#!/usr/bin/env bash
readonly dependency=("theova/base16-qutebrowser")
readonly app="qutebrowser"

readonly path="$1"
readonly package="$2"
readonly theme="$3"
readonly permanent="$4"

## Main Entrypoint
#
#  Finds the right theme template file and starts theme
#  switching and, if necessary, permanent setting processes.
main() {
	dbg_msg $app "Starting Processor"
	tfile="$path/$package/themes/default/base16-$theme.config.py"

	if ! file_exists "$tfile"; then
		dbg_msg $app "error" "Theme template $theme not found in package $package"
		exit 1
	fi

	if [[ $permanent == "true" ]]; then save; fi
	theme

	dbg_msg $app "Processor Done"
}

## Theme switcher
#
#  Makes sure that if any application instance is
#  currently running, it switches to new theme.
theme() {
	dbg_msg $app "Switching theme"
	# make sure qutebrowser is running
	pgrep qutebrowser >/dev/null || {
		dbg_msg $app "warn" "No instance running, not switching theme"
		return
	}
	qutebrowser --loglevel error ":config-source $tfile"
	dbg_msg $app "Successfully switched theme"
}

## Theme setter
#
#  Takes care of permanently writing the desired
#  base16 theme into application settings.
save() {
	dbg_msg $app "Saving theme"
	local qt_dir="${XDG_CONFIG_HOME:-/$HOME/.config}/qutebrowser"

	if [[ -d $qt_dir ]]; then
		cat "$tfile" >"$qt_dir/colorscheme.py"
		dbg_msg $app "Saved theme to $qt_dir/colorscheme.py"

		include "$qt_dir"
	else
		dbg_msg $app "warn" "No qutebrowser configuration directory found"
	fi
}

## Theme includer
#
#  Makes sure that theme is actually included in
#  default application startup routine.
#  This is the most invasive step of theming since it
#  rewrites within existing configuration files.
include() {
	local qt_dir="$1"
	dbg_msg $app "Including theme in configuration"

	if file_exists "$qt_dir/config.py"; then
		line_exists_or_append "$qt_dir/config.py" 'config.source("colorscheme.py")'
		dbg_msg $app "Successfully included theme in configuration"
	else
		dbg_msg $app "warn" "No default configuration file found"
	fi
}

# Safe sourcing: https://stackoverflow.com/a/12694189
DIR="${BASH_SOURCE%/*}"
if [[ ! -d $DIR ]]; then DIR="$PWD"; fi
# shellcheck source=utilities.sh
. "$DIR/utilities.sh"
## Dependency Checker
#
#  Makes sure the processor is called for the correct
#  base16 package, or refuses to run if it is not.
if printf '%s\n' "${dependency[@]}" | grep -q -P "^$package$"; then
	main
else
	dbg_msg $app "error" "Processor does not work for package $package"
fi