#!/bin/bash
set -u
set -e

# preliminaries
HOSTNAME="$1"
shift
READINGS="$*"

URL="http://${HOSTNAME}/api/dxs.json?"

# build up URL
for ADDURL in $READINGS; do
    URL="${URL}dxsEntries=${ADDURL}&"
    echo $URL
done
URL=$(echo $URL | sed 's/.$//') # remove last character (&) from URL
echo $URL

# get time and json
NOW="$(date +%s)"
CURLOUT=$(curl --connect-timeout 5 -s $URL)

# process json
for READING in $READINGS; do
    OUTPUT=$(echo $CURLOUT | jq ".dxsEntries[] | select(.dxsId == $READING) | .value")
#    OUTPUT=$(cat pico.json | jq ".dxsEntries[] | select(.dxsId == $READING) | .value")
    if [ -n "$OUTPUT" ]; then # only if value present
        printf "%d: %s = %s\\n" "${NOW}" "${READING}" "${OUTPUT}"
    else
        printf >&2 "no reading %s\\n" "${READING}"
        exit 1
    fi
done