#!/bin/bash -eu

# Copyright (c) Kim Alvefur

# This file is MIT/X11 licensed.

# Dependencies:

# - https://httpie.io/

# - https://github.com/stedolan/jq

# - some sort of XDG 'open' command

# Settings

HOST=""

DOMAIN=""

AUTH_METHOD="session-read-only"

AUTH_ID="rest"

if [ -f "${XDG_CONFIG_HOME:-$HOME/.config}/restrc" ]; then

	# Config file can contain the above settings

	source "${XDG_CONFIG_HOME:-$HOME/.config}/restrc"

fi

if [[ $# == 0 ]]; then

	echo "${0##*/} [-h HOST] [-u USER|--login] [/path] kind=(message|presence|iq) ...."

	# Last arguments are handed to HTTPie, so refer to its docs for further details

	exit 0

fi

if [[ "$1" == "-h" ]]; then

	HOST="$2"

	shift 2

elif [ -z "${HOST:-}" ]; then

	HOST="$(hostname)"

fi

if [[ "$HOST" != *.* ]]; then

	# Assumes subdomain of your DOMAIN

	if [ -z "${DOMAIN:-}" ]; then

		DOMAIN="$(hostname -d)"

	fi

	if [[ "$HOST" == *:* ]]; then

		HOST="${HOST%:*}.$DOMAIN:${HOST#*:}"

	else

		HOST="$HOST.$DOMAIN"

	fi

fi

if [[ "$1" == "-u" ]]; then

	# -u username

	AUTH_METHOD="auth"

	AUTH_ID="$2"

	shift 2

elif [[ "$1" == "-rw" ]]; then

	# To e.g. save Accept headers to the session

	AUTH_METHOD="session"

	shift 1

fi

if [[ "$1" == "--login" ]]; then

	shift 1

	# Check cache for OAuth client

	if [ -f "${XDG_CACHE_HOME:-$HOME/.cache}/rest/$HOST" ]; then

		source "${XDG_CACHE_HOME:-$HOME/.cache}/rest/$HOST" 

	fi

	OAUTH_META="$(http --check-status --json "https://$HOST/.well-known/oauth-authorization-server" Accept:application/json)"

	AUTHORIZATION_ENDPOINT="$(echo "$OAUTH_META" | jq -e -r '.authorization_endpoint')"

	if [ -z "${OAUTH_CLIENT_INFO:-}" ]; then

		# Register a new OAuth client

		REGISTRATION_ENDPOINT="$(echo "$OAUTH_META" | jq -e -r '.registration_endpoint')"

		OAUTH_CLIENT_INFO="$(http --check-status "$REGISTRATION_ENDPOINT" Content-Type:application/json Accept:application/json client_name=rest client_uri="https://modules.prosody.im/mod_rest" redirect_uris:='["urn:ietf:wg:oauth:2.0:oob"]')"

		mkdir -p "${XDG_CACHE_HOME:-$HOME/.cache}/rest/"

		typeset -p OAUTH_CLIENT_INFO >> "${XDG_CACHE_HOME:-$HOME/.cache}/rest/$HOST"

	fi

	CLIENT_ID="$(echo "$OAUTH_CLIENT_INFO" | jq -e -r '.client_id')"

	CLIENT_SECRET="$(echo "$OAUTH_CLIENT_INFO" | jq -e -r '.client_secret')"

	open "$AUTHORIZATION_ENDPOINT?response_type=code&client_id=$CLIENT_ID&scope=openid+prosody:user"

	read -p "Paste authorization code: " -s -r AUTHORIZATION_CODE

	TOKEN_ENDPOINT="$(echo "$OAUTH_META" | jq -e -r '.token_endpoint')"

	TOKEN="$(http --check-status --form "$TOKEN_ENDPOINT" 'grant_type=authorization_code' "client_id=$CLIENT_ID" "client_secret=$CLIENT_SECRET" "code=$AUTHORIZATION_CODE" | jq -e -r '.access_token')"

	USERINFO_ENDPOINT="$(echo "$OAUTH_META" | jq -e -r '.userinfo_endpoint')"

	if [ -n "${COLORTERM:-}" ]; then

		echo -ne '\e[1K\e[G'

	else

		echo

	fi

	http --check-status -b --session rest "$USERINFO_ENDPOINT" "Authorization:Bearer $TOKEN" Accept:application/json >&2

	AUTH_METHOD="session-read-only"

	AUTH_ID="rest"

fi

if [[ $# == 0 ]]; then

	# Just login?

	exit 0

fi

# For e.g /disco/example.com and such GET queries

GET_PATH=""

if [[ "$1" == /* ]]; then

	GET_PATH="$1"

	shift 1

fi

http --check-status -p b "--$AUTH_METHOD" "$AUTH_ID" "https://$HOST/rest$GET_PATH" "$@"