ?>"

// 変更後（?: でフォールバック）
value="<?php echo esc_attr((string) (($settings['license_api_url'] ?? '')
    ?: 'https://api.example.com/wp-json/mls/v1/license')); ?>"

function amu_ai_validate_rewrite_request(): void
{
    check_ajax_referer('amu_ai_rewriter', 'nonce');

    // ライセンスチェックを追加
    if ( ! function_exists('amu_ai_license_is_recently_valid') 
         || ! amu_ai_license_is_recently_valid() ) {
        wp_send_json_error( [
            'message' => 'ライセンスが有効ではありません。ライセンス設定を確認してください。'
        ], 403 );
    }

    // 以下は既存のコード
    $post_id = isset($_POST['postId']) ? (int) $_POST['postId'] : 0;
    if ($post_id <= 0 || ! current_user_can('edit_post', $post_id)) {
        wp_send_json_error(['message' => 'Permission denied.'], 403);
    }
}

import zipfile

with zipfile.ZipFile('original.zip') as zin, \
     zipfile.ZipFile('fixed.zip', 'w', zipfile.ZIP_DEFLATED) as zout:
    for item in zin.infolist():
        new_name = item.filename.replace('\\', '/')  # バックスラッシュを修正
        zout.writestr(new_name, zin.read(item.filename))

-- バックアップ後に対象を読み取り、購入記録と照合する。末尾4文字だけでは特定しない。
SELECT id, product_id, license_key_hash, license_key_last4, status
FROM wp_mls_licenses WHERE id = 0;

-- 0と識別子を、確認した対象の値へ置き換える。0のままでは対象なし。
UPDATE wp_mls_licenses SET status = 'revoked'
WHERE id = 0 AND product_id = 'CONFIRMED_PRODUCT_ID'
  AND license_key_hash = 'CONFIRMED_SHA256';

-- wp_は実際の接頭辞へ変更。購入記録・キーのハッシュ・ドメインを照合する。
SELECT id, license_key_hash, domain, status
FROM wp_mls_activations WHERE id = 0;

-- 0と識別子を、確認した1件の値へ置き換える。
UPDATE wp_mls_activations
SET status = 'inactive', deactivated_at = NOW()
WHERE id = 0 AND license_key_hash = 'CONFIRMED_SHA256'
  AND domain = 'confirmed.example.com';

<?php
/**
 * Plugin Name: Motoki License Server
 * Description: Gumroad連携WordPress有料プラグイン用ライセンス管理サーバー
 * Version: 1.0.0
 * Author: MOTOKI合同会社
 */

defined( 'ABSPATH' ) || exit;

define( 'MLS_VERSION', '1.0.0' );
define( 'MLS_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );

// ─────────────────────────────────────────────
// 有効化時: テーブル作成
// ─────────────────────────────────────────────
register_activation_hook( __FILE__, 'mls_activate' );
function mls_activate() {
    mls_create_tables();
}

function mls_create_tables() {
    global $wpdb;
    $charset = $wpdb->get_charset_collate();

    // licenses テーブル
    $sql_licenses = "CREATE TABLE IF NOT EXISTS {$wpdb->prefix}mls_licenses (
        id              BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
        license_key_hash VARCHAR(64)  NOT NULL,
        license_key_last4 CHAR(4)     NOT NULL,
        product_id      VARCHAR(100)  NOT NULL,
        status          ENUM('active','revoked','invalid') NOT NULL DEFAULT 'active',
        max_sites       TINYINT UNSIGNED NOT NULL DEFAULT 3,
        gumroad_email   VARCHAR(255)  NOT NULL DEFAULT '',
        gumroad_purchase_id VARCHAR(100) NOT NULL DEFAULT '',
        created_at      DATETIME      NOT NULL,
        updated_at      DATETIME      NOT NULL,
        last_verified_at DATETIME     NULL,
        PRIMARY KEY (id),
        UNIQUE KEY uq_hash_product (license_key_hash, product_id),
        KEY idx_hash (license_key_hash)
    ) $charset;";

    // activations テーブル
    $sql_activations = "CREATE TABLE IF NOT EXISTS {$wpdb->prefix}mls_activations (
        id              BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
        license_key_hash VARCHAR(64)  NOT NULL,
        site_hash       VARCHAR(64)   NOT NULL,
        domain          VARCHAR(255)  NOT NULL,
        normalized_site VARCHAR(255)  NOT NULL,
        status          ENUM('active','inactive') NOT NULL DEFAULT 'active',
        activated_at    DATETIME      NOT NULL,
        deactivated_at  DATETIME      NULL,
        last_seen_at    DATETIME      NOT NULL,
        PRIMARY KEY (id),
        UNIQUE KEY uq_license_site (license_key_hash, site_hash),
        KEY idx_license (license_key_hash)
    ) $charset;";

