#!/usr/bin/bash

# This script is designed to replace scrollkeeper-update
# It iterates through all the directories specified using -o <dir_list>
# If these aren't specified, the default convert_dir is used
# (typically /usr/share/omf) and checks whether the last-modified time for
# the directory has changed from the previous run.
# The previous timings are stored in output_dir/.rarian-update-mtimes
# in the file format:
# <mtime>:@:<dir_name>:@:<converted filenames>
# For top-level directories, the mtime is '0'
# When multiple scrolls are generated from a single omf subdir,
# the scroll names are seperated by a semi-colon.

# I'll annotate the rest of the scirpt
# If you want more info, please ping me and I'll try and help.


prefix=/usr
exec_prefix=/usr
bindir=/usr/bin
statedir=/var/lib/rarian
convert_dir=/usr/share/omf
datarootdir=/usr/share
datadir=/usr/share
output_dir=${datadir}/help
package_version=0.8.0
real_convert[0]=$convert_dir
skip_omf_translate=1

# Print the version info for this file
print_version()
{
	echo "`basename $0` version 0.9"
	echo "This script is distributed as part of Rarian v$package_version"
	echo "Use '`basename $0` --help' for options and instructions for running"
	echo ""
	echo "Have a nice day!"

	exit 0
}

# Standard help message
print_usage()
{
	echo "Usage: `basename $0` [OPTIONS]"
	echo "Update Rarian scrolls archive from scrollkeeper omf files."
	echo "Note: This script is a replacement for scrollkeeper-update, but"
	echo "does not update the scrollkeeper internal database."
	echo ""
	echo "Options:"
	echo -e "-o DIR, --omf-dir=DIR\t\tUse the specified omf directories for"
	echo -e "\t\t\t\tconversion. Multiple directories can be "
	echo -e "\t\t\t\tspecified using colon (:) separator."
	echo -e "-r DIR, --resulting-dir=DIR\tUse the specified directory for the"\
			"resulting"
	echo -e "\t\t\t\tscrolls.  If the directory doesn't exist, it"
	echo -e "\t\t\t\twill be created at run time."
	echo -e "\t\t\t\t Note: Multiple output paths are not supported"
	echo -e "--clean-index\t\t\tRebuild the index entirely.  This will rebuild"
	echo -e "\t\t\t\tall scroll files and may take a long time."
	echo -e "-v\t\t\t\tTurn Verbosity on."
	echo -e "-p\t\t\t\tSpecify a different place to store the mtimes file."
	echo -e "-q\t\t\t\tRun silently (default)."
	echo -e "-h, -?, --help\t\t\tPrint this help message and exit."
	echo ""
	echo "Using this script without option will use the default omf directory"
	echo "'$convert_dir' and the default output directory '$output_dir'"

	exit 0
}

# Nice print function to call when we're in verbose mode.
# In normal mode, it's a no-op.
print_verbose()
{
	if [ $verbose ]
	then
		echo "$1"
	fi
}


# Process_dir handles the calling of the migration program
# It calls the program with the correct parameters
# and moves the results to the correct place.
process_dir()
{
	fname_list=""
	old_basename=""
	for f in $1/*.omf; do
	    bname=$(basename $f)
	    bname=${bname%-*.omf}
		if [[ $bname != $old_basename ]]
		then
			old_basename=$bname
	    	filename=$bname.document
			fname_list=$fname_list$filename";"
		    if $bindir/rarian-sk-migrate $(dirname $f) ${bname%-*.omf} > $tmpdir/tmp.rarian
			then
        		cp $tmpdir/tmp.rarian $output_dir/$filename
	        	rm $tmpdir/tmp.rarian
		    else
    		    echo "Error: Cannot process file "$f".  See "$tmpdir"/tmp.rarian for the reason."
        		exit 5
		    fi
		fi
	done
	echo -e `stat -c %Y $1`':@:'$1':@:'$fname_list >> $tmpdir/rarian-updates
}

# Split up the omf dirs specified on the command line
# I've never seen this used in practice, but
# better safe than sorry
split_omf_dirs ()
{
	let counter=0
	while [ $convert_dir ]
	do
		entry=`echo $convert_dir | cut -d ':' -f 1`
		convert_dir=${convert_dir#$entry}
		convert_dir=${convert_dir#:}
		real_convert[$counter]=$entry
		let counter+=1
	done

}

# Determine whether the directory defined within the index file
# was specified in the convert_dirs
am_adding_dir ()
{
	let counter=0
	am_processing="0"
	for i in ${real_convert[@]}
	do
		if [[ $fname == $i ]]
		then
			real_convert[$counter]="0"
			am_processing="1"
			return
		fi
		let counter+=1
	done
}

# The directory wasn't specified.  This does nothing except cat the
# relevant lines from the old file to the new one
skip_directory ()
{
	read line
	time=`echo $line | awk -F ":@:" '{print $1}'`
	while [[ $time -ne 0 ]]
	do
		echo $line
		echo $line >> $tmpdir/rarian-updates
		read line
		time=`echo $line | awk -F ":@:" '{print $1}'`
	done
}

# Go through the given directory and add all subdirs (containing omfs)
# to the index file (and convert the omf's to scrolls)
add_all_files ()
{
	for i in $(ls $fname);
	do
		if [ -d $fname/$i ]
		then
			print_verbose "$fname/$i is new and will be added"
			process_dir $fname/$i
		fi
	done
	read line
}

