<?php

namespace App\Jobs;

use App\Models\MarkdownImport;
use App\Models\PreQuestionCandidate;
use App\Services\MarkdownQuestionParser;
use App\Services\PdfStorageService;
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\DB;
use Illuminate\Support\Facades\Log;

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

    public int $timeout = 300; // 5分钟超时
    public int $tries = 3;

    public function __construct(
        public int $markdownImportId,
        public int $sequenceStart,
        public int $sequenceEnd
    ) {
        //
    }

    public function handle(MarkdownQuestionParser $parser, PdfStorageService $uploader): void
    {
        $import = MarkdownImport::find($this->markdownImportId);
        if (!$import) {
            Log::error('MarkdownImport not found for batch', [
                'id' => $this->markdownImportId,
                'sequence_start' => $this->sequenceStart,
                'sequence_end' => $this->sequenceEnd,
            ]);
            return;
        }

        Log::info('Markdown batch started', [
            'import_id' => $this->markdownImportId,
            'sequence_start' => $this->sequenceStart,
            'sequence_end' => $this->sequenceEnd,
        ]);

        $records = PreQuestionCandidate::query()
            ->where('import_id', $this->markdownImportId)
            ->whereBetween('sequence', [$this->sequenceStart, $this->sequenceEnd])
            ->orderBy('sequence')
            ->get();

        $processed = 0;
        $failed = 0;
        $totalRecords = $records->count();

        // 初始化进度
        $this->refreshProgress();

        foreach ($records as $index => $record) {
            try {
                $meta = $record->meta ?? [];
                if (!empty($meta['ai_parsed'])) {
                    $processed++;
                    continue;
                }

                $existingConfidence = $record->confidence ?? $record->ai_confidence;

                // 置信度高（>=0.85）时跳过再次 AI 解析，直接计入进度
                if ($existingConfidence !== null && (float) $existingConfidence >= 0.85) {
                    $this->markParsed($record);
                    $processed++;
                    continue;
                }

                // 快速过滤卷子/区块标题，避免误判为题目再次走 AI
                if (!$this->isLikelyQuestion((string) $record->raw_markdown)) {
                    // 标记为已过滤，但不标记为已解析
                    $meta['ai_parsed'] = true;
                    $meta['ai_parsed_at'] = now()->toDateTimeString();
                    $meta['filtered_out'] = true; // 添加过滤标记

                    $record->update([
                        'is_question_candidate' => false,
                        'ai_confidence' => 0.0,
                        'confidence' => 0.0,
                        'is_valid_question' => false,
                        'status' => 'rejected',
                        'meta' => $meta,
                    ]);
                    $processed++;
                    continue;
                }

                // 已经处理过的不重复处理
                if (in_array($record->status, ['pending', 'reviewed', 'accepted', 'rejected'], true) && $record->stem !== null) {
                    $this->markParsed($record);
                    continue;
                }

                $parsed = $parser->parseRawMarkdown((string) $record->raw_markdown, (int) $record->index);

                $meta = $record->meta ?? [];
                $meta['ai_parsed'] = true;
                $meta['ai_parsed_at'] = now()->toDateTimeString();

                // 结构化后立即回传图片
                $uploadedImages = [];
                if (!empty($parsed['images'])) {
                    foreach ($parsed['images'] as $idx => $imgUrl) {
                        $path = "imports/images/{$record->id}_{$idx}.jpg";
                        $uploadedImages[] = $uploader->put($path, (string)@file_get_contents($imgUrl)) ?: $imgUrl;
                    }
                }
                $meta['images_uploaded'] = !empty($uploadedImages);

                $record->update([
                    'stem' => $parsed['stem'] ?? null,
                    'options' => $parsed['options'] ?? null,
                    'images' => !empty($uploadedImages) ? $uploadedImages : ($parsed['images'] ?? []),
                    'tables' => $parsed['tables'] ?? [],
                    'is_question_candidate' => (bool) ($parsed['is_question_candidate'] ?? false),
                    'ai_confidence' => $parsed['ai_confidence'] ?? null,
                    'status' => 'pending',
                    'meta' => $meta,
                ]);