    // logs テーブル
    $sql_logs = "CREATE TABLE IF NOT EXISTS {$wpdb->prefix}mls_logs (
        id              BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
        timestamp       DATETIME      NOT NULL,
        action          VARCHAR(20)   NOT NULL,
        license_key_last4 CHAR(4)    NOT NULL DEFAULT '',
        domain          VARCHAR(255)  NOT NULL DEFAULT '',
        result          VARCHAR(20)   NOT NULL,
        message         TEXT          NOT NULL,
        PRIMARY KEY (id),
        KEY idx_timestamp (timestamp)
    ) $charset;";

    require_once ABSPATH . 'wp-admin/includes/upgrade.php';
    dbDelta( $sql_licenses );
    dbDelta( $sql_activations );
    dbDelta( $sql_logs );
}

// ─────────────────────────────────────────────
// REST API 登録
// ─────────────────────────────────────────────
add_action( 'rest_api_init', 'mls_register_routes' );
function mls_register_routes() {
    register_rest_route( 'mls/v1', '/license', [
        'methods'             => 'POST',
        'callback'            => 'mls_handle_request',
        'permission_callback' => '__return_true', // 認証はアプリ側で行う
    ] );
}

// ─────────────────────────────────────────────
// メインハンドラ
// ─────────────────────────────────────────────
function mls_handle_request( WP_REST_Request $request ) {
    $body = $request->get_json_params();
    if ( empty( $body ) ) {
        // form-urlencoded フォールバック
        $body = $request->get_params();
    }

    $action = sanitize_text_field( $body['action'] ?? '' );

    switch ( $action ) {
        case 'activate':
            return mls_action_activate( $body );
        case 'validate':
            return mls_action_validate( $body );
        case 'deactivate':
            return mls_action_deactivate( $body );
        default:
            return mls_json_error( 'invalid_action', '不正なアクションです', 400 );
    }
}

// ─────────────────────────────────────────────
// activate
// ─────────────────────────────────────────────
function mls_action_activate( array $body ) {
    // バリデーション
    $v = mls_validate_input( $body, [ 'license_key', 'site_url' ] );
    if ( is_wp_error( $v ) ) {
        return mls_json_error( 'validation_error', $v->get_error_message(), 400 );
    }

    $license_key = $body['license_key'];
    $product_id  = mls_get_product_id( $body );
    $site_url    = $body['site_url'];

    $normalized  = mls_normalize_site_url( $site_url );
    $key_hash    = mls_sha256( $license_key );
    $site_hash   = mls_sha256( $normalized );
    $key_last4   = substr( $license_key, -4 );

    // Gumroad verify
    $gumroad = mls_verify_gumroad( $license_key, $product_id );
    if ( ! $gumroad['valid'] ) {
        mls_write_log( 'activate', $key_last4, $normalized, 'fail', 'Gumroad invalid: ' . $gumroad['reason'] );
        return mls_json_error( 'license_invalid', 'ライセンスが無効です', 403 );
    }

    global $wpdb;
    $now = current_time( 'mysql' );

    // licenses upsert
    $license = mls_find_license( $key_hash, $product_id );
    if ( ! $license ) {
        $wpdb->insert( $wpdb->prefix . 'mls_licenses', [
            'license_key_hash'    => $key_hash,
            'license_key_last4'   => $key_last4,
            'product_id'          => $product_id,
            'status'              => 'active',
            'max_sites'           => 3,
            'gumroad_email'       => $gumroad['email'],
            'gumroad_purchase_id' => $gumroad['purchase_id'],
            'created_at'          => $now,
            'updated_at'          => $now,
            'last_verified_at'    => $now,
        ] );
        $license = mls_find_license( $key_hash, $product_id );
    } else {
        // revoked チェック
        if ( $license->status === 'revoked' ) {
            mls_write_log( 'activate', $key_last4, $normalized, 'fail', 'License revoked' );
            return mls_json_error( 'license_revoked', 'このライセンスは無効化されています', 403 );
        }
        // last_verified_at 更新
        $wpdb->update(
            $wpdb->prefix . 'mls_licenses',
            [ 'last_verified_at' => $now, 'updated_at' => $now, 'gumroad_email' => $gumroad['email'] ],
            [ 'id' => $license->id ]
        );
    }

