#!/bin/bash
#
# Agricius - build tool for Judge0.
#
# Named after Saint Agricius of Trier - protector of carpenters, builders, confectioners, blacksmiths, tailors and butchers.

_err() {
    echo >&2 "Error: $*"
}

_die() {
    _err "$*"
    exit 1
}

__get_argument() {
    if [[ -n "$2" ]] && [[ ${2:0:1} != "-" ]]; then
        echo "$2"
    else
        _err "Argument for $1 is missing."
    fi
}

_positional_params=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        --cache-from)
            _cache="$(__get_argument $1 $2)"; [[ "$_cache" == "" ]] && exit 1
            shift 2
            ;;
        -*|--*)
            _die "Unknown option $1.
Usage: $0 [--cache-from image] command

Available commands:
    build       Build Docker images.
    publish     Push Docker images to repository. Implies build."
            ;;
        *)
            _positional_params="$_positional_params $1"
            shift
            ;;
    esac
done
eval set -- "$_positional_params"

if [[ "$_cache" != "" ]]; then
    docker pull $_cache
    _cache="--cache-from $_cache"
fi

JUDGE0_DOCKER_REPOSITORY=judge0/judge0

JUDGE0_PROJECT_ROOT="$(git rev-parse --show-toplevel)"
JUDGE0_COMMIT="$(git log -1 --format=%h --abbrev=8)"
JUDGE0_BRANCH="$(git rev-parse --abbrev-ref HEAD)"

JUDGE0_EDITION="$JUDGE0_BRANCH"
if [[ "$JUDGE0_BRANCH" == "master" ]]; then
    JUDGE0_EDITION="standard"
fi

JUDGE0_EDITION_SLUG="-$JUDGE0_EDITION"
if [[ "$JUDGE0_EDITION" == "standard" ]]; then
    JUDGE0_EDITION_SLUG=""
fi

JUDGE0_VERSION_TAG="$(git tag --points-at HEAD)"
JUDGE0_VERSION="${JUDGE0_VERSION_TAG:1}" # Remove the "v" the beginning.
JUDGE0_VERSION="${JUDGE0_VERSION%-*}" # Remove everything else after "-".

JUDGE0_PRODUCTION_IMAGES="$JUDGE0_DOCKER_REPOSITORY:$JUDGE0_COMMIT$JUDGE0_EDITION_SLUG"
if [[ "$JUDGE0_VERSION" != "" ]]; then
    JUDGE0_PRODUCTION_IMAGES="$JUDGE0_PRODUCTION_IMAGES $JUDGE0_DOCKER_REPOSITORY:latest$JUDGE0_EDITION_SLUG"
    JUDGE0_PRODUCTION_IMAGES="$JUDGE0_PRODUCTION_IMAGES $JUDGE0_DOCKER_REPOSITORY:$JUDGE0_VERSION$JUDGE0_EDITION_SLUG"
fi

JUDGE0_DEVELOPMENT_IMAGES="$JUDGE0_DOCKER_REPOSITORY:$JUDGE0_COMMIT-dev$JUDGE0_EDITION_SLUG"
if [[ "$JUDGE0_VERSION" != "" ]]; then
    JUDGE0_DEVELOPMENT_IMAGES="$JUDGE0_DEVELOPMENT_IMAGES $JUDGE0_DOCKER_REPOSITORY:latest$JUDGE0_EDITION_SLUG-dev"
    JUDGE0_DEVELOPMENT_IMAGES="$JUDGE0_DEVELOPMENT_IMAGES $JUDGE0_DOCKER_REPOSITORY:$JUDGE0_VERSION$JUDGE0_EDITION_SLUG-dev"
fi

env | grep JUDGE0_ | sort

pushd "$JUDGE0_PROJECT_ROOT"

function build_and_tag() {
    local _target=$1
    local _images=($2)
    local _main_image=${_images[0]}

    set -xe
    docker build -t $_main_image $_cache --target $_target .
    set +xe

    for (( i=0; i<${#_images[@]}; i++ )) do
        docker tag $_main_image ${_images[i]}
    done
}
build_and_tag production "$JUDGE0_PRODUCTION_IMAGES"
build_and_tag development "$JUDGE0_DEVELOPMENT_IMAGES"

_command="$1"
if [[ "$_command" == "publish" ]]; then
    if [[ "$JUDGE0_VERSION" == "" ]]; then
        _die "Cannot publish untagged version."
    fi
    _push_images() {
        local _images=($1)
        for (( i=1; i<${#_images[@]}; i++ )) do
            docker push ${_images[i]}
        done
    }
    _push_images "$JUDGE0_PRODUCTION_IMAGES"
    _push_images "$JUDGE0_DEVELOPMENT_IMAGES"
fi

_untag() {
    local _images=($1)
    for (( i=0; i<${#_images[@]}-1; i++ )) do
        docker rmi ${_images[i]}
    done
}
_untag "$JUDGE0_PRODUCTION_IMAGES"
_untag "$JUDGE0_DEVELOPMENT_IMAGES"

popd