#!/bin/bash

# AUTHOR: Clemens Schwaighofer
# DATE: 2015/8/4
# DESC: inits a screen with shells (sets titles) and runs command in those shells
#       reads all data from a config file
#
# open the screen config file
# - first line is the screen name
# - second line on are the screens + commands
# - a line is title#command
# - command can be empty, just creates a screen then
# - title can be empty, but not recommended
# - no hash is allowed in title or command

# EXAMPLE:
# ===========================
# FooScreen
# TitleA#cd ~/Folder
# TitleB#vim file
# TitleC#
# TitleD#ping foo.bar.com
# ===========================

set -e

ERROR=0;
if [ ! -f "$1" ]; then
	echo "Cannot find screen init config file '$1'";
	ERROR=1;
else
	# get the first line for the screen name
	SCREEN_NAME=$(head -n 1 "$1");
fi;

# check if we are in a screen one, if yes, exit
if [ -z "$STY" ]; then
	# check if the "work" screen exists
	# if [ -n "$SCREEN_NAME" ] && [[ -n $(screen -ls | grep ".$SCREEN_NAME\t") ]];
	if [ -n "$SCREEN_NAME" ] && screen -ls | grep -q ".$SCREEN_NAME\t"; then
		echo "Screen '$SCREEN_NAME' already exists";
		ERROR=1;
	fi;
else
	echo "Cannot run screen init script in a screen";
	ERROR=1;
fi;

if [ $ERROR -eq 1 ]; then
	exit;
fi;
# termcap (echo $TERMCAP)
# http://web.mit.edu/gnu/doc/html/screen_15.html#SEC89
# in screen ^-a . to dump current termcap
export SCREENCAP="SC|screen.xterm-256color|VT 100/ANSI X3.64 virtual terminal:\
:DO=\E[%dB:LE=\E[%dD:RI=\E[%dC:UP=\E[%dA:bs:bt=\E[Z:\
:cd=\E[J:ce=\E[K:cl=\E[H\E[J:cm=\E[%i%d;%dH:ct=\E[3g:\
:do=^J:nd=\E[C:pt:rc=\E8:rs=\Ec:sc=\E7:st=\EH:up=\EM:\
:le=^H:bl=^G:cr=^M:it#8:ho=\E[H:nw=\EE:ta=^I:is=\E)0:\
:li#92:co#228:am:xn:xv:LP:sr=\EM:al=\E[L:AL=\E[%dL:\
:cs=\E[%i%d;%dr:dl=\E[M:DL=\E[%dM:dc=\E[P:DC=\E[%dP:\
:im=\E[4h:ei=\E[4l:mi:IC=\E[%d@:ks=\E[?1h\E=:\
:ke=\E[?1l\E>:vi=\E[?25l:ve=\E[34h\E[?25h:vs=\E[34l:\
:ti=\E[?1049h:te=\E[?1049l:us=\E[4m:ue=\E[24m:so=\E[3m:\
:se=\E[23m:mb=\E[5m:md=\E[1m:mh=\E[2m:mr=\E[7m:me=\E[m:\
:ms:Co#8:pa#64:AF=\E[3%dm:AB=\E[4%dm:op=\E[39;49m:AX:\
:vb=\Eg:G0:as=\E(0:ae=\E(B:\
:ac=\140\140aaffggjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~..--++,,hhII00:\
:po=\E[5i:pf=\E[4i:Km=\E[M:k0=\E[10~:k1=\EOP:k2=\EOQ:\
:k3=\EOR:k4=\EOS:k5=\E[15~:k6=\E[17~:k7=\E[18~:\
:k8=\E[19~:k9=\E[20~:k;=\E[21~:F1=\E[23~:F2=\E[24~:\
:kB=\E[Z:kh=\E[1~:@1=\E[1~:kH=\E[4~:@7=\E[4~:kN=\E[6~:\
:kP=\E[5~:kI=\E[2~:kD=\E[3~:ku=\EOA:kd=\EOB:kr=\EOC:\
:kl=\EOD:km:";

# read the config file and init the screen
pos=0;
while read -r line;
do
	if [ $pos -eq 0 ]; then
		# should I clean the title to alphanumeric? (well yes, but not now)
		SCREEN_NAME=$line;
		if [ -z "$SCREEN_NAME" ]; then
			echo "[!] No screen name set";
			exit;
		fi;
		if [[ ! $SCREEN_NAME =~ ^[A-Za-z0-9-]+$ ]]; then
			echo "[!] Screen name must be alphanumeric (letters, numbers, and hyphens only): ${SCREEN_NAME}";
			exit;
		fi;
		# check that we do not create double entries
		if screen -list | grep -q "${SCREEN_NAME}"; then
			echo "[!] Screen with ${SCREEN_NAME} already exists";
			exit;
		fi;
	else
		# screen number is pos - 1
		SCREEN_POS=$(( pos-1 ));
		# extract screen title and command (should also be cleaned for title)
		SCREEN_TITLE=$(echo "$line" | cut -d "#" -f 1);
		SCREEN_CMD=$(echo "$line" | cut -d "#" -f 2);
		# skip lines that start with ";" these are comments, we do not use # as they are separators
		if [[ $line =~ ^\; ]]; then
			printf "[%2s] [SKIP] '%s' with command '%s'\n" $SCREEN_POS "$SCREEN_TITLE" "$SCREEN_CMD";
			continue;
		fi;
		# skip empty lines
		if [ -z "$line" ]; then
			continue;
		fi;
		# for the first screen, we need to init the screen and only set title
		# for the rest we set a new screen with title
		if [ $pos -eq 1 ]; then
			printf "===> * INIT screen with title '%s'\n" "$SCREEN_NAME";
			screen -dmS "$SCREEN_NAME";
			# set title for the first
			screen -r "$SCREEN_NAME" -p $SCREEN_POS -X title "$SCREEN_TITLE";
		else
			screen -r "$SCREEN_NAME" -X screen -t "$SCREEN_TITLE" $SCREEN_POS;
		fi;
		printf "[%2s] + ADD window with title '%s'\n" $SCREEN_POS "$SCREEN_TITLE";
		# run command on it (if there is one)
		if [ -n "$SCREEN_CMD" ]; then
			printf "     > RUN command '%s'\n" "$SCREEN_CMD";
			# if ^M is garbled: in vim do: i, ^V, ENTER, ESCAPE
			screen -r "$SCREEN_NAME" -p $SCREEN_POS -X stuff $"$SCREEN_CMD^M";
		fi;
	fi;
	pos=$(( pos+1 ));
done <<<"$(cat "${1}")";