#!/bin/bash
################################################################################
# Copy or move all unversioned files from one category to another.
################################################################################
# 
# Exit Error Codes:
# 
# The exit error codes are based on the /usr/include/sysexits.h for all
# non-zero errors.  An exit code of '0' is success.
#
###############################################################################
#
# Bugs:
# - Nothing to admit
#
###############################################################################
#
# Todo:
# - Add more Todo items
#
###############################################################################


###############################################################################
# Variables: Read-Only

########################################
# Error Codes
readonly Error_Data=65        # EX_DATAERR
readonly Error_NoInput=66     # EX_NOINPUT
readonly Error_NoPerm=77      # EX_NOPERM
readonly Error_TempFail=75    # EX_TEMPFAIL
readonly Error_Unavailable=69 # EX_UNAVAILABLE
readonly Error_Usage=64       # EX_USAGE

########################################
# Grep Exit Codes
readonly Grep_Found_Match=0
readonly Grep_No_Match=1
readonly Grep_Error=2

########################################
# Page Viewer
if [ -n "`command -v less 2> /dev/null`" ]
then
	readonly page_viewer="less --no-init --quit-if-one-screen"
elif [ -n "`command -v more 2> /dev/null`" ]
then
	readonly page_viewer="more"
else
	readonly page_viewer=""
fi

########################################
# Project Values
readonly program_name=`basename $0`
readonly project_path=$(fossil info | grep 'local-root:' | sed 's/.*: *\(.*\)[\/]/\1/')


###############################################################################
# Variables: Internal
action=""


###############################################################################
# Variables: Arg Configurable
category_new=""
category_old=""
debug_mode=""
dry_run=""
move_files=""
separator=":"
uv_file_list=""


###############################################################################
main()
{
	if [ -n "$dry_run" ]
	then
		action=ignore
	fi

	uv_file_list=$(fossil uv ls --glob "${category_old}${separator}*")

	if [ -n "$debug_mode" ]
	then
		echo "--- Internally Defined Values ---"
		echo "   page_viewer: \"$page_viewer\""
		echo "  program_name: \"$program_name\""
		echo "  project_path: \"$project_path\""
		echo "        action: \"$action\""
		echo ""
		echo "--- Argument Based Values ---"
		echo "  category_old: \"$category_old\""
		echo "  category_new: \"$category_new\""
		echo "       dry_run: \"$dry_run\""
		echo "    move_files: \"$move_files\""
		echo "     separator: \"$separator\""
		echo "  uv_file_list: \"$uv_file_list\""
		exit $Error_TempFail
	fi

	copy_files

	if [ -n "$move_files" ]
	then
		remove_files
	fi
}


################################################################################
# Copy the unversioned files to the new category
copy_files()
{
	temp_dir=".$$"
	mkdir $temp_dir

	for uv_file in $uv_file_list
	do
		file=$(echo $uv_file | sed "s/${category_old}${separator}//")

		$action fossil uv export $uv_file $temp_dir/$file
		$action fossil uv add $temp_dir/$file --as $category_new$separator$file
	done

	rm -rf $temp_dir
}


################################################################################
# Remove the unversioned files from the old category
remove_files()
{
	for uv_file in $uv_file_list
	do
		$action fossil uv remove $uv_file
	done
}


################################################################################
# Do nothing and do it well
ignore()
{
	echo $*
}


################################################################################
show_usage()
{
	if [ -n "$page_viewer" ]
	then
		usage | $page_viewer
	else
		usage
	fi
}


################################################################################
usage()
{
	cat <<- USAGE_END
	Usage: $program_name [Options] Old_Category New_Category

	Options:
	  --debug
	    Display the internal values that would be used to create the
	    requested class then exit.

	  -h, --help
	    Show this message and exit.

	  -m, --move
	    Instead of the default action of copying the unversioned files
	    to the new category, the files will be moved.

	  -n, --dry-run
	    Only print what would be done.  No file changes will be made.
	    Note: The destination directory must exist to use this option.

	  -s, --separator CHAR
	    Specify the character that separates the category name from the
	    file name in the repository.
	    Default: ":"

	Arguments:
	  Old_Category
	    The name of the old category.

	  New_Category
	    The name of the new category.

	USAGE_END
}


###############################################################################
# Parse the args
arg_list=()

while [ "$1" != "" ]
do
	case $1 in
		--debug)
			debug_mode="yes"
			;;
		-h|--help)
			show_usage
			exit 0
			;;
		-m|--move)
			move_files="yes"
			;;
		-n|--dry-run)
			dry_run="yes"
			;;
		-s|--separator)
			shift
			separator="$1"
			;;
		-*)
			echo "Error: Option \"$1\" is not supported."
			echo "Use \"-h\" for help:"
			echo "  $program_name -h"
			exit $Error_Usage
			;;
		*)
			arg_list+=($1)
			;;
	esac
	shift
done

# Bash Array Syntax
# ${array_name[@]}       Get all elements
# ${#array_name[@]}      Count all elements
# ${array_name[@]:I:N}   Get N elements starting at I

category_old=${arg_list[0]}
category_new=${arg_list[1]}


###############################################################################
# Make sure that all required information is present and valid

### Category: Source ###

if [ -z "$category_old" ]
then
	echo "Error: No old category name was provided"
	echo "Use \"-h\" for help:"
	echo "	$program_name -h"
	exit $Error_NoInput
fi

category_list="$(fossil uv ls | sed "s/${separator}.*/ /" | sort -u)"
echo "$category_list" | grep "^${category_old} " &> /dev/null
if [ "$?" == "$Grep_No_Match" ]
then
		echo "Error: Invalid old category, not found in repository"
		echo "Use \"-h\" for help:"
		echo "	$program_name -h"
		exit $Error_Unavailable
fi

### Category: Destination ###

if [ -z "$category_new" ]
then
	echo "Error: No new category name was provided"
	echo "Use \"-h\" for help:"
	echo "	$program_name -h"
	exit $Error_NoInput
fi


###############################################################################
# Everything is now ready
main
exit 0