app/ocr_engine.py

import os
import sys
import re
import subprocess
from pathlib import Path

def is_cuda_fully_functional():
    """Checks if CUDA is fully available and functional by running a quick subprocess check"""
    try:
        # Run in a separate process to avoid importing torch in the main GUI process
        cmd = [
            sys.executable, "-c",
            "import torch; import torch.nn as nn; "
            "print(torch.cuda.is_available() and len(torch.cuda.get_arch_list()) > 0 and float(nn.Conv2d(1, 1, 3).cuda()(torch.randn(1, 1, 8, 8).cuda()).to('cpu')[0,0,0,0]) is not None)"
        ]
        startupinfo = None
        if sys.platform == 'win32':
            startupinfo = subprocess.STARTUPINFO()
            startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
            
        res = subprocess.run(
            cmd, 
            capture_output=True, 
            text=True, 
            encoding="utf-8", 
            errors="ignore", 
            timeout=5,
            startupinfo=startupinfo
        )
        return res.stdout.strip() == "True"
    except Exception:
        return False

def extract_subtitles_from_video(video_path, blur_region, output_srt_path, log_fn=None):
    """
    Subprocess wrapper for subtitle extraction using PaddleOCR.
    This prevents importing torch/paddleocr in the main process.
    """
    if not blur_region:
        raise ValueError("Bạn phải khoanh vùng phụ đề trước khi chạy chế độ quét chữ!")

    video_path = Path(video_path)
    output_srt_path = Path(output_srt_path)
    
    # Format region: x,y,w,h,orig_w,orig_h
    region_str = ",".join(map(str, blur_region))
    
    worker_script = Path(__file__).parent / "core" / "ocr_worker_cli.py"
    
    cmd = [
        sys.executable,
        str(worker_script),
        "--video", str(video_path),
        "--output", str(output_srt_path),
        "--region", region_str
    ]
    
    if log_fn:
        log_fn(f"🚀 Khởi chạy quét phụ đề trong subprocess...")

    startupinfo = None
    if sys.platform == 'win32':
        startupinfo = subprocess.STARTUPINFO()
        startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW

    try:
        process = subprocess.Popen(
            cmd,
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT,
            text=True,
            encoding="utf-8",
            errors="ignore",
            startupinfo=startupinfo
        )
        
        # Parse output line-by-line
        for line in process.stdout:
            line_str = line.strip()
            if not line_str:
                continue
                
            # Parse progress: PROGRESS: XX%
            m = re.match(r"PROGRESS:\s*(\d+)%", line_str)
            if m:
                pct = int(m.group(1))
                filled_len = int(20 * pct / 100)
                bar = "█" * filled_len + "░" * (20 - filled_len)
                if log_fn:
                    # Output unified single-line progress bar
                    log_fn(f"\r[STAGE A] Processing Video: [{bar}] {pct}% | Scanning frame data...")
            else:
                if log_fn:
                    log_fn(line_str)
                    
        process.wait()
        
        if process.returncode != 0:
            raise Exception(f"Subprocess OCR failed with exit code {process.returncode}")
            
        return True
        
    except Exception as e:
        if log_fn:
            log_fn(f"❌ Lỗi quét OCR: {e}")
        raise