#!/bin/sh
# mcomp [TO] - compose mail

commajoin() {
	sed ':a;N;s/\n/, /;$!b a'
}

reffmt() {
	sed 's/^[^<]*//g;s/[^>]*$//g;s/>[^<]*</>\n</g' | uniq | sed 's/^/ /'
}

i=0
while [ -f "snd.$i" ]; do
	i=$((i+1))
done
draft="snd.$i"

{
	case "$0" in
	*mcomp*)
		echo -n "To: $1"
		[ "$#" -ge 1 ] && shift
		for rcpt; do
			echo -n ", $rcpt"
		done
		echo
		echo "Cc: "
		echo "Bcc: "
		echo "Subject: "
		from=$(mhdr -h local-mailbox ~/.santoku/profile)
		[ "$from" ] && echo "From: $from"
		cat ~/.santoku/headers 2>/dev/null
		echo
		echo
		;;
	*mrepl*)
		[ "$#" -eq 0 ] && set -- .
		to=$(mhdr -h reply-to "$1")
		[ -z "$to" ] && to=$(mhdr -h from "$1")
		echo "To: $to"
		echo "Cc: $(mhdr -d -A -h to:cc: "$1" | commajoin)"
		echo "Bcc: "
		s=$(mhdr -d -h subject "$1")
		os=
		while [ "$os" != "$s" ]; do
			os=$s
			s=${s# }
			s=${s#[Rr][Ee]:}
			s=${s#[Aa][Ww]:}
			s=${s#[Ff][Ww][Dd]:}
		done
		echo "Subject: Re: $s"
		cat ~/.santoku/headers 2>/dev/null
		echo -n "References:"
		{
			mhdr -h references "$1"
			mhdr -h message-id "$1"
		} | reffmt
		echo "In-Reply-To: $(mhdr -h message-id "$1")"
		echo

		echo "$(mhdr -d -h from "$1") wrote:"
		mshow -R "$1" |
			sed -e :a -e '/^\n*$/{$d;N;ba' -e '}' |
			sed 's/^/> /'
		echo
	esac

	if [ -f ~/.signature ]; then
		printf '%s\n' '-- '
		cat ~/.signature
	fi
} >$draft

c=e
while :; do
	case "$c" in
	s|send)
		if [ -e $draft.mime ]; then
			if [ $draft -ot $draft.mime ]; then
				if sendmail -t <$draft.mime; then
					rm $draft $draft.mime
					exit 0
				else
					echo "mcomp: sendmail failed, kept draft $draft"
					exit 2
				fi
			else
				echo "mcomp: re-run mmime first."
				c=
			fi
		else
			if sendmail -t <$draft; then
				rm $draft
				exit 0
			else
				echo "mcomp: sendmail failed, kept draft $draft"
				exit 2
			fi
		fi
		;;
	c|cancel)
		echo "mcomp: cancelled draft $draft"
		exit 1
		;;
	m|mime)
		mmime <$draft >$draft.mime
		mshow -t ./$draft.mime
		c=
		;;
	e|edit)
		c=
		if ! ${EDITOR:-vi} $draft; then
			c=c
		fi
		;;
	*)
		echo -n "What now? ([s]end, [c]ancel, [e]dit, [m]ime) "
		read -r c
		;;
	esac
done