audio_codebuddy/server/src/modules/audio/audio.service.ts

import { Audio, AudioDocument } from '../../models/Audio';
import { User } from '../../models/User';
import { PaginationResult } from '../../types';
import mongoose from 'mongoose';

// 获取用户音频列表
export async function getAudioList(
  userId: string,
  options: {
    page?: number;
    pageSize?: number;
    isFavorite?: boolean;
    keyword?: string;
    category?: string;
  }
): Promise<PaginationResult<AudioDocument>> {
  const { page = 1, pageSize = 10, isFavorite, keyword, category } = options;

  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return {
      list: [],
      total: 0,
      page,
      pageSize,
      totalPages: 0,
    };
  }

  const query: Record<string, unknown> = { userId };

  if (isFavorite !== undefined) {
    query.isFavorite = isFavorite;
  }

  if (keyword) {
    query.$or = [
      { title: { $regex: keyword, $options: 'i' } },
      { text: { $regex: keyword, $options: 'i' } },
    ];
  }

  if (category) {
    query.category = category;
  }

  const total = await Audio.countDocuments(query);
  const totalPages = Math.ceil(total / pageSize);

  const list = await Audio.find(query)
    .sort({ createdAt: -1 })
    .skip((page - 1) * pageSize)
    .limit(pageSize);

  return {
    list,
    total,
    page,
    pageSize,
    totalPages,
  };
}

// 获取单个音频
export async function getAudioById(audioId: string, userId: string): Promise<AudioDocument | null> {
  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return null;
  }
  return Audio.findOne({ _id: audioId, userId });
}

// 删除音频
export async function deleteAudio(audioId: string, userId: string): Promise<boolean> {
  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return false;
  }
  const result = await Audio.findOneAndDelete({ _id: audioId, userId });
  return !!result;
}

// 切换收藏状态
export async function toggleFavorite(audioId: string, userId: string): Promise<AudioDocument | null> {
  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return null;
  }
  const audio = await Audio.findOne({ _id: audioId, userId });
  if (!audio) return null;

  audio.isFavorite = !audio.isFavorite;
  await audio.save();
  return audio;
}

// 更新音频信息
export async function updateAudio(
  audioId: string,
  userId: string,
  data: { title?: string; tags?: string[] }
): Promise<AudioDocument | null> {
  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return null;
  }
  const audio = await Audio.findOne({ _id: audioId, userId });
  if (!audio) return null;

  if (data.title) audio.title = data.title;
  if (data.tags) audio.tags = data.tags;
  await audio.save();

  return audio;
}

// 获取用户使用统计
export async function getUserStats(userId: string): Promise<{
  totalAudios: number;
  totalDuration: number;
  totalWords: number;
  favoriteCount: number;
}> {
  // 验证 userId 是否为有效的 ObjectId
  if (!userId || !mongoose.Types.ObjectId.isValid(userId)) {
    return { totalAudios: 0, totalDuration: 0, totalWords: 0, favoriteCount: 0 };
  }

  const stats = await Audio.aggregate([
    { $match: { userId: userId } },
    {
      $group: {
        _id: null,
        totalAudios: { $sum: 1 },
        totalDuration: { $sum: '$audioDuration' },
        totalWords: { $sum: '$wordCount' },
        favoriteCount: {
          $sum: { $cond: [{ $eq: ['$isFavorite', true] }, 1, 0] },
        },
      },
    },
  ]);

  if (stats.length === 0) {
    return { totalAudios: 0, totalDuration: 0, totalWords: 0, favoriteCount: 0 };
  }

  return {
    totalAudios: stats[0].totalAudios,
    totalDuration: stats[0].totalDuration,
    totalWords: stats[0].totalWords,
    favoriteCount: stats[0].favoriteCount,
  };
}