const cloud = require('wx-server-sdk')
cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
const db = cloud.database()
const _ = db.command

exports.main = async (event, context) => {
  const { OPENID } = cloud.getWXContext()
  const { content, images = [], video, location, hashtags = [], mood, petId } = event

  if (!content?.trim() && images.length === 0) {
    return { code: -1, message: '内容不能为空' }
  }

  try {
    const post = {
      authorId: OPENID,
      petId: petId || null,
      content: (content || '').trim(),
      images,
      video: video || null,
      location: location || null,
      hashtags,
      mood: mood || null,
      likeCount: 0,
      commentCount: 0,
      createdAt: db.serverDate(),
      updatedAt: db.serverDate(),
    }

    const res = await db.collection('posts').add({ data: post })

    // 更新用户帖子统计
    await db.collection('users')
      .where({ openid: OPENID })
      .update({ data: { 'stats.posts': _.inc(1) } })

    // 更新话题统计
    if (hashtags.length > 0) {
      const batch = hashtags.map(tag =>
        db.collection('topics')
          .where({ tag })
          .get()
          .then(r => {
            if (r.data.length === 0) {
              return db.collection('topics').add({ data: { tag, count: 1, createdAt: db.serverDate() } })
            }
            return db.collection('topics').where({ tag }).update({ data: { count: _.inc(1) } })
          })
      )
      await Promise.all(batch).catch(() => {})
    }

    return { code: 0, data: { _id: res._id, ...post } }
  } catch (e) {
    return { code: -1, message: e.message }
  }
}