#!/usr/bin/env sh
export BUILDX_NO_DEFAULT_LOAD=true

: ${PREFER_BUILDCTL=}
: ${PREFER_LEGACY=}
: ${CI=}
: ${GITHUB_ACTIONS=}
: ${DOCKER_BUILDKIT=}
: ${TRAVIS_EVENT_TYPE=}
: ${TRAVIS_BRANCH=}
: ${CACHE_DIR=}

progressFlag=""
if [ "$CI" = "true" ]; then
  progressFlag="--progress=plain"
fi

newerEqualThan() { # $1=minimum wanted version $2=actual-version
  [ "$1" = "$(printf "$1\n$2" | sort -V | head -n 1)" ]
}

buildmode="legacy"
if [ "$PREFER_BUILDCTL" = "1" ]; then
  buildmode="buildkit"
else
  serverVersion=$(docker info --format '{{.ServerVersion}}')
  experimental=$(docker info --format '{{.ExperimentalBuild}}')
  if [ "$PREFER_LEGACY" != "1" ] && (newerEqualThan "18.09" $serverVersion ||
    (newerEqualThan "18.06" $serverVersion && [ "true" = "$experimental" ]) ||
    [ "$DOCKER_BUILDKIT" = "1" ]); then
    buildmode="docker-buildkit"
  fi
fi
if [ "$buildmode" = "legacy" ]; then
  echo >&2 "ERROR: \"legacy\" buildmode is no longer supported. Please enable DOCKER_BUILDKIT or install standalone BuildKit"
  exit 1
fi

buildxCmd() {
  if docker buildx version >/dev/null 2>&1; then
    set -x
    docker buildx "$@" $progressFlag
  elif buildx version >/dev/null 2>&1; then
    set -x
    buildx "$@" $progressFlag
  elif docker version >/dev/null 2>&1; then
    set -x
    DOCKER_BUILDKIT=1 docker "$@" $progressFlag
  else
    echo >&2 "ERROR: Please enable DOCKER_BUILDKIT or install standalone buildx"
    exit 1
  fi
}

cachetype=""
cacheref=""
currentref=""
if [ "$GITHUB_ACTIONS" = "true" ]; then
  currentref="git://github.com/$GITHUB_REPOSITORY#$GITHUB_REF"
  cachetype="local"
  cacheref="$CACHE_DIR"
elif [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then
  currentref="git://github.com/moby/buildkit#refs/pull/$TRAVIS_PULL_REQUEST/merge"
  cachetype="registry"
  cacheref="cicache.buildk.it/moby/buildkit/pr$TRAVIS_BUILD_ID"
elif [ -n "$TRAVIS_BRANCH" ]; then
  currentref="git://github.com/$TRAVIS_REPO_SLUG#$TRAVIS_BRANCH"
fi

currentcontext="."
currentcontextBuildctl="--local context=. --local dockerfile=."
if [ -n "$currentref" ]; then
  currentcontext="--build-arg BUILDKIT_CONTEXT_KEEP_GIT_DIR=1 $currentref"
  currentcontextBuildctl="--opt context=$currentref --opt build-arg:BUILDKIT_CONTEXT_KEEP_GIT_DIR=1"
fi