    $max_sites = (int) $license->max_sites;

    // 同一サイトが既にアクティブ → 冪等成功
    $existing = mls_find_active_activation( $key_hash, $site_hash );
    if ( $existing ) {
        $wpdb->update(
            $wpdb->prefix . 'mls_activations',
            [ 'last_seen_at' => $now ],
            [ 'id' => $existing->id ]
        );
        $count = mls_count_active_activations( $key_hash );
        mls_write_log( 'activate', $key_last4, $normalized, 'ok', 'Already active (idempotent)' );
        return rest_ensure_response( [
            'ok'        => true,
            'status'    => 'active',
            'message'   => 'already_active',
            'site_count' => $count,
            'max_sites' => $max_sites,
            'domain'    => $normalized,
        ] );
    }

    // 使用数チェック
    $count = mls_count_active_activations( $key_hash );
    if ( $count >= $max_sites ) {
        mls_write_log( 'activate', $key_last4, $normalized, 'fail', "Limit exceeded: {$count}/{$max_sites}" );
        return rest_ensure_response( [
            'ok'        => false,
            'status'    => 'limit_exceeded',
            'message'   => '有効化できるサイト数の上限に達しています',
            'site_count' => $count,
            'max_sites' => $max_sites,
        ] );
    }

    // activation 作成（UPSERT: inactive行があれば再active化）
    $row = $wpdb->get_row( $wpdb->prepare(
        "SELECT * FROM {$wpdb->prefix}mls_activations WHERE license_key_hash=%s AND site_hash=%s",
        $key_hash, $site_hash
    ) );

    if ( $row ) {
        $wpdb->update(
            $wpdb->prefix . 'mls_activations',
            [ 'status' => 'active', 'activated_at' => $now, 'deactivated_at' => null, 'last_seen_at' => $now, 'domain' => $normalized ],
            [ 'id' => $row->id ]
        );
    } else {
        $wpdb->insert( $wpdb->prefix . 'mls_activations', [
            'license_key_hash' => $key_hash,
            'site_hash'        => $site_hash,
            'domain'           => $normalized,
            'normalized_site'  => $normalized,
            'status'           => 'active',
            'activated_at'     => $now,
            'deactivated_at'   => null,
            'last_seen_at'     => $now,
        ] );
    }

    $count = mls_count_active_activations( $key_hash );
    mls_write_log( 'activate', $key_last4, $normalized, 'ok', "Activated. {$count}/{$max_sites}" );

    return rest_ensure_response( [
        'ok'        => true,
        'status'    => 'active',
        'message'   => 'activated',
        'site_count' => $count,
        'max_sites' => $max_sites,
        'domain'    => $normalized,
    ] );
}

// ─────────────────────────────────────────────
// validate
// ─────────────────────────────────────────────
function mls_action_validate( array $body ) {
    $v = mls_validate_input( $body, [ 'license_key', 'site_url' ] );
    if ( is_wp_error( $v ) ) {
        return mls_json_error( 'validation_error', $v->get_error_message(), 400 );
    }

    $license_key = $body['license_key'];
    $product_id  = mls_get_product_id( $body );
    $site_url    = $body['site_url'];

    $normalized = mls_normalize_site_url( $site_url );
    $key_hash   = mls_sha256( $license_key );
    $site_hash  = mls_sha256( $normalized );
    $key_last4  = substr( $license_key, -4 );

    // Gumroad verify
    $gumroad = mls_verify_gumroad( $license_key, $product_id );
    if ( ! $gumroad['valid'] ) {
        mls_write_log( 'validate', $key_last4, $normalized, 'fail', 'Gumroad invalid: ' . $gumroad['reason'] );
        return rest_ensure_response( [
            'ok'     => true,
            'valid'  => false,
            'status' => 'license_invalid',
        ] );
    }

    // ライセンス行チェック
    $license = mls_find_license( $key_hash, $product_id );
    if ( ! $license || $license->status === 'revoked' ) {
        mls_write_log( 'validate', $key_last4, $normalized, 'fail', 'License not found or revoked' );
        return rest_ensure_response( [
            'ok'     => true,
            'valid'  => false,
            'status' => 'license_revoked',
        ] );
    }

