#!/bin/bash

function printUsage() {
	echo "Please provide a valid level number";
	echo "usage $o <level>"
	exit 1
}

min_number() {
	    printf "%s\n" "$@" | sort -g | head -n1
}

level=$1

if [ -z "$1" ]; then 
	printUsage
fi

level=$1
if [ ! -d "/home/osm/tiles/$level" ]; then
	printUsage
fi
#echo level=$level
level100=$((4**$level))
#echo level100=$level100

previousLevel=$(($level-1))
if [ ! -d "/home/osm/tiles/$previousLevel" ]; then
	printUsage
fi
#echo previousLevel=$previousLevel
previousLevel100=$((4**$previousLevel))
#echo previousLevel100=$previousLevel100

# calculate tiles rendered in previousLevel
find /home/osm/tiles/$previousLevel/ -name "*.png" > /tmp/files.txt
read previousLevelTiles fileName <<< $(wc -l /tmp/files.txt)
#echo previousLevelTiles=$previousLevelTiles

# calculate files rendered in current level
find /home/osm/tiles/$level/ -name "*.png" > /tmp/files.txt
read levelTiles fileName <<< $(wc -l /tmp/files.txt)
#echo levelTiles=$levelTiles

# calculate progress
percentageRequired=$(echo "scale=5;$previousLevelTiles / $previousLevel100" | bc)
#echo percentageRequired=$percentageRequired
percentageRequired="$(min_number $percentageRequired 1)"
#echo percentageRequired=$percentageRequired
levelTarget=$(echo "$level100 * $percentageRequired" | bc)
#echo levelTarget=$levelTarget
levelCalculated=$(echo "scale=4;($levelTiles / $levelTarget)" | bc)
#echo levelCalculated=$levelCalculated
progress=$(echo "scale=2;($levelCalculated*100)/1" | bc)
progress="$(min_number $progress 100)"
echo progress=$progress%