#!/usr/bin/env bash

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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 -euox pipefail

MY_DIR="$(cd "$(dirname "$0")" && pwd)"
pushd "${MY_DIR}" &>/dev/null || exit 1

SOURCE_DIR="."
BUILD_DIR="_build"

function usage {
cat << EOF
usage: ${0} <command> [<args>]

These are  ${0} commands used in various situations:

    build              Build the documentation
    preview            Build a Docker image with a environment
    help               Display usage

EOF
}

function ensure_that_documentation_is_built {
    if [[ ! -f _build/html/index.html ]] ; then
        echo "Documentation is not built. Start build."
        sphinx-build -M html "${SOURCE_DIR}" "${BUILD_DIR}" -E
    fi
}

function start_preview {
    ensure_that_documentation_is_built
    pushd "${BUILD_DIR}/html"
    python -m http.server --cgi 3001
    popd
}

if [[ "$#" -eq 0 ]]; then
    echo "You must provide at least one command."
    echo
    usage
    exit 1
fi


CMD=$1

shift

# Check fundamentals commands
if [[ "${CMD}" == "build" ]] ; then
    sphinx-build -M html "." "_build" -E
    exit 0
elif [[ "${CMD}" == "preview" ]] ; then
    start_preview
    exit 0
else
    usage
    exit 0
fi


popd &>/dev/null || exit 1