#!/usr/bin/env bash

usage() {
	echo "Usage:
echo 'https://...' | openurl
openurl [-h] 'https://...']

Open a URL in your browser

The BROWSER environment variable must be set to browsers to use, parsed
with python's os.pathsep: https://docs.python.org/3/library/webbrowser.html

On termux, this requires installing the termux API package:
https://github.com/termux/termux-api

A URL can be passed as the first argument or piped into openurl"
	exit "${1:-0}"
}

if [[ "$1" == '-h' ]]; then
	usage 1
fi

main() {
	local URL OS

	if [[ -z "$BROWSER" ]]; then
		# shellcheck disable=SC2016
		echo -e 'openurl: The $BROWSER environment variable must be set. e.g. in your shell profile

export BROWSER="firefox-developer-edition:google-chrome"\n' >&2
		usage 1
	fi
	# if no URL was passed, read the first line from STDIN
	URL="${1:-$(head -n 1)}"

	# if misconfigured, prevent this from looping infinitely
	if [[ "$BROWSER" == 'openurl' ]]; then
		# shellcheck disable=SC2016
		printf "\$BROWSER can't be openurl, exiting\n" >&2
		return 1
	fi

	if [[ -z "$URL" ]]; then
		printf 'openurl: No URL passed as argument or piped into STDIN\n' >&2
		usage 1
	fi

	# remove trailing ¬ from the URL (used in my editor to denote end of line)
	URL="${URL%¬}"

	# https://github.com/purarue/ttt
	command -v tttlog >/dev/null 2>&1 && tttlog "openurl $URL"
	# print the URL back to STDOUT
	printf '%s\n' "$URL"

	OS="${ON_OS:-$(on_machine)}"
	case "${OS}" in
	linux* | windows*)
		setsid -f python3 -m webbrowser -t "$URL" >/dev/null
		;;
	mac*)
		exec python3 -m webbrowser -t "$URL"
		;;
	android_termux*)
		havecmd -V 'install the termux API package: https://github.com/termux/termux-api' termux-open-url || return $?
		exec termux-open-url "$URL"
		;;
	*)
		printf 'Unknown Operating System: %s\nAttempting open with "python3 -m webbrowser"' "$OS" >&2
		exec python3 -m webbrowser -t "$URL"
		;;
	esac
}

main "$@" || exit $?