    $max_sites = (int) $license->max_sites;
    $count     = mls_count_active_activations( $key_hash );

    // last_verified_at 更新
    global $wpdb;
    $now = current_time( 'mysql' );
    $wpdb->update(
        $wpdb->prefix . 'mls_licenses',
        [ 'last_verified_at' => $now, 'updated_at' => $now ],
        [ 'id' => $license->id ]
    );

    // activation チェック
    $activation = mls_find_active_activation( $key_hash, $site_hash );
    if ( $activation ) {
        $wpdb->update(
            $wpdb->prefix . 'mls_activations',
            [ 'last_seen_at' => $now ],
            [ 'id' => $activation->id ]
        );
        mls_write_log( 'validate', $key_last4, $normalized, 'ok', 'Valid' );
        return rest_ensure_response( [
            'ok'        => true,
            'valid'     => true,
            'status'    => 'active',
            'site_count' => $count,
            'max_sites' => $max_sites,
            'domain'    => $normalized,
        ] );
    }

    mls_write_log( 'validate', $key_last4, $normalized, 'fail', 'Not activated for this site' );
    return rest_ensure_response( [
        'ok'        => true,
        'valid'     => false,
        'status'    => 'not_activated_for_this_site',
        'site_count' => $count,
        'max_sites' => $max_sites,
    ] );
}

// ─────────────────────────────────────────────
// deactivate
// ─────────────────────────────────────────────
function mls_action_deactivate( array $body ) {
    $v = mls_validate_input( $body, [ 'license_key', 'site_url' ] );
    if ( is_wp_error( $v ) ) {
        return mls_json_error( 'validation_error', $v->get_error_message(), 400 );
    }

    $license_key = $body['license_key'];
    $product_id  = mls_get_product_id( $body );
    $site_url    = $body['site_url'];

    $normalized = mls_normalize_site_url( $site_url );
    $key_hash   = mls_sha256( $license_key );
    $site_hash  = mls_sha256( $normalized );
    $key_last4  = substr( $license_key, -4 );

    // Gumroad verify（解除時も確認）
    $gumroad = mls_verify_gumroad( $license_key, $product_id );
    if ( ! $gumroad['valid'] ) {
        mls_write_log( 'deactivate', $key_last4, $normalized, 'fail', 'Gumroad invalid' );
        return mls_json_error( 'license_invalid', 'ライセンスが無効です', 403 );
    }

    global $wpdb;
    $now = current_time( 'mysql' );

    $activation = mls_find_active_activation( $key_hash, $site_hash );
    if ( $activation ) {
        $wpdb->update(
            $wpdb->prefix . 'mls_activations',
            [ 'status' => 'inactive', 'deactivated_at' => $now ],
            [ 'id' => $activation->id ]
        );
    }

    $count = mls_count_active_activations( $key_hash );
    $license = mls_find_license( $key_hash, $product_id );
    $max_sites = $license ? (int) $license->max_sites : 3;

    mls_write_log( 'deactivate', $key_last4, $normalized, 'ok', "Deactivated. remaining: {$count}/{$max_sites}" );

    return rest_ensure_response( [
        'ok'        => true,
        'status'    => 'deactivated',
        'site_count' => $count,
        'max_sites' => $max_sites,
    ] );
}

// ─────────────────────────────────────────────
// Gumroad verify
// ─────────────────────────────────────────────
function mls_verify_gumroad( string $license_key, string $product_id ): array {
    // Gumroad verify APIに product_id（Base64形式）を送る。APIキー不要。
    $response = wp_remote_post( 'https://api.gumroad.com/v2/licenses/verify', [
        'timeout' => 10,
        'body'    => [
            'product_id'           => $product_id,
            'license_key'          => $license_key,
            'increment_uses_count' => 'false',
        ],
    ] );

    if ( is_wp_error( $response ) ) {
        return [ 'valid' => false, 'reason' => 'network_error', 'email' => '', 'purchase_id' => '' ];
    }

    $code = wp_remote_retrieve_response_code( $response );
    $data = json_decode( wp_remote_retrieve_body( $response ), true );

    if ( $code !== 200 || empty( $data['success'] ) ) {
        $reason = $data['message'] ?? 'invalid';
        return [ 'valid' => false, 'reason' => $reason, 'email' => '', 'purchase_id' => '' ];
    }

    $purchase = $data['purchase'] ?? [];

