#!/bin/bash
TOKEN=''
URL='https://api.telegram.org/bot'$TOKEN
FILE='https://api.telegram.org/file/bot'$TOKEN
POLL_TIME=30
IMG_DIR='./tg_imgs'

while true; do {
  objs="$(
    curl -s "$URL/getUpdates" \
      -d "offset=${offset:-0}" \
      -d "timeout=${POLL_TIME}" \
      -d 'allowed_updates=["message"]' \
      -m ${POLL_TIME} | jq '.result []'
  )"
  offset="$(($(jq '.update_id' <<< "$objs" | tail -n1) + 1))"
  jq -cr '.message | .photo, .from' <<< "$objs"
}; done | while read photo; do {
  read user
  [ "$photo" = null ] && continue
  jq -cr '.[] | .file_id, .width, .height, .file_size' <<< "$photo" | while read fid; do {
    read w; read h; read file_size;
    jq -cr '.id, .first_name, .last_name, .username' <<< "$user" | {
      read uid; read fname; read lname; read uname
      curl -s "$URL/getFile" -d "file_id=$fid" | jq -cr '.result .file_path' | {
        read path
        echo "[$(date)] Got image from $fname $lname (@$uname, id $uid), ID: $fid, ${w}x${h} $file_size bytes."
        ext="$(rev <<< "$path" | cut -d. -f1 | rev)"
        curl -s $FILE/$path > $IMG_DIR/$uid-$fid.$ext &
      }
    }
  }; done 
}; done