#!/usr/bin/env bash
# deploy.sh - quickstart with Docker MySQL + backend + frontend
# Usage: ./deploy.sh
set -euo pipefail

# ---------- CONFIG ----------
ROOT_DIR="$(pwd)"
BACKEND_DIR="backend"
FRONTEND_DIR="frontend"
BACKEND_LOG="backend.log"
FRONTEND_LOG="frontend.log"
VENV_DIR_ABS="$ROOT_DIR/$BACKEND_DIR/.venv"
MYSQL_CONTAINER="sqlilab_mysql"
MYSQL_PORT=3307
MYSQL_ROOT_PASSWORD="12345"
MYSQL_DATABASE="sqlilab"
PYTHON_BIN="python3"
PIP_BIN=""
DOCKER_CMD=""
# ----------------------------

timestamp(){ date +"%Y-%m-%d %H:%M:%S"; }
info(){ echo -e "$(timestamp) [INFO] $*"; }
fail(){ echo -e "$(timestamp) [ERROR] $*" >&2; exit 1; }
warn(){ echo -e "$(timestamp) [WARN] $*"; }

run_quiet(){ "$@" >/dev/null 2>&1 || true; }

# ---------- Docker helpers (unchanged) ----------
check_docker(){
  if ! command -v docker >/dev/null 2>&1; then
    return 1
  fi
  if docker info >/dev/null 2>&1; then
    DOCKER_CMD="docker"
    info "Docker CLI usable without sudo."
    return 0
  fi
  if sudo docker info >/dev/null 2>&1; then
    DOCKER_CMD="sudo docker"
    info "Docker CLI usable with sudo."
    return 0
  fi
  return 1
}

start_docker_daemon(){
  info "Attempting to start Docker daemon..."
  if command -v systemctl >/dev/null 2>&1; then
    run_quiet sudo systemctl daemon-reload
    run_quiet sudo systemctl enable docker || warn "systemctl enable returned non-zero"
    run_quiet sudo systemctl start docker || warn "systemctl start returned non-zero"
    for i in {1..30}; do
      if sudo docker info >/dev/null 2>&1; then
        DOCKER_CMD="sudo docker"
        info "Docker daemon ready (systemd)."
        return 0
      fi
      sleep 1
    done
    warn "Docker did not become ready via systemctl in 30s."
  else
    warn "systemctl not found; trying dockerd fallback."
  fi

  if command -v dockerd >/dev/null 2>&1; then
    if ! pgrep -x dockerd >/dev/null 2>&1; then
      sudo dockerd >> /var/log/docker-dockerd.log 2>&1 & disown || warn "Failed to start dockerd"
      info "Started dockerd in background (logs -> /var/log/docker-dockerd.log)"
    else
      warn "dockerd already running"
    fi
    for i in {1..30}; do
      if sudo docker info >/dev/null 2>&1; then
        DOCKER_CMD="sudo docker"
        info "Docker ready (dockerd fallback)."
        return 0
      fi
      sleep 1
    done
  fi
  return 1
}

ensure_docker_ready(){
  if check_docker; then return 0; fi
  warn "Docker CLI/daemon not usable; attempting to start daemon..."
  if start_docker_daemon && check_docker; then return 0; fi
  return 1
}

# ---------- Python / Node / pip checks ----------
info "Checking python & pip..."
if command -v python3 >/dev/null 2>&1; then
  PYTHON_BIN="python3"
else
  fail "python3 not found. Install Python 3."
fi

if command -v pip3 >/dev/null 2>&1; then
  PIP_BIN="pip3"
elif command -v pip >/dev/null 2>&1; then
  PIP_BIN="pip"
else
  info "Installing python3-pip..."
  sudo apt update -y
  sudo apt install -y python3-pip
  PIP_BIN="pip3"
fi

# info "Checking Node.js & npm..."
# if ! command -v node >/dev/null 2>&1 || ! command -v npm >/dev/null 2>&1; then
#   info "Installing Node.js (LTS)..."
#   sudo apt update -y
#   sudo apt install -y ca-certificates curl gnupg
#   sudo mkdir -p /etc/apt/keyrings
#   curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg
#   NODE_MAJOR=20
#   echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$NODE_MAJOR.x nodistro main" | sudo tee /etc/apt/sources.list.d/nodesource.list
#   sudo apt update -y
#   sudo apt install -y nodejs
# fi

# ---------- helper to start background processes ----------
start_bg(){
  local cmd="$1"; local logfile="$2"; local pidfile="$3"
  nohup bash -lc "$cmd" >>"$logfile" 2>&1 &
  local pid=$!
  echo "$pid" > "$pidfile"
  info "Started: '$cmd' (pid=$pid) -> $logfile"
}

