#!/bin/bash
set -e

# ───────────────────────────────────────────────────────────────────
# VM Bench Frontend — Installer for vm-bench LXC
#
# Run:  bash /mnt/converter/frontend/install.sh
#
# Installs system tools, Python dependencies, and the systemd
# service that serves the web UI on port 5000.
# ───────────────────────────────────────────────────────────────────

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
NC='\033[0m'

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
SERVICE_NAME="vm-bench"
SERVICE_FILE="${SCRIPT_DIR}/${SERVICE_NAME}.service"
SYSTEMD_DIR="/etc/systemd/system"

echo ""
echo "╔════════════════════════════════════════════╗"
echo "║  VM Bench Frontend Installer (LXC)        ║"
echo "╚════════════════════════════════════════════╝"
echo ""

# ───────────────────────────────────────────────────────────────────
# Step 1: System packages
# ───────────────────────────────────────────────────────────────────
echo "[1/5] Checking system packages..."

PACKAGES=()
REQUIRED=(
    python3          "python3"
    python3-pip      "pip3"
    wget             "wget"
    curl             "curl"
    openssh-client    "scp"
    sshpass           "sshpass"
)

for ((i=0; i<${#REQUIRED[@]}; i+=2)); do
    pkg="${REQUIRED[$i]}"
    bin="${REQUIRED[$i+1]}"
    if command -v "$bin" &>/dev/null; then
        echo "  ${GREEN}✓${NC} $bin"
    else
        echo "  ${YELLOW}○${NC} $bin (will install ${pkg})"
        PACKAGES+=("$pkg")
    fi
done

if [ ${#PACKAGES[@]} -gt 0 ]; then
    echo ""
    echo "  Installing missing packages: ${PACKAGES[*]}"
    apt-get update -qq
    apt-get install -y -qq "${PACKAGES[@]}"
    echo "  ${GREEN}✓${NC} System packages installed."
else
    echo "  ${GREEN}✓${NC} All system packages present."
fi

# ───────────────────────────────────────────────────────────────────
# Step 2: Python dependencies
# ───────────────────────────────────────────────────────────────────
echo ""
echo "[2/5] Installing Python dependencies..."

cd "$SCRIPT_DIR"
python3 -m pip install --break-system-packages -r requirements.txt -q
echo "  ${GREEN}✓${NC} Python dependencies installed."

# ───────────────────────────────────────────────────────────────────
# Step 3: Verify backend connectivity
# ───────────────────────────────────────────────────────────────────
echo ""
echo "[3/5] Checking backend connectivity..."

BACKEND_URL="${BACKEND_URL:-http://10.2.0.2:9000}"
if curl -sf --max-time 5 "${BACKEND_URL}/api/v1/health" > /dev/null 2>&1; then
    echo "  ${GREEN}✓${NC} Backend reachable at $BACKEND_URL"
else
    echo "  ${YELLOW}!${NC} Backend not reachable at $BACKEND_URL"
    echo "  The frontend will start, but conversion jobs will fail until the"
    echo "  backend is running on srv2. You can change BACKEND_URL in"
    echo "  ${SYSTEMD_DIR}/${SERVICE_NAME}.service"
fi

# ───────────────────────────────────────────────────────────────────
# Step 4: Systemd service
# ───────────────────────────────────────────────────────────────────
echo ""
echo "[4/5] Installing systemd service..."

if [ ! -f "$SERVICE_FILE" ]; then
    echo "  ${RED}✗${NC} Service file not found: $SERVICE_FILE"
    exit 1
fi

cp "$SERVICE_FILE" "$SYSTEMD_DIR/${SERVICE_NAME}.service"
systemctl daemon-reload
systemctl enable "$SERVICE_NAME"
echo "  ${GREEN}✓${NC} Service installed and enabled."

# ───────────────────────────────────────────────────────────────────
# Step 5: Start & verify
# ───────────────────────────────────────────────────────────────────
echo ""
echo "[5/5] Starting service..."

systemctl restart "$SERVICE_NAME"
sleep 2

if systemctl is-active --quiet "$SERVICE_NAME"; then
    echo "  ${GREEN}✓${NC} Frontend is RUNNING on port 5000"
    echo ""
    echo "  Open:    http://$(hostname -I 2>/dev/null | awk '{print $1}'):5000"
    echo "  Verify:  curl http://127.0.0.1:5000"
    echo "  Logs:    journalctl -u ${SERVICE_NAME} -f"
    echo "  Status:  systemctl status ${SERVICE_NAME}"
else
    echo "  ${RED}✗${NC} Service failed to start. Check logs:"
    echo "    journalctl -u ${SERVICE_NAME} -n 30"
    exit 1
fi

echo ""
echo "╔════════════════════════════════════════════╗"
echo "║  ${GREEN}Frontend installation complete.${NC}           ║"
echo "╚════════════════════════════════════════════╝"
echo ""