#!/bin/bash

# Copyright 2019 the Velero contributors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# docker-push is invoked by the CI/CD system to deploy docker images to Docker Hub.
# It will build images for all commits to main and all git tags.
# The highest, non-prerelease semantic version will also be given the `latest` tag.

set +x

if [[ -z "$CI" ]]; then
    echo "This script is intended to be run only on Github Actions." >&2
    exit 1
fi

# Return value is written into HIGHEST
HIGHEST=""
function highest_release() {
    # Loop through the tags since pre-release versions come before the actual versions.
    # Iterate til we find the first non-pre-release

    # This is not necessarily the most recently made tag; instead, we want it to be the highest semantic version.
    # The most recent tag could potentially be a lower semantic version, made as a point release for a previous series.
    # As an example, if v1.3.0 exists and we create v1.2.2, v1.3.0 should still be `latest`.
    # `git describe --tags $(git rev-list --tags --max-count=1)` would return the most recently made tag.

    for t in $(git tag -l --sort=-v:refname);
    do
        # If the tag has alpha, beta or rc in it, it's not "latest"
        if [[ "$t" == *"beta"* || "$t" == *"alpha"* || "$t" == *"rc"* ]]; then
            continue
        fi
        HIGHEST="$t"
        break
    done
}

triggeredBy=$(echo $GITHUB_REF | cut -d / -f 2)
if [[ "$triggeredBy" == "heads" ]]; then
    BRANCH=$(echo $GITHUB_REF | cut -d / -f 3)
    TAG=
elif [[ "$triggeredBy" == "tags" ]]; then
    BRANCH=
    TAG=$(echo $GITHUB_REF | cut -d / -f 3)
fi

if [[ "$BRANCH" == "main" ]]; then
    VERSION="$BRANCH"
elif [[ ! -z "$TAG" ]]; then
    # Explicitly checkout tags when building from a git tag.
    # This is not needed when building from main
    git fetch --tags
    # Calculate the latest release if there's a tag.
    highest_release
    VERSION="$TAG"
else
    echo "We're not on main and we're not building a tag, exit early."
    exit 0
fi

# Assume we're not tagging `latest` by default, and never on main.
TAG_LATEST=false
if [[ "$BRANCH" == "main" ]]; then
    echo "Building main, not tagging latest."
elif [[ "$TAG" == "$HIGHEST" ]]; then
    TAG_LATEST=true
fi

# Debugging info
echo "Highest tag found: $HIGHEST"
echo "BRANCH: $BRANCH"
echo "TAG: $TAG"
echo "TAG_LATEST: $TAG_LATEST"

echo "Building and pushing container images."

VERSION="$VERSION" TAG_LATEST="$TAG_LATEST" make container push
