#!/bin/bash
# utils.sh - Common utility functions for USM installer

# Colors for terminal output
readonly RED='\033[0;31m'
readonly GREEN='\033[0;32m'
readonly YELLOW='\033[1;33m'
readonly BLUE='\033[0;34m'
readonly CYAN='\033[0;36m'
readonly BOLD='\033[1m'
readonly NC='\033[0m' # No Color

# Logging functions
log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

log_step() {
    echo -e "${CYAN}==>${NC} ${BOLD}$1${NC}"
}

# Check if running as root
is_root() {
    [[ $EUID -eq 0 ]]
}

# Check if a command exists
command_exists() {
    command -v "$1" &>/dev/null
}

# Get the system's package manager
detect_package_manager() {
    if command_exists apt-get; then
        echo "apt"
    elif command_exists dnf; then
        echo "dnf"
    elif command_exists yum; then
        echo "dnf"  # Fallback to dnf implementation
    elif command_exists pacman; then
        echo "pacman"
    else
        echo "unknown"
    fi
}

# Get the system's sudo command
get_sudo() {
    if is_root; then
        echo ""
    elif command_exists sudo; then
        echo "sudo"
    elif command_exists doas; then
        echo "doas"
    else
        echo ""
    fi
}

# Confirm action with user
confirm() {
    local prompt="$1"
    local default="${2:-n}"
    local response
    
    if [[ "$ASSUME_YES" == "true" ]]; then
        return 0
    fi
    
    if [[ "$default" == "y" ]]; then
        prompt="$prompt [Y/n]: "
    else
        prompt="$prompt [y/N]: "
    fi
    
    read -r -p "$prompt" response
    response="${response:-$default}"
    
    [[ "$response" =~ ^[Yy]$ ]]
}

# Create directory if it doesn't exist
ensure_dir() {
    local dir="$1"
    if [[ ! -d "$dir" ]]; then
        mkdir -p "$dir"
    fi
}

# Extract XZ compressed data from this script
extract_payload() {
    local output_dir="$1"
    local script_path="$0"
    local payload_start
    
    # Find the payload marker
    payload_start=$(grep -an "^__PAYLOAD_START__$" "$script_path" | cut -d: -f1)
    
    if [[ -z "$payload_start" ]]; then
        log_error "Could not find payload in installer"
        return 1
    fi
    
    # Extract and decompress the payload
    tail -n +$((payload_start + 1)) "$script_path" | xz -d | tar -xf - -C "$output_dir"
}

# Cleanup function for traps
cleanup() {
    if [[ -n "$TEMP_DIR" && -d "$TEMP_DIR" ]]; then
        rm -rf "$TEMP_DIR"
    fi
}

# Set up temporary directory
setup_temp_dir() {
    TEMP_DIR=$(mktemp -d)
    trap cleanup EXIT
}

# Download a file
download_file() {
    local url="$1"
    local output="$2"
    
    if command_exists curl; then
        curl -fsSL "$url" -o "$output"
    elif command_exists wget; then
        wget -q "$url" -O "$output"
    else
        log_error "Neither curl nor wget is available"
        return 1
    fi
}

# Clone a git repository
clone_repo() {
    local url="$1"
    local dest="$2"
    local branch="${3:-main}"
    
    if ! command_exists git; then
        log_error "git is not installed"
        return 1
    fi
    
    git clone --depth 1 -b "$branch" "$url" "$dest" 2>/dev/null
}

# Get total size of a directory
get_dir_size() {
    local dir="$1"
    du -sb "$dir" 2>/dev/null | cut -f1
}

# Format bytes to human readable
format_size() {
    local bytes=$1
    local units=('B' 'KB' 'MB' 'GB' 'TB')
    local unit=0
    local size=$bytes
    
    while (( size > 1024 && unit < 4 )); do
        size=$((size / 1024))
        ((unit++))
    done
    
    echo "$size${units[$unit]}"
}