import os
import warnings
import torch
import gc
from transformers import AutoModelForVision2Seq, AutoProcessor, BitsAndBytesConfig, AutoConfig
from PIL import Image
import gradio as gr
from huggingface_hub import login

# Basic settings
warnings.filterwarnings('ignore')
os.environ["CUDA_VISIBLE_DEVICES"] = "0"

# Global variables
model = None
processor = None

# Clear CUDA cache
if torch.cuda.is_available():
    torch.cuda.empty_cache()
    gc.collect()
    print("เคลียร์ CUDA cache เรียบร้อยแล้ว")

# Login to Hugging Face Hub
if 'HUGGING_FACE_HUB_TOKEN' in os.environ:
    print("กำลังเข้าสู่ระบบ Hugging Face Hub...")
    login(token=os.environ['HUGGING_FACE_HUB_TOKEN'])
else:
    print("คำเตือน: ไม่พบ HUGGING_FACE_HUB_TOKEN")

def load_model_and_processor():
    """โหลดโมเดลและ processor"""
    global model, processor
    print("กำลังโหลดโมเดลและ processor...")
    
    try:
        # Model paths
        hub_model_path = "Aekanun/thai-handwriting-llm"
        
        # BitsAndBytes config
        bnb_config = BitsAndBytesConfig(
            load_in_4bit=True,
            bnb_4bit_use_double_quant=True,
            bnb_4bit_quant_type="nf4",
            bnb_4bit_compute_dtype=torch.bfloat16
        )

        # Load model configuration
        config = AutoConfig.from_pretrained(hub_model_path, trust_remote_code=True)
        config.model_type = "llava"  # กำหนด model_type
        
        # Load processor and model
        processor = AutoProcessor.from_pretrained(hub_model_path, trust_remote_code=True)
        
        print("กำลังโหลดโมเดลจาก Hub...")
        model = AutoModelForVision2Seq.from_pretrained(
            hub_model_path,
            config=config,
            device_map="auto",
            torch_dtype=torch.bfloat16,
            quantization_config=bnb_config,
            trust_remote_code=True
        )
        print("โหลดโมเดลสำเร็จ!")
        
        return True
    except Exception as e:
        print(f"เกิดข้อผิดพลาดในการโหลดโมเดล: {str(e)}")
        return False

def process_handwriting(image):
    """ฟังก์ชันสำหรับ Gradio interface"""
    global model, processor
    
    if image is None:
        return "กรุณาอัพโหลดรูปภาพ"
    
    try:
        # Ensure image is in PIL format
        if not isinstance(image, Image.Image):
            image = Image.fromarray(image)
            
        # Convert to RGB if needed
        if image.mode != "RGB":
            image = image.convert("RGB")
        
        # Create prompt
        prompt = """Transcribe the Thai handwritten text from the provided image.
Only return the transcription in Thai language."""

        # Create model inputs
        messages = [
            {
                "role": "user",
                "content": [
                    {"type": "text", "text": prompt},
                    {"type": "image", "image": image}
                ],
            }
        ]

        # Process with model
        text = processor.apply_chat_template(messages, tokenize=False)
        inputs = processor(text=text, images=image, return_tensors="pt")
        inputs = {k: v.to(model.device) for k, v in inputs.items()}

        # Generate
        with torch.no_grad():
            outputs = model.generate(
                **inputs,
                max_new_tokens=256,
                do_sample=False,
                pad_token_id=processor.tokenizer.pad_token_id
            )

        # Decode output
        transcription = processor.decode(outputs[0], skip_special_tokens=True)
        return transcription.strip()
        
    except Exception as e:
        return f"เกิดข้อผิดพลาด: {str(e)}"

# Initialize application
print("กำลังเริ่มต้นแอปพลิเคชัน...")
if load_model_and_processor():
    # Create Gradio interface
    demo = gr.Interface(
        fn=process_handwriting,
        inputs=gr.Image(type="pil", label="อัพโหลดรูปลายมือเขียนภาษาไทย"),
        outputs=gr.Textbox(label="ข้อความที่แปลงได้"),
        title="Thai Handwriting Recognition",
        description="อัพโหลดรูปภาพลายมือเขียนภาษาไทยเพื่อแปลงเป็นข้อความ",
        examples=[["example1.jpg"], ["example2.jpg"]]
    )

    if __name__ == "__main__":
        demo.launch()
else:
    print("ไม่สามารถเริ่มต้นแอปพลิเคชันได้")