import { Injectable, Logger } from '@nestjs/common';
import { DocumentImportRepository } from './document-import.repository';
import { KnowledgeItemsRepository } from '../knowledge-items/knowledge-items.repository';
import { KnowledgeImportWorkflow } from '../ai/workflows/knowledge-import.workflow';
import { RedisService } from '../../infrastructure/redis/redis.service';
import { QueueService } from '../../infrastructure/queue/queue.service';

@Injectable()
export class DocumentImportService {
  private readonly logger = new Logger(DocumentImportService.name);

  constructor(
    private readonly repository: DocumentImportRepository,
    private readonly knowledgeItemsRepo: KnowledgeItemsRepository,
    private readonly workflow: KnowledgeImportWorkflow,
    private readonly redis: RedisService,
    private readonly queue: QueueService,
  ) {}

  async createImport(dto: {
    userId?: string;
    knowledgeBaseId?: string;
    fileName?: string;
    sourceType?: string;
    rawText?: string;
  }) {
    const lockKey = `lock:document-import:${dto.fileName || Date.now()}`;
    const lockToken = await this.redis.lock(lockKey, 1800);
    if (!lockToken) {
      throw new Error('相同文件正在导入中，请稍候');
    }

    const job = await this.repository.create(dto);

    await this.redis.set(`job:document-import:${job.id}:status`, 'pending', 86400);
    await this.redis.set(`job:document-import:${job.id}:progress`, '0', 86400);
    await this.redis.set(`job:document-import:${job.id}:message`, '任务已加入队列', 86400);

    this.queue.add('document-import', {
      importId: job.id,
      userId: dto.userId || 'anonymous',
      knowledgeBaseId: dto.knowledgeBaseId,
      rawText: dto.rawText,
      fileName: dto.fileName,
    });

    this.processImport(job, dto.rawText, dto.knowledgeBaseId, lockKey, lockToken);

    return job;
  }

  private async processImport(
    job: { id: string; userId?: string },
    rawText: string | undefined,
    knowledgeBaseId: string | undefined,
    lockKey: string,
    lockToken: string,
  ) {
    try {
      if (!rawText) {
        await this.repository.updateStatus(job.id, 'completed');
        await this.redis.set(`job:document-import:${job.id}:status`, 'completed', 86400);
        await this.redis.set(`job:document-import:${job.id}:progress`, '100', 86400);
        await this.redis.set(`job:document-import:${job.id}:message`, '无需解析的空文件', 86400);
        await this.redis.unlock(lockKey, lockToken);
        return;
      }

      await this.repository.updateStatus(job.id, 'processing');
      await this.redis.set(`job:document-import:${job.id}:status`, 'parsing', 86400);
      await this.redis.set(`job:document-import:${job.id}:progress`, '25', 86400);
      await this.redis.set(`job:document-import:${job.id}:message`, 'AI 正在分析文本，提取知识点...', 86400);

      const result = await this.workflow.execute({
        userId: job.userId || 'anonymous',
        rawText,
        sourceName: undefined,
      });

      await this.redis.set(`job:document-import:${job.id}:status`, 'saving', 86400);
      await this.redis.set(`job:document-import:${job.id}:progress`, '80', 86400);
      await this.redis.set(`job:document-import:${job.id}:message`, `正在保存 ${result.knowledgePoints.length} 个知识点...`, 86400);

      if (knowledgeBaseId && result.knowledgePoints.length > 0) {
        for (let i = 0; i < result.knowledgePoints.length; i++) {
          const kp = result.knowledgePoints[i];
          await this.knowledgeItemsRepo.create(job.userId || 'anonymous', knowledgeBaseId, {
            title: kp.title,
            content: kp.content,
            itemType: 'lesson',
            orderIndex: kp.suggestedOrder ?? i + 1,
          });
        }
      }

      await this.repository.updateStatus(job.id, 'completed');
      await this.redis.set(`job:document-import:${job.id}:status`, 'completed', 86400);
      await this.redis.set(`job:document-import:${job.id}:progress`, '100', 86400);
      await this.redis.set(`job:document-import:${job.id}:message`, `成功提取 ${result.knowledgePoints.length} 个知识点`, 86400);
      await this.redis.unlock(lockKey, lockToken);
      this.logger.log(`Import ${job.id} completed: ${result.knowledgePoints.length} knowledge points`);
    } catch (error: any) {
      this.logger.error(`Import ${job.id} failed: ${error.message}`);
      await this.repository.updateStatus(job.id, 'failed');
      await this.redis.set(`job:document-import:${job.id}:status`, 'failed', 86400);
      await this.redis.set(`job:document-import:${job.id}:message`, `导入失败: ${error.message}`, 86400);
      await this.redis.unlock(lockKey, lockToken);
    }
  }

  async getStatus(id: string) {
    const redisStatus = await this.redis.get(`job:document-import:${id}:status`);
    const redisProgress = await this.redis.get(`job:document-import:${id}:progress`);
    const redisMessage = await this.redis.get(`job:document-import:${id}:message`);
    const dbJob = await this.repository.findById(id);

    return {
      id,
      fileName: dbJob?.sourceName,
      status: redisStatus || dbJob?.status || 'unknown',
      progress: redisProgress ? parseInt(redisProgress, 10) : 0,
      message: redisMessage || null,
    };
  }
}