#!/usr/bin/env bash
set -euo pipefail
umask 077

ROOT=$(CDPATH='' cd -- "$(dirname -- "$0")/.." && pwd)
action=${1:-plan}
ssh_target=${2:-whoneedhelp}

case "$action" in
  plan | prepare | apply) ;;
  *)
    echo "Usage: $0 [plan|prepare|apply] [SSH_TARGET]" >&2
    exit 2
    ;;
esac

for command in git mktemp realpath; do
  command -v "$command" >/dev/null 2>&1 || {
    echo "Required command is unavailable: $command" >&2
    exit 2
  }
done

candidate=$(git -C "$ROOT" rev-parse --verify HEAD)
artifact_root=${WNH_PRODUCTION_RELEASE_ARTIFACT_ROOT:-"$ROOT/output/releases"}
case "$artifact_root" in
  /*) ;;
  *)
    echo "WNH_PRODUCTION_RELEASE_ARTIFACT_ROOT must be an absolute path." >&2
    exit 2
    ;;
esac
mkdir -p "$artifact_root"
artifact_root=$(realpath --canonicalize-existing "$artifact_root")

worktree_root=${WNH_PRODUCTION_RELEASE_WORKTREE_ROOT:-"$ROOT/output/release-worktrees"}
case "$worktree_root" in
  /*) ;;
  *)
    echo "WNH_PRODUCTION_RELEASE_WORKTREE_ROOT must be an absolute path." >&2
    exit 2
    ;;
esac
mkdir -p "$worktree_root"
worktree_root=$(realpath --canonicalize-existing "$worktree_root")
chmod 700 "$worktree_root"

checkout=$(mktemp -d "$worktree_root/${candidate}.XXXXXX")
rmdir "$checkout"
worktree_added=false

cleanup() {
  local status=$?
  trap - EXIT HUP INT TERM
  if [[ "$worktree_added" == true ]]; then
    git -C "$ROOT" worktree remove --force "$checkout" >/dev/null 2>&1 || true
  fi
  if [[ -d "$checkout" ]]; then
    rmdir "$checkout" >/dev/null 2>&1 || true
  fi
  exit "$status"
}
trap cleanup EXIT
trap 'exit 129' HUP
trap 'exit 130' INT
trap 'exit 143' TERM

worktree_added=true
git -C "$ROOT" worktree add --quiet --detach "$checkout" "$candidate"

[[ -z "$(git -C "$checkout" status --porcelain --untracked-files=no)" ]] || {
  echo "The detached release checkout is unexpectedly dirty." >&2
  exit 2
}
[[ "$(git -C "$checkout" rev-parse --verify HEAD)" == "$candidate" ]] || {
  echo "The detached release checkout does not match the selected commit." >&2
  exit 2
}

printf 'Release candidate: %s\n' "$candidate"
printf 'Clean detached checkout: %s\n' "$checkout"
printf 'Artifact root: %s\n' "$artifact_root"

(
  cd "$checkout"
  WNH_PRODUCTION_RELEASE_ARTIFACT_ROOT="$artifact_root" \
    ./scripts/production-release.sh "$action" "$ssh_target"
)