                $processed++;

                // 每处理5个记录就更新一次进度，避免过于频繁
                if (($index + 1) % 5 === 0 || ($index + 1) === $totalRecords) {
                    $this->refreshProgress();
                }
            } catch (\Throwable $e) {
                $failed++;

                Log::error('Markdown batch item failed', [
                    'import_id' => $this->markdownImportId,
                    'candidate_id' => $record->id,
                    'sequence' => $record->sequence,
                    'index' => $record->index,
                    'error' => $e->getMessage(),
                    'trace' => $e->getTraceAsString(),
                ]);

                // 失败时也更新进度
                if (($index + 1) % 5 === 0 || ($index + 1) === $totalRecords) {
                    $this->refreshProgress();
                }
            }
        }

        $this->refreshProgress();

        Log::info('Markdown batch finished', [
            'import_id' => $this->markdownImportId,
            'sequence_start' => $this->sequenceStart,
            'sequence_end' => $this->sequenceEnd,
            'processed' => $processed,
            'failed' => $failed,
        ]);

        $this->finalizeIfDone();
    }

    /**
     * 任务失败时的处理
     */
    public function failed(\Throwable $exception): void
    {
        Log::error('Markdown batch job failed permanently', [
            'import_id' => $this->markdownImportId,
            'sequence_start' => $this->sequenceStart,
            'sequence_end' => $this->sequenceEnd,
            'attempts' => $this->attempts(),
            'error' => $exception->getMessage(),
            'trace' => $exception->getTraceAsString(),
        ]);

        // 标记导入记录为失败状态，避免卡住
        $import = MarkdownImport::find($this->markdownImportId);
        if ($import) {
            $import->update([
                'status' => MarkdownImport::STATUS_FAILED,
                'progress_stage' => MarkdownImport::STAGE_FAILED,
                'progress_message' => 'AI 解析任务失败',
                'error_message' => '队列任务执行失败，已超过最大重试次数',
                'processing_finished_at' => now(),
            ]);
        }
    }

    private function finalizeIfDone(): void
    {
        $import = MarkdownImport::find($this->markdownImportId);
        if (!$import) {
            return;
        }

        // 统一使用与 refreshProgress 相同的查询逻辑
        [$total, $parsed, $batchInfo] = $this->calculateProgress();

        // 只有当所有候选题都已处理（解析或过滤）完成时才更新状态
        if ($total > 0 && $parsed >= $total) {
            $updated = $import->update([
                'status' => MarkdownImport::STATUS_PARSED,
                'progress_stage' => MarkdownImport::STAGE_PARSED,
                'progress_message' => "解析完成，等待人工校对 ({$parsed}/{$total})",
                'progress_total' => $total,
                'progress_current' => $parsed,
                'progress_updated_at' => now(),
                'processing_finished_at' => now(),
            ]);

            if ($updated) {
                Log::info('Markdown import finalized', [
                    'import_id' => $this->markdownImportId,
                    'total_candidates' => $total,
                    'parsed_candidates' => $parsed,
                ]);
            }
        }
    }

    /**
     * 计算进度：返回 [总数量, 已处理数量]
     */
    private function calculateProgress(): array
    {
        // 总候选题数（排除被过滤的和已废弃的）
        $total = PreQuestionCandidate::query()
            ->where('import_id', $this->markdownImportId)
            ->where('status', '!=', PreQuestionCandidate::STATUS_SUPERSEDED)
            ->where(function ($query) {
                $query->whereNull('meta')
                    ->orWhereRaw("JSON_UNQUOTE(JSON_EXTRACT(meta, '$.filtered_out')) != 'true'");
            })
            ->count();

