#!/usr/bin/env bash
set -eo pipefail; [[ $TRACE ]] && set -x

# A script to bootstrap dokku.
# It expects to be run on Ubuntu 14.04 via 'sudo'
# If installing a tag higher than 0.3.13, it may install dokku via a package (so long as the package is higher than 0.3.13)
# It checks out the dokku source code from Github into ~/dokku and then runs 'make install' from dokku source.

# We wrap this whole script in functions, so that we won't execute
# until the entire script is downloaded.
# That's good because it prevents our output overlapping with wget's.
# It also means that we can't run a partially downloaded script.

proc ensure-environment {
  local FREE_MEMORY
  echo "Preparing to install $DOKKU_TAG from $DOKKU_REPO..."
  if ! command -v apt-get &>/dev/null {
    echo "This installation script requires apt-get. For manual installation instructions, consult http://dokku.viewdocs.io/dokku/advanced-installation/"
    exit 1
  }

  hostname -f > /dev/null !2 > !1 || do {
    echo "This installation script requires that you have a hostname set for the instance. Please set a hostname for 127.0.0.1 in your /etc/hosts"
    exit 1
  }

  setglobal FREE_MEMORY = $[grep MemTotal /proc/meminfo | awk '{print $2}]
  if [[ "$FREE_MEMORY" -lt 1003600 ]] {
    echo "For dokku to build containers, it is strongly suggested that you have 1024 megabytes or more of free memory"
    echo "If necessary, please consult this document to setup swap: http://dokku.viewdocs.io/dokku/advanced-installation/#vms-with-less-than-1gb-of-memory"
  }
}

proc install-requirements {
  echo "--> Ensuring we have the proper dependencies"
  apt-get update -qq > /dev/null
  if [[ $(lsb_release -sr) == "12.04" ]] {
    apt-get -qq -y install python-software-properties
  }
}

proc install-dokku {
  if [[ -n $DOKKU_BRANCH ]] {
    install-dokku-from-source "origin/$DOKKU_BRANCH"
  } elif [[ -n $DOKKU_TAG ]] {
    local DOKKU_SEMVER="$(DOKKU_TAG//v)"
    setglobal major = $[echo $DOKKU_SEMVER | awk '{split($0,a,"."); print a[1]}]
    setglobal minor = $[echo $DOKKU_SEMVER | awk '{split($0,a,"."); print a[2]}]
    setglobal patch = $[echo $DOKKU_SEMVER | awk '{split($0,a,"."); print a[3]}]

    # 0.3.13 was the first version with a debian package
    if [[ "$major" -eq "0" ]] && [[ "$minor" -eq "3" ]] && [[ "$patch" -ge "13" ]] {
      install-dokku-from-package $DOKKU_SEMVER
      echo "--> Running post-install dependency installation"
      dokku plugins-install-dependencies
    # 0.4.0 implemented a `plugin` plugin
    } elif [[ "$major" -eq "0" ]] && [[ "$minor" -ge "4" ]] && [[ "$patch" -ge "0" ]] {
      install-dokku-from-package $DOKKU_SEMVER
      echo "--> Running post-install dependency installation"
      sudo -E dokku plugin:install-dependencies --core
    } else {
      install-dokku-from-source $DOKKU_TAG
    }
  } else {
    install-dokku-from-package
    echo "--> Running post-install dependency installation"
    sudo -E dokku plugin:install-dependencies --core
  }
}


proc install-dokku-from-source {
  local DOKKU_CHECKOUT="$1"
  apt-get -qq -y install git make software-properties-common
  cd /root
  if [[ ! -d /root/dokku ]] {
    git clone $DOKKU_REPO /root/dokku
  }

  cd /root/dokku
  git fetch origin
  [[ -n $DOKKU_CHECKOUT ]] && git checkout $DOKKU_CHECKOUT
  make install
}

proc install-dokku-from-package {
  local DOKKU_CHECKOUT="$1"
  local NO_INSTALL_RECOMMENDS=$(DOKKU_NO_INSTALL_RECOMMENDS:="")

  if [[ -n $DOKKU_DOCKERFILE ]] {
    setglobal NO_INSTALL_RECOMMENDS = '" --no-install-recommends '"
  }

  echo "--> Initial apt-get update"
  apt-get update -qq > /dev/null
  apt-get -qq -y install apt-transport-https

  echo "--> Installing docker"
  if uname -r | grep -q linode {
    echo "--> NOTE: Using Linode? Docker might complain about missing AUFS support."
    echo "    See http://dokku.viewdocs.io/dokku/getting-started/install/linode/"
    echo "    Installation will continue in 10 seconds."
    sleep 10
  }
  wget -nv -O - https://get.docker.com/ | sh

  echo "--> Installing dokku"
  wget -nv -O - https://packagecloud.io/gpg.key | apt-key add -
  echo "deb https://packagecloud.io/dokku/dokku/ubuntu/ trusty main" | tee /etc/apt/sources.list.d/dokku.list
  apt-get update -qq > /dev/null

  [[ -n $DOKKU_VHOST_ENABLE ]]  && echo "dokku dokku/vhost_enable boolean $DOKKU_VHOST_ENABLE"   | sudo debconf-set-selections
  [[ -n $DOKKU_WEB_CONFIG ]]    && echo "dokku dokku/web_config boolean $DOKKU_WEB_CONFIG"       | sudo debconf-set-selections
  [[ -n $DOKKU_HOSTNAME ]]      && echo "dokku dokku/hostname string $DOKKU_HOSTNAME"            | sudo debconf-set-selections
  [[ -n $DOKKU_SKIP_KEY_FILE ]] && echo "dokku dokku/skip_key_file boolean $DOKKU_SKIP_KEY_FILE" | sudo debconf-set-selections
  [[ -n $DOKKU_KEY_FILE ]]      && echo "dokku dokku/key_file string $DOKKU_KEY_FILE"            | sudo debconf-set-selections

  if [[ -n $DOKKU_CHECKOUT ]] {
    # shellcheck disable=SC2086
    apt-get -qq -y $NO_INSTALL_RECOMMENDS install "dokku=$DOKKU_CHECKOUT"
  } else {
    # shellcheck disable=SC2086
    apt-get -qq -y $NO_INSTALL_RECOMMENDS install dokku
  }
}

proc main {
  export DEBIAN_FRONTEND=noninteractive
  export DOKKU_REPO=$(DOKKU_REPO:-"https://github.com/dokku/dokku.git")

  ensure-environment
  install-requirements
  install-dokku
}

main @Argv