import os
import gc
import gradio as gr
import numpy as np
import torch
import json
import spaces
import config
import utils
import logging
from PIL import Image, PngImagePlugin
from datetime import datetime
from diffusers.models import AutoencoderKL
from diffusers import StableDiffusionXLPipeline, StableDiffusionXLImg2ImgPipeline
from config import (
    MODEL,
    MIN_IMAGE_SIZE,
    MAX_IMAGE_SIZE,
    USE_TORCH_COMPILE,
    ENABLE_CPU_OFFLOAD,
    OUTPUT_DIR,
    DEFAULT_NEGATIVE_PROMPT,
    DEFAULT_ASPECT_RATIO,
    examples,
    sampler_list,
    aspect_ratios,
    style_list,
)
import time
from typing import List, Dict, Tuple, Optional

# Enhanced logging configuration
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
    datefmt='%Y-%m-%d %H:%M:%S'
)
logger = logging.getLogger(__name__)

# Constants
IS_COLAB = utils.is_google_colab() or os.getenv("IS_COLAB") == "1"
HF_TOKEN = os.getenv("HF_TOKEN")
CACHE_EXAMPLES = torch.cuda.is_available() and os.getenv("CACHE_EXAMPLES") == "1" 

# PyTorch settings for better performance and determinism
torch.backends.cudnn.deterministic = True
torch.backends.cudnn.benchmark = False
torch.backends.cuda.matmul.allow_tf32 = True

device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
logger.info(f"Using device: {device}")

class GenerationError(Exception):
    """Custom exception for generation errors"""
    pass

def validate_prompt(prompt: str) -> str:
    """Validate and clean up the input prompt."""
    if not isinstance(prompt, str):
        raise GenerationError("Prompt must be a string")
    try:
        # Ensure proper UTF-8 encoding/decoding
        prompt = prompt.encode('utf-8').decode('utf-8')
        # Add space between ! and ,
        prompt = prompt.replace("!,", "! ,")
    except UnicodeError:
        raise GenerationError("Invalid characters in prompt")
    
    # Only check if the prompt is completely empty or only whitespace
    if not prompt or prompt.isspace():
        raise GenerationError("Prompt cannot be empty")
    return prompt.strip()

def validate_dimensions(width: int, height: int) -> None:
    """Validate image dimensions."""
    if not MIN_IMAGE_SIZE <= width <= MAX_IMAGE_SIZE:
        raise GenerationError(f"Width must be between {MIN_IMAGE_SIZE} and {MAX_IMAGE_SIZE}")
        
    if not MIN_IMAGE_SIZE <= height <= MAX_IMAGE_SIZE:
        raise GenerationError(f"Height must be between {MIN_IMAGE_SIZE} and {MAX_IMAGE_SIZE}")

@spaces.GPU
def generate(
    prompt: str,
    negative_prompt: str = DEFAULT_NEGATIVE_PROMPT,
    seed: int = 0,
    custom_width: int = 1024,
    custom_height: int = 1024,
    guidance_scale: float = 6.0,
    num_inference_steps: int = 25,
    sampler: str = "Euler a",
    aspect_ratio_selector: str = DEFAULT_ASPECT_RATIO,
    style_selector: str = "(None)",
    use_upscaler: bool = False,
    upscaler_strength: float = 0.55,
    upscale_by: float = 1.5,
    add_quality_tags: bool = True,
    progress: gr.Progress = gr.Progress(track_tqdm=True),
) -> Tuple[List[str], Dict]:
    """Generate images based on the given parameters."""
    start_time = time.time()
    upscaler_pipe = None
    backup_scheduler = None
    
    try:
        # Memory management
        torch.cuda.empty_cache()
        gc.collect()

        # Input validation
        prompt = validate_prompt(prompt)
        if negative_prompt:
            negative_prompt = negative_prompt.encode('utf-8').decode('utf-8')
        
        validate_dimensions(custom_width, custom_height)
        
        # Set up generation
        generator = utils.seed_everything(seed)
        width, height = utils.aspect_ratio_handler(
            aspect_ratio_selector,
            custom_width,
            custom_height,
        )