    // 返金・紛争チェック
    if ( ! empty( $purchase['refunded'] ) || ! empty( $purchase['disputed'] ) || ! empty( $purchase['chargebacked'] ) ) {
        return [ 'valid' => false, 'reason' => 'refunded_or_disputed', 'email' => '', 'purchase_id' => '' ];
    }

    return [
        'valid'       => true,
        'reason'      => '',
        'email'       => sanitize_email( $purchase['email'] ?? '' ),
        'purchase_id' => sanitize_text_field( $purchase['id'] ?? $purchase['sale_id'] ?? '' ),
    ];
}

// ─────────────────────────────────────────────
// ユーティリティ関数
// ─────────────────────────────────────────────

/** site_url を正規化する */
function mls_normalize_site_url( string $url ): string {
    $url = strtolower( trim( $url ) );
    // schemeがなければ付加してparse_urlを通す
    if ( ! preg_match( '#^https?://#', $url ) ) {
        $url = 'https://' . $url;
    }
    $parsed = parse_url( $url );
    $host   = $parsed['host'] ?? $url;
    // www. 除去
    $host   = preg_replace( '/^www\./', '', $host );
    return $host;
}

/** SHA-256ハッシュ */
function mls_sha256( string $value ): string {
    return hash( 'sha256', $value );
}

/** ライセンス行取得 */
function mls_find_license( string $key_hash, string $product_id ) {
    global $wpdb;
    return $wpdb->get_row( $wpdb->prepare(
        "SELECT * FROM {$wpdb->prefix}mls_licenses WHERE license_key_hash=%s AND product_id=%s LIMIT 1",
        $key_hash, $product_id
    ) );
}

/** アクティブなactivation行取得 */
function mls_find_active_activation( string $key_hash, string $site_hash ) {
    global $wpdb;
    return $wpdb->get_row( $wpdb->prepare(
        "SELECT * FROM {$wpdb->prefix}mls_activations WHERE license_key_hash=%s AND site_hash=%s AND status='active' LIMIT 1",
        $key_hash, $site_hash
    ) );
}

/** アクティブなactivation数 */
function mls_count_active_activations( string $key_hash ): int {
    global $wpdb;
    return (int) $wpdb->get_var( $wpdb->prepare(
        "SELECT COUNT(*) FROM {$wpdb->prefix}mls_activations WHERE license_key_hash=%s AND status='active'",
        $key_hash
    ) );
}

/** ログ書き込み */
function mls_write_log( string $action, string $key_last4, string $domain, string $result, string $message ) {
    global $wpdb;
    $wpdb->insert( $wpdb->prefix . 'mls_logs', [
        'timestamp'         => current_time( 'mysql' ),
        'action'            => $action,
        'license_key_last4' => $key_last4,
        'domain'            => $domain,
        'result'            => $result,
        'message'           => $message,
    ] );

    // ログが10000行を超えたら古い行を削除
    $count = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->prefix}mls_logs" );
    if ( $count > 10000 ) {
        $wpdb->query( "DELETE FROM {$wpdb->prefix}mls_logs ORDER BY id ASC LIMIT 1000" );
    }
}

/** 入力バリデーション */
function mls_validate_input( array $body, array $required_keys ) {
    // product_slug → product_id へ正規化（amu-ai-publisher クライアント対応）
    if ( empty( $body['product_id'] ) && ! empty( $body['product_slug'] ) ) {
        $body['product_id'] = $body['product_slug'];
    }

    foreach ( $required_keys as $key ) {
        if ( empty( $body[ $key ] ) ) {
            return new WP_Error( 'missing_field', "必須パラメータが不足しています: {$key}" );
        }
    }

    // product_idの照合はGumroad verifyに任せるためここではチェックしない
    return true;
}

/** Gumroad verify用のproduct_idを取得（DB設定値を優先） */
function mls_get_product_id( array $body ): string {
    // DBに設定されたProduct IDを優先（Gumroad verify用）
    $configured = get_option( 'mls_product_id', '' );
    if ( $configured ) {
        return trim( $configured );
    }
    // フォールバック: リクエストのproduct_id or product_slug
    if ( ! empty( $body['product_id'] ) ) {
        return sanitize_text_field( $body['product_id'] );
    }
    return sanitize_text_field( $body['product_slug'] ?? '' );
}

/** エラーレスポンス */
function mls_json_error( string $code, string $message, int $status = 400 ) {
    return new WP_REST_Response( [
        'ok'      => false,
        'status'  => $code,
        'message' => $message,
    ], $status );
}