        // 真正完成AI解析的判断：有 stem 字段且不为空，或有有效的 ai_confidence
        // 或已经被过滤 (filtered_out=true)
        $parsed = PreQuestionCandidate::query()
            ->where('import_id', $this->markdownImportId)
            ->where('status', '!=', PreQuestionCandidate::STATUS_SUPERSEDED)
            ->where(function ($query) {
                $query->whereNull('meta')
                    ->orWhereRaw("JSON_UNQUOTE(JSON_EXTRACT(meta, '$.filtered_out')) != 'true'");
            })
            ->where(function ($query) {
                $query->where(function ($q) {
                    // 有题目内容
                    $q->whereNotNull('stem')
                      ->where('stem', '!=', '');
                })->orWhere(function ($q) {
                    // 或有有效的AI置信度
                    $q->whereNotNull('ai_confidence')
                      ->where('ai_confidence', '>', 0);
                });
            })
            ->count();

        // 计算当前正在处理的批次信息
        $batchInfo = sprintf(
            '批次 %d-%d',
            $this->sequenceStart,
            $this->sequenceEnd
        );

        return [$total, $parsed, $batchInfo];
    }

    private function refreshProgress(): void
    {
        [$total, $parsed, $batchInfo] = $this->calculateProgress();

        // 计算有stem但AI置信度为0的数量（可能是非题目被错误解析）
        $stemOnlyCount = PreQuestionCandidate::query()
            ->where('import_id', $this->markdownImportId)
            ->where('status', '!=', PreQuestionCandidate::STATUS_SUPERSEDED)
            ->where(function ($query) {
                $query->whereNull('meta')
                    ->orWhereRaw("JSON_UNQUOTE(JSON_EXTRACT(meta, '$.filtered_out')) != 'true'");
            })
            ->whereNotNull('stem')
            ->where('stem', '!=', '')
            ->where(function ($query) {
                $query->whereNull('ai_confidence')
                    ->orWhere('ai_confidence', '=', 0);
            })
            ->count();

        // 被过滤的记录数
        $filteredCount = PreQuestionCandidate::query()
            ->where('import_id', $this->markdownImportId)
            ->where('status', '!=', PreQuestionCandidate::STATUS_SUPERSEDED)
            ->whereRaw("JSON_UNQUOTE(JSON_EXTRACT(meta, '$.filtered_out')) = 'true'")
            ->count();

        $import = MarkdownImport::find($this->markdownImportId);
        if ($import) {
            $import->update([
                'progress_total' => $total,
                'progress_current' => min($parsed, $total),
                'progress_updated_at' => now(),
                'progress_stage' => MarkdownImport::STAGE_AI_PARSING,
                'progress_message' => "{$batchInfo} | AI 解析中… {$parsed}/{$total}" .
                    ($stemOnlyCount > 0 ? " (含{$stemOnlyCount}个待筛选)" : '') .
                    ($filteredCount > 0 ? " (已过滤{$filteredCount}个非题目)" : ''),
            ]);
        }
    }

    private function markParsed(PreQuestionCandidate $record): void
    {
        // 只有在记录真正有解析结果时才标记为已解析
        if (!empty($record->stem) || (!empty($record->ai_confidence) && $record->ai_confidence > 0)) {
            $meta = $record->meta ?? [];
            if (empty($meta['ai_parsed'])) {
                $meta['ai_parsed'] = true;
                $meta['ai_parsed_at'] = now()->toDateTimeString();
                $record->update(['meta' => $meta]);
            }
        }
    }

    /**
     * 轻量启发式判断是否像一道题目，过滤卷子/部分标题和说明文字。
     */
    private function isLikelyQuestion(string $raw): bool
    {
        $text = trim(strip_tags($raw));
        $length = mb_strlen($text);

        // Markdown 标题或“卷/部分/说明”且文本很短，视为非题
        if (preg_match('/^#+\\s+/m', $raw)) {
            return false;
        }

        if (preg_match('/(第[一二三四五六七八九十IVX]+[卷部分]|题型|说明|试卷)/u', $text) && $length <= 80) {
            return false;
        }

        // 过短且无问句/命令词/选项特征
        if ($length < 25 && !preg_match('/[\\?？求解求证计算]|[A-D]\\.|（本小题满分/u', $text)) {
            return false;
        }

        return true;
    }
}