<?php

declare(strict_types=1);

namespace app\common\service;

use app\admin\model\split\Ticket;

/**
 * 工单同步失败分阶段重试状态机
 *
 * 达连续失败阈值后按配置时间点（相对锚点的绝对分钟偏移）自动重试；
 * 任一次成功则清零恢复常态，全部失败则永久终止自动同步。
 */
class SplitTicketSyncFailRetryService
{
    /**
     * 是否已永久终止自动同步（重试时间点已全部用尽）
     *
     * @param Ticket|array<string, mixed> $ticket
     */
    public function isPermanentlyStopped($ticket): bool
    {
        return (int) ($this->readField($ticket, 'sync_auto_sync_stopped') ?? 0) === 1;
    }

    /**
     * 是否处于失败重试等待/重试周期内（未永久终止）
     *
     * @param Ticket|array<string, mixed> $ticket
     */
    public function isInRetryMode($ticket): bool
    {
        if ($this->isPermanentlyStopped($ticket)) {
            return false;
        }

        return (int) ($this->readField($ticket, 'sync_fail_pause_at') ?? 0) > 0;
    }

    /**
     * 首次达失败阈值时进入重试态（工单保持 normal，不关单）
     *
     * @return array<string, mixed> 需合并进 save 的字段；无变更时返回空数组
     */
    public function enterRetryIfNeeded(Ticket $ticket, int $failCount, int $threshold): array
    {
        if ($failCount < $threshold || !SplitSyncConfigService::hasFailRetrySchedule()) {
            return [];
        }
        if ($this->isInRetryMode($ticket)) {
            return [];
        }

        return [
            'sync_fail_pause_at'      => time(),
            'sync_fail_retry_index'   => 0,
            'sync_auto_sync_stopped'  => 0,
        ];
    }

    /**
     * 计划内重试失败后递进索引；用尽全部时间点后标记永久终止
     *
     * @return array<string, mixed>
     */
    public function onRetryFailure(Ticket $ticket): array
    {
        $schedule = SplitSyncConfigService::getFailRetryMinutes();
        $index = (int) ($ticket['sync_fail_retry_index'] ?? 0) + 1;
        $update = ['sync_fail_retry_index' => $index];

        if ($index >= count($schedule)) {
            $update['sync_auto_sync_stopped'] = 1;
        }

        return $update;
    }

    /**
     * 同步成功时清零失败计数与重试相关字段
     *
     * @return array<string, mixed>
     */
    public function clearOnSuccessFields(): array
    {
        return [
            'sync_fail_count'         => 0,
            'sync_fail_pause_at'      => null,
            'sync_fail_retry_index'   => 0,
            'sync_auto_sync_stopped'  => 0,
        ];
    }

    /**
     * Cron 自动重试是否已到点；未到点返回 skip 原因，到点返回 null（允许执行）
     *
     * @param Ticket|array<string, mixed> $ticket
     */
    public function shouldAllowAutoRetry($ticket, ?int $now = null): ?string
    {
        if (!$this->isInRetryMode($ticket)) {
            return null;
        }
        if ($this->isPermanentlyStopped($ticket)) {
            return '自动同步已终止（重试已用尽）';
        }

        $nextAt = $this->getNextRetryAt($ticket);
        if ($nextAt === null) {
            return '自动同步已终止（重试已用尽）';
        }

        $now = $now ?? time();
        if ($now < $nextAt) {
            $attempt = (int) ($this->readField($ticket, 'sync_fail_retry_index') ?? 0) + 1;

            return sprintf(
                '失败重试等待中，将于 %s 进行第 %d 次重试',
                date('Y-m-d H:i:s', $nextAt),
                $attempt
            );
        }

        return null;
    }

    /**
     * 下一次计划重试的 Unix 时间戳；无待重试时返回 null
     *
     * @param Ticket|array<string, mixed> $ticket
     */
    public function getNextRetryAt($ticket): ?int
    {
        if (!$this->isInRetryMode($ticket) || $this->isPermanentlyStopped($ticket)) {
            return null;
        }

        $schedule = SplitSyncConfigService::getFailRetryMinutes();
        if ($schedule === []) {
            return null;
        }

        $index = (int) ($this->readField($ticket, 'sync_fail_retry_index') ?? 0);
        if ($index >= count($schedule)) {
            return null;
        }

        $pauseAt = (int) ($this->readField($ticket, 'sync_fail_pause_at') ?? 0);
        if ($pauseAt <= 0) {
            return null;
        }

        return $pauseAt + $schedule[$index] * 60;
    }

    /**
     * @param Ticket|array<string, mixed> $ticket
     */
    private function readField($ticket, string $field)
    {
        if ($ticket instanceof Ticket) {
            return $ticket->getData($field) ?? ($ticket[$field] ?? null);
        }

        return $ticket[$field] ?? null;
    }
}