import gradio as gr
import os
import tempfile
import shutil
import re
import json
import datetime
from pathlib import Path
from huggingface_hub import HfApi, hf_hub_download
from safetensors.torch import load_file, save_file
import torch
import torch.nn.functional as F
import traceback
import math
try:
    from modelscope.hub.file_download import model_file_download as ms_file_download
    from modelscope.hub.api import HubApi as ModelScopeApi
    MODELScope_AVAILABLE = True
except ImportError:
    MODELScope_AVAILABLE = False

def low_rank_decomposition(weight, rank=64):
    """Handle both 2D and 4D tensors for LoRA decomposition."""
    original_shape = weight.shape
    original_dtype = weight.dtype
    
    try:
        # Handle 2D tensors (linear layers, attention)
        if weight.ndim == 2:
            U, S, Vh = torch.linalg.svd(weight.float(), full_matrices=False)
            if rank > len(S):
                rank = len(S) // 2  # Use half the available rank if requested rank is too high
            U = U[:, :rank] @ torch.diag(torch.sqrt(S[:rank]))
            Vh = torch.diag(torch.sqrt(S[:rank])) @ Vh[:rank, :]
            return U.contiguous(), Vh.contiguous()
        
        # Handle 4D tensors (convolutional layers)
        elif weight.ndim == 4:
            # Strategy 1: Reshape to 2D and decompose
            out_ch, in_ch, kH, kW = weight.shape
            
            # For small conv kernels, use spatial decomposition
            if kH * kW <= 9:  # 3x3 kernel or smaller
                weight_2d = weight.permute(0, 2, 3, 1).reshape(out_ch * kH * kW, in_ch)
                U, S, Vh = torch.linalg.svd(weight_2d.float(), full_matrices=False)
                
                if rank > len(S):
                    rank = max(8, len(S) // 2)
                
                U = U[:, :rank] @ torch.diag(torch.sqrt(S[:rank]))
                Vh = torch.diag(torch.sqrt(S[:rank])) @ Vh[:rank, :]
                
                # Reshape back to convolutional format
                U = U.view(out_ch, kH, kW, rank).permute(0, 3, 1, 2).contiguous()
                Vh = Vh.view(rank, in_ch, 1, 1).contiguous()
                return U, Vh
            
            # For larger kernels, use channel-wise decomposition
            else:
                weight_2d = weight.view(out_ch, -1)
                U, S, Vh = torch.linalg.svd(weight_2d.float(), full_matrices=False)
                
                if rank > len(S):
                    rank = max(8, len(S) // 2)
                
                U = U[:, :rank] @ torch.diag(torch.sqrt(S[:rank]))
                Vh = torch.diag(torch.sqrt(S[:rank])) @ Vh[:rank, :]
                U = U.view(out_ch, rank, 1, 1).contiguous()
                Vh = Vh.view(rank, in_ch, kH, kW).contiguous()
                return U, Vh
        
        # Handle 3D tensors (rare, but sometimes in attention mechanisms)
        elif weight.ndim == 3:
            out_ch, mid_ch, in_ch = weight.shape
            weight_2d = weight.reshape(out_ch * mid_ch, in_ch)
            U, S, Vh = torch.linalg.svd(weight_2d.float(), full_matrices=False)
            
            if rank > len(S):
                rank = max(8, len(S) // 2)
            
            U = U[:, :rank] @ torch.diag(torch.sqrt(S[:rank]))
            Vh = torch.diag(torch.sqrt(S[:rank])) @ Vh[:rank, :]
            U = U.view(out_ch, mid_ch, rank).contiguous()
            Vh = Vh.view(rank, in_ch).contiguous()
            return U, Vh
            
    except Exception as e:
        print(f"Decomposition error for tensor with shape {original_shape}: {str(e)}")
        traceback.print_exc()
    
    return None, None

def should_apply_lora(key, weight, architecture, lora_rank):
    """Determine if LoRA should be applied to a specific weight based on architecture selection."""
    
