#!/usr/bin/env bash
set -euo pipefail

# Kidcam Deployment Script for Ubuntu 20.04 (Jetson Nano)

readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
readonly PROJECT_ROOT="$(cd "${SCRIPT_DIR}/../.." && pwd)"
readonly KIDCAM_USER="kidcam"
readonly INSTALL_DIR="/opt/kidcam"
readonly CONFIG_DIR="/etc/kidcam"
readonly VENV_DIR="${INSTALL_DIR}/venv"

log_info() {
    echo "[INFO] $*" >&2
}

log_error() {
    echo "[ERROR] $*" >&2
}

log_success() {
    echo "[SUCCESS] $*" >&2
}

check_system() {
    log_info "Checking system requirements..."
    
    if [[ "$(uname -s)" != "Linux" ]]; then
        log_error "This script requires Linux"
        exit 1
    fi
    
    if [[ "$(uname -m)" != "aarch64" ]]; then
        log_error "This script is designed for aarch64 (ARM64) architecture"
        log_error "Found: $(uname -m)"
        exit 1
    fi
    
    if ! grep -q "Ubuntu" /etc/os-release; then
        log_error "This script is designed for Ubuntu"
        log_error "Found: $(cat /etc/os-release | grep PRETTY_NAME)"
        exit 1
    fi
    
    if [[ $EUID -ne 0 ]]; then
        log_error "This script must be run as root (use sudo)"
        exit 1
    fi
    
    log_success "System requirements verified"
}

create_user() {
    if id "${KIDCAM_USER}" &>/dev/null; then
        log_info "User '${KIDCAM_USER}' already exists"
    else
        log_info "Creating user '${KIDCAM_USER}'..."
        useradd --system --no-create-home --shell /usr/sbin/nologin \
                --comment "Kidcam service account" "${KIDCAM_USER}"
        usermod -aG video "${KIDCAM_USER}"
        log_success "User '${KIDCAM_USER}' created"
    fi
}

install_system_dependencies() {
    log_info "Installing system dependencies..."
    
    apt-get update
    apt-get install -y \
        python3 \
        python3-pip \
        python3-venv \
        python3-dev \
        libopencv-dev \
        python3-opencv \
        gstreamer1.0-tools \
        gstreamer1.0-plugins-base \
        gstreamer1.0-plugins-good \
        gstreamer1.0-plugins-bad \
        gstreamer1.0-plugins-ugly \
        gstreamer1.0-libav \
        libgstreamer1.0-dev \
        libgstreamer-plugins-base1.0-dev \
        v4l-utils \
        build-essential \
        cmake \
        pkg-config
    
    log_success "System dependencies installed"
}

setup_directories() {
    log_info "Setting up directories..."
    
    mkdir -p "${INSTALL_DIR}"
    mkdir -p "${CONFIG_DIR}"
    mkdir -p "${INSTALL_DIR}/_/tmp"
    
    log_info "Copying project files..."
    rsync -av --exclude='_/' --exclude='.git' --exclude='*.pyc' \
        "${PROJECT_ROOT}/" "${INSTALL_DIR}/"
    
    chown -R "${KIDCAM_USER}:${KIDCAM_USER}" "${INSTALL_DIR}"
    chown -R "${KIDCAM_USER}:${KIDCAM_USER}" "${CONFIG_DIR}"
    chmod 755 "${INSTALL_DIR}"
    chmod 750 "${CONFIG_DIR}"
    
    log_success "Directories configured"
}

setup_python_environment() {
    log_info "Setting up Python virtual environment..."
    
    if [[ ! -d "${VENV_DIR}" ]]; then
        sudo -u "${KIDCAM_USER}" python3 -m venv "${VENV_DIR}"
        log_success "Virtual environment created"
    else
        log_info "Virtual environment already exists"
    fi
    
    log_info "Installing Python packages..."
    sudo -u "${KIDCAM_USER}" "${VENV_DIR}/bin/pip" install --upgrade pip wheel setuptools
    
    # Install packages with careful dependency management
    sudo -u "${KIDCAM_USER}" "${VENV_DIR}/bin/pip" install \
        ultralytics \
        python-telegram-bot \
        opencv-python \
        torch torchvision --index-url https://download.pytorch.org/whl/cpu \
        numpy \
        pillow
    
    log_success "Python packages installed"
}

create_config() {
    local config_file="${CONFIG_DIR}/config.env"
    
    if [[ -f "${config_file}" ]]; then
        log_info "Config file already exists at ${config_file}"
        log_info "Skipping config creation. Review existing configuration."
    else
        log_info "Creating example configuration..."
        cat > "${config_file}" <<'EOF'
# Kidcam Configuration
# Copy this file to /etc/kidcam/config.env and edit with your values

# Camera device (default: /dev/video0)
CAMERA_DEVICE=/dev/video0

# RTSP stream port (default: 8554)
STREAM_PORT=8554

# Person detection confidence threshold (0.0-1.0, default: 0.5)
DETECTION_CONFIDENCE=0.5

# Cooldown period in minutes after detection (default: 5)
COOLDOWN_MINUTES=5

# Telegram Bot Configuration
# Get your bot token from @BotFather on Telegram
TELEGRAM_BOT_TOKEN=your-bot-token-here

# Get your chat ID by messaging your bot and checking:
# https://api.telegram.org/bot<YOUR_BOT_TOKEN>/getUpdates
TELEGRAM_CHAT_ID=your-chat-id-here

# Python path for imports
PYTHONPATH=/opt/kidcam
EOF
        
        chown "${KIDCAM_USER}:${KIDCAM_USER}" "${config_file}"
        chmod 640 "${config_file}"
        
        log_success "Example config created at ${config_file}"
        log_info "IMPORTANT: Edit ${config_file} with your Telegram credentials"
    fi
}

install_systemd_service() {
    log_info "Installing systemd service..."
    
    cp "${SCRIPT_DIR}/kidcam.service" /etc/systemd/system/
    chmod 644 /etc/systemd/system/kidcam.service
    
    # Update ExecStart to use virtualenv python
    sed -i "s|ExecStart=/usr/bin/python3|ExecStart=${VENV_DIR}/bin/python3|" \
        /etc/systemd/system/kidcam.service
    
    systemctl daemon-reload
    systemctl enable kidcam.service
    
    log_success "Systemd service installed and enabled"
}

main() {
    log_info "Starting Kidcam deployment..."
    
    check_system
    create_user
    install_system_dependencies
    setup_directories
    setup_python_environment
    create_config
    install_systemd_service
    
    log_success "Deployment complete!"
    echo ""
    log_info "Next steps:"
    echo "  1. Edit /etc/kidcam/config.env with your Telegram credentials"
    echo "  2. Test camera access: v4l2-ctl --list-devices"
    echo "  3. Start service: sudo systemctl start kidcam"
    echo "  4. Check logs: sudo journalctl -u kidcam -f"
    echo ""
    log_info "For more information, see ${INSTALL_DIR}/Biz/Kidcam/README.md"
}

main "$@"