#!/usr/bin/env nix-shell
#! nix-shell -i bash -p coreutils curl git jq moreutils nix nix-prefetch
# shellcheck shell=bash
# vim: ft=sh
#
# Update a terraform provider to the latest version advertised at the
# provider source address.
#
set -euo pipefail
shopt -s inherit_errexit

show_usage() {
  cat <<DOC
Usage: ./update-provider [--force] [--no-build] [<owner>/]<provider>

Update a single provider in the providers.json inventory file.

For example to update 'terraform-providers.aws' run:

    ./update-provider aws

If the provider is not in the list already, use the form '<owner>/<provider>'
to add the provider to the list:

    ./update-provider hetznercloud/hcloud

Options:

  * --force: Force the update even if the version matches.
  * --no-build: Don't build provider
DOC
}

build=1
force=
provider=
spdx=1

while [[ $# -gt 0 ]]; do
  case "$1" in
  -h | --help)
    show_usage
    exit
    ;;
  --force)
    force=1
    shift
    ;;
  --no-build)
    build=0
    shift
    ;;
  --no-spdx)
    spdx=0
    shift
    ;;
  *)
    if [[ -n ${provider} ]]; then
      echo "ERROR: provider name was passed two times: '${provider}' and '$1'"
      echo "Use --help for more info"
      exit 1
    fi
    provider=$1
    shift
    ;;
  esac
done

if [[ -z ${provider} ]]; then
  echo "ERROR: No providers specified!"
  echo
  show_usage
  exit 1
fi

# Usage: read_attr <key>
read_attr() {
  jq -r ".\"${provider}\".\"$1\"" providers.json
}

# Usage: update_attr <key> <value>
update_attr() {
  if [[ $2 == "null" ]]; then
    jq -S ".\"${provider}\".\"$1\" = null" providers.json | sponge providers.json
  else
    jq -S ".\"${provider}\".\"$1\" = \"$2\"" providers.json | sponge providers.json
  fi
}

repo_root=$(git rev-parse --show-toplevel)

generate_hash() {
  nix-prefetch -I nixpkgs="${repo_root}" \
    "{ sha256 }: (import ${repo_root} {}).terraform-providers.${provider}.$1.overrideAttrs (_: { inherit sha256; })"
}

echo_provider() {
  echo "== terraform-providers.${provider}: $* =="
}

pushd "$(dirname "$0")" >/dev/null

if [[ ${provider} =~ ^[^/]+/[^/]+$ ]]; then
  homepage="https://registry.terraform.io/providers/${provider}"
  provider=$(basename "${provider}")
  echo_provider "init"
  update_attr homepage "${homepage}"
  # create empty stings so nix-prefetch works
  update_attr hash ""
  update_attr vendorHash ""
fi

homepage="$(read_attr homepage)"

registry_response=$(curl -s "${homepage//providers/v1/providers}")

old_rev="$(read_attr rev)"
rev="$(jq -r '.tag' <<<"${registry_response}")"
if [[ ${force} != 1 ]]; then
  if [[ ${old_rev} == "${rev}" ]]; then
    echo_provider "already at version ${rev}"
    exit
  fi
  if [[ ${rev//v/} =~ [[:alpha:]] ]]; then
    echo_provider "not updating to unstable version ${rev}"
    exit
  fi
fi
echo_provider "updating from ${old_rev} to ${rev}"
update_attr rev "${rev}"

provider_source_url="$(jq -r '.source' <<<"${registry_response}")"

org="$(echo "${provider_source_url}" | cut -d '/' -f 4)"
update_attr owner "${org}"
repo="$(echo "${provider_source_url}" | cut -d '/' -f 5)"
update_attr repo "${repo}"

if [[ ${spdx} == 1 ]]; then
  spdx="$(curl -L -s ${GITHUB_TOKEN:+-u ":${GITHUB_TOKEN}"} "https://api.github.com/repos/${org}/${repo}/license" | jq -r '.license.spdx_id')"
  update_attr spdx "${spdx}"
fi

echo_provider "calculating hash"
hash=$(generate_hash src)
update_attr hash "${hash}"

old_vendor_hash="$(read_attr vendorHash)"
if [[ ${old_vendor_hash} != null ]]; then
  echo_provider "calculating vendorHash"
  vendorHash=$(generate_hash go-modules)
  update_attr vendorHash "${vendorHash}"
fi

# Check that the provider builds
if [[ ${build} == 1 ]]; then
  echo_provider "building"
  nix-build --no-out-link "${repo_root}" -A "terraform-providers.${provider}"
fi

popd >/dev/null