#!/bin/bash

# apt-layer Installation Script
# This script installs the apt-layer tool, its dependencies, creates necessary directories and files,
# and sets up the system to use apt-layer. If already installed, it will update the tool.
#
# Usage:
#   ./install-apt-layer.sh                    # Install or update apt-layer
#   ./install-apt-layer.sh --uninstall        # Remove apt-layer and all its files
#   ./install-apt-layer.sh --reinstall        # Remove and reinstall (reset to default state)
#   ./install-apt-layer.sh --help             # Show this help message

set -euo pipefail

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

# Function to print colored output
print_status() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

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

print_header() {
    echo -e "${BLUE}================================${NC}"
    echo -e "${BLUE}$1${NC}"
    echo -e "${BLUE}================================${NC}"
}

# Function to show help
show_help() {
    cat << 'EOF'
apt-layer Installation Script

This script installs the apt-layer tool, its dependencies, creates necessary directories and files,
and sets up the system to use apt-layer.

Usage:
  ./install-apt-layer.sh                    # Install or update apt-layer
  ./install-apt-layer.sh --uninstall        # Remove apt-layer and all its files
  ./install-apt-layer.sh --reinstall        # Remove and reinstall (reset to default state)
  ./install-apt-layer.sh --help             # Show this help message

What this script does:
  - Downloads the latest apt-layer.sh from the repository
  - Installs required dependencies (jq, dos2unix, etc.)
  - Creates necessary directories (/var/lib/apt-layer, /var/log/apt-layer, etc.)
  - Sets up configuration files
  - Makes apt-layer executable and available system-wide
  - Initializes the apt-layer system

Dependencies:
  - curl or wget (for downloading)
  - jq (for JSON processing)
  - dos2unix (for Windows line ending conversion)
  - sudo (for system installation)

EOF
}

# Function to check if running as root
check_root() {
    if [[ $EUID -eq 0 ]]; then
        print_error "This script should not be run as root. Use sudo for specific commands."
        exit 1
    fi
}

# Function to check dependencies
check_dependencies() {
    print_status "Checking dependencies..."
    
    local missing_deps=()
    
    # Check for curl or wget
    if ! command -v curl >/dev/null 2>&1 && ! command -v wget >/dev/null 2>&1; then
        missing_deps+=("curl or wget")
    fi
    
    # Check for jq
    if ! command -v jq >/dev/null 2>&1; then
        missing_deps+=("jq")
    fi
    
    # Check for dos2unix
    if ! command -v dos2unix >/dev/null 2>&1; then
        missing_deps+=("dos2unix")
    fi
    
    if [[ ${#missing_deps[@]} -gt 0 ]]; then
        print_error "Missing required dependencies: ${missing_deps[*]}"
        print_status "Installing missing dependencies..."
        
        # Try to install dependencies
        if command -v apt-get >/dev/null 2>&1; then
            sudo apt-get update
            sudo apt-get install -y "${missing_deps[@]}"
        elif command -v dnf >/dev/null 2>&1; then
            sudo dnf install -y "${missing_deps[@]}"
        elif command -v yum >/dev/null 2>&1; then
            sudo yum install -y "${missing_deps[@]}"
        else
            print_error "Could not automatically install dependencies. Please install manually:"
            print_error "  ${missing_deps[*]}"
            exit 1
        fi
    fi
    
    print_success "All dependencies satisfied"
}

# Function to download apt-layer
download_apt_layer() {
    print_status "Downloading apt-layer..."
    
    local download_url="https://git.raines.xyz/robojerk/particle-os-tools/raw/branch/main/apt-layer.sh"
    local temp_file="/tmp/apt-layer.sh"
    
    # Download using curl or wget
    if command -v curl >/dev/null 2>&1; then
        if curl -L -o "$temp_file" "$download_url"; then
            print_success "Downloaded apt-layer using curl"
        else
            print_error "Failed to download apt-layer using curl"
            return 1
        fi
    elif command -v wget >/dev/null 2>&1; then
        if wget -O "$temp_file" "$download_url"; then
            print_success "Downloaded apt-layer using wget"
        else
            print_error "Failed to download apt-layer using wget"
            return 1
        fi
    else
        print_error "No download tool available (curl or wget)"
        return 1
    fi
    
    # Verify the downloaded file
    if [[ ! -f "$temp_file" ]] || [[ ! -s "$temp_file" ]]; then
        print_error "Downloaded file is empty or missing"
        return 1
    fi
    
    # Convert line endings if needed
    if command -v dos2unix >/dev/null 2>&1; then
        dos2unix "$temp_file" 2>/dev/null || true
    fi
    
