databag/net/server/internal/api_removeChannel.go

package databag

import (
  "errors"
  "net/http"
  "gorm.io/gorm"
  "github.com/gorilla/mux"
  "databag/internal/store"
)

func RemoveChannel(w http.ResponseWriter, r *http.Request) {
  var err error
  var code int

  // scan parameters
  params := mux.Vars(r)
  channelId := params["channelId"]

  // validate contact access
  var account *store.Account
  var contact *store.Card
  tokenType := ParamTokenType(r);
  if tokenType == APP_TOKENAGENT {
    account, code, err = ParamAgentToken(r, false);
    if err != nil {
      ErrResponse(w, code, err);
      return
    }
  } else if tokenType == APP_TOKENCONTACT {
    contact, code, err = ParamContactToken(r, true)
    if err != nil {
      ErrResponse(w, code, err);
      return
    }
    account = &contact.Account
  } else {
    err = errors.New("unknown token type")
    code = http.StatusBadRequest
    return
  }

  // load channel
  var slot store.ChannelSlot
  if err = store.DB.Preload("Channel.Cards").Preload("Channel.Groups.Cards").Where("account_id = ? AND channel_slot_id = ?", account.ID, channelId).First(&slot).Error; err != nil {
    if errors.Is(err, gorm.ErrRecordNotFound) {
      ErrResponse(w, http.StatusNotFound, err)
    } else {
      ErrResponse(w, http.StatusInternalServerError, err)
    }
    return
  }
  if slot.Channel == nil {
    ErrResponse(w, http.StatusNotFound, errors.New("referenced empty channel"))
    return
  }

  // determine affected contact list
  cards := make(map[string]store.Card)
  for _, card := range slot.Channel.Cards {
    cards[card.Guid] = card
  }
  for _, group := range slot.Channel.Groups {
    for _, card := range group.Cards {
      cards[card.Guid] = card
    }
  }

  if contact == nil {
    err = store.DB.Transaction(func(tx *gorm.DB) error {
      if res := tx.Model(&slot.Channel).Association("Groups").Clear(); res != nil {
        return res
      }
      slot.Channel.Groups = []store.Group{}
      if res := tx.Model(&slot.Channel).Association("Cards").Clear(); res != nil {
        return res
      }
      slot.Channel.Cards = []store.Card{}
      if res := tx.Where("channel_id = ?", slot.Channel.ID).Delete(&store.Tag{}).Error; res != nil {
        return res
      }
      if res := tx.Where("channel_id = ?", slot.Channel.ID).Delete(&store.TagSlot{}).Error; res != nil {
        return res
      }
      if res := tx.Where("channel_id = ?", slot.Channel.ID).Delete(&store.Asset{}).Error; res != nil {
        return res
      }
      if res := tx.Where("channel_id = ?", slot.Channel.ID).Delete(&store.Topic{}).Error; res != nil {
        return res
      }
      if res := tx.Where("channel_id = ?", slot.Channel.ID).Delete(&store.TopicSlot{}).Error; res != nil {
        return res
      }
      slot.Channel.Topics = []store.Topic{}
      if res := tx.Delete(&slot.Channel).Error; res != nil {
        return res
      }
      slot.Channel = nil
      if res := tx.Model(&slot).Update("channel_id", 0).Error; res != nil {
        return res
      }
      if res := tx.Model(&slot).Update("revision", account.ChannelRevision + 1).Error; res != nil {
        return res
      }
      if res := tx.Model(account).Update("channel_revision", account.ChannelRevision + 1).Error; res != nil {
        return res
      }
      return nil
    })
    if err != nil {
      ErrResponse(w, http.StatusInternalServerError, err)
      return
    }

    // cleanup file assets
    go garbageCollect(account)
  } else {
    if _, member := cards[contact.Guid]; !member {
      ErrResponse(w, http.StatusNotFound, errors.New("member channel not found"));
      return
    }
    err = store.DB.Transaction(func(tx *gorm.DB) error {
      if res := tx.Model(&slot.Channel).Association("Cards").Delete(contact); res != nil {
        return res
      }
      if res := tx.Model(&slot.Channel).Update("detail_revision", account.ChannelRevision + 1).Error; res != nil {
        return res
      }
      if res := tx.Model(&slot).Update("revision", account.ChannelRevision + 1).Error; res != nil {
        return res
      }
      if res := tx.Model(&account).Update("channel_revision", account.ChannelRevision + 1).Error; res != nil {
        return res
      }
      return nil
    })
    if err != nil {
      ErrResponse(w, http.StatusInternalServerError, err)
      return
    }
  }

  SetStatus(account)
  for _, card := range cards {
    SetContactChannelNotification(account, &card)
  }
  WriteResponse(w, nil)
}