#!/bin/sh
# shi - an imageboard in POSIX shell, using the gnu coreutils
# Copyright (C) 2018 oneseveneight
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
# TODO: Banners
# TODO: Return post number on posting
# TODO: Post info only links top posts on boards page
# TODO: Shellcheck
# TODO: Handling of tar files that are too large or malformed
# TODO: Pages
# TODO: Implement http server within shi

IFS=''
LOG=log.txt
TEMPLATEDIR="templates"

alias echo='echo [shi.sh]:'
newPost() {
	POSTTYPE=$2
	POSTNUM=$(basename "$1")
	DATE=$(date -Ru)
	USER=$(cat "$1"/user)
	POSTTEXT=$(sed -e 's/&/&amp;/g' \
		-e 's/</\&lt;/g' \
		-e 's/>/\&gt;/g' \
		-e 's/\([@\#$%^&*()~-=_+:;{}\[,.?\/]\)/\\\1/g' "$1"/content)
	POSTTEXT=$(echo $POSTTEXT | sed -e ':a;N;$!ba;s/\n/<br>/g')
	POSTTITLE=$(cat "$1"/title)
	echo "Creating post" > $LOG
	for f in "$1"/*.jpg "$1"/*.jpeg "$1"/*.png "$1"/*.gif
	do
		test -f $f && IMAGEPATH=$f
	done

	if test -f "$IMAGEPATH"
	then
		echo "Found image at $IMAGEPATH" >> $LOG
		IMAGENAME=$(basename "$IMAGEPATH")
		IMAGESIZE=$(du -sh "$IMAGEPATH"| cut -f 1 -d '	')
		DIR=$(pwd | sed 's/\//\\\//g')
		THUMBPATH=$(echo "$IMAGEPATH" | sed -e 's/\..*$/_thumb\.jpeg/')
		if echo "$IMAGEPATH" | grep '.gif'
		then
			echo "Image is a gif" >> $LOG
			convert "$IMAGEPATH"'[0]' "$THUMBPATH" # If image is a gif, take the first frame
		else
			echo "Image is static" >> $LOG
			convert "$IMAGEPATH" "$THUMBPATH" # Convert the image to a jpeg
		fi
		convert "$THUMBPATH" -define jpeg:extent=100kb "$THUMBPATH" #Resizes the copy to < 100kb
		IMAGEPATH=$(echo "$IMAGEPATH" | sed -e "s/$DIR//" -e 's/\//\\\//g')
		THUMBPATH=$(echo "$THUMBPATH" | sed -e "s/$DIR//" -e 's/\//\\\//g')
	else
		echo "No image found" >> $LOG
		IMAGENAME=""
		IMAGESIZE="" IMAGEPATH=""
	fi

	if test -n "$IMAGENAME"
	then
		echo "Generating an image post" >> $LOG
		TEMPLATE=$TEMPLATEDIR/$POSTTYPE.template
		while read -r line
		do
			echo "$line" |
			sed -e "s/{{{ POSTNUM }}}/$POSTNUM/g" \
				-e "s/{{{ DATE }}}/$DATE/g" \
				-e "s/{{{ USER }}}/$USER/g" \
				-e "s/{{{ POSTTITLE }}}/$POSTTITLE/g" \
				-e "s/{{{ POSTTEXT }}}/$POSTTEXT/g" \
				-e "s/{{{ IMAGEPATH }}}/$IMAGEPATH/g" \
				-e "s/{{{ THUMBPATH }}}/$THUMBPATH/g" \
				-e "s/{{{ IMAGENAME }}}/$IMAGENAME/g" \
				-e "s/{{{ IMAGESIZE }}}/$IMAGESIZE/g"
		done < "$TEMPLATE"
	else
		echo "Generating a text post" >> $LOG
		TEMPLATE=$TEMPLATEDIR/$POSTTYPE-noimage.template
		while read -r line
		do
			echo "$line" |
			sed -e "s/{{{ POSTNUM }}}/$POSTNUM/g" \
				-e "s/{{{ USER }}}/$USER/g" \
				-e "s/{{{ DATE }}}/$DATE/g" \
				-e "s/{{{ POSTTITLE }}}/$POSTTITLE/g" \
				-e "s/{{{ POSTTEXT }}}/$POSTTEXT/g"
		done < "$TEMPLATE"
	fi

}

addPostToBoard() {
	POSTDIR="$1"
	POSTNUM="$(basename $POSTDIR)"
	BOARDDIR="$(dirname $POSTDIR)"
	REPLYNUM=$(grep -E "<!--BEGIN REPLY [0-9]*-->" "$POSTDIR"/index.html | wc -l)
	echo "Adding post to board" >> $LOG
	echo "Found $REPLYNUM replies" >> $LOG

	if [ $REPLYNUM -gt '4' ]
	then
		echo "More than 4 replies found, trimming" >> $LOG
		FIRSTREPLY=$(tac "$POSTDIR"/index.html \
			| grep -Em5 "<!--BEGIN REPLY [0-9]+-->" \
			| tail -n 1 \
			| sed 's/^.* \([0-9]\+\).*$/\1/g')
		echo "First reply: $FIRSTREPLY" >> $LOG

