#!/usr/local/bin/bash
set -exu;
env | sort | grep -v DRONE

##
## check input
##

BUILDKIT_HOST=${PLUGIN_ADDR:-${BUILDKIT_HOST:-}}
if [[ -z "${BUILDKIT_HOST:-}" ]]; then
	echo "Missing buildkit addr."
	exit 1
fi
BUILDCTL_CONTEXT=${PLUGIN_CONTEXT:-$(pwd)}
BUILDCTL_DOCKERFILE=$(dirname "${PLUGIN_DOCKERFILE:-$BUILDCTL_CONTEXT/Dockerfile}")
if [[ ! -f $BUILDCTL_DOCKERFILE/Dockerfile ]]; then
	echo "Dockerfile $BUILDCTL_DOCKERFILE/Dockerfile not found!"
	exit 1
fi
BUILDCTL_FRONTEND=${PLUGIN_FRONTEND:-dockerfile.v0}
if [[ "$BUILDCTL_FRONTEND" != "dockerfile.v0" ]]; then
	echo "Only frontend 'dockerfile.v0' testet and supported yet."
	exit 1
fi

SOURCE_DATE_EPOCH=${PLUGIN_SOURCE_DATE_EPOCH:-${SOURCE_DATE_EPOCH:-0}}

##
## build command
##

COMMAND="buildctl"
COMMAND="$COMMAND --addr $BUILDKIT_HOST"
COMMAND="$COMMAND build"
COMMAND="$COMMAND --frontend $BUILDCTL_FRONTEND"
COMMAND="$COMMAND --local context='$BUILDCTL_CONTEXT'"
COMMAND="$COMMAND --local dockerfile='$BUILDCTL_DOCKERFILE'"
if [[ "${PLUGIN_PLATFORM:-}" == "true" ]]; then
	COMMAND="$COMMAND --opt platform='$PLUGIN_PLATFORM'"
fi
# https://github.com/moby/buildkit/blob/master/README.md#output
if [[ ! -z "${PLUGIN_NAMES:-}" ]]; then
	COMMAND="$COMMAND --output type=image,name=$PLUGIN_NAMES,push=${PLUGIN_PUSH:-true}"
fi

# custom args, e.g. docker run --rm --volume=$(pwd):$(pwd) --workdir=$(pwd) --env=CI=test kokuwaio/buildkit --opt buildarg=foo=bar
if [[ -n "${1:-}" ]]; then
	COMMAND="$COMMAND $*"
fi

##
## execute command
##

echo -e "${COMMAND// --/\\n  --}\n"
eval "$COMMAND"