#!/bin/bash

# ============================================================
# setup.sh - Automated Deployment Script for ATS-Doku
# Compatible with Linux environments
# ============================================================

set -e  # Exit on error

# --- Colors ---
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'

log()   { echo -e "${GREEN}[INFO]${NC}  $1"; }
warn()  { echo -e "${YELLOW}[WARN]${NC}  $1"; }
error() { echo -e "${RED}[ERROR]${NC} $1"; exit 1; }

# --- Configuration ---
APP_NAME="ats-doku"
APP_USER="ats"
APP_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
VENV_DIR="$APP_DIR/.venv"
PYTHON_MIN="3.12"
PORT=9000
SERVICE_FILE="/etc/systemd/system/${APP_NAME}.service"

# ============================================================
# 1. Root check for system-level operations
# ============================================================
if [ "$EUID" -ne 0 ]; then
    error "Please run as root or with sudo: sudo ./setup.sh"
fi

# ============================================================
# 2. Check Python version
# ============================================================
log "Checking Python version..."

if ! command -v python3 &>/dev/null; then
    error "Python3 not found. Please install Python $PYTHON_MIN or higher."
fi

PYTHON_VERSION=$(python3 -c 'import sys; print(f"{sys.version_info.major}.{sys.version_info.minor}")')
ACTUAL_MAJOR=$(echo "$PYTHON_VERSION" | cut -d. -f1)
ACTUAL_MINOR=$(echo "$PYTHON_VERSION" | cut -d. -f2)

if [ "$ACTUAL_MAJOR" -lt 3 ] || ([ "$ACTUAL_MAJOR" -eq 3 ] && [ "$ACTUAL_MINOR" -lt 12 ]); then
    error "Python $PYTHON_MIN or higher required. Found: $PYTHON_VERSION"
fi

log "Python $PYTHON_VERSION found ✓"

# ============================================================
# 3. Check system dependencies
# ============================================================
log "Checking system dependencies..."

for cmd in pip3 sqlite3; do
    if ! command -v "$cmd" &>/dev/null; then
        warn "$cmd not found. Attempting installation..."
        if command -v apt-get &>/dev/null; then
            apt-get install -y python3-pip sqlite3
        elif command -v dnf &>/dev/null; then
            dnf install -y python3-pip sqlite
        elif command -v pacman &>/dev/null; then
            pacman -S --noconfirm python-pip sqlite
        else
            error "Package manager not recognized. Please install $cmd manually."
        fi
    fi
done

log "System dependencies OK ✓"

# ============================================================
# 4. Create 'ats' system user if not exists
# ============================================================
log "Checking for system user '$APP_USER'..."

if id "$APP_USER" &>/dev/null; then
    warn "User '$APP_USER' already exists. Skipping creation."
else
    log "Creating system user '$APP_USER'..."
    useradd \
        --system \
        --no-create-home \
        --shell /usr/sbin/nologin \
        --comment "ATS Doku Service User" \
        "$APP_USER"
    log "User '$APP_USER' created ✓"
fi

# ============================================================
# 5. Set directory ownership
# ============================================================
log "Setting ownership of $APP_DIR to '$APP_USER'..."
chown -R "$APP_USER":"$APP_USER" "$APP_DIR"
log "Ownership set ✓"

# ============================================================
# 6. Create virtual environment
# ============================================================
log "Creating virtual environment in $VENV_DIR..."

if [ -d "$VENV_DIR" ]; then
    warn "Virtual environment already exists. Skipping creation."
else
    python3 -m venv "$VENV_DIR"
    chown -R "$APP_USER":"$APP_USER" "$VENV_DIR"
    log "Virtual environment created ✓"
fi

# ============================================================
# 7. Install Python dependencies
# ============================================================
log "Installing Python dependencies..."

sudo -u "$APP_USER" "$VENV_DIR/bin/pip" install --upgrade pip --quiet

if [ -f "$APP_DIR/requirements.txt" ]; then
    sudo -u "$APP_USER" "$VENV_DIR/bin/pip" install -r "$APP_DIR/requirements.txt" --quiet
    log "requirements.txt installed ✓"
else
    warn "No requirements.txt found. Installing NiceGUI directly..."
    sudo -u "$APP_USER" "$VENV_DIR/bin/pip" install nicegui --quiet
    log "NiceGUI installed ✓"
fi

# ============================================================
# 8. Ensure data directory exists
# ============================================================
log "Checking data directory..."

DATA_DIR="$APP_DIR/data"

if [ ! -d "$DATA_DIR" ]; then
    mkdir -p "$DATA_DIR"
    chown "$APP_USER":"$APP_USER" "$DATA_DIR"
    log "Directory 'data' created ✓"
fi

DB_FILE="$APP_DIR/ats_doku.db"
if [ ! -f "$DB_FILE" ]; then
    warn "Database file not found. It will be created automatically on first start."
else
    chown "$APP_USER":"$APP_USER" "$DB_FILE"
fi

# ============================================================
# 9. Open firewall port (optional)
# ============================================================
if command -v ufw &>/dev/null; then
    log "Opening port $PORT in UFW firewall..."
    ufw allow "$PORT"/tcp &>/dev/null || warn "Could not set UFW rule."
fi

# ============================================================
# 10. Create and enable systemd service
# ============================================================
log "Creating systemd service: $SERVICE_FILE"

cat > "$SERVICE_FILE" <<EOF
[Unit]
Description=ATS Traeger Dokumentation (NiceGUI)
After=network.target

[Service]
Type=simple
User=$APP_USER
Group=$APP_USER
WorkingDirectory=$APP_DIR
ExecStart=$VENV_DIR/bin/python $APP_DIR/main.py
Restart=on-failure
RestartSec=5
Environment=PYTHONUNBUFFERED=1

# Security hardening
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=strict
ReadWritePaths=$APP_DIR

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable "$APP_NAME"
systemctl restart "$APP_NAME"

log "Service '$APP_NAME' started and enabled ✓"

# ============================================================
# Done
# ============================================================
echo ""
echo -e "${GREEN}============================================${NC}"
echo -e "${GREEN}  Setup complete!${NC}"
echo -e "${GREEN}  App available at: http://localhost:$PORT${NC}"
echo -e "${GREEN}  Service status:   sudo systemctl status $APP_NAME${NC}"
echo -e "${GREEN}  Live logs:        sudo journalctl -u $APP_NAME -f${NC}"
echo -e "${GREEN}============================================${NC}"