#!/usr/bin/env bash

print_err() {
    printf "%s\n" "$1" >&2
}

# Blessed Stack Overflow
rawurlencode() {
    (set +x
    local string="${1}"
    local strlen=${#string}
    local encoded=""
    local pos c o

    for ((pos=0 ; pos<strlen; pos++)); do
        c=${string:$pos:1}
        case "$c" in
            [-_.~a-zA-Z0-9] ) o="$c" ;;
            * )               printf -v o '%%%02x' "'$c"
        esac
        encoded+="$o"
    done
    echo "$encoded")
}

if [ -z "$USER" ] || [ -z "$PASS" ]; then
    print_err "You must provide USER and PASS"
    exit 1
elif [ -z "$ADDRESS" ] || [ -z "$ROOM" ]; then
    print_err "You must provide ADDRESS and ROOM"
    exit 1
elif [ -z "$MESSAGE" ]; then
    print_err "You must provide MESSAGE"
    exit 1
fi

if [ "$(curl -XGET "$ADDRESS/_matrix/client/r0/login" 2>/dev/null |
    jq 'any(.flows[].type; .== "m.login.password")')" != "true" ]; then
    print_err "Login method not supported"
    exit 1
fi


LOGIN_JSON="$(printf '%s\n%s' "$USER" "$PASS" |
    jq -Rn '[inputs] | {type: "m.login.password", user: .[0], password: .[1]}')" &>/dev/null
TOKEN="$(curl -XPOST \
    -d "$LOGIN_JSON" \
    "$ADDRESS/_matrix/client/r0/login" 2>/dev/null| jq .access_token --raw-output)"

if [ -z "$TOKEN" ] || [ "$TOKEN" == "null" ]; then
    print_err "Error during login"
    exit 1
fi

MESSAGE_JSON="$(printf '%s' "$MESSAGE" |
    jq --raw-input --slurp '{msgtype: "m.text", body: .}')"
curl -XPOST \
    -d "$MESSAGE_JSON" \
    "$ADDRESS/_matrix/client/r0/rooms/$(rawurlencode "$ROOM")/send/m.room.message?access_token=$(rawurlencode "$TOKEN")" 2>/dev/null