#!/usr/bin/env bash
# Installs crypto-trader as a systemd service on Ubuntu/Debian.
# Must be run as root (or with sudo): sudo bash install.sh
#
# What this does:
#   1. Copies the project to /opt/crypto-trader
#   2. Creates a dedicated system user 'crypto-trader'
#   3. Sets up a Python virtual environment
#   4. Installs and enables the systemd service + timer
set -euo pipefail

INSTALL_DIR="/opt/crypto-trader"
SERVICE_USER="crypto-trader"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

if [ "$(id -u)" -ne 0 ]; then
  echo "ERROR: Run this with sudo: sudo bash install.sh"
  exit 1
fi

echo "Installing crypto-trader to $INSTALL_DIR ..."

# ── 1. Create install directory ───────────────────────────────────────────
mkdir -p "$INSTALL_DIR"

# ── 2. Copy project files ─────────────────────────────────────────────────
# Skip if already running from the install directory
if [ "$SCRIPT_DIR" != "$INSTALL_DIR" ]; then
  for item in *.py *.txt *.sh *.md .env.example systemd; do
    [ -e "$SCRIPT_DIR/$item" ] && cp -r "$SCRIPT_DIR/$item" "$INSTALL_DIR/"
  done
fi

# ── 3. Create dedicated system user ──────────────────────────────────────
if ! id -u "$SERVICE_USER" &>/dev/null; then
  useradd --system --no-create-home --shell /usr/sbin/nologin "$SERVICE_USER"
  echo "Created system user: $SERVICE_USER"
fi

# ── 4. Set up .env (API keys) ─────────────────────────────────────────────
if [ ! -f "$INSTALL_DIR/.env" ]; then
  cp "$INSTALL_DIR/.env.example" "$INSTALL_DIR/.env"
  chmod 600 "$INSTALL_DIR/.env"
  chown "$SERVICE_USER:$SERVICE_USER" "$INSTALL_DIR/.env"
  echo ""
  echo ">>> Created $INSTALL_DIR/.env — add your Kraken API keys before starting:"
  echo "    sudo nano $INSTALL_DIR/.env"
  echo ""
fi

# ── 5. Python virtual environment ─────────────────────────────────────────
# python3 is pre-installed on Ubuntu but python3-venv is a separate package
# that is frequently absent — install it unconditionally (apt is idempotent)
echo "Ensuring python3-venv and pip are available..."
apt-get install -y python3-venv python3-pip

# Check for pip specifically — a previous failed run may have left an incomplete venv
if [ ! -f "$INSTALL_DIR/venv/bin/pip" ]; then
  rm -rf "$INSTALL_DIR/venv"
  python3 -m venv "$INSTALL_DIR/venv" || {
    echo "ERROR: 'python3 -m venv' failed. Try: apt-get install python3-venv"
    exit 1
  }
fi
"$INSTALL_DIR/venv/bin/pip" install --upgrade pip -q
"$INSTALL_DIR/venv/bin/pip" install -r "$INSTALL_DIR/requirements.txt" -q
echo "Python dependencies installed"

# ── 6. Ownership ─────────────────────────────────────────────────────────
chown -R "$SERVICE_USER:$SERVICE_USER" "$INSTALL_DIR"
# positions.json and bot.log need to be writable by the service user
touch "$INSTALL_DIR/positions.json" "$INSTALL_DIR/bot.log" 2>/dev/null || true
chown "$SERVICE_USER:$SERVICE_USER" "$INSTALL_DIR/positions.json" "$INSTALL_DIR/bot.log" 2>/dev/null || true

# ── 7. Systemd units ──────────────────────────────────────────────────────
cp "$INSTALL_DIR/systemd/crypto-trader.service" /etc/systemd/system/
cp "$INSTALL_DIR/systemd/crypto-trader.timer"   /etc/systemd/system/

systemctl daemon-reload
systemctl enable crypto-trader.timer

echo ""
echo "Installation complete."
echo ""
echo "Next steps:"
echo "  1. Edit API keys:    sudo nano $INSTALL_DIR/.env"
echo "  2. Test paper mode:  sudo -u $SERVICE_USER $INSTALL_DIR/venv/bin/python $INSTALL_DIR/bot.py"
echo "  3. Start the timer:  sudo systemctl start crypto-trader.timer"
echo "  4. View logs:        journalctl -u crypto-trader.service -f"
echo "  5. Check schedule:   systemctl list-timers crypto-trader.timer"