#!/usr/bin/env bash

### Install PR ###
#
# This script takes a GitHub pull request number as an argument and loads the
# images into a local Kubernetes cluster. It then installs the CLI so that it
# can be used to install with any specific configuration needed.
#
# It requires a GitHub personal access token in the $GITHUB_TOKEN environment
# variable.

set -eo pipefail

# Read script flags and arguments
while :
do
  case $1 in
    -h|--help)
      echo "Install Linkerd with the changes made in a GitHub Pull Request."
      echo ""
      echo "Usage:"
      echo "    --cluster: The name of the cluster to use"
      echo ""
      echo "    # Install Linkerd into the current cluster"
      echo "    bin/install-pr 1234"
      echo ""
      echo "    # Install Linkerd into the current k3d cluster"
      echo "    bin/install-pr --k3d 1234"
      echo ""
      echo "    # Install Linkerd into the current KinD cluster"
      echo "    bin/install-pr --kind 1234"
      echo ""
      echo "    # Install Linkerd into the 'pr-1234' k3d cluster"
      echo "    bin/install-pr --k3d --cluster pr-1234 1234"
      exit 0
      ;;
    --cluster)
      cluster=$2
      shift
      ;;
    --kind)
      is_kind=1
      ;;
    --k3d)
      is_k3d=1
      ;;
    -?*)
      echo "Error: Unknown option: $1" >&2
      exit 1
      ;;
    *)
      break
  esac
  shift
done

pr=$1

if [ -z "$pr" ]
then
  echo "Error: ${0##*/} accepts 1 argument" >&2
  echo "Usage:" >&2
  echo "    ${0##*/} ####" >&2
  exit 1
fi

if [ -z "$GITHUB_TOKEN" ]
then
  # shellcheck disable=SC2016
  echo 'Error: Generate a personal access token at https://github.com/settings/tokens and set it in the $GITHUB_TOKEN env var'
  exit 1
fi

linkerd2_pulls_url="https://api.github.com/repos/linkerd/linkerd2/pulls"
linkerd2_integration_url="https://api.github.com/repos/linkerd/linkerd2/actions/workflows/integration_tests.yml"

# Get the URL for downloading the artifacts archive
auth="Authorization: token $GITHUB_TOKEN"
branch=$(curl -sL -H "$auth" "$linkerd2_pulls_url/$pr" | jq -r '.head.ref')
artifacts=$(curl -sL -H "$auth" "$linkerd2_integration_url/runs?branch=$branch" | jq -r '.workflow_runs[0].artifacts_url')
archive=$(curl -sL -H "$auth" "$artifacts" | jq -r '.artifacts[0].archive_download_url')

bindir=$( cd "${BASH_SOURCE[0]%/*}" && pwd )
dir=$(mktemp -d -t "linkerd-pr-$pr.XXXXXXXXXX")

cd "$dir" || exit

echo "### Downloading images ###"

curl -L -o archive.zip -H "$auth" "$archive"
unzip -o archive.zip -d image-archives/

echo "### Loading images into Docker ###"

image=$(docker load -i image-archives/cli-bin.tar | sed 's/Loaded image: //')
tag=$(echo "$image" | cut -f 2 -d ":")

if [ $is_kind ] || [ $is_k3d ]
then
  distro="k3d"
  if [ $is_kind ]
  then
    distro="kind"
  fi
  "$bindir"/image-load --"$distro" --archive "$cluster"
else
  for image in cni-plugin controller debug grafana proxy web
  do
    image=$(docker load -i "image-archives/$image.tar" | sed 's/Loaded image: //')
    docker push "$image"
  done
fi

cd -

rm -rf "$dir"

case $(uname) in
  Darwin)
    platform="darwin"
    ;;
  Linux)
    platform="linux"
    ;;
  *)
    platform="windows"
    ;;
esac

linkerd=$("$bindir"/docker-pull-binaries "$tag" | awk -v platform=$platform '$0 ~ platform')

echo ""
echo "Linkerd CLI available:"
echo "$linkerd"