#!/usr/bin/env bash

# This simple script can be used to set up a CI node running MacOS.
# An additional requirement that is *not* handled by this script is the
# installation of Xcode, which requires manual intervention.
#
# This script should first be run from an administrator account to install
# the dependencies necessary for running CI. It can be run without having
# to clone the LLVM repository with:
#
#   $ /bin/bash -c "$(curl -fsSl https://raw.githubusercontent.com/llvm/llvm-project/main/libcxx/utils/ci/macos-ci-setup)"
#
# If you perform system updates, you should re-run the script from the
# administrator account -- this allows updating the packages used for
# CI and the BuildKite agent tags.
#
# Once the necessary dependencies have been installed, you can switch
# to a non-administrator account and run the script again, passing the
# --setup-launchd argument. That will install a Launchd agent to run the
# BuildKite agent whenever the current user is logged in. You should enable
# automatic login for that user, so that if the CI node goes down, the user
# is logged back in automatically when the node goes up again, and the
# BuildKite agent starts automatically.
#
# Alternatively, you can simply run the BuildKite agent by hand using:
#
#   $ caffeinate -s buildkite-agent start --build-path /tmp/buildkite-builds

set -e

# Install a Launchd agent that will automatically start the BuildKite agent at login
if [[ ${1} == "--setup-launchd" ]]; then
  HOMEBREW_PREFIX="$(brew --prefix)"
  mkdir -p ~/Library/LaunchAgents
  cat <<EOF > ~/Library/LaunchAgents/libcxx.buildkite-agent.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>libcxx.buildkite-agent</string>

  <key>ProgramArguments</key>
  <array>
    <string>${HOMEBREW_PREFIX}/bin/buildkite-agent</string>
    <string>start</string>
    <string>--build-path</string>
    <string>${HOME}/libcxx.buildkite-agent/builds</string>
  </array>

  <key>EnvironmentVariables</key>
  <dict>
    <key>PATH</key>
    <string>${HOMEBREW_PREFIX}/bin:/usr/bin:/bin:/usr/sbin:/sbin</string>
  </dict>

  <key>RunAtLoad</key>
  <true/>

  <key>KeepAlive</key>
  <dict>
    <key>SuccessfulExit</key>
    <false/>
  </dict>

  <key>ProcessType</key>
  <string>Interactive</string>

  <key>ThrottleInterval</key>
  <integer>30</integer>

  <key>StandardOutPath</key>
  <string>${HOME}/libcxx.buildkite-agent/stdout.log</string>

  <key>StandardErrorPath</key>
  <string>${HOME}/libcxx.buildkite-agent/stderr.log</string>
</dict>
</plist>
EOF

  echo "Starting BuildKite agent"
  launchctl load ~/Library/LaunchAgents/libcxx.buildkite-agent.plist

else
  echo "Installing CI dependencies for macOS"

  if [[ -z "${BUILDKITE_AGENT_TOKEN}" ]]; then
    echo "The BUILDKITE_AGENT_TOKEN environment variable must be set to a BuildKite Agent token when calling this script."
    exit 1
  fi

  # Install Homebrew
  if ! which -s brew; then
    /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
  fi

  # Install the required tools to run CI
  brew update
  for package in sphinx-doc python3 ninja cmake clang-format buildkite/buildkite/buildkite-agent; do
    if brew ls --versions "${package}" >/dev/null; then
      brew upgrade "${package}"
    else
      brew install "${package}"
    fi
  done
  python3 -m pip install --upgrade psutil

  echo "Setting up BuildKite Agent config"
  version="$(sw_vers -productVersion | sed -E 's/([0-9]+).([0-9]+).[0-9]+/\1.\2/')"
  arch="$(uname -m)"
  cat <<EOF > "$(brew --prefix)/etc/buildkite-agent/buildkite-agent.cfg"
token="${BUILDKITE_AGENT_TOKEN}"
tags="queue=libcxx-builders,arch=${arch},os=macos,os=macos${version}"
build-path=/tmp/buildkite-builds # Note that this is actually overwritten when starting the agent with launchd
EOF
fi