# If the given directory actually exists within the omf dir
dirs_contains ()
{
	let counter=0
	am_processing="0"
	for i in ${entries[@]}
	do
		if [[ $1 == $i ]]
		then
			entries[$counter]="0"
			am_processing="1"
			return
		fi
		let counter+=1
	done
}

# The meat.  Goes through and checks each directory mtime against the
# cached version.  If they're different, regenerate the scroll.
# If the dir has been removed, delete.
process_directory ()
{
	let counter=0
	for i in  $(ls $fname)
	do
		entries[$counter]="$fname/$i"
		let counter+=1
	done

	read line

	old_time=`echo $line | awk -F ":@:" '{print $1}'`

	while [[ $old_time && $old_time != "0" ]]
	do
		name=`echo $line | awk -F ":@:" '{print $2}'`

		dirs_contains $name

		if [[ $am_processing != "0" ]]
		then
			new_time=`stat -c %Y $name`
			if [[ $new_time -ne $old_time ]]
			then
				print_verbose "Directory $name has changed.  Updating."
				process_dir $name
			else
				echo $line >> $tmpdir/rarian-updates
			fi
		else
			filenames=`echo $line | awk -F ":@:" '{print $3}'`
			while [[ $filenames ]]
			do
				entry=`echo $filenames | cut -d ';' -f 1`
				print_verbose "Directory resonsible for $entry has been removed.  Deleting"
				filenames=${filenames#$entry}
				filenames=${filenames#;}
				mv $entry $tmpdir
			done

		fi

		read line
		old_time=`echo $line | awk -F ":@:" '{print $1}'`
	done

	for i in ${entries[@]}
	do
		if [[ $i != "0" ]]
		then
			print_verbose "Directory $i is new and will be added."
			process_dir $i
		fi
	done
}



# Beginning of the main chunk of the script

# Sorry for the stupid naming of options.
# They are inherited from scrollkeeper :(

# We use TEMP as set -- seems to nuke the return value of getopt
TEMP=`getopt -u -n$(basename $0) -o "o:r:p:vqnhV" \
    --longoptions="clean-index,omf-dir:,resulting-dir:,help,version" -- "$@"` \
    || print_usage

if [ $? != 0 ] ; then
	print_usage
	exit 0
fi

eval set -- "$TEMP"

while true; do
    case "$1" in
		-o | --omf-dir )
			convert_dir=$2
			update_output_dir=1
			shift 2
			;;
		-r | --result-dir )
			output_dir=$2
			overload_update=1
			shift 2
			;;
		-v )
			verbose=1
			shift
			;;
		-q )
			shift
			;;
        --clean-index )
        	clean_index=1
			shift
            ;;	      
		-h | -\? | --help )
			print_usage
			;;
		-n )
			# Scrollkeeper compat.  Actually do nothing
			shift
			;;
	        -p )
	                statedir=$2
	                shift 2
			;;
		-V | --version )
			print_version
			;;
         * )
         	break
         	;;
    esac
done

if [ $verbose ]
then
	echo "Verbosity turned on"
fi

if [ $skip_omf_translate = 0 ]
then

split_omf_dirs

if [ $update_output_dir ] && [ ! $overload_update ]
then
    # We assume here that people are sensible and put the 
    # omf files in <prefix>/share/omf
    # Also assumes only a single omf path
    print_verbose "Using non-installed location"
    output_dir=`dirname $real_convert[0]`/help
fi

print_verbose "Outputting to $output_dir"

if [ $clean_index ]
then
	print_verbose "Removing index file $statedir/rarian-update-mtimes"
	rm $statedir/rarian-update-mtimes > /dev/null 2>&1
fi


tmpdir=/tmp/rarian-$RANDOM
mkdir $tmpdir

if [ ! -d $output_dir ]
then
	mkdir -p $output_dir
fi

if [ ! -d $statedir ]
then
	mkdir -p $statedir
fi


res=$(touch $statedir/rarian-update-mtimes > /dev/null 2>&1)

if [ $? -ne 0  ]
then
	echo "Error: Unable to write to the output directory $output_dir."
	echo "write permission is needed in order to run"
	echo "this script.  If you don't have it, things"
	echo "break.  Please run this script with the correct"
	echo "permissions (normally root).  Exiting."
	exit 3
fi

exec < $statedir/rarian-update-mtimes

read line
fname=`echo $line | awk -F ":@:" '{print $2}'`


while [[ $fname != "" ]]
do
	print_verbose "Processing directory $fname"
	echo "0:@:$fname" >> $tmpdir/rarian-updates
	am_adding_dir $fname
	if [[ ! $(ls $fname 2>&1) ]]
	then
	    print_verbose "Previous directory $fname no longer exists"
	else
	    if [[ $am_processing != "0" ]]
	    then
		process_directory
	    else
		skip_directory
	    fi
	    fname=`echo $line | awk -F ":@:" '{print $2}'`
	fi
done

for i in ${real_convert[@]}
do
    if [[ $i != "0" ]]
    then
	res=$(ls $i 2>/dev/null)
	if [[ ! $res ]]
	then
	    print_verbose "Path $i does not exist.  Ignoring"
	else
	    
	    print_verbose "Adding contents of directory $i"
	    fname=$i
	    echo "0:@:$fname" >> $tmpdir/rarian-updates
	    add_all_files
	fi
    fi
done

rm -f $statedir/rarian-update-mtimes
if [ -e $tmpdir/rarian-updates ]
then
    mv $tmpdir/rarian-updates $statedir/rarian-update-mtimes
fi
rm -rf $tmpdir

fi # ENABLE_OMF_READ