wpmind/includes/Failover/ProviderHealthTracker.php

<?php
/**
 * Provider Health Tracker - Provider 健康状态追踪
 *
 * 记录每个 Provider 的请求历史和健康分数
 *
 * @package WPMind
 * @since 1.5.0
 */

declare(strict_types=1);

namespace WPMind\Failover;

class ProviderHealthTracker
{
    private const TRANSIENT_KEY = 'wpmind_provider_health';
    private const HISTORY_SIZE  = 20;   // 保留最近 20 次请求记录
    private const CACHE_TTL     = 3600; // 缓存 1 小时

    /**
     * 记录请求结果
     *
     * @param string $providerId Provider ID
     * @param bool   $success    是否成功
     * @param int    $latencyMs  延迟（毫秒）
     */
    public static function record(string $providerId, bool $success, int $latencyMs = 0): void
    {
        $health = self::get_all_health();

        if (!isset($health[$providerId])) {
            $health[$providerId] = [
                'history'     => [],
                'total'       => 0,
                'failures'    => 0,
                'avg_latency' => 0,
            ];
        }

        $provider = &$health[$providerId];

        // 添加到历史记录
        $provider['history'][] = [
            'success' => $success,
            'latency' => $latencyMs,
            'time'    => time(),
        ];

        // 保持历史记录大小
        if (count($provider['history']) > self::HISTORY_SIZE) {
            array_shift($provider['history']);
        }

        // 更新统计
        $provider['total']++;
        if (!$success) {
            $provider['failures']++;
        }

        // 计算平均延迟（只计算成功的请求）
        $successfulLatencies = [];
        foreach ($provider['history'] as $record) {
            if ($record['success']) {
                $successfulLatencies[] = $record['latency'];
            }
        }

        if (!empty($successfulLatencies)) {
            $provider['avg_latency'] = (int) round(
                array_sum($successfulLatencies) / count($successfulLatencies)
            );
        }

        $provider['last_updated'] = time();

        set_transient(self::TRANSIENT_KEY, $health, self::CACHE_TTL);
    }

    /**
     * 获取 Provider 健康分数 (0-100)
     *
     * 分数计算：
     * - 基于最近 N 次请求的成功率
     * - 无数据时返回 100（假设健康）
     *
     * @param string $providerId Provider ID
     * @return int 健康分数
     */
    public static function get_health_score(string $providerId): int
    {
        $health = self::get_all_health();

        if (!isset($health[$providerId]) || empty($health[$providerId]['history'])) {
            return 100;
        }

        $history = $health[$providerId]['history'];
        $recentSuccesses = array_filter($history, fn($h) => $h['success']);
        $successRate = count($recentSuccesses) / count($history);

        return (int) round($successRate * 100);
    }

    /**
     * 获取 Provider 平均延迟
     *
     * @param string $providerId Provider ID
     * @return int 平均延迟（毫秒）
     */
    public static function get_average_latency(string $providerId): int
    {
        $health = self::get_all_health();
        return $health[$providerId]['avg_latency'] ?? 0;
    }

    /**
     * 获取 Provider 详细状态
     *
     * @param string $providerId Provider ID
     * @return array 状态详情
     */
    public static function get_provider_status(string $providerId): array
    {
        $health = self::get_all_health();

        if (!isset($health[$providerId])) {
            return [
                'health_score' => 100,
                'avg_latency'  => 0,
                'total'        => 0,
                'failures'     => 0,
                'success_rate' => 100,
            ];
        }

        $provider = $health[$providerId];
        $total = count($provider['history']);
        $successes = count(array_filter($provider['history'], fn($h) => $h['success']));

        return [
            'health_score' => self::get_health_score($providerId),
            'avg_latency'  => $provider['avg_latency'] ?? 0,
            'total'        => $provider['total'] ?? 0,
            'failures'     => $provider['failures'] ?? 0,
            'success_rate' => $total > 0 ? round(($successes / $total) * 100) : 100,
            'last_updated' => $provider['last_updated'] ?? null,
        ];
    }

    /**
     * 获取所有 Provider 的健康状态
     *
     * @return array 所有 Provider 的健康数据
     */
    public static function get_all_health(): array
    {
        $data = get_transient(self::TRANSIENT_KEY);
        return is_array($data) ? $data : [];
    }

    /**
     * 清除所有健康数据
     */
    public static function clear_all(): void
    {
        delete_transient(self::TRANSIENT_KEY);
    }

    /**
     * 清除指定 Provider 的健康数据
     *
     * @param string $providerId Provider ID
     */
    public static function clear_provider(string $providerId): void
    {
        $health = self::get_all_health();
        unset($health[$providerId]);
        set_transient(self::TRANSIENT_KEY, $health, self::CACHE_TTL);
    }
}