#!/bin/bash

err_report() {
  echo "Error on line $1"
}

trap 'err_report $LINENO' ERR

usage() {
  echo "Usage: $0
Options:
  $1" 1>&2;
  exit 1;
}


force_create=0;


while getopts "hv" o; do
  case "${o}" in
    v) go_version=${OPTARG}
       ;;
    h) usage "-v (optional) go lang version (default: 1.10.1)
       -h help" >&2;
       exit 0;;
    \?) usage "-v (optional) go lang version (default: 1.10.1)
        -h help" >&2;
       exit 1;;
    :) echo "Option -$OPTARG requires an argument." >&2
       exit 1;;
    esac
done

if [ ! "$go_version" ]
then
  go_version='1.10.1';
fi

version="$go_version";

unameOut="$(uname -s)"
case "${unameOut}" in
    Linux*)     machine=$(echo "$unameOut" | tr '[:upper:]' '[:lower:]');
                ;;
    Darwin*)    machine=$(echo "$unameOut" | tr '[:upper:]' '[:lower:]');
                ;;
    *)          machine="UNKNOWN:${unameOut}"
esac

# get the user running the script
user=$(whoami | awk '{print $1}');
echo "User: "$user;

COMPANY_NAME=company

if [ $machine == 'linux' ]; then
  echo "OS type: Linux"
  company_home="/home/$user/$COMPANY_NAME";
  bashrc_path="/home/$user/.bashrc";
elif [ $machine == 'darwin' ]; then
  echo "OS type: OS X"
  company_home="/Users/$user/$COMPANY_NAME";
  bashrc_path="/Users/$user/.bash_profile";
else
  echo "OS type: unknown"
  company_home="/home/$user/$COMPANY_NAME";
  bashrc_path="/home/$user/.profile";
fi

mkdir -p $company_home;
# chown -R $user:$user $company_home;

function source_env {
  source $bashrc_path;
}


if [ ! -f go$version.$machine-amd64.tar.gz ]; then
  # download only if go source is not present
  echo "Downloading go lang version for "${machine}
  echo go$version.$machine-amd64.tar.gz;
  wget https://storage.googleapis.com/golang/go$version.$machine-amd64.tar.gz;
  chown -R $user:$user go$version.$machine-amd64.tar.gz;
else
  echo "Using existing go source: go"$version.$machine-amd64.tar.gz;
  chown -R $user:$user go$version.$machine-amd64.tar.gz;
fi

sudo tar -C /usr/local -xzf go$version.$machine-amd64.tar.gz;

echo "Go downloaded and extracted to /usr/local/go."

echo "Setting GOROOT and GOPATH in bashrc"

echo '# company configurations' >> $bashrc_path;

echo 'export COMPANY_NAME=company' >> $bashrc_path;

source_env

echo '# go configurations' >> $bashrc_path;
echo 'export PATH=$PATH:/usr/local/go/bin' >> $bashrc_path;

source_env

go_workspace=$company_home/go;
mkdir -p $go_workspace $go_workspace/src $go_workspace/pkg $go_workspace/bin

echo "export GOPATH=$company_home/go" >> $bashrc_path;

source_env

echo "go lang installed in the below path: "
eval echo "location: /usr/local/go/bin";
eval echo "GOPATH: ${go_workspace}";

/usr/local/go/bin/go version;