// ─────────────────────────────────────────────
// 管理画面: 設定ページ
// ─────────────────────────────────────────────
add_action( 'admin_menu', 'mls_admin_menu' );
function mls_admin_menu() {
    add_options_page(
        'License Server 設定',
        'License Server',
        'manage_options',
        'mls-settings',
        'mls_settings_page'
    );
}

add_action( 'admin_init', 'mls_register_settings' );
function mls_register_settings() {
    register_setting( 'mls_options', 'mls_product_id', [
        'sanitize_callback' => function( $val ) { return trim( (string) $val ); },
    ] );
}

function mls_settings_page() {
    global $wpdb;
    ?>
    <div class="wrap">
        <h1>License Server 設定</h1>
        <form method="post" action="options.php">
            <?php settings_fields( 'mls_options' ); ?>
            <table class="form-table">
                <tr>
                    <th>Gumroad Product ID</th>
                    <td>
                        <input type="text" name="mls_product_id"
                            value="<?php echo esc_attr( get_option( 'mls_product_id' ) ); ?>"
                            class="regular-text" />
                        <p class="description">Gumroad管理画面の「Use your product ID to verify licenses」のID（例: xxxxxxxxxxxxxxxxxxx-X==）</p>
                    </td>
                </tr>
            </table>
            <?php submit_button(); ?>
        </form>

        <h2>エンドポイント</h2>
        <code><?php echo esc_url( rest_url( 'mls/v1/license' ) ); ?></code>

        <h2>ライセンス一覧</h2>
        <?php
        $licenses = $wpdb->get_results( "SELECT * FROM {$wpdb->prefix}mls_licenses ORDER BY created_at DESC LIMIT 50" );
        if ( $licenses ) :
        ?>
        <table class="wp-list-table widefat striped">
            <thead><tr>
                <th>Key末尾4桁</th><th>Product ID</th><th>Status</th>
                <th>Email</th><th>使用数/上限</th><th>最終確認</th>
            </tr></thead>
            <tbody>
            <?php foreach ( $licenses as $lic ) :
                $count = mls_count_active_activations( $lic->license_key_hash );
            ?>
                <tr>
                    <td>****<?php echo esc_html( $lic->license_key_last4 ); ?></td>
                    <td><?php echo esc_html( $lic->product_id ); ?></td>
                    <td><?php echo esc_html( $lic->status ); ?></td>
                    <td><?php echo esc_html( $lic->gumroad_email ); ?></td>
                    <td><?php echo esc_html( $count . '/' . $lic->max_sites ); ?></td>
                    <td><?php echo esc_html( $lic->last_verified_at ); ?></td>
                </tr>
            <?php endforeach; ?>
            </tbody>
        </table>
        <?php else : ?>
        <p>まだライセンスデータがありません。</p>
        <?php endif; ?>

        <h2>最近のログ</h2>
        <?php
        $logs = $wpdb->get_results( "SELECT * FROM {$wpdb->prefix}mls_logs ORDER BY id DESC LIMIT 50" );
        if ( $logs ) :
        ?>
        <table class="wp-list-table widefat striped">
            <thead><tr>
                <th>日時</th><th>Action</th><th>Key末尾4桁</th><th>Domain</th><th>Result</th><th>Message</th>
            </tr></thead>
            <tbody>
            <?php foreach ( $logs as $log ) : ?>
                <tr>
                    <td><?php echo esc_html( $log->timestamp ); ?></td>
                    <td><?php echo esc_html( $log->action ); ?></td>
                    <td>****<?php echo esc_html( $log->license_key_last4 ); ?></td>
                    <td><?php echo esc_html( $log->domain ); ?></td>
                    <td style="color:<?php echo $log->result === 'ok' ? 'green' : 'red'; ?>">
                        <?php echo esc_html( $log->result ); ?></td>
                    <td><?php echo esc_html( $log->message ); ?></td>
                </tr>
            <?php endforeach; ?>
            </tbody>
        </table>
        <?php else : ?>
        <p>ログはありません。</p>
        <?php endif; ?>
    </div>
    <?php
}

<?php
/**
 * ライセンス認証クライアント（公開サンプル）
 *
 * 販売プラグイン側に組み込む認証処理です。
 * ライセンスサーバーのエンドポイントに activate / validate / deactivate を送信します。
 *
 * File: inc/license-client.php
 */

declare(strict_types=1);

