func fetchGroupHistory(api *slack.Client, ID string) []slack.Message {
historyParams := slack.NewHistoryParameters()
historyParams.Count = 1000
// Fetch History
history, err := api.GetGroupHistory(ID, historyParams)
check(err)
messages := history.Messages
latest := messages[len(messages)-1].Timestamp
for {
if history.HasMore != true {
break
}
historyParams.Latest = latest
history, err = api.GetGroupHistory(ID, historyParams)
check(err)
length := len(history.Messages)
if length > 0 {
latest = history.Messages[length-1].Timestamp
messages = append(messages, history.Messages...)
}
}
return messages
}