math_cms/app/Jobs/GenerateExamPdfJob.php

<?php

namespace App\Jobs;

use App\Models\Paper;
use App\Services\ExamPdfExportService;
use App\Services\QuestionBankService;
use App\Services\PaperPayloadService;
use App\Services\TaskManager;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\Log;

class GenerateExamPdfJob implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    public string $taskId;
    public string $paperId;

    /**
     * 【优化】增加任务超时时间，给Chrome充足渲染时间
     */
    public $timeout = 180;  // 从90秒增加到180秒（3分钟）

    /**
     * 【保持】重试次数，配合并发控制
     */
    public $tries = 3;

    public function __construct(string $taskId, string $paperId)
    {
        $this->taskId = $taskId;
        $this->paperId = $paperId;
        $this->onQueue('pdf_generation');
    }

    public function handle(
        ExamPdfExportService $pdfExportService,
        QuestionBankService $questionBankService,
        PaperPayloadService $paperPayloadService,
        TaskManager $taskManager
    ): void {
        $jobId = $this->uuid ?? 'unknown';
        $startTime = microtime(true);

        try {
            Log::info('开始处理PDF生成队列任务', [
                'job_id' => $jobId,
                'task_id' => $this->taskId,
                'paper_id' => $this->paperId,
                'attempt' => $this->attempts(),
            ]);

            // 【并发控制】检查当前并发数量
            if (!$this->acquireLock()) {
                $waitTime = rand(5, 15); // 等待5-15秒后重试
                Log::warning('GenerateExamPdfJob: 并发限制，等待后重试', [
                    'job_id' => $jobId,
                    'wait_time' => $waitTime,
                    'current_concurrent' => $this->getConcurrentCount()
                ]);

                // 释放队列槽位，等待后重试
                $this->release($waitTime);
                return;
            }

            Log::info('GenerateExamPdfJob: 获得执行权限', [
                'job_id' => $jobId,
                'concurrent_count' => $this->getConcurrentCount()
            ]);

            // 【新增】快速检查：如果任务已完成，直接跳过
            $task = $taskManager->getTaskStatus($this->taskId);
            if ($task && $task['status'] === 'completed') {
                Log::info('【跳过执行】任务已完成，无需重复生成PDF', [
                    'task_id' => $this->taskId,
                    'paper_id' => $this->paperId,
                    'status' => $task['status']
                ]);
                return;
            }

            // 【修复】首先检查试卷是否存在
            $paperModel = Paper::with('questions')->find($this->paperId);
            if (!$paperModel) {
                Log::error('PDF生成队列任务失败：试卷不存在', [
                    'task_id' => $this->taskId,
                    'paper_id' => $this->paperId,
                    'attempt' => $this->attempts(),
                ]);

                // 如果试卷不存在，判断是否需要重试
                if ($this->attempts() < $this->tries) {
                    Log::info('试卷不存在，将在2秒后重试', [
                        'task_id' => $this->taskId,
                        'paper_id' => $this->paperId,
                        'attempt' => $this->attempts(),
                        'next_attempt' => $this->attempts() + 1,
                    ]);
                    // 延迟2秒后重试（缩短间隔，减少对回调的影响）
                    $this->release(2);
                    return;
                } else {
                    Log::error('试卷不存在且已达到最大重试次数，标记任务失败', [
                        'task_id' => $this->taskId,
                        'paper_id' => $this->paperId,
                        'attempts' => $this->attempts(),
                    ]);
                    $taskManager->markTaskFailed($this->taskId, "试卷不存在: {$this->paperId}");
                    return;
                }
            }

            // 检查试卷是否有题目
            if ($paperModel->questions->isEmpty()) {
                Log::error('PDF生成队列任务失败：试卷没有题目数据', [
                    'task_id' => $this->taskId,
                    'paper_id' => $this->paperId,
                    'question_count' => 0,
                ]);

                if ($this->attempts() < $this->tries) {
                    Log::info('试卷没有题目，将在1秒后重试', [
                        'task_id' => $this->taskId,
                        'paper_id' => $this->paperId,
                        'attempt' => $this->attempts(),
                    ]);
                    // 延迟1秒后重试（更短间隔）
                    $this->release(1);
                    return;
                } else {
                    $taskManager->markTaskFailed($this->taskId, "试卷没有题目数据: {$this->paperId}");
                    return;
                }
            }

            $taskManager->updateTaskProgress($this->taskId, 10, '开始生成试卷PDF...');

            // 生成试卷PDF
            $pdfUrl = $pdfExportService->generateExamPdf($this->paperId)
                ?? $questionBankService->exportExamToPdf($this->paperId)
                ?? route('filament.admin.auth.intelligent-exam.pdf', ['paper_id' => $this->paperId, 'answer' => 'false']);

            $taskManager->updateTaskProgress($this->taskId, 50, '试卷PDF生成完成，开始生成判卷PDF...');

            // 生成判卷PDF
            $gradingPdfUrl = $pdfExportService->generateGradingPdf($this->paperId)
                ?? route('filament.admin.auth.intelligent-exam.pdf', ['paper_id' => $this->paperId, 'answer' => 'true']);

            $taskManager->updateTaskProgress($this->taskId, 70, '判卷PDF生成完成，开始合并PDF...');