# ---------- sanity checks ----------
[ -d "$BACKEND_DIR" ] || fail "Backend directory '$BACKEND_DIR' not found."
# [ -d "$FRONTEND_DIR" ] || fail "Frontend directory '$FRONTEND_DIR' not found."
[ -f "$BACKEND_DIR/init.sql" ] || fail "BACKEND_DIR/init.sql not found. Please create $BACKEND_DIR/init.sql"

# ---------- Install Docker (if missing) ----------
info "Checking Docker installation..."
DOCKER_WAS_INSTALLED=false
if ! command -v docker >/dev/null 2>&1; then
  info "Docker not found. Installing Docker..."
  DOCKER_WAS_INSTALLED=true
  sudo apt update
  sudo apt install -y ca-certificates curl gnupg lsb-release
  sudo mkdir -p /etc/apt/keyrings
  curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
  echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/debian bookworm stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
  sudo apt update
  sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
  sudo usermod -aG docker "$USER" || warn "usermod returned non-zero"
  info "Docker installation completed."
fi

if ! ensure_docker_ready; then
  if [ "$DOCKER_WAS_INSTALLED" = true ]; then
    fail "Docker daemon not running after install. Check: sudo systemctl status docker and logs."
  else
    fail "Docker is installed but not usable. Try: sudo systemctl start docker"
  fi
fi

info "Docker ready. Using command: $DOCKER_CMD"
if [ "$DOCKER_CMD" = "sudo docker" ]; then
  warn "docker requires sudo in this shell. Run: newgrp docker OR log out/in to use docker without sudo."
fi

# ---------- DOCKER MYSQL SETUP ----------
info "Setting up MySQL Docker container..."
if $DOCKER_CMD ps -a --format '{{.Names}}' | grep -q "^${MYSQL_CONTAINER}$"; then
  info "Removing existing MySQL container..."
  $DOCKER_CMD stop "$MYSQL_CONTAINER" 2>/dev/null || true
  $DOCKER_CMD rm "$MYSQL_CONTAINER" 2>/dev/null || true
fi

info "Pulling MySQL 8.0 image..."
$DOCKER_CMD pull mysql:8.0

info "Starting MySQL container..."
$DOCKER_CMD run -d \
  --name "$MYSQL_CONTAINER" \
  -e MYSQL_ROOT_PASSWORD="$MYSQL_ROOT_PASSWORD" \
  -e MYSQL_DATABASE="$MYSQL_DATABASE" \
  -e MYSQL_ROOT_HOST='%' \
  -p "$MYSQL_PORT:3306" \
  -v "$ROOT_DIR/$BACKEND_DIR/init.sql:/docker-entrypoint-initdb.d/init.sql:ro" \
  mysql:8.0 \
  --default-authentication-plugin=mysql_native_password

info "Waiting for MySQL to be ready..."
for i in {1..60}; do
  if $DOCKER_CMD exec "$MYSQL_CONTAINER" mysqladmin ping -h localhost -uroot -p"$MYSQL_ROOT_PASSWORD" >/dev/null 2>&1; then
    info "MySQL ready."
    break
  fi
  sleep 1
  if [ "$i" -eq 60 ]; then
    fail "MySQL failed to start. Check logs: $DOCKER_CMD logs $MYSQL_CONTAINER"
  fi
done

sleep 3

# ---------- BACKEND PREP: ensure python3-venv installed, create venv, install requirements & gunicorn ----------
info "Preparing backend virtualenv and dependencies..."

info "Ensuring python3-venv and pip are installed..."
sudo apt update -y
sudo apt install -y python3-venv python3-pip

# create venv if missing (use absolute path)
if [ ! -d "$VENV_DIR_ABS" ]; then
  info "Creating virtualenv at $VENV_DIR_ABS"
  $PYTHON_BIN -m venv "$VENV_DIR_ABS" || fail "Failed to create virtualenv at $VENV_DIR_ABS"
fi

# Activate and install requirements inside venv
# shellcheck source=/dev/null
. "$VENV_DIR_ABS/bin/activate" || fail "Failed to activate virtualenv at $VENV_DIR_ABS"

info "Upgrading pip & installing backend requirements..."
pip install --upgrade pip setuptools wheel >/dev/null
if [ -f "$ROOT_DIR/$BACKEND_DIR/requirements.txt" ]; then
  pip install -r "$ROOT_DIR/$BACKEND_DIR/requirements.txt" || warn "pip install -r returned non-zero"
else
  warn "requirements.txt not found in $BACKEND_DIR"
fi

info "Installing gunicorn..."
pip install --upgrade gunicorn >/dev/null || warn "pip install gunicorn returned non-zero"

deactivate || true

# compute gunicorn binary absolute path and verify
GUNICORN_BIN="$VENV_DIR_ABS/bin/gunicorn"
if [ ! -x "$GUNICORN_BIN" ]; then
  fail "gunicorn binary not found at $GUNICORN_BIN (venv may be broken)"
fi