    # Skip bias terms, batchnorm, and very small tensors
    if 'bias' in key or 'norm' in key.lower() or 'bn' in key.lower():
        return False
    
    # Skip very small tensors
    if weight.numel() < 100:
        return False
    
    # Architecture-specific rules
    lower_key = key.lower()
    
    if architecture == "text_encoder":
        # Text encoder: focus on embeddings and attention layers
        return ('emb' in lower_key or 'embed' in lower_key or 
                'attn' in lower_key or 'qkv' in lower_key or 'mlp' in lower_key)
    
    elif architecture == "unet_transformer":
        # UNet transformers: focus on attention blocks
        return ('attn' in lower_key or 'transformer' in lower_key or 
                'qkv' in lower_key or 'to_out' in lower_key)
    
    elif architecture == "unet_conv":
        # UNet convolutional layers
        return ('conv' in lower_key or 'resnet' in lower_key or 
                'downsample' in lower_key or 'upsample' in lower_key)
    
    elif architecture == "vae":
        # VAE components
        return ('encoder' in lower_key or 'decoder' in lower_key or 
                'conv' in lower_key or 'post_quant' in lower_key)
    
    elif architecture == "all":
        # Apply to all eligible tensors
        return True
    
    elif architecture == "auto":
        # Auto-detect based on tensor properties
        if weight.ndim == 2 and min(weight.shape) > lora_rank:
            return True
        if weight.ndim == 4 and (weight.shape[0] > lora_rank or weight.shape[1] > lora_rank):
            return True
        return False
    
    return False

def convert_safetensors_to_fp8_with_lora(safetensors_path, output_dir, fp8_format, lora_rank=64, architecture="auto", progress=gr.Progress()):
    progress(0.1, desc="Starting FP8 conversion with LoRA extraction...")
    try:
        def read_safetensors_metadata(path):
            with open(path, 'rb') as f:
                header_size = int.from_bytes(f.read(8), 'little')
                header_json = f.read(header_size).decode('utf-8')
                header = json.loads(header_json)
                return header.get('__metadata__', {})
        
        metadata = read_safetensors_metadata(safetensors_path)
        progress(0.2, desc="Loaded metadata.")
        
        state_dict = load_file(safetensors_path)
        progress(0.4, desc="Loaded weights.")
        
        # Architecture analysis
        architecture_stats = {
            'text_encoder': 0,
            'unet_transformer': 0,
            'unet_conv': 0,
            'vae': 0,
            'other': 0
        }
        
        for key in state_dict:
            lower_key = key.lower()
            if 'text' in lower_key or 'emb' in lower_key:
                architecture_stats['text_encoder'] += 1
            elif 'attn' in lower_key or 'transformer' in lower_key:
                architecture_stats['unet_transformer'] += 1
            elif 'conv' in lower_key or 'resnet' in lower_key:
                architecture_stats['unet_conv'] += 1
            elif 'vae' in lower_key or 'encoder' in lower_key or 'decoder' in lower_key:
                architecture_stats['vae'] += 1
            else:
                architecture_stats['other'] += 1
        
        print("Architecture analysis:")
        for arch, count in architecture_stats.items():
            print(f"- {arch}: {count} layers")
        
        if fp8_format == "e5m2":
            fp8_dtype = torch.float8_e5m2
        else:
            fp8_dtype = torch.float8_e4m3fn
        
        sd_fp8 = {}
        lora_weights = {}
        lora_stats = {
            'total_layers': len(state_dict),
            'layers_analyzed': 0,
            'layers_eligible': 0,
            'layers_processed': 0,
            'layers_skipped': [],
            'architecture_distro': architecture_stats
        }
        
        total = len(state_dict)
        lora_keys = []
        
        for i, key in enumerate(state_dict):
            progress(0.4 + 0.4 * (i / total), desc=f"Processing {i+1}/{total}: {key.split('.')[-1]}")
            weight = state_dict[key]
            lora_stats['layers_analyzed'] += 1
            
            if weight.dtype in [torch.float16, torch.float32, torch.bfloat16]:
                fp8_weight = weight.to(fp8_dtype)
                sd_fp8[key] = fp8_weight
                
                # Determine if we should apply LoRA
                eligible_for_lora = should_apply_lora(key, weight, architecture, lora_rank)
                
                if eligible_for_lora:
                    lora_stats['layers_eligible'] += 1
                    
                    try:
                        # Adjust rank based on tensor size
                        actual_rank = lora_rank
                        if weight.ndim == 2:
                            actual_rank = min(lora_rank, min(weight.shape) // 2)
                        elif weight.ndim == 4:
                            actual_rank = min(lora_rank, max(weight.shape[0], weight.shape[1]) // 4)
                        
                        if actual_rank < 4:  # Minimum rank threshold
                            lora_stats['layers_skipped'].append(f"{key}: rank too small ({actual_rank})")
                            continue
                        
