#!/bin/bash

SED=/usr/bin/sed
CURL="/usr/bin/curl -s"
DATE=/bin/date
TOKEN=${TOKEN:?"TOKEN environment variable expected"}
NYLAS_API="https://$TOKEN:@api.nylas.com"

setCursor() {
  if [ -z $AT ]; then
    CURSOR=$($CURL -X POST "$NYLAS_API/delta/latest_cursor" |$SED -n 's/\s*"cursor": "\(.*\)"/\1/p'|tr -d '[:space:]')
  else
    TIME_IN_S=$($DATE -v "$AT" '+%s')
    CURSOR=$($CURL --data "{\"start\":$TIME_IN_S}" "$NYLAS_API/delta/generate_cursor" |$SED -n 's/\s*"cursor": "\(.*\)"/\1/p'|tr -d '[:space:]')
  fi
}

main() {
  command=$1
  shift
  case "$command" in
    stream)
      if [ -z "$CURSOR" ]; then
        setCursor
      fi
      $CURL -G -N $NYLAS_API/delta/streaming --data-urlencode "cursor=$CURSOR" $*
      ;;
    cursor)
      setCursor $*
      if [ -z "$TIME_IN_S" ]; then
        echo "Latest Cursor> $CURSOR"
      else
        echo "Cursor at $(date -r $TIME_IN_S)> $CURSOR"
      fi
      ;;
    download)
      $CURL -O -J "$NYLAS_API/files/$*/download"
      ;;
    search)
      QUERY=$1
      shift
      $CURL -G -N $NYLAS_API/threads/search/streaming --data-urlencode "q=$QUERY"
      ;;
    *)
      case "$command" in
        get|post|delete|head|put)
          METHOD=`echo "$command" | tr '[a-z]' '[A-Z]'`
          ENDPOINT=$1
          shift
          $CURL -X $METHOD $NYLAS_API$ENDPOINT $*
          ;;
        *)
        cat<<-EOL

  -------------------------------------------------------------------
  NOTE: For more info about the TIME_DELTA, check 'man date at -v'
  -------------------------------------------------------------------

  Usage:

      TOKEN=token AT=TIME_DETLA $0 stream - to stream deltas       # will stream deltas
      TOKEN=token $0 [get|post|delete|head|put] /ENDPOINT [ARGS]   # will hit Nylas
      TOKEN=token $0 cursor                                        # will return a Nylas cursor
      TOKEN=token $0 search "from:foo@bar.com"                     # will search for threads
      TOKEN=token $0 download FILE_ID                              # will download a file locally

  Examples:

      TOKEN=token $0 AT=-1H stream --data-urlencode "include_types=file" |jq
      TOKEN=token $0 cursor -3M
      TOKEN=token $0 get /messages/:id
      TOKEN=token $0 get /files/:id
      TOKEN=token $0 put /threads/:id -d '{"folder_id":FOLDER_ID}'
EOL
          ;;
      esac
      ;;
  esac
}
[[ "$0" == "$BASH_SOURCE" ]] && main $@