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

APP_ROOT="${APP_ROOT:-/opt/desineuron-velocity-site}"
REPO_URL="${REPO_URL:-https://git.desineuron.in/sagnik/Project_Velocity.git}"
BRANCH="${BRANCH:-main}"
REPO_DIR="${REPO_DIR:-$APP_ROOT/repo}"
APP_DIR="${APP_DIR:-$REPO_DIR/app}"
BUILD_DIR="${BUILD_DIR:-$APP_DIR/dist}"
SERVE_ROOT="${SERVE_ROOT:-/var/www/velocity.desineuron.in}"
CURRENT_DIR="${CURRENT_DIR:-$SERVE_ROOT/current}"
STATE_DIR="${STATE_DIR:-$APP_ROOT/state}"
REVISION_FILE="${REVISION_FILE:-$STATE_DIR/current_revision.txt}"
PERSISTENT_VIDEO_DIR="${PERSISTENT_VIDEO_DIR:-$APP_ROOT/shared/videos}"
BACKEND_SERVICE="${BACKEND_SERVICE:-desineuron-velocity-backend}"
BACKEND_HEALTH_URL="${BACKEND_HEALTH_URL:-http://127.0.0.1:8001/health}"
BACKEND_HEALTH_TIMEOUT_S="${BACKEND_HEALTH_TIMEOUT_S:-60}"
RUN_BACKEND_RESTART="${RUN_BACKEND_RESTART:-1}"
RUN_DB_MIGRATIONS="${RUN_DB_MIGRATIONS:-0}"
DB_MIGRATION_CMD="${DB_MIGRATION_CMD:-}"

mkdir -p "$APP_ROOT" "$STATE_DIR" "$SERVE_ROOT" "$PERSISTENT_VIDEO_DIR"

if ! command -v git >/dev/null 2>&1; then
  echo "git is required" >&2
  exit 1
fi

if ! command -v npm >/dev/null 2>&1; then
  echo "npm is required" >&2
  exit 1
fi

if ! command -v curl >/dev/null 2>&1; then
  echo "curl is required" >&2
  exit 1
fi

if [ ! -d "$REPO_DIR/.git" ]; then
  git clone "$REPO_URL" "$REPO_DIR"
fi

git -C "$REPO_DIR" fetch --all --prune
REMOTE_REVISION="$(git -C "$REPO_DIR" rev-parse "origin/$BRANCH")"
CURRENT_REVISION=""
if [ -f "$REVISION_FILE" ]; then
  CURRENT_REVISION="$(tr -d '\r\n' < "$REVISION_FILE")"
fi

if [ -n "$CURRENT_REVISION" ] && [ "$CURRENT_REVISION" = "$REMOTE_REVISION" ]; then
  date -u +"%Y-%m-%dT%H:%M:%SZ" > "$STATE_DIR/last_check_utc.txt"
  echo "No new revision on origin/$BRANCH. Current revision: $CURRENT_REVISION"
  exit 0
fi

git -C "$REPO_DIR" checkout "$BRANCH"
git -C "$REPO_DIR" reset --hard "origin/$BRANCH"

pushd "$APP_DIR" >/dev/null
if [ -f package-lock.json ]; then
  npm ci
else
  npm install
fi
npm run build
popd >/dev/null

rm -rf "$CURRENT_DIR"
mkdir -p "$CURRENT_DIR"
cp -a "$BUILD_DIR"/. "$CURRENT_DIR"/

if [ -d "$PERSISTENT_VIDEO_DIR" ] && [ "$(find "$PERSISTENT_VIDEO_DIR" -maxdepth 1 -type f | wc -l)" -gt 0 ]; then
  mkdir -p "$CURRENT_DIR/videos"
  cp -a "$PERSISTENT_VIDEO_DIR"/. "$CURRENT_DIR/videos"/
fi

if [ "$RUN_DB_MIGRATIONS" = "1" ] && [ -n "$DB_MIGRATION_CMD" ]; then
  echo "Running DB migration command..."
  bash -lc "$DB_MIGRATION_CMD"
fi

if [ "$RUN_BACKEND_RESTART" = "1" ]; then
  echo "Restarting backend service: $BACKEND_SERVICE"
  systemctl restart "$BACKEND_SERVICE"
fi

echo "Waiting for backend health: $BACKEND_HEALTH_URL"
deadline=$(( $(date +%s) + BACKEND_HEALTH_TIMEOUT_S ))
until curl -fsS "$BACKEND_HEALTH_URL" >/dev/null 2>&1; do
  if [ "$(date +%s)" -ge "$deadline" ]; then
    echo "Backend health check failed for $BACKEND_HEALTH_URL" >&2
    if command -v journalctl >/dev/null 2>&1; then
      journalctl -u "$BACKEND_SERVICE" -n 80 --no-pager || true
    fi
    exit 1
  fi
  sleep 2
done

printf '%s\n' "$REMOTE_REVISION" > "$REVISION_FILE"
date -u +"%Y-%m-%dT%H:%M:%SZ" > "$STATE_DIR/last_deploy_utc.txt"

echo "Deployed revision $(cat "$REVISION_FILE") to $CURRENT_DIR"