#!/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.
#

# Determine the current working directory
_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
# Preserve the calling directory
_CALLING_DIR="$(pwd)"

# Installs any application tarball given a URL, the expected tarball name,
# and, optionally, a checkable binary path to determine if the binary has
# already been installed
## Arg1 - URL
## Arg2 - Tarball Name
## Arg3 - Checkable Binary
install_app() {
  local remote_tarball="$1/$2"
  local local_tarball="${_DIR}/$2"
  local binary="${_DIR}/$3"

  # setup `curl` and `wget` silent options if we're running on Jenkins
  local curl_opts=""
  local wget_opts=""
  if [ -n "$AMPLAB_JENKINS" ]; then
    curl_opts="-s"
    wget_opts="--quiet"
  else
    curl_opts="--progress-bar"
    wget_opts="--progress=bar:force"
  fi

  if [ -z "$3" -o ! -f "$binary" ]; then
    # check if we already have the tarball
    # check if we have curl installed
    # download application
    [ ! -f "${local_tarball}" ] && [ $(command -v curl) ] && \
      echo "exec: curl ${curl_opts} ${remote_tarball}" && \
      curl ${curl_opts} "${remote_tarball}" > "${local_tarball}"
    # if the file still doesn't exist, lets try `wget` and cross our fingers
    [ ! -f "${local_tarball}" ] && [ $(command -v wget) ] && \
      echo "exec: wget ${wget_opts} ${remote_tarball}" && \
      wget ${wget_opts} -O "${local_tarball}" "${remote_tarball}"
    # if both were unsuccessful, exit
    [ ! -f "${local_tarball}" ] && \
      echo -n "ERROR: Cannot download $2 with cURL or wget; " && \
      echo "please install manually and try again." && \
      exit 2
    cd "${_DIR}" && tar -xzf "$2"
    rm -rf "$local_tarball"
  fi
}

# Install maven under the build/ folder
install_mvn() {
  install_app \
    "http://archive.apache.org/dist/maven/maven-3/3.2.5/binaries" \
    "apache-maven-3.2.5-bin.tar.gz" \
    "apache-maven-3.2.5/bin/mvn"
  MVN_BIN="${_DIR}/apache-maven-3.2.5/bin/mvn"
}

# Install zinc under the build/ folder
install_zinc() {
  local zinc_path="zinc-0.3.5.3/bin/zinc"
  [ ! -f "${zinc_path}" ] && ZINC_INSTALL_FLAG=1
  install_app \
    "http://downloads.typesafe.com/zinc/0.3.5.3" \
    "zinc-0.3.5.3.tgz" \
    "${zinc_path}"
  ZINC_BIN="${_DIR}/${zinc_path}"
}

# Determine the Scala version from the root pom.xml file, set the Scala URL,
# and, with that, download the specific version of Scala necessary under
# the build/ folder
install_scala() {
  # determine the Scala version used in Spark
  local scala_version=`grep "scala.version" "${_DIR}/../pom.xml" | \
                       head -1 | cut -f2 -d'>' | cut -f1 -d'<'`
  local scala_bin="${_DIR}/scala-${scala_version}/bin/scala"

  install_app \
    "http://downloads.typesafe.com/scala/${scala_version}" \
    "scala-${scala_version}.tgz" \
    "scala-${scala_version}/bin/scala"

  SCALA_COMPILER="$(cd "$(dirname ${scala_bin})/../lib" && pwd)/scala-compiler.jar"
  SCALA_LIBRARY="$(cd "$(dirname ${scala_bin})/../lib" && pwd)/scala-library.jar"
}

# Determines if a given application is already installed. If not, will attempt
# to install
## Arg1 - application name
## Arg2 - Alternate path to local install under build/ dir
check_and_install_app() {
  # create the local environment variable in uppercase
  local app_bin="`echo $1 | awk '{print toupper(\$0)}'`_BIN"
  # some black magic to set the generated app variable (i.e. MVN_BIN) into the
  # environment
  eval "${app_bin}=`which $1 2>/dev/null`"

  if [ -z "`which $1 2>/dev/null`" ]; then
    install_$1
  fi
}

# Setup healthy defaults for the Zinc port if none were provided from
# the environment
ZINC_PORT=${ZINC_PORT:-"3030"}

# Check and install all applications necessary to build Spark
check_and_install_app "mvn"

# Install the proper version of Scala and Zinc for the build
install_zinc
install_scala

# Reset the current working directory
cd "${_CALLING_DIR}"

# Now that zinc is ensured to be installed, check its status and, if its
# not running or just installed, start it
if [ -n "${ZINC_INSTALL_FLAG}" -o -z "`${ZINC_BIN} -status`" ]; then
  ${ZINC_BIN} -shutdown
  ${ZINC_BIN} -start -port ${ZINC_PORT} \
    -scala-compiler "${SCALA_COMPILER}" \
    -scala-library "${SCALA_LIBRARY}" &>/dev/null
fi

# Set any `mvn` options if not already present
export MAVEN_OPTS=${MAVEN_OPTS:-"-Xmx2g -XX:MaxPermSize=512M -XX:ReservedCodeCacheSize=512m"}

# Last, call the `mvn` command as usual
${MVN_BIN} "$@"