#!/usr/bin/env bash

set -Eeuo pipefail

REMOTE="${BLISS_DEPLOY_REMOTE:-root@134.122.14.193}"
APP_DIR="${BLISS_DEPLOY_APP_DIR:-/home/nodejs/bliss2}"
ROOT_DIR="$(cd "$(dirname "$0")" && pwd)"
LOCAL_BRANCH="${BLISS_DEPLOY_BRANCH:-main}"
TRANSFER_DIR="$(mktemp -d)"
CONTROL_SOCKET="$TRANSFER_DIR/ssh-control"
LOCAL_BUNDLE="$TRANSFER_DIR/bliss.bundle"

cleanup() {
  ssh -S "$CONTROL_SOCKET" -O exit "$REMOTE" >/dev/null 2>&1 || true
  rm -rf "$TRANSFER_DIR"
}
trap cleanup EXIT

echo "Updating $REMOTE:$APP_DIR"
echo "You may be prompted for the droplet passcode."

git -C "$ROOT_DIR" rev-parse --verify "$LOCAL_BRANCH" >/dev/null
echo "Bundling committed local branch $LOCAL_BRANCH..."
git -C "$ROOT_DIR" bundle create "$LOCAL_BUNDLE" "$LOCAL_BRANCH"

ssh -M -S "$CONTROL_SOCKET" -o ControlPersist=60 -o ConnectTimeout=15 -fnNT "$REMOTE"
REMOTE_BUNDLE="$(ssh -S "$CONTROL_SOCKET" "$REMOTE" mktemp /tmp/bliss-deploy.XXXXXX.bundle)"
scp -q -o ControlPath="$CONTROL_SOCKET" "$LOCAL_BUNDLE" "$REMOTE:$REMOTE_BUNDLE"

ssh -S "$CONTROL_SOCKET" "$REMOTE" bash -s -- "$APP_DIR" "$REMOTE_BUNDLE" "$LOCAL_BRANCH" <<'REMOTE_SCRIPT'
set -Eeuo pipefail

APP_DIR="$1"
DEPLOY_BUNDLE="$2"
DEPLOY_BRANCH="$3"
cleanup_bundle() {
  rm -f "$DEPLOY_BUNDLE"
}
trap cleanup_bundle EXIT

cd "$APP_DIR"

test -f package.json || { echo "No package.json in $APP_DIR" >&2; exit 1; }
test -d .git || { echo "$APP_DIR is not a Git checkout" >&2; exit 1; }

if [[ -n "$(git status --porcelain --untracked-files=no)" ]]; then
  echo "Refusing to pull: the deployed checkout has uncommitted tracked changes:" >&2
  git status --short --untracked-files=no >&2
  exit 1
fi

OLD_HEAD="$(git rev-parse HEAD)"
OLD_LOCK="$(sha256sum package-lock.json 2>/dev/null | awk '{print $1}' || true)"

echo "Pulling Git changes..."
git fetch "$DEPLOY_BUNDLE" "$DEPLOY_BRANCH"
git merge --ff-only FETCH_HEAD

NEW_HEAD="$(git rev-parse HEAD)"
NEW_LOCK="$(sha256sum package-lock.json 2>/dev/null | awk '{print $1}' || true)"

if [[ ! -d node_modules || "$OLD_LOCK" != "$NEW_LOCK" ]]; then
  echo "Installing production dependencies..."
  if [[ -f package-lock.json ]]; then
    npm ci --omit=dev
  else
    npm install --omit=dev
  fi
else
  echo "Dependencies unchanged; skipping npm install."
fi

mapfile -t APP_PIDS < <(
  for process_dir in /proc/[0-9]*; do
    [[ "$(readlink "$process_dir/cwd" 2>/dev/null || true)" == "$APP_DIR" ]] || continue
    [[ "$(cat "$process_dir/comm" 2>/dev/null || true)" == "node" ]] || continue
    basename "$process_dir"
  done
)

if [[ "${#APP_PIDS[@]}" -eq 0 ]]; then
  echo "No running Node process found for $APP_DIR; refusing to guess how to start it." >&2
  exit 1
fi

APP_PID="${APP_PIDS[0]}"
SERVICE=""

while IFS= read -r unit; do
  [[ -n "$unit" ]] || continue
  if [[ "$(systemctl show -p MainPID --value "$unit" 2>/dev/null || true)" == "$APP_PID" ]]; then
    SERVICE="$unit"
    break
  fi
done < <(systemctl list-units --type=service --all --no-legend --plain 2>/dev/null | awk '{print $1}')

if [[ -n "$SERVICE" ]]; then
  echo "Restarting systemd service $SERVICE..."
  systemctl restart "$SERVICE"
  systemctl is-active --quiet "$SERVICE"
  systemctl --no-pager --full status "$SERVICE" | sed -n '1,12p'
elif command -v pm2 >/dev/null 2>&1 && pm2 pid all 2>/dev/null | grep -qx "$APP_PID"; then
  echo "Restarting PM2 process $APP_PID..."
  pm2 restart "$APP_PID" --update-env
  pm2 show "$APP_PID"
else
  echo "Found Node PID $APP_PID, but it is not managed by systemd or PM2." >&2
  echo "The code was updated from $OLD_HEAD to $NEW_HEAD, but the process was not restarted." >&2
  echo "Refusing to kill it without knowing the correct startup mechanism." >&2
  exit 1
fi

echo "Deployment updated successfully: $OLD_HEAD -> $NEW_HEAD"
REMOTE_SCRIPT