    # Make executable
    chmod +x "$temp_file"
    
    print_success "apt-layer downloaded and prepared"
}

# Function to install apt-layer
install_apt_layer() {
    print_status "Installing apt-layer..."
    
    local temp_file="/tmp/apt-layer.sh"
    local install_dir="/usr/local/bin"
    local config_dir="/usr/local/etc/apt-layer"
    
    # Create installation directory if it doesn't exist
    sudo mkdir -p "$install_dir"
    
    # Install apt-layer
    sudo cp "$temp_file" "$install_dir/apt-layer"
    sudo chmod +x "$install_dir/apt-layer"
    
    # Create configuration directory
    sudo mkdir -p "$config_dir"
    
    # Create paths.json configuration
    sudo tee "$config_dir/paths.json" >/dev/null <<EOF
{
  "apt_layer_paths": {
    "description": "apt-layer system path configuration",
    "version": "1.0",
    "main_directories": {
      "workspace": {
        "path": "/var/lib/apt-layer",
        "description": "Main apt-layer workspace directory",
        "permissions": "755",
        "owner": "root:root"
      },
      "logs": {
        "path": "/var/log/apt-layer",
        "description": "apt-layer log files directory",
        "permissions": "755",
        "owner": "root:root"
      },
      "cache": {
        "path": "/var/cache/apt-layer",
        "description": "apt-layer cache directory",
        "permissions": "755",
        "owner": "root:root"
      }
    },
    "workspace_subdirectories": {
      "build": {
        "path": "/var/lib/apt-layer/build",
        "description": "Build artifacts and temporary files",
        "permissions": "755",
        "owner": "root:root"
      },
      "live_overlay": {
        "path": "/var/lib/apt-layer/live-overlay",
        "description": "Live overlay system for temporary changes",
        "permissions": "755",
        "owner": "root:root"
      },
      "composefs": {
        "path": "/var/lib/apt-layer/composefs",
        "description": "ComposeFS layers and metadata",
        "permissions": "755",
        "owner": "root:root"
      },
      "ostree_commits": {
        "path": "/var/lib/apt-layer/ostree-commits",
        "description": "OSTree commit history and metadata",
        "permissions": "755",
        "owner": "root:root"
      },
      "deployments": {
        "path": "/var/lib/apt-layer/deployments",
        "description": "Deployment directories and state",
        "permissions": "755",
        "owner": "root:root"
      },
      "history": {
        "path": "/var/lib/apt-layer/history",
        "description": "Deployment history and rollback data",
        "permissions": "755",
        "owner": "root:root"
      },
      "bootloader": {
        "path": "/var/lib/apt-layer/bootloader",
        "description": "Bootloader state and configuration",
        "permissions": "755",
        "owner": "root:root"
      },
      "transaction_state": {
        "path": "/var/lib/apt-layer/transaction-state",
        "description": "Transaction state and temporary data",
        "permissions": "755",
        "owner": "root:root"
      }
    },
    "files": {
      "deployment_db": {
        "path": "/var/lib/apt-layer/deployments.json",
        "description": "Deployment database file",
        "permissions": "644",
        "owner": "root:root"
      },
      "current_deployment": {
        "path": "/var/lib/apt-layer/current-deployment",
        "description": "Current deployment identifier file",
        "permissions": "644",
        "owner": "root:root"
      },
      "pending_deployment": {
        "path": "/var/lib/apt-layer/pending-deployment",
        "description": "Pending deployment identifier file",
        "permissions": "644",
        "owner": "root:root"
      },
      "transaction_log": {
        "path": "/var/lib/apt-layer/transaction.log",
        "description": "Transaction log file",
        "permissions": "644",
        "owner": "root:root"
      }
    },
    "fallback_paths": {
      "description": "Fallback paths for different environments",
      "wsl": {
        "workspace": "/mnt/wsl/apt-layer",
        "logs": "/mnt/wsl/apt-layer/logs",
        "cache": "/mnt/wsl/apt-layer/cache"
      },
      "container": {
        "workspace": "/tmp/apt-layer",
        "logs": "/tmp/apt-layer/logs",
        "cache": "/tmp/apt-layer/cache"
      },
      "test": {
        "workspace": "/tmp/apt-layer-test",
        "logs": "/tmp/apt-layer-test/logs",
        "cache": "/tmp/apt-layer-test/cache"
      }
    },
    "environment_variables": {
      "description": "Environment variable mappings",
      "APT_LAYER_WORKSPACE": "workspace",
      "APT_LAYER_LOG_DIR": "logs",
      "APT_LAYER_CACHE_DIR": "cache",
      "BUILD_DIR": "workspace_subdirectories.build",
      "LIVE_OVERLAY_DIR": "workspace_subdirectories.live_overlay",
      "COMPOSEFS_DIR": "workspace_subdirectories.composefs",
      "OSTREE_COMMITS_DIR": "workspace_subdirectories.ostree_commits",
      "DEPLOYMENTS_DIR": "workspace_subdirectories.deployments",
      "HISTORY_DIR": "workspace_subdirectories.history",
      "BOOTLOADER_STATE_DIR": "workspace_subdirectories.bootloader",
      "TRANSACTION_STATE": "workspace_subdirectories.transaction_state",
      "DEPLOYMENT_DB": "files.deployment_db",
      "CURRENT_DEPLOYMENT_FILE": "files.current_deployment",
      "PENDING_DEPLOYMENT_FILE": "files.pending_deployment",
      "TRANSACTION_LOG": "files.transaction_log"
    }
  }
} 
EOF
    