        # Process prompts
        if add_quality_tags:
            prompt = "{prompt}, masterpiece, high score, great score, absurdres".format(prompt=prompt)

        prompt, negative_prompt = utils.preprocess_prompt(
            styles, style_selector, prompt, negative_prompt
        )    

        width, height = utils.preprocess_image_dimensions(width, height)

        # Set up pipeline
        backup_scheduler = pipe.scheduler
        pipe.scheduler = utils.get_scheduler(pipe.scheduler.config, sampler)

        if use_upscaler:
            upscaler_pipe = StableDiffusionXLImg2ImgPipeline(**pipe.components)
            
        # Prepare metadata
        metadata = {
            "prompt": prompt,
            "negative_prompt": negative_prompt,
            "resolution": f"{width} x {height}",
            "guidance_scale": guidance_scale,
            "num_inference_steps": num_inference_steps,
            "style_preset": style_selector,
            "seed": seed,
            "sampler": sampler,
            "Model": "Animagine XL 4.0",
            "Model hash": "6327eca98b",
        }

        if use_upscaler:
            new_width = int(width * upscale_by)
            new_height = int(height * upscale_by)
            metadata["use_upscaler"] = {
                "upscale_method": "nearest-exact",
                "upscaler_strength": upscaler_strength,
                "upscale_by": upscale_by,
                "new_resolution": f"{new_width} x {new_height}",
            }
        else:
            metadata["use_upscaler"] = None
        
        logger.info(f"Starting generation with parameters: {json.dumps(metadata, indent=4)}")

        # Generate images
        if use_upscaler:
            latents = pipe(
                prompt=prompt,
                negative_prompt=negative_prompt,
                width=width,
                height=height,
                guidance_scale=guidance_scale,
                num_inference_steps=num_inference_steps,
                generator=generator,
                output_type="latent",
            ).images
            upscaled_latents = utils.upscale(latents, "nearest-exact", upscale_by)
            images = upscaler_pipe(
                prompt=prompt,
                negative_prompt=negative_prompt,
                image=upscaled_latents,
                guidance_scale=guidance_scale,
                num_inference_steps=num_inference_steps,
                strength=upscaler_strength,
                generator=generator,
                output_type="pil",
            ).images
        else:
            images = pipe(
                prompt=prompt,
                negative_prompt=negative_prompt,
                width=width,
                height=height,
                guidance_scale=guidance_scale,
                num_inference_steps=num_inference_steps,
                generator=generator,
                output_type="pil",
            ).images

        # Save images
        if images:
            total = len(images)
            image_paths = []
            for idx, image in enumerate(images, 1):
                progress(idx/total, desc="Saving images...")
                path = utils.save_image(image, metadata, OUTPUT_DIR, IS_COLAB)
                image_paths.append(path)
                logger.info(f"Image {idx}/{total} saved as {path}")

        generation_time = time.time() - start_time
        logger.info(f"Generation completed successfully in {generation_time:.2f} seconds")
        metadata["generation_time"] = f"{generation_time:.2f}s"
        
        return image_paths, metadata

    except GenerationError as e:
        logger.warning(f"Generation validation error: {str(e)}")
        raise gr.Error(str(e))
    except Exception as e:
        logger.exception("Unexpected error during generation")
        raise gr.Error(f"Generation failed: {str(e)}")
    finally:
        # Cleanup
        torch.cuda.empty_cache()
        gc.collect()
        
        if upscaler_pipe is not None:
            del upscaler_pipe
        
        if backup_scheduler is not None and pipe is not None:
            pipe.scheduler = backup_scheduler
            
        utils.free_memory()

# Model initialization
if torch.cuda.is_available():
    try:
        logger.info("Loading VAE and pipeline...")
        vae = AutoencoderKL.from_pretrained(
            "madebyollin/sdxl-vae-fp16-fix",
            torch_dtype=torch.float16,
        )
        pipe = utils.load_pipeline(MODEL, device, vae=vae)
        logger.info("Pipeline loaded successfully on GPU!")
    except Exception as e:
        logger.error(f"Error loading VAE, falling back to default: {e}")
        pipe = utils.load_pipeline(MODEL, device)
else:
    logger.warning("CUDA not available, running on CPU")
    pipe = None

