import gradio as gr
import numpy as np
import random
import os
import spaces
import torch
from diffusers import DiffusionPipeline
from transformers import pipeline, AutoTokenizer
from huggingface_hub import login

hf_token = os.getenv("hf_token")
login(token=hf_token)

MAX_SEED = np.iinfo(np.int32).max
MAX_IMAGE_SIZE = 2048

_text_gen_pipeline = None
_image_gen_pipeline = None

@spaces.GPU()
def get_image_gen_pipeline():
    global _image_gen_pipeline
    if _image_gen_pipeline is None:
        try:
            device = "cuda" if torch.cuda.is_available() else "cpu"
            dtype = torch.bfloat16
            _image_gen_pipeline = DiffusionPipeline.from_pretrained(
                "black-forest-labs/FLUX.1-schnell",
                torch_dtype=dtype
            ).to(device)
        except Exception as e:
            print(f"Error loading image generation model: {e}")
            return None
    return _image_gen_pipeline

@spaces.GPU()
def get_text_gen_pipeline():
    global _text_gen_pipeline
    if _text_gen_pipeline is None:
        try:
            device = "cuda" if torch.cuda.is_available() else "cpu"
            tokenizer = AutoTokenizer.from_pretrained(
                "mistralai/Mistral-7B-Instruct-v0.3",
                use_fast=True  # Ensure fast tokenizer
            )
            _text_gen_pipeline = pipeline(
                "text-generation",
                model="mistralai/Mistral-7B-Instruct-v0.3",
                tokenizer=tokenizer,
                max_new_tokens=2048,
                device=device,
            )
        except Exception as e:
            print(f"Error loading text generation model: {e}")
            return None
    return _text_gen_pipeline

@spaces.GPU()
def refine_prompt(prompt):
    text_gen = get_text_gen_pipeline()
    if text_gen is None:
        return "Text generation model is unavailable."
    try:
        messages = [
            {"role": "system", "content": "Vous êtes un designer produit avec de solides connaissances dans la génération de texte en image. Vous recevrez une demande de produit sous forme de description succincte, et votre mission sera d'imaginer un nouveau design de produit répondant à ce besoin.\n\nLe réponse générée sera exclusivement un prompt pour une IA de texte to image (Flux).\n\nCe prompt devra inclure une description visuelle de l'objet doit être une stricte description de produit, sans narration, et ne doit pas dépasser 2048 jetons.\nVous devez aussi explicitement mentionner les caractéristiques esthétiques visuelles du rendu image (ex : photoréaliste, haute qualité, focale, etc.). Le fond de l'image générée doit être entièrement blanc."},
            {"role": "user", "content": prompt},
        ]
        refined_prompt = text_gen(messages)
        
        # Extract just the assistant's content from the response
        try:
            messages = refined_prompt[0]['generated_text']
            # Find the last message with role 'assistant'
            assistant_messages = [msg for msg in messages if msg['role'] == 'assistant']
            if not assistant_messages:
                return "Error: No assistant response found"
            assistant_content = assistant_messages[-1]['content']
            return assistant_content
        except (KeyError, IndexError):
            return "Error: Unexpected response format from the model"
    except Exception as e:
        return f"Error refining prompt: {str(e)}"

def validate_dimensions(width, height):
    if width * height > MAX_IMAGE_SIZE * MAX_IMAGE_SIZE:
        return False, "Image dimensions too large"
    return True, None

@spaces.GPU()
def infer(prompt, seed=42, randomize_seed=False, width=1024, height=1024, num_inference_steps=4, progress=gr.Progress(track_tqdm=True)):
    try:
        progress(0, desc="Starting generation...")
        
        pipe = get_image_gen_pipeline()
        if pipe is None:
            return None, "Image generation model is unavailable."
        
        # Validate that prompt is not empty
        if not prompt or prompt.strip() == "":
            return None, "Please provide a valid prompt."