    # Set proper permissions
    sudo chmod 644 "$config_dir/paths.json"
    
    # Initialize apt-layer system
    print_status "Initializing apt-layer system..."
    if sudo apt-layer --init; then
        print_success "apt-layer system initialized"
    else
        print_warning "apt-layer system initialization failed, but installation completed"
    fi
    
    # Clean up temporary file
    rm -f "$temp_file"
    
    print_success "apt-layer installed successfully"
    print_status "You can now use 'apt-layer --help' to see available commands"
}

# Function to uninstall apt-layer
uninstall_apt_layer() {
    print_status "Uninstalling apt-layer..."
    
    local install_dir="/usr/local/bin"
    local config_dir="/usr/local/etc/apt-layer"
    
    # Remove apt-layer binary
    if [[ -f "$install_dir/apt-layer" ]]; then
        sudo rm -f "$install_dir/apt-layer"
        print_status "Removed apt-layer binary"
    fi
    
    # Remove configuration directory
    if [[ -d "$config_dir" ]]; then
        sudo rm -rf "$config_dir"
        print_status "Removed configuration directory"
    fi
    
    # Remove apt-layer directories (optional - ask user)
    if [[ -d "/var/lib/apt-layer" ]] || [[ -d "/var/log/apt-layer" ]] || [[ -d "/var/cache/apt-layer" ]]; then
        echo -e "${YELLOW}Do you want to remove all apt-layer data directories? (y/N)${NC}"
        read -r response
        if [[ "$response" =~ ^[Yy]$ ]]; then
            sudo rm -rf "/var/lib/apt-layer" "/var/log/apt-layer" "/var/cache/apt-layer"
            print_status "Removed all apt-layer data directories"
        else
            print_status "Keeping apt-layer data directories"
        fi
    fi
    
    print_success "apt-layer uninstalled successfully"
}

# Function to reinstall apt-layer
reinstall_apt_layer() {
    print_status "Reinstalling apt-layer..."
    
    # Uninstall first
    uninstall_apt_layer
    
    # Install again
    install_apt_layer
    
    print_success "apt-layer reinstalled successfully"
}

# Function to check if apt-layer is installed
is_apt_layer_installed() {
    command -v apt-layer >/dev/null 2>&1
}

# Function to check if apt-layer is up to date
check_for_updates() {
    print_status "Checking for updates..."
    
    if ! is_apt_layer_installed; then
        return 0  # Not installed, so no update needed
    fi
    
    # For now, we'll always download the latest version
    # In the future, this could check version numbers or timestamps
    return 1  # Update needed
}

# Main installation function
main_install() {
    print_header "apt-layer Installation"
    
    # Check if running as root
    check_root
    
    # Check dependencies
    check_dependencies
    
    # Check if already installed
    if is_apt_layer_installed; then
        print_status "apt-layer is already installed"
        if check_for_updates; then
            print_status "apt-layer is up to date"
            return 0
        else
            print_status "Updating apt-layer..."
        fi
    else
        print_status "Installing apt-layer..."
    fi
    
    # Download and install
    if download_apt_layer && install_apt_layer; then
        print_success "apt-layer installation completed successfully"
        print_status "You can now use 'apt-layer --help' to see available commands"
        return 0
    else
        print_error "apt-layer installation failed"
        return 1
    fi
}

# Main function
main() {
    case "${1:-}" in
        --help|-h)
            show_help
            exit 0
            ;;
        --uninstall)
            print_header "apt-layer Uninstallation"
            uninstall_apt_layer
            exit 0
            ;;
        --reinstall)
            print_header "apt-layer Reinstallation"
            reinstall_apt_layer
            exit 0
            ;;
        "")
            main_install
            exit $?
            ;;
        *)
            print_error "Unknown option: $1"
            show_help
            exit 1
            ;;
    esac
}

# Run main function with all arguments
main "$@"