#!/bin/bash

# CMtec Update System - OS Detection Library
# Detects operating system, distribution, version, and environment

# Initialize system info array
declare -A SYSTEM_INFO

# Detect operating system and distribution
detect_system() {
    log INFO "Detecting system information..."
    
    # Basic OS detection
    SYSTEM_INFO[OS]=$(uname -s)
    SYSTEM_INFO[ARCH]=$(uname -m)
    SYSTEM_INFO[HOSTNAME]=$(hostname | tr '[:lower:]' '[:upper:]')
    SYSTEM_INFO[KERNEL]=$(uname -r)
    
    # Detect distribution
    if [ -f /etc/os-release ]; then
        source /etc/os-release
        SYSTEM_INFO[DISTRO]=$(echo "$ID" | tr '[:upper:]' '[:lower:]')
        SYSTEM_INFO[VERSION]="$VERSION_ID"
        SYSTEM_INFO[PRETTY_NAME]="$PRETTY_NAME"
    elif [ -f /etc/arch-release ]; then
        SYSTEM_INFO[DISTRO]="arch"
        SYSTEM_INFO[VERSION]="rolling"
        SYSTEM_INFO[PRETTY_NAME]="Arch Linux"
    elif [ -f /etc/debian_version ]; then
        SYSTEM_INFO[DISTRO]="debian"
        SYSTEM_INFO[VERSION]=$(cat /etc/debian_version)
        SYSTEM_INFO[PRETTY_NAME]="Debian GNU/Linux"
    else
        log ERROR "Unable to detect Linux distribution"
        return 1
    fi
    
    # Detect environment specifics
    detect_environment
    
    # Log system information
    log SUCCESS "System detected: ${SYSTEM_INFO[PRETTY_NAME]} (${SYSTEM_INFO[DISTRO]})"
    log INFO "Hostname: ${SYSTEM_INFO[HOSTNAME]}"
    log INFO "Architecture: ${SYSTEM_INFO[ARCH]}"
    log INFO "Environment: ${SYSTEM_INFO[ENVIRONMENT]}"
    
    return 0
}

# Detect specific environment (WSL, Desktop, Container, etc.)
detect_environment() {
    local env_flags=()
    
    # Check for WSL
    if [[ "$(systemd-detect-virt 2>/dev/null)" == *"wsl"* ]] || \
       [ -f /proc/sys/fs/binfmt_misc/WSLInterop ] || \
       grep -qi "microsoft" /proc/version 2>/dev/null; then
        env_flags+=("wsl")
        SYSTEM_INFO[WSL]="yes"
    else
        SYSTEM_INFO[WSL]="no"
    fi
    
    # Check for container environment
    if [ -f /.dockerenv ] || \
       [[ "$(systemd-detect-virt 2>/dev/null)" == "docker" ]] || \
       [[ "$(systemd-detect-virt 2>/dev/null)" == "podman" ]]; then
        env_flags+=("container")
        SYSTEM_INFO[CONTAINER]="yes"
    else
        SYSTEM_INFO[CONTAINER]="no"
    fi
    
    # Check for desktop environment
    detect_desktop_environment
    
    # Check for virtualization
    local virt=$(systemd-detect-virt 2>/dev/null)
    if [ "$virt" != "none" ] && [ -n "$virt" ]; then
        env_flags+=("vm")
        SYSTEM_INFO[VIRTUALIZATION]="$virt"
    else
        SYSTEM_INFO[VIRTUALIZATION]="none"
    fi
    
    # Set environment string
    if [ ${#env_flags[@]} -gt 0 ]; then
        SYSTEM_INFO[ENVIRONMENT]=$(IFS=,; echo "${env_flags[*]}")
    else
        SYSTEM_INFO[ENVIRONMENT]="native"
    fi
}

# Detect desktop environment
detect_desktop_environment() {
    local desktop_env=""
    
    # Check for various desktop environments
    if [ -n "$XDG_CURRENT_DESKTOP" ]; then
        desktop_env="$XDG_CURRENT_DESKTOP"
    elif [ -n "$DESKTOP_SESSION" ]; then
        desktop_env="$DESKTOP_SESSION"
    elif [ -n "$GDMSESSION" ]; then
        desktop_env="$GDMSESSION"
    elif pgrep -x "gnome-session" >/dev/null; then
        desktop_env="GNOME"
    elif pgrep -x "kded5" >/dev/null || pgrep -x "kded6" >/dev/null; then
        desktop_env="KDE"
    elif pgrep -x "xfce4-session" >/dev/null; then
        desktop_env="XFCE"
    elif pgrep -x "hyprland" >/dev/null; then
        desktop_env="Hyprland"
    fi
    
