#!/usr/bin/env bash

set -euo pipefail

fail() {
  printf 'release-service client: %s\n' "$*" >&2
  exit 1
}

require_safe_value() {
  local name="$1"
  local value="$2"
  local pattern="$3"

  [[ -n "${value}" ]] || fail "${name} is required"
  [[ "${value}" =~ ${pattern} ]] || fail "${name} contains unsupported characters"
}

decode_required_file() {
  local output_path="$1"
  local encoded_value="$2"
  local description="$3"

  [[ -n "${encoded_value}" ]] || fail "${description} base64 secret is required"
  printf '%s' "${encoded_value}" | base64 -d >"${output_path}" || fail \
    "${description} base64 secret is invalid"
  [[ -s "${output_path}" ]] || fail "${description} decoded to an empty file"
}

[[ $# -ge 3 ]] || fail \
  "usage: release-service.sh <service-group> <run-id> <exact-image-ref...> [--refresh-data]"

service_group="$1"
run_id="$2"
shift 2

refresh_data=false
if [[ "${!#}" == "--refresh-data" ]]; then
  refresh_data=true
  set -- "${@:1:$(($# - 1))}"
fi

case "${service_group}" in
  state-corp-backend)
    expected_refs=2
    ;;
  state-corp-frontend)
    expected_refs=1
    ;;
  *)
    fail "unsupported service group: ${service_group}"
    ;;
esac

[[ $# -eq ${expected_refs} ]] || fail \
  "${service_group} requires exactly ${expected_refs} image reference(s)"
require_safe_value "run id" "${run_id}" '^[A-Za-z0-9._:-]+$'

release_host="${RELEASE_HOST:-}"
release_user="${RELEASE_USER:-}"
release_proxy="${RELEASE_PROXY:-}"
release_service_path="${RELEASE_SERVICE_PATH:-}"

require_safe_value "RELEASE_HOST" "${release_host}" '^[A-Za-z0-9._:-]+$'
require_safe_value "RELEASE_USER" "${release_user}" '^[A-Za-z0-9._-]+$'
require_safe_value \
  "RELEASE_SERVICE_PATH" "${release_service_path}" '^/[A-Za-z0-9._/-]+$'
case "${release_service_path}" in
  /opt/ecos-dev/release-service)
    image_ref_pattern='^[A-Za-z0-9._:/-]+@sha256:[a-f0-9]{64}$'
    [[ "${refresh_data}" == false ]] || fail "dev releases cannot refresh data"
    ;;
  /opt/ecos-main/release-service)
    image_ref_pattern='^[A-Za-z0-9._:/-]+@sha256:[a-f0-9]{64}$'
    ;;
  /ecos/release-service)
    image_ref_pattern='^[A-Za-z0-9._:/-]+@sha256:[a-f0-9]{64}$'
    [[ "${refresh_data}" == false ]] || fail "customer releases cannot refresh data"
    ;;
  *)
    fail "unsupported RELEASE_SERVICE_PATH"
    ;;
esac
if [[ "${refresh_data}" == true && "${service_group}" != state-corp-backend ]]; then
  fail "only an internal-main backend release can refresh data"
fi
image_refs=("$@")
for image_ref in "${image_refs[@]}"; do
  [[ "${image_ref}" =~ ${image_ref_pattern} ]] || fail \
    "image reference does not match the selected release target contract"
done
if [[ -n "${release_proxy}" ]]; then
  require_safe_value "RELEASE_PROXY" "${release_proxy}" '^[A-Za-z0-9._@:-]+$'
fi

ssh_tmp_dir="$(mktemp -d)"
trap 'rm -rf "${ssh_tmp_dir}"' EXIT
key_path="${ssh_tmp_dir}/deploy-key"
known_hosts_path="${ssh_tmp_dir}/known-hosts"

decode_required_file \
  "${key_path}" \
  "${RELEASE_SSH_KEY_B64:-}" \
  "deploy SSH key"
decode_required_file \
  "${known_hosts_path}" \
  "${RELEASE_KNOWN_HOSTS_B64:-}" \
  "pinned SSH known_hosts"
chmod 0600 "${key_path}" "${known_hosts_path}"

ssh_options=(
  -i "${key_path}"
  -o BatchMode=yes
  -o ConnectTimeout=15
  -o GlobalKnownHostsFile=/dev/null
  -o IdentitiesOnly=yes
  -o LogLevel=ERROR
  -o StrictHostKeyChecking=yes
  -o "UserKnownHostsFile=${known_hosts_path}"
)

if [[ -n "${release_proxy}" ]]; then
  proxy_command="ssh -i ${key_path} -o BatchMode=yes -o ConnectTimeout=15"
  proxy_command+=" -o GlobalKnownHostsFile=/dev/null -o IdentitiesOnly=yes"
  proxy_command+=" -o LogLevel=ERROR -o StrictHostKeyChecking=yes"
  proxy_command+=" -o UserKnownHostsFile=${known_hosts_path}"
  proxy_command+=" -W %h:%p ${release_proxy}"
  ssh_options+=(-o "ProxyCommand=${proxy_command}")
fi

remote_args=("${service_group}" "${run_id}" "${image_refs[@]}")
if [[ "${refresh_data}" == true ]]; then
  remote_args+=(--refresh-data)
fi
printf -v remote_command '%q ' "${release_service_path}" "${remote_args[@]}"
remote_command="${remote_command% }"

# The command is deliberately assembled and validated on the client.
# shellcheck disable=SC2029
ssh "${ssh_options[@]}" \
  "${release_user}@${release_host}" \
  "${remote_command}"