import os
import torch
import gradio as gr
from transformers import AutoTokenizer, AutoModelForCausalLM
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = FastAPI()

model_name = "google/gemma-2-2b-it"
tokenizer = None
model = None

try:
    logger.info(f"Loading model: {model_name}")
    tokenizer = AutoTokenizer.from_pretrained(model_name, token=os.getenv("HF_TOKEN"))
    use_gpu = torch.cuda.is_available()
    logger.info(f"GPU available: {use_gpu}")
    model = AutoModelForCausalLM.from_pretrained(
        model_name,
        torch_dtype=torch.float16,  # メモリ削減
        device_map="cpu",  # GPU利用不可
        token=os.getenv("HF_TOKEN"),
        low_cpu_mem_usage=True
    )
    logger.info("Model loaded successfully")
except Exception as e:
    logger.error(f"Model load error: {e}")
    raise

def generate_text(text, max_length=50):
    try:
        logger.info(f"Generating text for input: {text}")
        inputs = tokenizer(text, return_tensors="pt", max_length=512, truncation=True).to("cpu")
        outputs = model.generate(**inputs, max_length=max_length)
        result = tokenizer.decode(outputs[0], skip_special_tokens=True)
        logger.info(f"Generated text: {result}")
        return result
    except Exception as e:
        logger.error(f"Generation error: {e}")
        return f"Error: {str(e)}"

iface = gr.Interface(
    fn=generate_text,
    inputs=[gr.Textbox(label="Input Text"), gr.Slider(10, 100, value=50, label="Max Length")],
    outputs=gr.Textbox(label="Generated Text"),
    title="Gemma 2 API"
)

if __name__ == "__main__":
    try:
        logger.info("Launching Gradio interface")
        iface.launch(server_name="0.0.0.0", server_port=8080)
    except Exception as e:
        logger.error(f"Gradio launch error: {e}")
        raise