    # Special checks for distribution-specific detection
    case "${SYSTEM_INFO[DISTRO]}" in
        "ubuntu")
            if dpkg -l | grep -q "ubuntu-desktop"; then
                SYSTEM_INFO[DESKTOP]="yes"
                SYSTEM_INFO[DESKTOP_ENV]="${desktop_env:-GNOME}"
            else
                SYSTEM_INFO[DESKTOP]="no"
            fi
            ;;
        "arch")
            if pacman -Qs | grep -E "(gnome|kde|xfce|hyprland)" >/dev/null; then
                SYSTEM_INFO[DESKTOP]="yes"
                SYSTEM_INFO[DESKTOP_ENV]="$desktop_env"
            else
                SYSTEM_INFO[DESKTOP]="no"
            fi
            ;;
        *)
            if [ -n "$desktop_env" ]; then
                SYSTEM_INFO[DESKTOP]="yes"
                SYSTEM_INFO[DESKTOP_ENV]="$desktop_env"
            else
                SYSTEM_INFO[DESKTOP]="no"
            fi
            ;;
    esac
}

# Detect hardware capabilities
detect_hardware() {
    log INFO "Detecting hardware capabilities..."
    
    # GPU Detection
    detect_gpu
    
    # Audio system detection
    detect_audio_system
    
    # Network capabilities
    detect_network_capabilities
    
    log SUCCESS "Hardware detection completed"
}

# Detect GPU type and capabilities
detect_gpu() {
    local gpu_info=$(lspci | grep -i vga 2>/dev/null)
    
    SYSTEM_INFO[NVIDIA_GPU]="no"
    SYSTEM_INFO[NVIDIA_1080_GPU]="no"
    SYSTEM_INFO[AMD_GPU]="no"
    SYSTEM_INFO[INTEL_GPU]="no"
    
    if echo "$gpu_info" | grep -qi nvidia; then
        SYSTEM_INFO[NVIDIA_GPU]="yes"
        if echo "$gpu_info" | grep -qi "GTX 1080\\|RTX"; then
            SYSTEM_INFO[NVIDIA_1080_GPU]="yes"
        fi
        log INFO "NVIDIA GPU detected"
    fi
    
    if echo "$gpu_info" | grep -qi "amd\\|radeon"; then
        SYSTEM_INFO[AMD_GPU]="yes"
        log INFO "AMD GPU detected"
    fi
    
    if echo "$gpu_info" | grep -qi intel; then
        SYSTEM_INFO[INTEL_GPU]="yes"
        log INFO "Intel GPU detected"
    fi
}

# Detect audio system
detect_audio_system() {
    if command_exists pulseaudio; then
        SYSTEM_INFO[AUDIO_SYSTEM]="pulseaudio"
    elif command_exists pipewire; then
        SYSTEM_INFO[AUDIO_SYSTEM]="pipewire"
    elif command_exists alsa; then
        SYSTEM_INFO[AUDIO_SYSTEM]="alsa"
    else
        SYSTEM_INFO[AUDIO_SYSTEM]="unknown"
    fi
    
    log INFO "Audio system: ${SYSTEM_INFO[AUDIO_SYSTEM]}"
}

# Detect network capabilities
detect_network_capabilities() {
    SYSTEM_INFO[BLUETOOTH]="no"
    SYSTEM_INFO[WIFI]="no"
    
    if command_exists bluetoothctl || [ -d /sys/class/bluetooth ]; then
        SYSTEM_INFO[BLUETOOTH]="yes"
    fi
    
    if ip link show | grep -q "wlan\\|wifi\\|wireless" || \
       nmcli dev status 2>/dev/null | grep -q wifi; then
        SYSTEM_INFO[WIFI]="yes"
    fi
}

# Get system capabilities summary
get_capabilities() {
    local capabilities=()
    
    [ "${SYSTEM_INFO[DESKTOP]}" == "yes" ] && capabilities+=("desktop")
    [ "${SYSTEM_INFO[NVIDIA_GPU]}" == "yes" ] && capabilities+=("nvidia")
    [ "${SYSTEM_INFO[AMD_GPU]}" == "yes" ] && capabilities+=("amd")
    [ "${SYSTEM_INFO[BLUETOOTH]}" == "yes" ] && capabilities+=("bluetooth")
    [ "${SYSTEM_INFO[WIFI]}" == "yes" ] && capabilities+=("wifi")
    [ "${SYSTEM_INFO[WSL]}" == "yes" ] && capabilities+=("wsl")
    [ "${SYSTEM_INFO[CONTAINER]}" == "yes" ] && capabilities+=("container")
    
    echo "${capabilities[@]}"
}

# Check if current system supports a specific feature
supports_feature() {
    local feature="$1"
    
    case "$feature" in
        "desktop")
            [ "${SYSTEM_INFO[DESKTOP]}" == "yes" ]
            ;;
        "gpu")
            [ "${SYSTEM_INFO[NVIDIA_GPU]}" == "yes" ] || \
            [ "${SYSTEM_INFO[AMD_GPU]}" == "yes" ]
            ;;
        "nvidia")
            [ "${SYSTEM_INFO[NVIDIA_GPU]}" == "yes" ]
            ;;
        "bluetooth")
            [ "${SYSTEM_INFO[BLUETOOTH]}" == "yes" ]
            ;;
        "wsl")
            [ "${SYSTEM_INFO[WSL]}" == "yes" ]
            ;;
        "container")
            [ "${SYSTEM_INFO[CONTAINER]}" == "yes" ]
            ;;
        *)
            return 1
            ;;
    esac
}

# Source guard to prevent double-sourcing
if [ -z "$DETECT_LIB_LOADED" ]; then
    DETECT_LIB_LOADED=true
fi