#!/usr/bin/env bash

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

usage() {
    print_err "Usage: $0 [option]..."
    print_err ""
    print_err "  -h, --help"
    print_err "    print this usage screen and exit"
    print_err "  -f, --format"
    print_err "    should the message be formatted using 'pandoc'."
    print_err "    Must be either 'true' or 'false'."
    print_err "  -t, --type"
    print_err "    which message type should be sent must be one of"
    print_err "    'text' or 'notice', or 'auto'."
    print_err "    The special value 'auto' defaults to 'notice', unless"
    print_err "    'CI_PIPELINE_STATUS'/'DRONE_BUILD_STATUS' indicates a failure."
}

# 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")
}

default_woodpecker_message() {
    local msg="Build ${CI_PIPELINE_STATUS}"
    local woodpecker_url="${CI_PIPELINE_URL}"
    if [ "$FORMAT" == "true" ]; then
        msg="$msg [${CI_REPO}#${CI_COMMIT_SHA:0:8}]($woodpecker_url)"
    else
        msg="$msg $woodpecker_url"
    fi
    msg="$msg (${CI_COMMIT_TAG:-$CI_COMMIT_BRANCH})"
    printf '%s' "$msg"
}

default_drone_message() {
    local msg="Build ${DRONE_BUILD_STATUS}"
    local drone_url="${DRONE_SYSTEM_PROTO}://${DRONE_SYSTEM_HOST}/${DRONE_REPO}/${DRONE_BUILD_NUMBER}"
    if [ "$FORMAT" == "true" ]; then
        msg="$msg [${DRONE_REPO_OWNER}/${DRONE_REPO_NAME}#${DRONE_COMMIT:0:8}]($drone_url)"
    else
        msg="$msg $drone_url"
    fi
    msg="$msg (${DRONE_TAG:-$DRONE_BRANCH})"
    printf '%s' "$msg"
}

ensure_variables() {
    if [ "$CI" == "woodpecker" ] && [ -z "$MESSAGE" ]; then
        MESSAGE="$(default_woodpecker_message)"
    elif [ "$DRONE" == "true" ] && [ -z "$MESSAGE" ]; then
        MESSAGE="$(default_drone_message)"
    fi

    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
}

get_message_type() {
    if [ "$MSG_TYPE" == "auto" ]; then
        if [ "$CI_PIPELINE_STATUS" == "failure" ]; then
            MSG_TYPE="text"
        elif [ "$DRONE_BUILD_STATUS" == "failure" ]; then
            MSG_TYPE="text"
        else
            MSG_TYPE="notice"
        fi
    fi

    printf '%s' "m.$MSG_TYPE"
}

make_message_json() {
    {
        printf '%s' "$1" |
            jq --raw-input --slurp "{msgtype: \"$(get_message_type)\", body: .}"
        [ "$FORMAT" == "true" ] && printf '%s' "$1" |
            pandoc |
            jq --raw-input --slurp "{format: \"org.matrix.custom.html\", formatted_body: .}"
    } | jq -s 'add'
}

send_message() {
    local login_json
    local token
    local message_json

    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="$(make_message_json "$MESSAGE")"
    curl -XPOST \
        -d "$message_json" \
        "$ADDRESS/_matrix/client/r0/rooms/$(rawurlencode "$ROOM")/send/m.room.message?access_token=$(rawurlencode "$token")" 2>/dev/null
}

MSG_TYPE='auto'
FORMAT='true'

while [ $# -gt 0 ]; do
    opt="$1"
    shift

    case "$opt" in
        -f|--format)
            arg="$1"
            shift

            if [ "$arg" == "true" ] || [ "$arg" == "false" ]; then
                FORMAT="$arg"
                continue
            fi

            print_err "Must give value 'true' or 'false' with '-t|--type'"
            exit 1
            ;;
        -t|--type)
            arg="$1"
            shift

            if [ -z "$arg" ]; then
                print_err "Must give a message type when using '-t|--type'"
                exit 1
            fi

            for type in text notice auto; do
                if [ "$arg" == "$type" ]; then
                    continue 2 # Go to next argument
                fi
            done
            print_err "Invalid message type '$arg'"
            exit 1
            ;;
        -h|--help)
            usage
            exit
            ;;
        *)
            print_err "Unknown argument '$opt'"
            usage
            exit 1
            ;;
    esac
done

ensure_variables
send_message