# Process styles
styles = {k["name"]: (k["prompt"], k["negative_prompt"]) for k in style_list}

with gr.Blocks(css="style.css", theme="Nymbo/Nymbo_Theme_5") as demo:
    gr.HTML(
        """
        <div class="header">
            <div class="title">ANIM4GINE</div>
            <div class="subtitle">Gradio demo for <a href="https://huggingface.co/CagliostroLab/Animagine-XL-4.0" target="_blank">Animagine XL 4.0</a></div>
        </div>
        """,
    )
    
    with gr.Row():
        with gr.Column(scale=2):
            with gr.Group():
                prompt = gr.Text(
                    label="Prompt",
                    max_lines=5,
                    placeholder="Describe what you want to generate",
                    info="Enter your image generation prompt here. Be specific and descriptive for better results.",
                )
                negative_prompt = gr.Text(
                    label="Negative Prompt",
                    max_lines=5,
                    placeholder="Describe what you want to avoid",
                    value=DEFAULT_NEGATIVE_PROMPT,
                    info="Specify elements you don't want in the image.",
                )
                add_quality_tags = gr.Checkbox(
                    label="Quality Tags",
                    value=True,
                    info="Add quality-enhancing tags to your prompt automatically.",
                )
            with gr.Accordion(label="More Settings", open=False):
                with gr.Group():
                    aspect_ratio_selector = gr.Radio(
                        label="Aspect Ratio",
                        choices=aspect_ratios,
                        value=DEFAULT_ASPECT_RATIO,
                        container=True,
                        info="Choose the dimensions of your image.",
                    )
                with gr.Group(visible=False) as custom_resolution:
                    with gr.Row():
                        custom_width = gr.Slider(
                            label="Width",
                            minimum=MIN_IMAGE_SIZE,
                            maximum=MAX_IMAGE_SIZE,
                            step=8,
                            value=1024,
                            info=f"Image width (must be between {MIN_IMAGE_SIZE} and {MAX_IMAGE_SIZE})",
                        )
                        custom_height = gr.Slider(
                            label="Height",
                            minimum=MIN_IMAGE_SIZE,
                            maximum=MAX_IMAGE_SIZE,
                            step=8,
                            value=1024,
                            info=f"Image height (must be between {MIN_IMAGE_SIZE} and {MAX_IMAGE_SIZE})",
                        )
                with gr.Group():
                    use_upscaler = gr.Checkbox(
                        label="Use Upscaler",
                        value=False,
                        info="Enable high-resolution upscaling.",
                    )
                    with gr.Row() as upscaler_row:
                        upscaler_strength = gr.Slider(
                            label="Strength",
                            minimum=0,
                            maximum=1,
                            step=0.05,
                            value=0.55,
                            visible=False,
                            info="Control how much the upscaler affects the final image.",
                        )
                        upscale_by = gr.Slider(
                            label="Upscale by",
                            minimum=1,
                            maximum=1.5,
                            step=0.1,
                            value=1.5,
                            visible=False,
                            info="Multiplier for the final image resolution.",
                        )
                with gr.Accordion(label="Advanced Parameters", open=False):
                    with gr.Group():
                        style_selector = gr.Dropdown(
                            label="Style Preset",
                            interactive=True,
                            choices=list(styles.keys()),
                            value="(None)",
                            info="Apply a predefined style to your generation.",
                        )
                    with gr.Group():
                        sampler = gr.Dropdown(
                            label="Sampler",
                            choices=sampler_list,
                            interactive=True,
                            value="Euler a",
                            info="Different samplers can produce varying results.",
                        )
                    with gr.Group():
                        seed = gr.Slider(
                            label="Seed",
                            minimum=0,
                            maximum=utils.MAX_SEED,
                            step=1,
                            value=0,
                            info="Set a specific seed for reproducible results.",
                        )
                        randomize_seed = gr.Checkbox(
                            label="Randomize seed",
                            value=True,
                            info="Generate a new random seed for each image.",
                        )
                    with gr.Group():
                        with gr.Row():
                            guidance_scale = gr.Slider(
                                label="Guidance scale",
                                minimum=1,
                                maximum=12,
                                step=0.1,
                                value=5.0,
                                info="Higher values make the image more closely match your prompt.",
                            )
                            num_inference_steps = gr.Slider(
                                label="Number of inference steps",
                                minimum=1,
                                maximum=50,
                                step=1,
                                value=28,
                                info="More steps generally mean higher quality but slower generation.",
                            )
        