            // 【优化】生成合并PDF（试卷 + 判卷） - 使用快速合并模式
            $mergedPdfUrl = $pdfExportService->generateMergedPdf($this->paperId, function($percentage, $message) use ($taskManager) {
                // 进度更新：70% 开始，最高到 95%
                $progress = 70 + ($percentage / 100) * 25;
                $taskManager->updateTaskProgress($this->taskId, round($progress, 0), $message);
            });

            // 【新增】验证合并后的PDF URL
            if (!$mergedPdfUrl) {
                Log::error('PDF生成队列任务失败：合并PDF失败', [
                    'task_id' => $this->taskId,
                    'paper_id' => $this->paperId,
                    'attempt' => $this->attempts(),
                ]);

                if ($this->attempts() < $this->tries) {
                    Log::info('合并PDF失败，将在3秒后重试', [
                        'task_id' => $this->taskId,
                        'paper_id' => $this->paperId,
                        'attempt' => $this->attempts(),
                        'next_attempt' => $this->attempts() + 1,
                    ]);
                    // 延迟3秒后重试
                    $this->release(3);
                    return;
                } else {
                    Log::error('合并PDF失败且已达到最大重试次数，标记任务失败', [
                        'task_id' => $this->taskId,
                        'paper_id' => $this->paperId,
                        'attempts' => $this->attempts(),
                    ]);
                    $taskManager->markTaskFailed($this->taskId, "合并PDF失败: {$this->paperId}");
                    return;
                }
            }

            Log::info('PDF合并成功验证', [
                'task_id' => $this->taskId,
                'paper_id' => $this->paperId,
                'merged_pdf_url' => $mergedPdfUrl,
                'url_length' => strlen($mergedPdfUrl)
            ]);

            // 构建完整的试卷内容
            $examContent = $paperPayloadService->buildExamContent($paperModel);

            // 标记任务完成（包含合并后的PDF URL）
            $taskManager->markTaskCompleted($this->taskId, [
                'exam_content' => $examContent,
                'pdfs' => [
                    'exam_paper_pdf' => $pdfUrl,
                    'grading_pdf' => $gradingPdfUrl,
                    'all_pdf' => $mergedPdfUrl, // 【新增】合并后的完整PDF
                ],
            ]);

            Log::info('PDF生成队列任务完成', [
                'task_id' => $this->taskId,
                'paper_id' => $this->paperId,
                'pdf_url' => $pdfUrl,
                'grading_pdf_url' => $gradingPdfUrl,
                'merged_pdf_url' => $mergedPdfUrl,
                'question_count' => $paperModel->questions->count(),
            ]);

            // 发送回调通知（在合并PDF完成后）
            $taskManager->sendCallback($this->taskId);

        } catch (\Exception $e) {
            $elapsed = microtime(true) - $startTime;

            Log::error('PDF生成队列任务失败', [
                'job_id' => $jobId,
                'task_id' => $this->taskId,
                'paper_id' => $this->paperId,
                'attempt' => $this->attempts(),
                'max_attempts' => $this->tries,
                'elapsed' => round($elapsed, 2) . 's',
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
            ]);

            // 如果是第一次失败且试卷可能还在创建中，等待后重试
            if ($this->attempts() < $this->tries && strpos($e->getMessage(), '不存在') !== false) {
                Log::info('检测到试卷不存在错误，将在2秒后重试', [
                    'task_id' => $this->taskId,
                    'paper_id' => $this->paperId,
                    'attempt' => $this->attempts(),
                ]);
                $this->release(2);
                return;
            }

            $taskManager->markTaskFailed($this->taskId, $e->getMessage());
        } finally {
            // 【并发控制】释放锁
            $this->releaseLock();
            $currentCount = $this->getConcurrentCount();

            Log::info('GenerateExamPdfJob: 任务完成', [
                'job_id' => $jobId,
                'total_elapsed' => round(microtime(true) - $startTime, 2) . 's',
                'remaining_concurrent' => $currentCount
            ]);
        }
    }

    /**
     * 【并发控制】获取执行锁
     */
    private function acquireLock(): bool
    {
        $currentCount = $this->getConcurrentCount();

        if ($currentCount >= self::MAX_CONCURRENT_JOBS) {
            return false;
        }

        // 增加计数器
        Redis::incr(self::REDIS_KEY_CONCURRENT);

        // 设置锁过期时间（2小时）
        $lockKey = self::REDIS_KEY_LOCK_PREFIX . $this->taskId;
        Redis::setex($lockKey, 7200, 1);

        return true;
    }

    /**
     * 【并发控制】释放执行锁
     */
    private function releaseLock(): void
    {
        // 减少计数器
        $currentCount = Redis::decr(self::REDIS_KEY_CONCURRENT);
        if ($currentCount < 0) {
            Redis::set(self::REDIS_KEY_CONCURRENT, 0);
        }

        // 删除锁
        $lockKey = self::REDIS_KEY_LOCK_PREFIX . $this->taskId;
        Redis::del($lockKey);
    }

    /**
     * 【并发控制】获取当前并发数量
     */
    private function getConcurrentCount(): int
    {
        $count = Redis::get(self::REDIS_KEY_CONCURRENT);
        return $count ? (int)$count : 0;
    }
}