#!/bin/bash
usage(){
	echo "zchain-chk - Check and fix zchain"
	echo "---------------------------------"
	echo "Usage:"
	echo "	--help, -h				Print this help and exit"
	echo "	--chain <ipns-link>, -n <ipns-link>	Crawl specified chain"
	echo "  --fix					#TODO Fix your chain"
	echo ""
	echo "Note that combined flags don't work for now"
	echo "Running with no flags crawls your chain"
}
# Start of tests
#entrance="QmW5WVXCJfhb4peHG6cbEdamC24vZzMX2Vz386vpENh38U"
#entrance="QmNjQq7GkuXGF8kFT1z2Mv3i4JhY7sBXVUmHDiR1zkQjoE"
#entrance="QmbFMke1KXqnYyBBWxB74N4c5SBnJMVAiMNRcGu6x1AwQH"
# End of tests
if [ ! -z "$1" ] && [ "$1" == "-h" ] || [ "$1" == "--help" ]
then
	usage
	exit
elif [ ! -z "$1" ] && [ "$1" == "-n" ] || [ "$1" == "--chain" ]
then
	entrance="$(ipns-resolve $2)"
elif [ ! -z "$1" ]
then
	entrance="$1"
else
	# By default we enter from the latest block
	# We can alter this by changing this value
	entrance="$(cat $ZLATEST)"
fi
# We assign the IPFS CIDv0 of an empty file as this is used
# as our GENESIS block, hence the "seed" that the tree grows
# from.
seed="$(cat $ZGENESIS)"

# We assume that we found the entrance inside a block, hence
# ZBLOCK is labeled as previous
zblock="$entrance"

# Enter temp folder
TEMPASSIN="/tmp/aktmp_$(date -u +%s)"
mkdir $TEMPASSIN
cd $TEMPASSIN
counter=0
# The loop
# We break the loop from inside the loop
while true
do
	if [ $counter == 0 ]
	then
		echo 'Start checking'
	fi
	counter=$(expr $counter + 1)
	# Check if $zblock exists as variable
	if [ ! -v $zblock ]
	then
		# Check if it is not our seed cause if it is we skip this part
		if [ "$zblock" != "$seed" ]
		then
			# Reset timestamp since it's introduced later
			timestamp=''
			# Announce to stdout which ZBLOCK is being read at the moment
			logthis "Examining $zblock"
			#echo'{"zblock":"'$zblock'",'

			# We create files named after each ZBLOCK IPFS CID for later
			# reference. Files are empty.
			touch $ZBLOCKDIR/$zblock
			logthis "Created reference"

			# We concatenate the zblock's contents, pipe them through filter
			# json2bash and output them to tmp-file
			ipfs cat $zblock | json2bash > $TEMPASSIN/tmp-zblock
			logthis "ZBLOCK $zblock READ"

			# Supposingly you are on a safe environment and you only have
			# access to your chain, I would consider mild secure to source
			# the files into your bash.
			# File an issue/pull request if you think it can be done better!!
			source $TEMPASSIN/tmp-zblock
			logthis "ZBLOCK SOURCED"

			# Same as above applies to BLOCK and DATA subparts of each ZBLOCK
			# BLOCKS
			#echo'"block":"'$block'",'
			ipfs cat $block | json2bash > $TEMPASSIN/tmp-block
			source $TEMPASSIN/tmp-block
			logthis "BLOCK $block SOURCED"
			touch $BLOCKDIR/$block
			logthis "BLOCK REFERENCED"
			module="$(echo $action | sed -e 's/\// /g' | awk '{ print $1 }')"
			logthis "DATA is $module module."
			command="$(echo $action | sed -e 's/\// /g' | awk '{ print $2 }')"
			logthis "COMMAND is $command"
			if [ ! -v $timestamp ]
			then
				echo "$timestamp : $zblock -> $block -> $previous"
			fi
			#echo'"block_signature":"'$block_signature'",'
			#echo'"detach":"'$detach'",'
			#echo'"module":"'$module'",'
			#echo'"action":"'$command'",'
			#echo'"gpg":"'$gpg'",'
			#profile show $data
			# DATA (but we don't source it's stuff)
			# Only print to stdout
			#ipfs cat $data
			touch $DATADIR/$data

			# Now, since we sourced the BLOCK to our terminal, we can search
			# for $previous variable. In case we don't find one, we exit with
			# code 0
			if [ -v $previous ]
			then
				logthis "Block $block has no previous zblock"
				echo "Chain with no genesis"
				#echo'"previous":"genesis"},{"genesis":"genesis"}]'
				exit 0

			# Otherwise, we inform of the sequence
			else
				##echo"$zblock after $previous"
				#echo'"previous":"'$previous'"},' 
				zblock=$previous
			fi

		# Now check if it is equal to the seed
		# which apparently means we reached the seed.
		elif [ "$zblock" == "$seed" ]
		then
			##echo"$zblock is GENESIS block"
			##echo'"'$zblock'":{ "GENESIS":"GENESIS"}] '
			#echo'{"genesis":"genesis"}]'
			echo "Chain is OK with GENESIS block = $seed"
			logthis "Counter $counter"
			exit 0
		fi
	# And finally, if nothing is there exit with error
	else 
		#echo"Check not passed... No previous IPFS CID"
		exit 1
	fi
done