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

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

notmine() {
	mine="$(maddr -a -h local-mailbox:alternate-mailboxes: $MBLAZE/profile)"
	grep -Fv -e "$mine"
}

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

msgid() {
	mgenmid 2>/dev/null | sed 's/^/Message-Id: /'
}

msgdate() {
	printf 'Date: '
	mdate
}

needs_multipart() {
	mhdr -h attach "$1" >/dev/null ||
		grep -q '^#[^ ]*/[^ ]* ' "$1"
}

MBLAZE=${MBLAZE:-$HOME/.mblaze}

sendmail=$(mhdr -h sendmail "$MBLAZE/profile")
sendmail_args=$(mhdr -h sendmail-args "$MBLAZE/profile")
sendmail="${sendmail:-sendmail} ${sendmail_args:--t}"

outbox=$(mhdr -h outbox "$MBLAZE/profile")
if [ -z "$outbox" ]; then
	i=0
	while [ -f "snd.$i" ]; do
		i=$((i+1))
	done
	draft="./snd.$i"
	draftmime="./snd.$i.mime"
else
	draft="$(true | mdeliver -v -c -XD "$outbox")"
	if [ -z "$draft" ]; then
		printf '%s\n' "$0: failed to create draft in outbox $outbox." 1>&2
		exit 1
	fi
	draftmime="$(printf '%s\n' "$draft" | sed 's,\(.*\)/cur/,\1/tmp/mime-,')"
fi

{
	case "$0" in
	*mcom*)
		printf 'To: '
		printf '%s\n' "$@" | commajoin
		printf '%s: \n' Cc Bcc Subject
		from=$(mhdr -h local-mailbox "$MBLAZE/profile")
		[ "$from" ] && printf 'From: %s\n' "$from"
		cat "$MBLAZE/headers" 2>/dev/null
		msgid
		msgdate
		printf '\n\n'
		;;
	*mrep*)
		[ "$#" -eq 0 ] && set -- .
		ng=$(mhdr -h newsgroups "$1")
		if [ "$ng" ]; then
			printf 'Newsgroups: %s\n' "$ng"
		else
			to=$(mhdr -h reply-to "$1")
			[ -z "$to" ] && to=$(mhdr -h from "$1")
			printf 'To: %s\n' "$to"
			printf 'Cc: %s\n' \
			       "$(mhdr -d -A -h to:cc: "$1" |notmine |commajoin)"
			printf 'Bcc: \n'
		fi
		printf 'Subject: Re: %s\n' "$(mscan -f '%S' "$1")"
		from=$(mhdr -h local-mailbox "$MBLAZE/profile")
		[ "$from" ] && printf 'From: %s\n' "$from"
		cat "$MBLAZE/headers" 2>/dev/null
		mid=$(mhdr -h message-id "$1")
		if [ "$mid" ]; then
			printf 'References: '
			{
				mhdr -h references "$1"
				printf '%s\n' "$mid"
			} | reffmt
			printf 'In-Reply-To: %s\n' "$mid"
		fi
		msgid
		msgdate
		printf '\n'

		mquote "$1"
		printf '\n'
	esac

	if [ -f "$MBLAZE/signature" ]; then
		SIGNATURE="$MBLAZE/signature"
	elif [ -f ~/.signature ]; then
		SIGNATURE="$HOME/.signature"
	fi

	if [ -n "$SIGNATURE" ]; then
		printf '%s\n' '-- '
		cat "$SIGNATURE"
	fi
} >$draft

c=e
while :; do
	case "$c" in
	s|send)
		case "$(mhdr -h newsgroups "$draft")" in
			*gmane.*) sendmail="mblow -s news.gmane.org";;
			*.*) sendmail="mblow";;
		esac

		if [ -e $draftmime ]; then
			if [ $draft -ot $draftmime ]; then
				if $sendmail <$draftmime; then
					if [ "$outbox" ]; then
						mv $draftmime $draft
						mflag -d $draft
					else
						rm $draft $draftmime
					fi
					exit 0
				else
					printf '%s\n' "mcom: $sendmail failed, kept draft $draft"
					exit 2
				fi
			else
				printf 'mcom: re-run mmime first.\n'
				c=
			fi
		else
			if mmime -c <$draft; then
				if $sendmail <$draft; then
					if [ "$outbox" ]; then
						mflag -d $draft
					else
						rm $draft
					fi
					exit 0
				else
					printf '%s\n' "mcom: $sendmail failed, kept draft $draft"
					exit 2
				fi
			else
				printf '%s\n' "mcom: message needs to be MIME-encoded first."
				c=
			fi
		fi
		;;
	c|cancel)
		printf '%s\n' "mcom: cancelled draft $draft"
		exit 1
		;;
	m|mime)
		if needs_multipart "$draft"; then
			(
				IFS='
'
				msed '/attach/d' $draft
				for f in $(mhdr -M -h attach $draft); do
					printf '#%s %s\n' \
					       "$(file -Lbi $f | sed 's/ //g')" \
					       "$f"
				done
			) | mmime >$draftmime
		else
			mmime -r <"$draft" >"$draftmime"
		fi
		mshow -t $draftmime
		c=
		;;
	e|edit)
		c=
		if ! ${EDITOR:-vi} $draft; then
			c=c
		fi
		;;
	d|delete)
		rm -i $draft
		if ! [ -f $draft ]; then
			rm -f $draftmime
			printf '%s\n' "mcom: deleted draft $draft"
			exit 0
		fi
		c=
		;;
	*)
		printf 'What now? ([s]end, [c]ancel, [d]elete, [e]dit, [m]ime) '
		read -r c
		;;
	esac
done