#!/usr/bin/env bash
# This is an attempt to replace xdg-open with something sane.

usage() { printf '%s [-dhv] <uri/file>\n' "${0##*/}"; }

usage() {
	cat <<- EOF
		sx-open [-dhv] <uri/file>
		Flags:
		  -d   Dry run
		  -v   Verbose
		  -h   Help
	EOF
}

act() {
	(( verbose )) && printf 'CMD: %s\n' "$*" >&2
	(( dry_run )) || { "$@"; return $?; }

	return 0
}

# handle_uri <res> <uri>
# 1: cmd failed
# 3: no handler
handle_uri() {
	declare -n result=$1
	declare h cmd regex target=$2

	for h in "${uri_handlers[@]}"; do
		IFS='=' read cmd regex <<< "$h"

		if [[ "$target" =~ ${regex} ]]; then
			act ${cmd} "$target"; result=$?
			(( result )) && return 1

			return 0
		fi
	done

	return 3
}

# handle_file <res> <file>
# 1: cmd failed
# 2: no such file
# 3: no handler
handle_file() {
	declare -n result=$1
	declare m \
		target_mimetype charset \
		cmd regex \
		target=$2

	[[ -e "$target" ]] || return 3

	IFS=';' read target_mimetype charset <<< $( file -ib "$target" )

	for m in "${mime_handlers[@]}"; do
		IFS='=' read cmd regex <<< "$m"

		if [[ "$target_mimetype" =~ ${regex} ]]; then
			act ${cmd} "$target"; result=$?
			(( result )) && return 1

			return 0
		fi
	done

	return 3
}

# DSL
uri() { uri_handlers+=( "$1=$2" ); }
mime() { mime_handlers+=( "$1=$2" ); }

is_uri() [[ $1 =~ ^[a-zA-Z][a-zA-Z0-9\+\.\-]+:.+ ]]

main() {
	declare cmd_result target

	# Source the config file.
	cfg_file="$HOME/.config/sx-open.cfg"
	[[ -f "$cfg_file" ]] && { source "$cfg_file"; }

	while (( $# )); do
		case $1 in
			(-d)
				printf 'Dry run: not actually running the handler\n' >&2

				dry_run=1
				verbose=1
			;;

			(-h) usage; return 0;;

			(-v) verbose=1;;

			(--) shift; break;;
			(*) break;;
		esac

		shift
	done

	target=$1

	[[ "$target" ]] || { usage; exit; }

	# Treat file:// as local paths.
	[[ "$target" =~ ^file:(//)?(/.+) ]] && target=${BASH_REMATCH[2]}

	if [[ -e "$target" ]]; then
		[[ "$target" =~ ^/.* ]] || { target="${PWD}/${target}"; } # Turn relative paths to absolute ones.

		handle_file cmd_result "$target"
	elif is_uri "$target"; then
		handle_uri cmd_result "$target"
	else
		printf 'No such file or directory: %s\n' "$target" >&2
		return 2
	fi

	case $? in
		(1)
			printf 'Action failed with exit code: %s\n' "$cmd_result" >&2
			return 4
		;;

		(3)
			printf 'No handlers found\n' >&2
			return 3
		;;
	esac

	return 0
}

main "$@"