scwrypts/zsh/system/i3/create-local-font-override

#!/bin/zsh
DEPENDENCIES+=(
	diff
)
REQUIRED_ENV+=(
	I3__MODEL_CONFIG
)

CHECK_ENVIRONMENT
#####################################################################

REGEX_FONT='^\(font [^0-9]*\)\(.*\)'
REGEX_DMENU="^\\(.*dmenu_run .*-fn '[^0-9]*\\)\\([0-9]*\\)'"
REGEX_BORDER='^\(for_window.*border pixel \)\(.*\)'

INSTALL() {
	local USAGE="
		usage: [...options...]

		options
		  -f, --force             force replacement of existing i3config
		  -n, --no-link           if output config and template are the same, don't create link

		  -h, --help              print this message and exit

		environment
		  I3__MODEL_CONFIG        fully-qualified path to sourced i3config
		  I3__GLOBAL_FONT_SIZE    global font size
		  I3__DMENU_FONT_SIZE     (optional) font size for 'dmenu' command
		  I3__BORDER_PIXEL_SIZE   (optional) pixel-width of window borders

		I3 provides no way to include dynamic variables in your config.
		The main difference I want between my i3 configurations is font-size
		to match the current monitor. Since i3-msg provides no way to change
		font size, I run this command to update those variables on a local
		copy of my sourced config
	"
	local FORCE=0
	local AUTOLINK=1
	while [[ $# -gt 0 ]]
	do
		case $1 in 
			-f | --force ) FORCE=1 ;;
			-n | --no-link ) AUTOLINK=0 ;;
			-h | --help ) USAGE; exit 0 ;;
		esac
		shift 1
	done

	STATUS 'reading local i3config'
	[[ ^$I3__MODEL_CONFIG$ =~ ^$HOME/.config/i3/config$ ]] && {
		STATUS "model configuration is default configuration"
		I3__MODEL_CONFIG="$I3__MODEL_CONFIG.template"
		[ ! -f "$I3__MODEL_CONFIG" ] && {
			STATUS "creating template"
			cp "$HOME/.config/i3/config" "$I3__MODEL_CONFIG.template"
		}
		STATUS "referring to '$I3__MODEL_CONFIG'"
	}
	local CONFIG=$(cat "$I3__MODEL_CONFIG")
	[ ! $CONFIG ] && FAIL 1 "failed to read config at '$I3__MODEL_CONFIG'"

	local CONFIG_FILE="$HOME/.config/i3/config"
	[ ! -d $(dirname "$CONFIG_FILE") ] && mkdir -p "$(dirname "$CONFIG_FILE")"

	[ -f "$CONFIG_FILE" ] && mv "$CONFIG_FILE" "$CONFIG_FILE.bak"

	[ $I3__GLOBAL_FONT_SIZE ] && {
		STATUS "setting global font size to '$I3__GLOBAL_FONT_SIZE'"
		CONFIG=$(echo $CONFIG | sed "s/$REGEX_FONT/\\1$I3__GLOBAL_FONT_SIZE/")
	}

	[ $I3__DMENU_FONT_SIZE ] && {
		STATUS "setting dmenu font size to '$I3__DMENU_FONT_SIZE'"
		CONFIG=$(echo $CONFIG | sed "s/$REGEX_DMENU/\\1$I3__DMENU_FONT_SIZE'/")
	}

	[ $I3__BORDER_PIXEL_SIZE ] && {
		STATUS "setting border pixel size to '$I3__BORDER_PIXEL_SIZE'"
		CONFIG=$(echo $CONFIG | sed "s/$REGEX_BORDER/\\1$I3__BORDER_PIXEL_SIZE/")
	}

	echo $CONFIG > "$CONFIG_FILE"
	[ -f "$CONFIG_FILE.bak" ] \
		&& diff "$CONFIG_FILE" "$CONFIG_FILE.bak" -q >/dev/null \
		&& mv "$CONFIG_FILE.bak" "$CONFIG_FILE" \
		&& INFO "no changes were made" \
		;

	[[ $AUTOLINK -eq 1 ]] \
		&& diff "$CONFIG_FILE" "$I3__MODEL_CONFIG" -q >/dev/null \
		&& rm "$CONFIG_FILE" \
		&& ln -s "$I3__MODEL_CONFIG" "$CONFIG_FILE" \
		&& INFO "output is the same as model, i3config has been linked to model" \
		;

	[[ $FORCE -eq 1 ]] && rm "$CONFIG.bak" >/dev/null 2>&1
	return 0
}

#####################################################################
INSTALL $@