# ---------- DETECT app.py location and set APP_MODULE ----------
# prefer backend/app.py, fallback to backend/backend/app.py
if [ -f "$ROOT_DIR/$BACKEND_DIR/app.py" ]; then
  APP_MODULE="backend.app:app"
  START_CWD="$ROOT_DIR"
elif [ -f "$ROOT_DIR/$BACKEND_DIR/backend/app.py" ]; then
  APP_MODULE="backend.backend.app:app"
  START_CWD="$ROOT_DIR"
else
  # if neither exists, fail early with helpful message
  fail "Could not find app.py under $BACKEND_DIR. Please ensure backend/app.py exists."
fi
info "Using APP_MODULE=$APP_MODULE"

# ---------- START BACKEND (Flask dev server, no Gunicorn) ----------
info "Starting backend with Flask development server (no Gunicorn)..."

BACKEND_APP="app.py"  # your backend/app.py

if sudo ss -ltnp 2>/dev/null | grep -q ':5000'; then
  warn "Port 5000 already in use; skipping backend start."
else
  BACKEND_CMD="bash -lc 'cd \"$ROOT_DIR/$BACKEND_DIR\" && \
    source \"$VENV_DIR_ABS/bin/activate\" && \
    FLASK_APP=$BACKEND_APP FLASK_ENV=development flask run --host=0.0.0.0 --port=5000'"
  
  BACKEND_PIDFILE="$ROOT_DIR/backend.pid"
  start_bg "$BACKEND_CMD" "$ROOT_DIR/$BACKEND_LOG" "$BACKEND_PIDFILE"
fi
# # ---------- FRONTEND ----------
# info "Starting frontend..."
# if [ -f "$ROOT_DIR/$FRONTEND_DIR/package.json" ]; then
#   cd "$ROOT_DIR/$FRONTEND_DIR"
#   if [[ "$(pwd)" == /mnt/* ]]; then
#     info "Detected WSL/Windows FS. Cleaning node_modules..."
#     rm -rf node_modules package-lock.json
#     npm install
#   else
#     if [ -f "package-lock.json" ]; then
#       if ! npm ci; then
#         rm -rf node_modules
#         npm install
#       fi
#     else
#       npm install
#     fi
#   fi

#   FRONTEND_START_CMD=${FRONTEND_START_CMD:-"npm run dev"}
#   FRONTEND_PIDFILE="$ROOT_DIR/frontend.pid"
#   start_bg "$FRONTEND_START_CMD" "$ROOT_DIR/$FRONTEND_LOG" "$FRONTEND_PIDFILE"
#   cd "$ROOT_DIR"
# else
#   warn "No package.json in frontend/ — skipping frontend start."
# fi

# ---------- FINISH ---------- 
echo ""
echo "========================================="
echo "🚀 Application Started (or attempted)!"
echo "========================================="
echo "$(timestamp) MySQL (Docker) → localhost:$MYSQL_PORT"
echo "                   Container: $MYSQL_CONTAINER"
echo "                   Database: $MYSQL_DATABASE"
echo ""
echo "$(timestamp) Backend → http://localhost:5000"
echo "                   Log: $BACKEND_LOG"
echo "                   PID: $(cat backend.pid 2>/dev/null || echo 'N/A')"
echo ""
# echo "$(timestamp) Frontend → http://localhost:5173"
# echo "                   Log: $FRONTEND_LOG"
# echo "                   PID: $(cat frontend.pid 2>/dev/null || echo 'N/A')"
echo "========================================="
echo ""
echo "Useful commands:"
echo "  tail -f $BACKEND_LOG"
# echo "  tail -f $FRONTEND_LOG"
echo "  $DOCKER_CMD logs -f $MYSQL_CONTAINER"
echo "  $DOCKER_CMD exec -it $MYSQL_CONTAINER mysql -uroot -p$MYSQL_ROOT_PASSWORD $MYSQL_DATABASE"
echo "  kill \$(cat backend.pid 2>/dev/null || echo '') && kill \$(cat frontend.pid 2>/dev/null || echo '') && $DOCKER_CMD stop $MYSQL_CONTAINER"
echo "========================================="