        # Validate width/height dimensions
        is_valid, error_msg = validate_dimensions(width, height)
        if not is_valid:
            return None, error_msg

        if randomize_seed:
            seed = random.randint(0, MAX_SEED)
        
        progress(0.2, desc="Setting up generator...")
        generator = torch.Generator().manual_seed(seed)
        
        progress(0.4, desc="Generating image...")
        with torch.autocast('cuda'):
            image = pipe(
                prompt=prompt, 
                width=width,
                height=height,
                num_inference_steps=num_inference_steps, 
                generator=generator,
                guidance_scale=5.0,
                max_sequence_length=2048
            ).images[0]

        torch.cuda.empty_cache()  # Clean up GPU memory after generation
        progress(1.0, desc="Done!")
        return image, seed
    except Exception as e:
        return None, f"Error generating image: {str(e)}"
 
examples = [
    "a tiny astronaut hatching from an egg on the moon",
    "a cat holding a sign that says hello world",
    "an anime illustration of a wiener schnitzel",
]

css="""
#col-container {
    margin: 0 auto;
    max-width: 520px;
}
"""

with gr.Blocks(css=css) as demo:
    
    # Compute the model loading status message ahead of creating the Info component.
    model_status = "Models loaded successfully!"

    info = gr.Info(model_status)

    with gr.Column(elem_id="col-container"):
        gr.Markdown(f"""# Text to Product
        Using Mistral + Flux + Trellis
        """)
        
        with gr.Row():
            
            prompt = gr.Text(
                label="Prompt",
                show_label=False,
                max_lines=1,
                placeholder="Enter your prompt",
                container=False,
            )
            
            prompt_button = gr.Button("Refine prompt", scale=0)
        
        refined_prompt = gr.Text(
            label="Refined Prompt", 
            show_label=False,
            max_lines=10, 
            placeholder="Prompt refined by Mistral", 
            container=False,
            max_length=2048,
            )
        
        
        run_button = gr.Button("Create visual", scale=0)

        generated_image = gr.Image(label="Generated Image", show_label=False)
        
        with gr.Accordion("Advanced Settings Mistral", open=False):
            gr.Slider(
                label="Temperature",
                value=0.9,
                minimum=0.0,
                maximum=1.0,
                step=0.05,
                interactive=True,
                info="Higher values produce more diverse outputs",
            ),
            gr.Slider(
                label="Max new tokens",
                value=256,
                minimum=0,
                maximum=1048,
                step=64,
                interactive=True,
                info="The maximum numbers of new tokens",
            ),
            gr.Slider(
                label="Top-p (nucleus sampling)",
                value=0.90,
                minimum=0.0,
                maximum=1,
                step=0.05,
                interactive=True,
                info="Higher values sample more low-probability tokens",
            ),
            gr.Slider(
                label="Repetition penalty",
                value=1.2,
                minimum=1.0,
                maximum=2.0,
                step=0.05,
                interactive=True,
                info="Penalize repeated tokens",
            )
        
        with gr.Accordion("Advanced Settings Flux", open=False):
            
            seed = gr.Slider(
                label="Seed",
                minimum=0,
                maximum=MAX_SEED,
                step=1,
                value=0,
            )
            
            randomize_seed = gr.Checkbox(label="Randomize seed", value=True)
            
            with gr.Row():
                
                width = gr.Slider(
                    label="Width",
                    minimum=256,
                    maximum=MAX_IMAGE_SIZE,
                    step=32,
                    value=1024,
                )
                
                height = gr.Slider(
                    label="Height",
                    minimum=256,
                    maximum=MAX_IMAGE_SIZE,
                    step=32,
                    value=1024,
                )
            
            with gr.Row():
                
  
                num_inference_steps = gr.Slider(
                    label="Number of inference steps",
                    minimum=1,
                    maximum=50,
                    step=1,
                    value=4,
                )
        
        gr.Examples(
            examples=examples,
            fn=infer,
            inputs=[prompt],
            outputs=[generated_image, seed],
            cache_examples=True,
            cache_mode='lazy'
        )


    gr.on(
        triggers=[prompt_button.click, prompt.submit],
        fn = refine_prompt,
        inputs = [prompt],
        outputs = [refined_prompt]
    )

    gr.on(
        triggers=[run_button.click],
        fn = infer,
        inputs = [refined_prompt, seed, randomize_seed, width, height, num_inference_steps],
        outputs = [generated_image, seed]
    )

demo.launch()