# tool/core/cmd/get_file.py
import struct
import zlib
from pathlib import Path
from core.utils import console, console_err
from core.protocol import COMMANDS

class get_file:
    def __init__(self, bus):
        self.bus = bus

    def get(self, source_path: str, dest_path: str):
        try:
            p = Path(dest_path)
            p.parent.mkdir(parents=True, exist_ok=True)
            with open(p, 'wb') as f:
                pass 
        except Exception as e:
            console_err.print(f"Fehler: Kann Zieldatei nicht anlegen: {e}")
            return None

        source_path_bytes = source_path.encode('utf-8')
        payload = struct.pack('B', len(source_path_bytes)) + source_path_bytes
        device_file_crc = None
        try:
            self.bus.send_request(COMMANDS['crc_32'], payload)
            crc_resp = self.bus.receive_response(length=4)
            if crc_resp and crc_resp.get('type') == 'response':
                device_file_crc = struct.unpack('<I', crc_resp['data'])[0]
        except Exception:
            device_file_crc = None

        self.bus.send_request(COMMANDS['get_file'], payload)
        
        stream_res = self.bus.receive_stream()  
        
        if not stream_res or stream_res.get('type') == 'error':
            return None

        file_data = stream_res['data']
        remote_crc = stream_res['crc32']

        if local_crc == remote_crc:
            with open(p, 'wb') as f:
                f.write(file_data)
            success = True
        else:
            with open(p, 'wb') as f:
                f.write(file_data)
            success = False

        return {
            'success': success,
            'source_path': source_path,
            'dest_path': dest_path,
            'crc32_remote': remote_crc,
            'crc32_local': local_crc,
            'crc32_device_file': device_file_crc,
            'size': len(file_data)
        }

    def print(self, result):
        if not result:
            return

        if result['success']:
            console.print(f"✓ Datei [info]{result['source_path']}[/info] erfolgreich heruntergeladen.")
            console.print(f"  • Größe:      [info]{result['size'] / 1024:.2f} KB[/info]")
        else:
            console_err.print(f"❌ CRC-FEHLER: Datei [error]{result['source_path']}[/error] wurde nicht korrekt empfangen!")
        
        console.print(f"  • Remote CRC: [info]{result['crc32_remote']:08X}[/info]")
        console.print(f"  • Local CRC:  [info]{result['crc32_local']:08X}[/info]")
        if result.get('crc32_device_file') is not None:
            console.print(f"  • Device CRC: [info]{result['crc32_device_file']:08X}[/info]")
        console.print(f"  • Zielpfad:   [info]{result['dest_path']}[/info]")