#!/bin/bash

set -e

usage() {
    echo Usage: `basename "$0"` "runwis [args] --args <wis args>"
    echo "--args: All parameters after this point get passed to wis"
    echo "--public_ip: The public ip address that users will connect to."
    echo "--public_listen_port: The public port that users will connect to."
    echo "--instance_name: Name of the VM instance this server is running on."
    echo "--image_tag: The tag of the docker image being used, if known."
    echo "--build_type: release or debug."
    echo "--gce_metadata: Query Google GCE metadata for public ip and instance name."
    echo "--help: Displays this usage information."
}

function download_content() {
    local WICONTENT_URL="${1}"
    local WICONTENT_DIR=/wi/server/docker/wicontent
    local ETAG_FILEPATH="${WICONTENT_DIR}/wicontent.tar.gz-etag"
    local TARBALL_FILEPATH="${WICONTENT_DIR}/wicontent.tar.gz"
    local LAST_ETAG="force"

    # No url? Don't attempt download.
    if [ -z "$WICONTENT_URL" ]; then
        return
    fi

    # Grab the last ETag if it exists
    if [ -f "${ETAG_FILEPATH}" ]; then
        LAST_ETAG=$(cat "${ETAG_FILEPATH}")
    fi

    # Request the file with If-None-Match
    local ETAG=$(curl -s -D - "${WICONTENT_URL}" -H 'If-None-Match: "'${LAST_ETAG}'"' -o /tmp/out.bin | grep ETag | cut -d: -f2 | cut -d\" -f2)

    # If we have an ETag there was a response. If it doesn't match last one
    # then there is a file change
    if [[ ! -z "${ETAG}" ]] && [[ "${ETAG}" != "${LAST_ETAG}" ]]; then
        mv /tmp/out.bin "${TARBALL_FILEPATH}"
        tar -xf "${TARBALL_FILEPATH}" -C "${WICONTENT_DIR}"
        echo -n "${ETAG}" > "${ETAG_FILEPATH}" 
    fi
}

# Run normally if not runwis
if [ "$1" != "runwis" ]; then
    exec "$@"
fi

# Need to be user wi
if [ "$(whoami)" != "wi" ]; then
    exec gosu wi "$0" "$@"
fi
shift

# Poll for content?
if [ "${1}" == "--poll-content" ]; then
    while true; do
        sleep 300
        download_content "${2}"
    done
fi

# Parse parameters
until [ -z "$1" ]; do
    case "$1" in
    --args)
        shift
        break
        ;;

    --debugger)
        shift
        DEBUGGER="$1 --args"
        ;;

    --public_ip)
        shift
        PUBLIC_IP="$1"
        ;;

    --public_listen_port)
        shift
        PUBLIC_LISTEN_PORT="$1"
        ;;

    --instance_name)
        shift
        INSTANCE_NAME="$1"
        ;;

    --image_tag)
        shift
        IMAGE_TAG="$1"
        ;;

    --build_type)
        shift
        BUILD_TYPE="$1"
        ;;

    --gce_metadata)
        QUERY_GCE_METADATA="1"
        ;;

    --wicontent_url)
        shift
        WICONTENT_URL="$1"
        ;;

    --help)
        usage
        exit 0
        ;;

    *)
        echo Unknown argument \'$1\'
        usage
        exit 1
        ;;

    esac
    shift
done

if [ ! -z $QUERY_GCE_METADATA ]; then
    INSTANCE_NAME=$(curl -s "http://metadata.google.internal/computeMetadata/v1/instance/hostname" -H "Metadata-Flavor: Google" | cut -d. -f1)
    PUBLIC_IP=$(curl -s "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/access-configs/0/external-ip" -H "Metadata-Flavor: Google")
fi

# This is the full public address        
PUBLIC_ADDRESS=$PUBLIC_IP:$PUBLIC_LISTEN_PORT

# Tie together instance name and image tag for convenient querying
EXTRA_INFO='{"instance_name":"'${INSTANCE_NAME}'","image_tag":"'${IMAGE_TAG}'"}'

# Download content before running server
download_content "${WICONTENT_URL}"

# Poll for new content in the background 
"$0" runwis --poll-content "${WICONTENT_URL}" &

# Run the server and restart if it crashes
while [ 1 ]; do
    ${DEBUGGER} /wi/server/docker/${BUILD_TYPE}/wis --missionpack_dir /wi/server/docker/wicontent/wi --htdata /wi/game/htdata832.pdb --stats_path /api/addgamestats --server_info_path /api/serverinfo --server_info_expires 60 --public_address "$PUBLIC_ADDRESS" --server_info_extra "$EXTRA_INFO" "$@"

    if [ ! -z "${DEBUGGER}" ]; then
        exit 0
    fi

    sleep 1
done