		POSTHTML=$(sed -e ':a' -e 'N' -e '$!ba' \
			-e "s/.*\(<!--BEGIN OP POST $POSTNUM-->.*<!--END OP POST $POSTNUM-->\).*/\1/g" \
			-e "s/<!--BEGIN REPLY [0-9]\+-->.*<!--END REPLY $FIRSTREPLY-->//g" \
			"$POSTDIR"/index.html)
	else
		POSTHTML=$(sed -e ':a' -e 'N' -e '$!ba' \
			-e "s/.*\(<!--BEGIN OP POST $POSTNUM-->.*<!--END OP POST $POSTNUM-->\).*/\1/g" \
			"$POSTDIR"/index.html)
	fi

	sed -i \
		-e ':a' \
		-e 'N' \
		-e '$!ba' \
		-e "s/<!--BEGIN OP POST $POSTNUM-->.*<!--END OP POST $POSTNUM-->//g" "$BOARDDIR"/index.html

	TEMPFILE=$(mktemp)
	while read -r line
	do
		if echo "$line" | grep -q "<!--BEGIN POSTS-->"
		then
			printf "\t\t<!--BEGIN POSTS-->\n%s\n" "$POSTHTML"
			#test -z $(find $POSTDIR/* -type d) || \
				#printf "\t\t\t\t\t</div>\n\t\t\t\t</div>\n\t\t\t\t<!--END OP POST %s-->\n" "$POSTNUM"
		else
			echo "$line"
		fi
	done < "$BOARDDIR"/index.html > "$TEMPFILE"
	cat "$TEMPFILE" > "$BOARDDIR"/index.html

}
addNewPost() {
	post="$1"
	if basename "$post" | grep -qE "[0-9]$" && [ "$(basename "$post")" -gt "$2" ]
	then
		TEMPFILE=$(mktemp)
		if dirname "$post" | grep -qE "[0-9]*+/[0-9]*$" # If reply generate a reply
		then
			echo "Post type: reply" > $LOG
			PARENT=$(dirname "$post" | sed 's/^.*\/\([0-9]\+\)/\1/')
			while read -r line
			do
				if echo "$line" | grep -q "<!--END REPLIES $PARENT-->"
				then
					newPost "$post" "reply"
					printf "\t\t\t\t\t\t<!--END REPLIES %s-->\n" "$PARENT"
				else
					echo "$line"
				fi
			done < "$post/../index.html" > "$TEMPFILE"
			cat "$TEMPFILE" > "$post/../index.html"
			addPostToBoard "$(dirname "$post")"
		else # Else generate an op post
			echo "Post type: OP post" >> $LOG
			while read -r line
			do
				echo "$line"
				if echo "$line" | grep -q "<!--BEGIN POSTS-->"
				then
					newPost "$post" "oppost"
				fi
			done < "$(dirname "$post")/index.html.template" > "$TEMPFILE"
			cat "$TEMPFILE" > "$post"/index.html
			rm "$TEMPFILE"
			addPostToBoard "$post"
		fi
	fi
}
update() {
	echo "Posting started at $(date -u)" >> $LOG
	find "$1" | while read -r post
	do
		addNewPost "$post"
	done
	echo $(( $2 + 1 )) > ./latest
	echo "Posting finished at $(date -u)" >> $LOG
}

INBOX="inbox/"
while nc -lp 7070 | tar -x -C $INBOX || rm -rf $INBOX/*
do
	for dir in $INBOX*
	do
		echo "Received post" >> $LOG
		REPLY=$(basename "$dir" | sed 's/-.*//g')
		LATEST=$(cat "./latest")

		if echo "$REPLY" | grep -qE "[0-9]$"
		then
			PARENT=$(find ./ -maxdepth 3 -name "$REPLY" -not -path '*/\.*')
			PARENT=$(dirname "$PARENT")
			BOARD=$(realpath "$PARENT")
		else
			PARENT="./boards"
			BOARD=$(realpath "$PARENT"/"$REPLY")
		fi

		if [ -d "$PARENT/$REPLY" ]
		then
			IMAGE=$(echo "$dir"/* | tr ' ' '\n' |grep -E '(png|jpg|gif)' | head -n 1)
			mkdir "$PARENT/$REPLY"/$(( LATEST + 1 ))
			NEW_POST_DIR="$PARENT/$REPLY"/$(( LATEST + 1 ))

			cp "$IMAGE" "$NEW_POST_DIR" >/dev/null 2>&1
			cut -c -80 "$dir/title" > "$NEW_POST_DIR"/title
			cut -c -2000 "$dir/content" > "$NEW_POST_DIR"/content
			cut -c -20 "$dir/user" > "$NEW_POST_DIR"/user
			cp "$NEW_POST_DIR"/../main.css $NEW_POST_DIR

			rm -rf "$dir"

			update "$BOARD" "$LATEST"
		else
			rm -rf "$dir"
		fi
	done
done