#!/bin/bash -ex
#
# Copyright 2016-2017, Intel Corporation
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in
#       the documentation and/or other materials provided with the
#       distribution.
#
#     * Neither the name of the copyright holder nor the names of its
#       contributors may be used to endorse or promote products derived
#       from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#
# pull-or-rebuild-image.sh - rebuilds the Docker image used in the
#                            current Travis build if necessary.
#
# The script rebuilds the Docker image if the Dockerfile for the current
# OS version (Dockerfile.${OS}-${OS_VER}) or any .sh script from the directory
# with Dockerfiles were modified and committed.
#
# If the Travis build is not of the "pull_request" type (i.e. in case of
# merge after pull_request) and it succeed, the Docker image should be pushed
# to the Docker Hub repository. An empty file is created to signal that to
# further scripts.
#
# If the Docker image does not have to be rebuilt, it will be pulled from
# Docker Hub.
#

if [[ "$TRAVIS_EVENT_TYPE" == "cron" || "$TRAVIS_BRANCH" == "coverity_scan" ]]; then
	if [[ $TYPE != "coverity" ]]; then
		echo "Skipping non-Coverity job for cron/Coverity build"
		exit 0
	fi
else
	if [[ $TYPE = "coverity" ]]; then
		echo "Skipping Coverity job for non cron/Coverity build"
		exit 0
	fi
fi

if [[ -z "$OS" || -z "$OS_VER" ]]; then
	echo "ERROR: The variables OS and OS_VER have to be set properly " \
             "(eg. OS=ubuntu, OS_VER=16.04)."
	exit 1
fi

if [[ -z "$HOST_WORKDIR" ]]; then
	echo "ERROR: The variable HOST_WORKDIR has to contain a path to " \
		"the root of this project on the host machine"
	exit 1
fi

if [ -n "$TRAVIS_COMMIT_RANGE" ]; then
	if ! git rev-list $TRAVIS_COMMIT_RANGE; then
		TRAVIS_COMMIT_RANGE=
	fi
fi

# Find all the commits for the current build
if [[ -n "$TRAVIS_COMMIT_RANGE" ]]; then
	commits=$(git rev-list $TRAVIS_COMMIT_RANGE)
else
	commits=$TRAVIS_COMMIT
fi
echo "Commits in the commit range:"
for commit in $commits; do echo $commit; done

# Get the list of files modified by the commits
files=$(for commit in $commits; do git diff-tree --no-commit-id --name-only \
	-r $commit; done | sort -u)
echo "Files modified within the commit range:"
for file in $files; do echo $file; done

# Path to directory with Dockerfiles and image building scripts
images_dir_name=images
base_dir=utils/docker/$images_dir_name

# Check if committed file modifications require the Docker image to be rebuilt
for file in $files; do
	# Check if modified files are relevant to the current build
	if [[ $file =~ ^($base_dir)\/Dockerfile\.($OS)-($OS_VER)$ ]] \
		|| [[ $file =~ ^($base_dir)\/.*\.sh$ ]]
	then
		# Rebuild Docker image for the current OS version
		echo "Rebuilding the Docker image for the Dockerfile.$OS-$OS_VER"
		pushd $images_dir_name
		./build-image.sh ${DOCKER_REPO} ${OS}-${OS_VER}
		popd

		# Check if the image has to be pushed to Docker Hub
		# (i.e. the build is triggered by commits to the ${GITHUB_REPO}
		# repository's master branch, and the Travis build is not
		# of the "pull_request" type). In that case, create the empty
		# file.
		if [[ $TRAVIS_REPO_SLUG == "${GITHUB_REPO}" \
			&& $TRAVIS_BRANCH == "master" \
			&& $TRAVIS_EVENT_TYPE != "pull_request"
			&& $PUSH_IMAGE == "1" ]]
		then
			echo "The image will be pushed to Docker Hub"
			touch push_image_to_repo_flag
		else
			echo "Skip pushing the image to Docker Hub"
		fi
		exit 0
	fi
done

# Getting here means rebuilding the Docker image is not required.
# Pull the image from Docker Hub.
docker pull ${DOCKER_REPO}:${OS}-${OS_VER}
