#!/bin/bash

# Data Visualization Display Wall - Systemd Installer
# Requirements: Node.js, NPM, Systemd (Linux)

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

echo -e "${BLUE}=== Data Visualization Display Wall Installer ===${NC}"

# 1. Check permissions
if [ "$EUID" -ne 0 ]; then
  echo -e "${RED}Please run as root (sudo ./Install.sh)${NC}"
  exit 1
fi

# 2. Get current directory and user
PROJECT_DIR=$(pwd)
REAL_USER=${SUDO_USER:-$USER}
USER_HOME=$(getent passwd "$REAL_USER" | cut -d: -f6)

echo -e "Project Directory: ${GREEN}$PROJECT_DIR${NC}"
echo -e "Running User:      ${GREEN}$REAL_USER${NC}"

# 3. Check for mandatory files
if [ ! -f "server/index.js" ]; then
    echo -e "${RED}Error: server/index.js not found. Please run this script from the project root.${NC}"
    exit 1
fi

# 4. Check for dependencies
echo -e "${BLUE}Checking dependencies...${NC}"
check_dep() {
    if ! command -v "$1" &> /dev/null; then
        echo -e "${RED}$1 is not installed. Please install $1 first.${NC}"
        exit 1
    fi
}
check_dep node
check_dep npm

# 5. Check for .env file
if [ ! -f ".env" ]; then
    echo -e "${YELLOW}Warning: .env file not found.${NC}"
    if [ -f ".env.example" ]; then
        echo -e "Creating .env from .env.example..."
        cp .env.example .env
        chown "$REAL_USER":"$REAL_USER" .env
        echo -e "${GREEN}Created .env file. Please ensure values are correct.${NC}"
    else
        echo -e "${RED}Error: .env.example not found. Configuration missing.${NC}"
    fi
fi

# 6. Install NPM dependencies
echo -e "${BLUE}Installing dependencies...${NC}"
# Run npm install as the real user to avoid permission issues in node_modules
sudo -u "$REAL_USER" npm install

if [ $? -ne 0 ]; then
    echo -e "${RED}NPM install failed.${NC}"
    exit 1
fi

# 7. Create Systemd Service File
SERVICE_FILE="/etc/systemd/system/data-wall.service"
NODE_PATH=$(command -v node)

echo -e "${BLUE}Creating systemd service at $SERVICE_FILE...${NC}"

cat <<EOF > "$SERVICE_FILE"
[Unit]
Description=Data Visualization Display Wall
After=network.target mysql.service redis-server.service valkey-server.service
Wants=mysql.service

[Service]
Type=simple
User=$REAL_USER
WorkingDirectory=$PROJECT_DIR
ExecStart=$NODE_PATH server/index.js
Restart=always
RestartSec=10
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=data-wall
# Pass environment via .env file injection
EnvironmentFile=-$PROJECT_DIR/.env
Environment=NODE_ENV=production

# Security Hardening
CapabilityBoundingSet=
NoNewPrivileges=true
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target
EOF

# 8. Reload Systemd and Start
echo -e "${BLUE}Reloading systemd and restarting service...${NC}"
systemctl daemon-reload
systemctl enable data-wall
systemctl restart data-wall

# 9. Check Status
echo -e "${BLUE}Checking service status...${NC}"
sleep 2
if systemctl is-active --quiet data-wall; then
    echo -e "${GREEN}SUCCESS: Service is now running.${NC}"
    PORT=$(grep "^PORT=" .env | cut -d'=' -f2)
    PORT=${PORT:-3000}
    echo -e "Dashboard URL: ${YELLOW}http://localhost:${PORT}${NC}"
    echo -e "View logs:     ${BLUE}journalctl -u data-wall -f${NC}"
else
    echo -e "${RED}FAILED: Service failed to start.${NC}"
    echo -e "Check logs with: ${BLUE}journalctl -u data-wall -xe${NC}"
fi

echo -e "${BLUE}================================================${NC}"