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

// ─────────────────────────────────────────────
// ライセンス状態の管理
// ─────────────────────────────────────────────

function amu_ai_license_default_state(): array
{
    return [
        'status'     => 'inactive',
        'last_check' => '',
        'domain'     => '',
        'site_count' => 0,
        'max_sites'  => 0,
        'message'    => '',
    ];
}

function amu_ai_license_get_state(): array
{
    $state = get_option('amu_ai_license_state', []);
    return wp_parse_args(is_array($state) ? $state : [], amu_ai_license_default_state());
}

function amu_ai_license_update_state(array $state): void
{
    $current = amu_ai_license_get_state();
    update_option('amu_ai_license_state', array_merge($current, $state), false);
}

function amu_ai_license_reset_state(): void
{
    update_option('amu_ai_license_state', amu_ai_license_default_state(), false);
}

// ─────────────────────────────────────────────
// 設定値の取得
// ─────────────────────────────────────────────

/** ライセンスサーバーのエンドポイントURL */
function amu_ai_license_get_api_url(): string
{
    $settings = get_option('amu_ai_settings', []);
    return untrailingslashit((string) ($settings['license_api_url'] ?? ''));
}

/** このサイトのドメイン（正規化済み） */
function amu_ai_license_get_current_domain(): string
{
    $host = wp_parse_url(home_url('/'), PHP_URL_HOST);
    $host = is_string($host) ? strtolower($host) : '';
    return preg_replace('/^www\./', '', $host) ?? $host;
}

// ─────────────────────────────────────────────
// ライセンスサーバーへのリクエスト
// ─────────────────────────────────────────────

/**
 * ライセンスサーバーに action を送信する共通関数
 *
 * @param string $action  activate / validate / deactivate
 * @return array|WP_Error レスポンスJSON配列 or WP_Error
 */
function amu_ai_license_request(string $action)
{
    $settings    = get_option('amu_ai_settings', []);
    $license_key = (string) ($settings['license_key'] ?? '');
    $api_url     = amu_ai_license_get_api_url();

    if ($license_key === '' || $api_url === '') {
        return new WP_Error('amu_ai_license_missing_config', 'ライセンスキーまたはAPIのURLが未設定です。');
    }

    $response = wp_remote_post($api_url, [
        'timeout' => 10,
        'headers' => ['Content-Type' => 'application/json; charset=utf-8'],
        'body'    => wp_json_encode([
            'action'         => $action,
            'product_slug'   => 'your-plugin-slug', // プラグインのスラッグに変更
            'license_key'    => $license_key,
            'site_url'       => home_url('/'),
            'plugin_version' => '1.0.0', // プラグインのバージョンに変更
        ]),
    ]);

    if (is_wp_error($response)) {
        return $response;
    }

    $code = (int) wp_remote_retrieve_response_code($response);
    $body = (string) wp_remote_retrieve_body($response);
    $data = json_decode($body, true);

    if ($code < 200 || $code >= 300 || ! is_array($data)) {
        return new WP_Error('amu_ai_license_invalid_response', 'ライセンスサーバーからの応答が不正です。');
    }

    return $data;
}

// ─────────────────────────────────────────────
// レスポンスをDBに保存
// ─────────────────────────────────────────────

function amu_ai_license_store_response(array $data, string $fallback_status = 'inactive'): void
{
    amu_ai_license_update_state([
        'status'     => (string) ($data['status'] ?? $fallback_status),
        'last_check' => current_time('mysql'),
        'domain'     => (string) ($data['domain'] ?? amu_ai_license_get_current_domain()),
        'site_count' => (int) ($data['site_count'] ?? 0),
        'max_sites'  => (int) ($data['max_sites'] ?? 0),
        'message'    => (string) ($data['message'] ?? ''),
    ]);
}

// ─────────────────────────────────────────────
// 有効性チェック
// ─────────────────────────────────────────────

/**
 * ライセンスが有効かどうかを判定する
 *
 * - status が 'active' であること
 * - 最終確認から7日以内であること（通信失敗時の猶予期間）
 *
 * 有料機能のガードに使う: if ( ! amu_ai_license_is_recently_valid() ) { return; }
 */
function amu_ai_license_is_recently_valid(): bool
{
    $state = amu_ai_license_get_state();

    if (($state['status'] ?? '') !== 'active') {
        return false;
    }

    $last_check = strtotime((string) ($state['last_check'] ?? ''));
    if (! $last_check) {
        return false;
    }

