#!/bin/bash -e

# Calculate start time as unix timestamp.

PLATFORM=`uname`

_date_to_unix_timestamp () {
    if [  "$PLATFORM" = "Darwin" ] ; then
        date -j -f "%b %d %T %Z %Y" "$1" "+%s"
    elif [  "$PLATFORM" = "Linux" ] ; then
        date -d "$1" "+%s"
    else
        echo "I don't know if your date can read a format and a time, failing"
        exit 99
    fi
}

_timestamp_to_time_string () {
    if [  "$PLATFORM" = "Darwin" ] ; then
        date -j -f "%s" "$1" +"%Y-%m-%dT%H:%M:%SZ"
    elif [  "$PLATFORM" = "Linux" ] ; then
        date -d "@$1" +"%Y-%m-%dT%H:%M:%SZ"
    fi
}

# Starting the test at "Jan 01 00:00:00 GMT 2000"
TIME=`_date_to_unix_timestamp "Jan 01 00:00:00 GMT 2000"`


# Set defaults.
INTERVAL=10      # 1s
NUMCLIENTS=10
NUMSERIES=1

# Parse arguments
while getopts "s:c:i:h" opt; do
	case $opt in
	i)
		INTERVAL=$OPTARG
		;;
	c)
		NUMCLIENTS=$OPTARG
		;;
	s)
		NUMSERIES=$OPTARG
		;;
	h)
		echo "urlgen is a utility for generating URL files for siege."
		echo ""
		echo "Usage:"
		echo "	urlgen.sh [OPTIONS]"
		echo ""
		echo "The following arguments can be specified:"
		echo ""
		echo "	-i seconds"
	    echo "	    Interval between requests."
	    echo "	    Defaults to 10 seconds."
		echo ""
		echo "	-s num"
	    echo "	    Number of unique series to generate."
	    echo "	    Defaults to 1 series."
		echo ""
		echo "	-c num"
	    echo "	    Number of clients to simulate."
	    echo "	    One request per client."
	    echo "	    Defaults to 10 clients."
		echo ""
		exit 1
		;;
	esac
done

# Generate a new request every interval per client.
for i in `seq 1 $NUMCLIENTS`;
do
	# Move forward the current time.
	TIME=$((TIME+INTERVAL))
	TIMESTAMP=`_timestamp_to_time_string $TIME`

	# Generate a URL for each series.
	for series in `seq 1 $NUMSERIES`;
	do
		# Generate a URL for each second in the interval.
		POINTS=""
		for j in `seq 0 $INTERVAL`;
		do
			# Format the timestamp to ISO 8601.
			let CURRTIME=TIME+j
			TIMESTAMP=`_timestamp_to_time_string $CURRTIME`

			# Add comma separator.
			if [ "$j" -ne "0" ]
			then
				POINTS=$POINTS,
			fi

			# Append the point.
			POINTS=$POINTS'{"name": "cpu", "tags": {"host": "server'$series'"}, "time": "'$TIMESTAMP'","fields": {"value": 100}}'
		done

		# Write out point.
		echo 'http://localhost:8086/write POST {"database" : "db", "retentionPolicy" : "raw", "points": ['$POINTS']}'
	done

	# Move forward the current time.
	let TIME=TIME+INTERVAL
done