#!/bin/bash
# Script:	mutt_mbox_split.sh
# Task:		Script for splitting mbox files by timeframe
# Author:	Benjamin 'blindcoder' Schieder
# E-Mail:	blindcoder@scavenger.homeip.net
# Version:	0.1

# global variables
SCRIPTNAME=$(basename ${0} .sh)

EXIT_SUCCESS=0
EXIT_FAILURE=1
EXIT_ERROR=2
EXIT_BUG=10

# variables for option switches with default values
VERBOSE="n"
DEBUG="n"
PREFIX=""
SUFFIX=""
DATEBEGIN=""
DATEEND=""

# functions
function usage {
cat >&2 <<EOF
Usage: ${SCRIPTNAME} [-h] [-v] [-p] PREFIX [-a] SUFFIX -b DATEBEGIN -e DATEEND mboxfiles ...
This script will sort all mail from the specified mboxfiles into new
mbox files with the specified prefix or suffix.
Both parameters -p and -a can be present, although one MUST be present.

Parameters:
	-h		this help
	-v		verbose mode
	-d		debug mode
			don't actually run the mutt command, but display
			the config file and call to mutt
	-p PREFIX	prepend PREFIX to mbox filenames
	-s SUFFIX	append SUFFIX to mbox filenames
	-b DATEBEGIN	inclusive date from when to sart sorting
			must be in format DD/MM/YYYY
	-e DATEEND	inclusive date until when to sort
			must be in format DD/MM/YYYY
	mboxfiles	list of mbox files to sort

	Example:
	${SCRIPTNAME} -p 2008_ -s .yearlyarchive -b 01/01/2008 -e 31/12/2008 \
		~/Mail/*.mbox

		This will sort all *.mbox files in ~/Mail that arrived in
		2008 into new files. For example the file
		\`~/Mail/Cron.mbox\`
		will be sorted into a new file
		\`~/Mail/2008_Cron.mbox.yearlyarchive\`
EOF
	[[ ${#} -eq 1 ]] && exit ${1} || exit ${EXIT_FAILURE}
}

while getopts ':dvhp:s:b:e:' OPTION ; do
	case ${OPTION} in
		v)	VERBOSE=y
			;;
		d)	DEBUG=y
			;;
		h)	usage ${EXIT_SUCCESS}
			;;
		p)	PREFIX="${OPTARG}"
			;;
		s)	SUFFIX="${OPTARG}"
			;;
		b)	DATEBEGIN="${OPTARG}"
			;;
		e)	DATEEND="${OPTARG}"
			;;
		\?)	echo "unknown option \"-${OPTARG}\"." >&2
			usage ${EXIT_ERROR}
			;;
		:)	echo "option \"-${OPTARG}\" requires an argument." >&2
			usage ${EXIT_ERROR}
			;;
		*)	echo "Impossible error. parameter: ${OPTION}" >&2
			usage ${EXIT_BUG}
			;;
	esac
done

# skip parsed options
shift $(( OPTIND - 1 ))

if (( $# < 1 )) ; then
	echo "I need at least one argument!" >&2
	usage ${EXIT_ERROR}
fi

if [ -z "${PREFIX}${SUFFIX}" ]; then
	echo "I need a prefix or suffix or both!" >&2
	usage ${EXIT_ERROR}
fi

if [ -z "${DATEBEGIN}" ]; then
	echo "Please specify -b" >&2
	usage ${EXIT_ERROR}
fi

if [ -z "${DATEEND}" ]; then
	echo "Please specify -e" >&2
	usage ${EXIT_ERROR}
fi

TMP="`mktemp`"
if [ ! -f "${TMP}" ] ; then
	echo "Could not create temporary file!" >&2
	exit ${EXIT_FAILURE}
fi

trap 'rm -f ${TMP}' EXIT

# loop through all arguments
for ARG ; do
	if [ "${ARG##*/}" == "${ARG}" ] ; then
		ARG="./${ARG}"
	fi
	if [ ! -s "${ARG}" ] ; then
		echo "Skipping file \"${ARG}\" because it is empty."
		continue
	fi
	if [[ ${VERBOSE} = y ]] ; then
		echo "splitting file ${ARG}"
		echo "New file will be called ${ARG%/*}/${PREFIX}${ARG##*/}${SUFFIX}"
	fi
	cat >${TMP} <<EOF
unset confirmcreate
set delete=yes
set folder=/dev/null

folder-hook . 'push "T~dDATEBEGIN-DATEEND\\n;sMYNEWMBOX\\n$%q"'
EOF
	sed -e "s,DATEBEGIN,${DATEBEGIN},g" -e "s,DATEEND,${DATEEND},g" -e "s,MYNEWMBOX,${ARG%/*}/${PREFIX}${ARG##*/}${SUFFIX},g" -i ${TMP}
	if [[ ${DEBUG} = y ]] ; then
		cat ${TMP}
		echo mutt -F ${TMP} -f ${ARG}
	else
		mutt -F ${TMP} -f ${ARG}
	fi
done

exit ${EXIT_SUCCESS}