    // 7日以内なら有効（ライセンスサーバーが一時的にダウンしても猶予を持つ）
    return $last_check >= (time() - DAY_IN_SECONDS * 7);
}

// ─────────────────────────────────────────────
// 管理画面のアクションハンドラ
// ─────────────────────────────────────────────

/** 有効化ボタン押下 */
function amu_ai_license_handle_activate(): void
{
    if (! current_user_can('manage_options')) {
        wp_die('Permission denied.');
    }
    check_admin_referer('amu_ai_license_activate');

    $response = amu_ai_license_request('activate');

    if (is_wp_error($response)) {
        amu_ai_license_set_notice('error', $response->get_error_message());
    } else {
        amu_ai_license_store_response($response, 'inactive');
        amu_ai_license_set_notice('success', (string) ($response['message'] ?? 'ライセンスを有効化しました。'));
    }

    wp_safe_redirect(wp_get_referer() ?: admin_url('options-general.php?page=your-plugin-license'));
    exit;
}
add_action('admin_post_amu_ai_license_activate', 'amu_ai_license_handle_activate');

/** 検証ボタン押下 */
function amu_ai_license_handle_validate(): void
{
    if (! current_user_can('manage_options')) {
        wp_die('Permission denied.');
    }
    check_admin_referer('amu_ai_license_validate');

    $response = amu_ai_license_request('validate');

    if (is_wp_error($response)) {
        amu_ai_license_set_notice('error', $response->get_error_message());
    } else {
        amu_ai_license_store_response($response, ! empty($response['valid']) ? 'active' : 'inactive');
        amu_ai_license_set_notice('success', (string) ($response['message'] ?? 'ライセンス状態を確認しました。'));
    }

    wp_safe_redirect(wp_get_referer() ?: admin_url('options-general.php?page=your-plugin-license'));
    exit;
}
add_action('admin_post_amu_ai_license_validate', 'amu_ai_license_handle_validate');

/** 解除ボタン押下 */
function amu_ai_license_handle_deactivate(): void
{
    if (! current_user_can('manage_options')) {
        wp_die('Permission denied.');
    }
    check_admin_referer('amu_ai_license_deactivate');

    $response = amu_ai_license_request('deactivate');

    if (is_wp_error($response)) {
        amu_ai_license_set_notice('error', $response->get_error_message());
    } else {
        amu_ai_license_store_response($response, 'inactive');
        amu_ai_license_set_notice('success', (string) ($response['message'] ?? 'このサイトのライセンスを解除しました。'));
    }

    wp_safe_redirect(wp_get_referer() ?: admin_url('options-general.php?page=your-plugin-license'));
    exit;
}
add_action('admin_post_amu_ai_license_deactivate', 'amu_ai_license_handle_deactivate');

// ─────────────────────────────────────────────
// 管理画面の通知
// ─────────────────────────────────────────────

function amu_ai_license_set_notice(string $type, string $message): void
{
    if (! is_user_logged_in()) {
        return;
    }
    set_transient('amu_ai_license_notice_' . get_current_user_id(), [
        'type'    => $type,
        'message' => $message,
    ], 60);
}

function amu_ai_license_render_notice(): void
{
    if (! is_user_logged_in()) {
        return;
    }
    $key    = 'amu_ai_license_notice_' . get_current_user_id();
    $notice = get_transient($key);
    if (! is_array($notice) || empty($notice['message'])) {
        return;
    }
    delete_transient($key);
    $class = ($notice['type'] ?? 'success') === 'error' ? 'notice-error' : 'notice-success';
    echo '<div class="notice ' . esc_attr($class) . '"><p>' . esc_html((string) $notice['message']) . '</p></div>';
}
add_action('admin_notices', 'amu_ai_license_render_notice');

// ─────────────────────────────────────────────
// 有料機能のガード例
// ─────────────────────────────────────────────

/**
 * AJAXリクエストの共通バリデーション関数にライセンスチェックを追加する例
 *
 * function your_plugin_validate_request(): void
 * {
 *     check_ajax_referer('your_plugin_nonce', 'nonce');
 *
 *     // ライセンスチェック
 *     if ( ! amu_ai_license_is_recently_valid() ) {
 *         wp_send_json_error([
 *             'message' => 'ライセンスが有効ではありません。ライセンス設定を確認してください。'
 *         ], 403);
 *     }
 *
 *     // 以降は通常の権限チェック等
 * }
 */