#!/bin/bash
if [[ "$1" == "" ]]; then
  echo "ERROR: Please specifiy the version"
  exit 1
else
  REVISION=$1
fi

################################################################################
# Implementation
################################################################################

# find_revision(version)
get_source_tag() {
  curl -s https://go.googlecode.com/hg/.hgtags | awk '{print $2;}' | grep "$1" > /dev/null 2>&1
  if [[ $? -ne 0 ]]; then
    return 1
  fi
  SOURCE_TAG=`curl -s https://go.googlecode.com/hg/.hgtags | awk '{print $2;}' | grep "$1" | tail -n 1`
}

# download_revision(revision, destination)
download_revision() {
  hg clone -u $1 https://go.googlecode.com/hg/ $2
  if [[ $? -ne 0 ]]; then
    return 1
  fi
}

# compile_go(source)
compile_go() {
  unset GOARCH
  unset GOOS
  unset GOPATH
  export GOBIN=$1/bin
  export PATH=$GOBIN:$PATH
  export GOROOT=$1
  cd $1/src && ./all.bash
  if [[ $? -ne 0 ]]; then
    return 1
  fi
}

################################################################################
# Interface
################################################################################

download() {
  echo " * Downloading..."
  download_revision $SOURCE_TAG $SOURCE_ROOT > $GVM_ROOT/logs/$SOURCE_TAG-download.log 2>&1
  if [[ $? -ne 0 ]]; then
    echo "Failed to download version $SOURCE_TAG. See logs in $GVM_ROOT/logs/$SOURCE_TAG-download.log for details"
    exit 1
  fi
}

copy_source() {
  cp -r $SOURCE_ROOT $INSTALL_ROOT
  if [[ $? -ne 0 ]]; then
    echo "Failed to copy from cache"
    exit 1
  fi
}

setup_install_env() {
  get_source_tag $REVISION
  if [[ $? -ne 0 ]]; then
    echo "Failed to find go release version: '$1'"
    exit 1
  fi

  SOURCE_ROOT=$GVM_ROOT/archive/$SOURCE_TAG
  INSTALL_ROOT=$GVM_ROOT/gos/$SOURCE_TAG

  if [[ -d $INSTALL_ROOT ]]; then
    echo "Already installed!"
    exit 1
  else
    echo "Installing version $SOURCE_TAG"
  fi

  if [[ ! -d $SOURCE_ROOT ]]; then
    download
  fi

  trap 'rm -rf $INSTALL_ROOT' INT
  copy_source
}

compile() {
  echo " * Compiling..."
  compile_go $INSTALL_ROOT > $GVM_ROOT/logs/$SOURCE_TAG-compile.log 2>&1
  if [[ $? -ne 0 ]]; then
    echo "Failed to install version $SOURCE_TAG. See logs in $GVM_ROOT/logs/$SOURCE_TAG-compile.log for details"
    rm -rf $INSTALL_ROOT
    exit 1
  fi
}

install_gb() {
  echo " * Installing gb..."
  goinstall github.com/skelterjohn/go-gb/gb
  if [[ $? -ne 0 ]]; then
    echo "Failed to install gb"
    exit 1
  fi
}

install_goprotobuf() {
  echo " * Installing goprotobuf..."
  if [[ "$SOURCE_TAG" == "release.r60.3" ]]; then
    goinstall goprotobuf.googlecode.com/hg/proto
    if [[ $? -ne 0 ]]; then
      echo "Failed to install goprotobuf"
      exit 1
    fi
    cd $GOROOT/src/pkg/goprotobuf.googlecode.com/hg/compiler
    make install > $GVM_ROOT/logs/$SOURCE_TAG-pb-compiler.log 2>&1
    if [[ $? -ne 0 ]]; then
      echo "Failed to install goprotobuf compiler"
      exit 1
    fi
  else
    echo "   Don't know how to install goprotobuf for $SOURCE_TAG"
  fi
}

create_env_file() {
  gvm_go_name=$SOURCE_TAG
  mkdir -p $GVM_ROOT/environments
  mkdir -p $GVM_ROOT/pkgsets/$SOURCE_TAG/global
  new_env_file=$GVM_ROOT/environments/$SOURCE_TAG
  echo "export gvm_go_name; gvm_go_name=\"$gvm_go_name\"" > $new_env_file
  echo "unset gvm_pkgset_name" >> $new_env_file
  echo "export GOROOT; GOROOT=\"\$GVM_ROOT/gos/$gvm_go_name\"" >> $new_env_file
  echo "export GOPATH; GOPATH=\"\$GVM_ROOT/pkgsets/$gvm_go_name/global\"" >> $new_env_file
  echo "export PATH; PATH=\"\$GVM_ROOT/pkgsets/$gvm_go_name/global/bin:\$GVM_ROOT/gos/$gvm_go_name/bin:\$GVM_ROOT/bin:\$PATH\"" >> $new_env_file
}

main() {
  setup_install_env
  compile
  create_env_file
  install_gb
  install_goprotobuf
}

main