#! /bin/bash

set -e

SUDO=${SUDO-sudo}
GITHUB_USER=${GITHUB_USER:-weaveworks}
DOCKERHUB_USER=${DOCKERHUB_USER:-weaveworks}
RELEASE_NAME=${RELEASE_NAME:-"Weave Scope"}
RELEASE_DESCRIPTION=${RELEASE_DESCRIPTION:-"Container Visibility"}

PWD=`pwd`

setup() {
    ## Get the new version number from the most recent tag
    if ! LATEST_TAG=$(git describe --abbrev=0 --match='v*' 2>/dev/null) ; then
        echo "Could not find an annotated 'v*' version tag." >&2
        exit 1
    fi
    LATEST_TAG_SHA=$(git rev-parse $LATEST_TAG)
    LATEST_RELEASE_SHA=$(git rev-parse latest_release)
    VERSION=${LATEST_TAG#v}
    # NB does not check that this tag is on master
    RELEASE_DIR=./releases/$LATEST_TAG
}

build() {
    setup

    echo "== Clone repo at $LATEST_TAG for version $VERSION"
    if [ -d $RELEASE_DIR ]; then
        echo -e "\u2757 Release directory $RELEASE_DIR already exists, you may want to" >&2
        echo -e "\trm -rf $RELEASE_DIR" >&2
        exit 1
    fi

    ## Clone the repo at the tag and go there
    mkdir -p releases
    git clone -q -b $LATEST_TAG . $RELEASE_DIR 2>/dev/null
    cd $RELEASE_DIR

    ## Check that the top changelog entry is this version
    if ! latest_changelog=$(grep -o "## Release [0-9].*" -m1 ./CHANGELOG.md) || \
       ! [ `echo "$latest_changelog" | grep -o '[0-9][^ ]*'` == "$VERSION" ]; then
        echo -e "\u2757 Latest changelog entry \"$latest_changelog\" does not match the release version $VERSION" >&2
        exit 1
    fi

    echo
    echo "== Build and test"

    ## Inject the version numbers and build the distributables
    ## (library versions?)
    sed -i -e "s/^SCRIPT_VERSION=.*$/SCRIPT_VERSION=\"$VERSION\"/" ./scope
    make SUDO=$SUDO SCOPE_VERSION=$VERSION DOCKERHUB_USER=$DOCKERHUB_USER

    if ./bin/test; then
        echo -e '\u2713 Tests pass'
    else
        echo -e "\u2757 Tests failed, probably best not publish this one" >&2
        exit 1
    fi

    ## Run tests with the distributables, including version check
    v=$(./app/app -version | grep -o '[0-9].*')
    if ! [ "$v" == "$VERSION" ]; then
        echo "Version of distributable "$v" does not match release version $VERSION" >&2
        exit 1
    fi

    echo -e '\u2713 Build OK'
    echo '** Release artefacts in' $RELEASE_DIR
}

publish() {
    setup
    cd $PWD/$RELEASE_DIR

    echo "== Sanity checks"

    if ! which github-release >/dev/null; then
        echo "Please install git-release:" >&2
        echo -e "\tgo get github.com/aktau/github-release" >&2
        echo "and create a git token per https://github.com/aktau/github-release" >&2
        exit 1
    fi

    if ! [ $(git rev-list -1 $LATEST_TAG) == $(git rev-list -1 latest_release) ]; then
        echo -e "\u2757 The tag latest_release does not point to the same commit as $LATEST_TAG"
        exit 1
    fi

    ## Check that the tag exists by looking at github
    if ! curl -sSf https://api.github.com/repos/$GITHUB_USER/scope/git/tags/$LATEST_TAG_SHA >/dev/null 2>&1; then
        echo -e "\u2757 Tag $LATEST_TAG is not on GitHub, or is not the same as the local tag" >&2
        echo -e "\thttps://github.com/$GITHUB_USER/scope/tags" >&2
        echo "You may need to" >&2
        echo -e "\tgit push git@github.com:$GITHUB_USER/scope $LATEST_TAG"
        exit 1
    fi

    ## Check that the 'latest_release' tag exists by looking at github
    if ! curl -sSf https://api.github.com/repos/$GITHUB_USER/scope/git/tags/$LATEST_RELEASE_SHA >/dev/null 2>&1; then
        echo -e "\u2757 Tag latest_release is not on GitHub, or is not the same as the local tag" >&2
        echo -e "\thttps://github.com/$GITHUB_USER/scope/tags" >&2
        echo "You may need to" >&2
        echo -e "\tgit tag -af latest_release"
        echo -e "\tgit push -f git@github.com:$GITHUB_USER/scope latest_release"
        exit 1
    fi

    echo -e "\u2713 Tag $LATEST_TAG exists in GitHub repo $GITHUB_USER/scope"

    ## Check that the version doesn't already exist by looking at github
    ## releases
    if github-release info --user $GITHUB_USER --repo scope --tag $LATEST_TAG >/dev/null 2>&1; then
        echo -e "\u2757 Release $LATEST_TAG already exists on GitHub" >&2
        echo -e "\thttps://github.com/$GITHUB_USER/scope/releases/$LATEST_TAG" >&2
        exit 1
    fi

    echo '** Sanity checks OK for publishing tag' $LATEST_TAG as $DOCKERHUB_USER/scope:$VERSION

    echo "== Tagging and publishing images on docker hub as user $DOCKERHUB_USER"
    $SUDO docker tag -f $DOCKERHUB_USER/scope $DOCKERHUB_USER/scope:$VERSION
    $SUDO docker push   $DOCKERHUB_USER/scope:$VERSION

    echo "== Creating GitHub release $RELEASE_NAME $VERSION"
    # This cannot be done as a draft because of a bug in
    # github-release: https://github.com/aktau/github-release/issues/7
    github-release release \
        --user $GITHUB_USER \
        --repo scope \
        --tag $LATEST_TAG \
        --name "$RELEASE_NAME $VERSION" \
        --description "$RELEASE_DESCRIPTION"

    github-release upload \
        --user $GITHUB_USER \
        --repo scope \
        --tag $LATEST_TAG \
        --name "scope" \
        --file "./scope"

    echo "** Published release $RELEASE_NAME $VERSION"
    echo -e "\thttps://github.com/$GITHUB_USER/scope/releases/$LATEST_TAG"

    if github-release info --user $GITHUB_USER --repo scope \
        --tag latest_release >/dev/null 2>&1; then
        github-release delete \
            --user $GITHUB_USER \
            --repo scope \
            --tag latest_release
    fi

    github-release release \
        --user $GITHUB_USER \
        --repo scope \
        --tag latest_release \
        --name "$RELEASE_NAME latest ($VERSION)" \
        --description "$RELEASE_DESCRIPTION"

    github-release upload \
        --user $GITHUB_USER \
        --repo scope \
        --tag latest_release \
        --name "scope" \
        --file "./scope"

    echo "** Published $RELEASE_NAME as latest_release at"
    echo -e "\thttps://github.com/$GITHUB_USER/scope/releases/latest_release"
}

usage() {
    echo "Usage:"
    echo -e "\t./bin/release build"
    echo "-- Build artefacts for the latest version tag"
    echo -e "\t./bin/release publish"
    echo "-- Publish the artefacts for the latest tag to GitHub and DockerHub"
}

case "$1" in
    build)
        build
        ;;
    publish)
        publish
        ;;
    *)
        echo "Unknown command \"$1\""
        usage
        ;;
esac