        with gr.Column(scale=3):
            with gr.Blocks():
                run_button = gr.Button("Generate", variant="primary", elem_id="generate-button")
            result = gr.Gallery(
                label="Generated Images",
                columns=1,
                height='768px',
                preview=True,
                show_label=True,
            )
            with gr.Accordion(label="Generation Parameters", open=False):
                gr_metadata = gr.JSON(
                    label="Image Metadata",
                    show_label=True,
                )
            gr.Examples(
                examples=examples,
                inputs=prompt,
                outputs=[result, gr_metadata],
                fn=lambda *args, **kwargs: generate(*args, use_upscaler=True, **kwargs),
                cache_examples=CACHE_EXAMPLES,
            )
    
    # Discord button in a new full row
    with gr.Row():
        gr.HTML(
            """
            <a href="https://discord.com/invite/cqh9tZgbGc" target="_blank" class="discord-btn">
                <svg class="discord-icon" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 127.14 96.36"><path fill="currentColor" d="M107.7,8.07A105.15,105.15,0,0,0,81.47,0a72.06,72.06,0,0,0-3.36,6.83A97.68,97.68,0,0,0,49,6.83,72.37,72.37,0,0,0,45.64,0,105.89,105.89,0,0,0,19.39,8.09C2.79,32.65-1.71,56.6.54,80.21h0A105.73,105.73,0,0,0,32.71,96.36,77.7,77.7,0,0,0,39.6,85.25a68.42,68.42,0,0,1-10.85-5.18c.91-.66,1.8-1.34,2.66-2a75.57,75.57,0,0,0,64.32,0c.87.71,1.76,1.39,2.66,2a68.68,68.68,0,0,1-10.87,5.19,77,77,0,0,0,6.89,11.1A105.25,105.25,0,0,0,126.6,80.22h0C129.24,52.84,122.09,29.11,107.7,8.07ZM42.45,65.69C36.18,65.69,31,60,31,53s5-12.74,11.43-12.74S54,46,53.89,53,48.84,65.69,42.45,65.69Zm42.24,0C78.41,65.69,73.25,60,73.25,53s5-12.74,11.44-12.74S96.23,46,96.12,53,91.08,65.69,84.69,65.69Z"/></svg>
                <span class="discord-text">Join our Discord Server</span>
            </a>
            """
        )

    use_upscaler.change(
        fn=lambda x: [gr.update(visible=x), gr.update(visible=x)],
        inputs=use_upscaler,
        outputs=[upscaler_strength, upscale_by],
        queue=False,
        api_name=False,
    )
    aspect_ratio_selector.change(
        fn=lambda x: gr.update(visible=x == "Custom"),
        inputs=aspect_ratio_selector,
        outputs=custom_resolution,
        queue=False,
        api_name=False,
    )

    # Combine all triggers including keyboard shortcuts
    gr.on(
        triggers=[
            prompt.submit,
            negative_prompt.submit,
            run_button.click,
        ],
        fn=utils.randomize_seed_fn,
        inputs=[seed, randomize_seed],
        outputs=seed,
        queue=False,
        api_name=False,
    ).then(
        fn=lambda: gr.update(interactive=False, value="Generating..."),
        outputs=run_button,
    ).then(
        fn=generate,
        inputs=[
            prompt,
            negative_prompt,
            seed,
            custom_width,
            custom_height,
            guidance_scale,
            num_inference_steps,
            sampler,
            aspect_ratio_selector,
            style_selector,
            use_upscaler,
            upscaler_strength,
            upscale_by,
            add_quality_tags,
        ],
        outputs=[result, gr_metadata],
    ).then(
        fn=lambda: gr.update(interactive=True, value="Generate"),
        outputs=run_button,
    )

if __name__ == "__main__":
    demo.queue(max_size=20).launch(debug=IS_COLAB, share=IS_COLAB)