#!/usr/bin/env bash
# Copyright 2020 The Kubernetes Authors.
#
# 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.

set -o errexit
set -o nounset
set -o pipefail

version::get_git_vars() {
    # shellcheck disable=SC1083
    GIT_COMMIT="${GIT_COMMIT:-$(git rev-parse HEAD^{commit})}"

    if [[ -z "${GIT_TREE_STATE:-}" ]]; then
        if git_status=$(git status --porcelain 2>/dev/null) && [[ -z ${git_status} ]]; then
            GIT_TREE_STATE="clean"
        else
            GIT_TREE_STATE="dirty"
        fi
    fi

    GIT_VERSION=${GIT_VERSION:-$(git describe --tags --abbrev=14 2>/dev/null)}
    GIT_RELEASE_TAG=${GIT_RELEASE_TAG:-$(git describe --abbrev=0 --tags)}
    GIT_RELEASE_COMMIT=${GIT_RELEASE_COMMIT:-$(git rev-list -n 1 "${GIT_RELEASE_TAG}")}

    export GIT_COMMIT \
           GIT_RELEASE_COMMIT \
           GIT_RELEASE_TAG \
           GIT_TREE_STATE \
           GIT_VERSION
}

version::get_build_date() {
    BUILD_DATE=${BUILD_DATE:-$(date ${SOURCE_DATE_EPOCH:+"--date=@${SOURCE_DATE_EPOCH}"} -u +'%Y-%m-%dT%H:%M:%SZ')}

    export BUILD_DATE
}

version::format_git_version() {
    # Do nothing if GIT_VERSION is not set
    if [[ -z "${GIT_VERSION:-}" ]]; then
        return
    fi

    # This translates the "git describe" to an actual semver.org
    # compatible semantic version that looks something like this:
    #   v1.1.0-alpha.0.6+84c76d1142ea4d
    #
    # TODO: We continue calling this "git version" because so many
    # downstream consumers are expecting it there.
    # shellcheck disable=SC2001
    DASHES_IN_VERSION=$(echo "${GIT_VERSION}" | sed "s/[^-]//g")
    if [[ "${DASHES_IN_VERSION}" == "---" ]] ; then
        # We have distance to subversion (v1.1.0-subversion-1-gCommitHash)
        # shellcheck disable=SC2001
        GIT_VERSION=$(echo "${GIT_VERSION}" | sed "s/-\([0-9]\{1,\}\)-g\([0-9a-f]\{14\}\)$/.\1\-\2/")
    elif [[ "${DASHES_IN_VERSION}" == "--" ]] ; then
        # We have distance to base tag (v1.1.0-1-gCommitHash)
        # shellcheck disable=SC2001
        GIT_VERSION=$(echo "${GIT_VERSION}" | sed "s/-g\([0-9a-f]\{14\}\)$/-\1/")
    fi
    if [[ "${GIT_TREE_STATE:-}" == "dirty" ]]; then
        # git describe --dirty only considers changes to existing files, but
        # that is problematic since new untracked .go files affect the build,
        # so use our idea of "dirty" from git status instead.
        GIT_VERSION+="-dirty"
    fi

    # Try to match the "git describe" output to a regex to try to extract
    # the "major" and "minor" versions and whether this is the exact tagged
    # version or whether the tree is between two tagged versions.
    if [[ "${GIT_VERSION}" =~ ^v([0-9]+)\.([0-9]+)(\.[0-9]+)?([-].*)?([+].*)?$ ]]; then
        GIT_MAJOR=${BASH_REMATCH[1]}
        GIT_MINOR=${BASH_REMATCH[2]}
    fi

    # If GIT_VERSION is not a valid Semantic Version, then refuse to build.
    if ! [[ "${GIT_VERSION}" =~ ^v([0-9]+)\.([0-9]+)(\.[0-9]+)?(-[0-9A-Za-z.-]+)?(\+[0-9A-Za-z.-]+)?$ ]]; then
        echo "GIT_VERSION should be a valid Semantic Version. Current value: ${GIT_VERSION}"
        echo "Please see more details here: https://semver.org"
        exit 1
    fi
}

# stolen from k8s.io/hack/lib/version.sh and modified
# Prints the value that needs to be passed to the -ldflags parameter of go build
version::ldflags() {
    version::format_git_version

    local -a ldflags
    function add_ldflag() {
        local key=${1}
        local val=${2}

        # Don't add empty values
        if [[ -z "${val}" ]]; then
            echo "ldflags: ${key} is not set" >&2
            return
        fi

        ldflags+=(
            "-X 'github.com/k-orc/openstack-resource-controller/v2/internal/version.${key}=${val}'"
        )
    }

    add_ldflag "buildDate" "${BUILD_DATE:-}"
    add_ldflag "gitCommit" "${GIT_COMMIT:-}"
    add_ldflag "gitTreeState" "${GIT_TREE_STATE:-}"
    add_ldflag "gitMajor" "${GIT_MAJOR:-}"
    add_ldflag "gitMinor" "${GIT_MINOR:-}"
    add_ldflag "gitVersion" "${GIT_VERSION:-}"
    add_ldflag "gitReleaseCommit" "${GIT_RELEASE_COMMIT:-}"

  # The -ldflags parameter takes a single string, so join the output.
  echo "${ldflags[*]-}"
}
