<?php

namespace App\Module\ThirdParty\Events;

use App\Module\ThirdParty\Models\ThirdPartyService;
use App\Module\ThirdParty\Enums\SERVICE_STATUS;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Queue\SerializesModels;

/**
 * 服务状态变更事件
 * 
 * 当第三方服务状态发生变更时触发此事件
 */
class ServiceStatusChangedEvent
{
    use Dispatchable, SerializesModels;

    /**
     * 第三方服务实例
     *
     * @var ThirdPartyService
     */
    public ThirdPartyService $service;

    /**
     * 原状态
     *
     * @var SERVICE_STATUS
     */
    public SERVICE_STATUS $oldStatus;

    /**
     * 新状态
     *
     * @var SERVICE_STATUS
     */
    public SERVICE_STATUS $newStatus;

    /**
     * 状态变更原因
     *
     * @var string|null
     */
    public ?string $reason;

    /**
     * 变更时间
     *
     * @var \Carbon\Carbon
     */
    public \Carbon\Carbon $changedAt;

    /**
     * 额外数据
     *
     * @var array
     */
    public array $metadata;

    /**
     * 创建事件实例
     *
     * @param ThirdPartyService $service
     * @param SERVICE_STATUS $oldStatus
     * @param SERVICE_STATUS $newStatus
     * @param string|null $reason
     * @param array $metadata
     */
    public function __construct(
        ThirdPartyService $service,
        SERVICE_STATUS $oldStatus,
        SERVICE_STATUS $newStatus,
        ?string $reason = null,
        array $metadata = []
    ) {
        $this->service = $service;
        $this->oldStatus = $oldStatus;
        $this->newStatus = $newStatus;
        $this->reason = $reason;
        $this->changedAt = now();
        $this->metadata = $metadata;
    }

    /**
     * 获取事件数据数组
     *
     * @return array
     */
    public function toArray(): array
    {
        return [
            'service_id' => $this->service->id,
            'service_code' => $this->service->code,
            'service_name' => $this->service->name,
            'old_status' => $this->oldStatus->value,
            'old_status_label' => $this->oldStatus->getLabel(),
            'new_status' => $this->newStatus->value,
            'new_status_label' => $this->newStatus->getLabel(),
            'reason' => $this->reason,
            'changed_at' => $this->changedAt->toISOString(),
            'metadata' => $this->metadata,
        ];
    }

    /**
     * 判断是否为严重状态变更
     *
     * @return bool
     */
    public function isCriticalChange(): bool
    {
        // 从正常状态变为错误状态
        if ($this->oldStatus === SERVICE_STATUS::ACTIVE && 
            in_array($this->newStatus, [SERVICE_STATUS::ERROR, SERVICE_STATUS::DISABLED])) {
            return true;
        }

        // 变为过期状态
        if ($this->newStatus === SERVICE_STATUS::EXPIRED) {
            return true;
        }

        return false;
    }

    /**
     * 判断是否为恢复状态变更
     *
     * @return bool
     */
    public function isRecoveryChange(): bool
    {
        // 从错误状态恢复到正常状态
        if (in_array($this->oldStatus, [SERVICE_STATUS::ERROR, SERVICE_STATUS::DISABLED, SERVICE_STATUS::MAINTENANCE]) &&
            $this->newStatus === SERVICE_STATUS::ACTIVE) {
            return true;
        }

        return false;
    }

    /**
     * 获取告警级别
     *
     * @return string
     */
    public function getAlertLevel(): string
    {
        if ($this->isCriticalChange()) {
            return 'CRITICAL';
        }

        if ($this->isRecoveryChange()) {
            return 'INFO';
        }

        if ($this->newStatus === SERVICE_STATUS::MAINTENANCE) {
            return 'WARNING';
        }

        return 'INFO';
    }

    /**
     * 获取通知消息
     *
     * @return string
     */
    public function getNotificationMessage(): string
    {
        $serviceName = $this->service->name;
        $oldLabel = $this->oldStatus->getLabel();
        $newLabel = $this->newStatus->getLabel();

        $message = "第三方服务 [{$serviceName}] 状态从 [{$oldLabel}] 变更为 [{$newLabel}]";

        if ($this->reason) {
            $message .= "，原因：{$this->reason}";
        }

        return $message;
    }

    /**
     * 判断是否需要发送通知
     *
     * @return bool
     */
    public function shouldNotify(): bool
    {
        // 严重变更或恢复变更需要通知
        return $this->isCriticalChange() || $this->isRecoveryChange();
    }
}