"""
Auto-update functionality
Handles remote version checking and application updates
"""

import os
import subprocess
import re
import logging
from config_settings import (
    AUTO_UPDATE_SERVER_HOST,
    AUTO_UPDATE_SERVER_USER,
    AUTO_UPDATE_SERVER_PASSWORD,
    AUTO_UPDATE_SERVER_APP_PATH,
    AUTO_UPDATE_SERVER_REPO_PATH,
    UPDATE_TIMEOUT,
    REPO_SYNC_TIMEOUT
)
from logger_module import log_with_server


def get_app_version(file_path):
    """
    Extract version from app file
    Version is expected to be in the first line as: #App version X.X
    
    Args:
        file_path: Path to the app.py file
    
    Returns:
        float: Version number or None
    """
    try:
        with open(file_path, 'r') as f:
            first_line = f.readline()
            if 'version' in first_line.lower():
                version_match = re.search(r'version\s+(\d+\.?\d*)', first_line, re.IGNORECASE)
                if version_match:
                    return float(version_match.group(1))
    except Exception as e:
        logging.error(f"Could not determine version from {file_path}: {e}")
    
    return None


def check_remote_version(hostname, device_ip):
    """
    Check the version of the app on the remote server
    
    Returns:
        float: Remote version or None
    """
    temp_dir = "/tmp/app_update"
    
    try:
        # Create temporary directory
        subprocess.run(['mkdir', '-p', temp_dir], check=True)
        
        # Download remote app.py to check version
        scp_command = [
            'sshpass', '-p', AUTO_UPDATE_SERVER_PASSWORD,
            'scp', '-o', 'StrictHostKeyChecking=no', '-o', 'UserKnownHostsFile=/dev/null',
            f'{AUTO_UPDATE_SERVER_USER}@{AUTO_UPDATE_SERVER_HOST}:{AUTO_UPDATE_SERVER_APP_PATH}',
            f'{temp_dir}/app.py'
        ]
        
        result = subprocess.run(scp_command, capture_output=True, text=True, timeout=UPDATE_TIMEOUT)
        if result.returncode != 0:
            log_with_server(f"Failed to download remote app.py: {result.stderr}", hostname, device_ip)
            return None
        
        remote_version = get_app_version(f'{temp_dir}/app.py')
        log_with_server(f"Remote version: {remote_version}", hostname, device_ip)
        return remote_version
        
    except subprocess.TimeoutExpired:
        log_with_server("Connection to server timed out", hostname, device_ip)
        return None
    except Exception as e:
        log_with_server(f"Error checking remote version: {e}", hostname, device_ip)
        return None


def perform_auto_update(local_app_path, local_repo_path, hostname, device_ip):
    """
    Perform the auto-update process
    
    Args:
        local_app_path: Path to local app.py
        local_repo_path: Path to local repository
        hostname: Device hostname
        device_ip: Device IP
    
    Returns:
        dict with update status information
    """
    temp_dir = "/tmp/app_update"
    
    try:
        # Get current local version
        current_version = get_app_version(local_app_path)
        if current_version is None:
            log_with_server(f"Could not determine local version", hostname, device_ip)
            return {"error": "Could not determine local version", "status": "failed"}
        
        # Create temporary directory
        subprocess.run(['mkdir', '-p', temp_dir], check=True)
        
        # Get remote version
        remote_version = check_remote_version(hostname, device_ip)
        if remote_version is None:
            return {"error": "Could not determine remote version", "status": "failed"}
        
        # Compare versions
        if remote_version <= current_version:
            log_with_server(f"No update needed. Current: {current_version}, Remote: {remote_version}", hostname, device_ip)
            return {
                "status": "no_update_needed",
                "current_version": current_version,
                "remote_version": remote_version,
                "message": "Application is already up to date"
            }
        
        # Download updated files
        log_with_server(f"Update available! Downloading version {remote_version}", hostname, device_ip)
        
        # Create backup of current app
        backup_path = f"{local_app_path}.backup.{current_version}"
        subprocess.run(['cp', local_app_path, backup_path], check=True)
        log_with_server(f"Backup created: {backup_path}", hostname, device_ip)
        
        # Download new app.py
        subprocess.run(['cp', f'{temp_dir}/app.py', local_app_path], check=True)
        log_with_server("New app.py downloaded successfully", hostname, device_ip)
        
        # Download repository folder
        repo_scp_command = [
            'sshpass', '-p', AUTO_UPDATE_SERVER_PASSWORD,
            'scp', '-r', '-o', 'StrictHostKeyChecking=no', '-o', 'UserKnownHostsFile=/dev/null',
            f'{AUTO_UPDATE_SERVER_USER}@{AUTO_UPDATE_SERVER_HOST}:{AUTO_UPDATE_SERVER_REPO_PATH}',
            f'{local_repo_path}_new'
        ]
        
        result = subprocess.run(repo_scp_command, capture_output=True, text=True, timeout=REPO_SYNC_TIMEOUT)
        if result.returncode == 0:
            subprocess.run(['rm', '-rf', local_repo_path], check=True)
            subprocess.run(['mv', f'{local_repo_path}_new', local_repo_path], check=True)
            log_with_server("Repository updated successfully", hostname, device_ip)
        else:
            log_with_server(f"Repository update failed: {result.stderr}", hostname, device_ip)
        
        log_with_server("Update completed successfully. Scheduling restart...", hostname, device_ip)
        
        # Schedule device restart
        restart_script = '''#!/bin/bash
sleep 3
sudo reboot
'''
        with open('/tmp/restart_device.sh', 'w') as f:
            f.write(restart_script)
        subprocess.run(['chmod', '+x', '/tmp/restart_device.sh'], check=True)
        subprocess.Popen(['/tmp/restart_device.sh'], 
                       stdout=subprocess.DEVNULL, 
                       stderr=subprocess.DEVNULL)
        
        return {
            "status": "success",
            "message": f"Updated from version {current_version} to {remote_version}. Device restarting...",
            "old_version": current_version,
            "new_version": remote_version,
            "restart_scheduled": True
        }
        
    except Exception as e:
        log_with_server(f"Auto-update error: {str(e)}", hostname, device_ip)
        return {"error": f"Auto-update failed: {str(e)}", "status": "failed"}
    finally:
        # Cleanup temp directory
        try:
            subprocess.run(['rm', '-rf', temp_dir], check=True)
        except:
            pass