                        U, V = low_rank_decomposition(weight, rank=actual_rank)
                        if U is not None and V is not None:
                            lora_weights[f"lora_A.{key}"] = U.to(torch.float16)
                            lora_weights[f"lora_B.{key}"] = V.to(torch.float16)
                            lora_keys.append(key)
                            lora_stats['layers_processed'] += 1
                        else:
                            lora_stats['layers_skipped'].append(f"{key}: decomposition returned None")
                    except Exception as e:
                        error_msg = f"{key}: {str(e)}"
                        lora_stats['layers_skipped'].append(error_msg)
                        print(f"LoRA decomposition error: {error_msg}")
                        traceback.print_exc()
                else:
                    reason = "not eligible for selected architecture" if architecture != "auto" else f"ndim={weight.ndim}, min(shape)={min(weight.shape) if weight.ndim > 0 else 'N/A'}"
                    lora_stats['layers_skipped'].append(f"{key}: {reason}")
            else:
                sd_fp8[key] = weight
                lora_stats['layers_skipped'].append(f"{key}: unsupported dtype {weight.dtype}")
        
        base_name = os.path.splitext(os.path.basename(safetensors_path))[0]
        fp8_path = os.path.join(output_dir, f"{base_name}-fp8-{fp8_format}.safetensors")
        lora_path = os.path.join(output_dir, f"{base_name}-lora-r{lora_rank}-{architecture}.safetensors")
        
        save_file(sd_fp8, fp8_path, metadata={"format": "pt", "fp8_format": fp8_format, **metadata})
        
        # Always save LoRA file, even if empty
        lora_metadata = {
            "format": "pt", 
            "lora_rank": str(lora_rank),
            "architecture": architecture,
            "stats": json.dumps(lora_stats)
        }
        
        save_file(lora_weights, lora_path, metadata=lora_metadata)
        
        # Generate detailed statistics message
        stats_msg = f"""
📊 LoRA Extraction Statistics:
- Total layers analyzed: {lora_stats['layers_analyzed']}
- Layers eligible for LoRA: {lora_stats['layers_eligible']}
- Successfully processed: {lora_stats['layers_processed']}
- Architecture: {architecture}
- FP8 Format: {fp8_format.upper()}

Top skipped layers:
{chr(10).join(lora_stats['layers_skipped'][:10])}
"""
        
        progress(0.9, desc="Saved FP8 and LoRA files.")
        progress(1.0, desc="✅ FP8 + LoRA extraction complete!")
        
        if lora_stats['layers_processed'] == 0:
            stats_msg += "\n\n⚠️ WARNING: No LoRA weights were generated. Try a different architecture selection or lower rank."
        
        return True, f"FP8 ({fp8_format}) and rank-{lora_rank} LoRA saved.\n{stats_msg}", lora_stats

    except Exception as e:
        error_msg = f"Conversion error: {str(e)}\n{traceback.format_exc()}"
        print(error_msg)
        return False, error_msg, None

def parse_hf_url(url):
    url = url.strip().rstrip("/")
    if not url.startswith("https://huggingface.co/"):
        raise ValueError("URL must start with https://huggingface.co/")
    path = url.replace("https://huggingface.co/", "")
    parts = path.split("/")
    if len(parts) < 2:
        raise ValueError("Invalid repo format")
    repo_id = "/".join(parts[:2])
    subfolder = ""
    if len(parts) > 3 and parts[2] == "tree":
        subfolder = "/".join(parts[4:]) if len(parts) > 4 else ""
    elif len(parts) > 2:
        subfolder = "/".join(parts[2:])
    return repo_id, subfolder

def download_safetensors_file(source_type, repo_url, filename, hf_token=None, progress=gr.Progress()):
    temp_dir = tempfile.mkdtemp()
    try:
        if source_type == "huggingface":
            repo_id, subfolder = parse_hf_url(repo_url)
            safetensors_path = hf_hub_download(
                repo_id=repo_id,
                filename=filename,
                subfolder=subfolder or None,
                cache_dir=temp_dir,
                token=hf_token,
                resume_download=True
            )
        elif source_type == "modelscope":
            if not MODELScope_AVAILABLE:
                raise ImportError("ModelScope not installed")
            repo_id = repo_url.strip()
            safetensors_path = ms_file_download(model_id=repo_id, file_path=filename)
        else:
            raise ValueError("Unknown source")
        return safetensors_path, temp_dir
    except Exception as e:
        shutil.rmtree(temp_dir, ignore_errors=True)
        raise e

def upload_to_target(target_type, new_repo_id, output_dir, fp8_format, architecture, hf_token=None, modelscope_token=None, private_repo=False):
    if target_type == "huggingface":
        api = HfApi(token=hf_token)
        api.create_repo(repo_id=new_repo_id, private=private_repo, repo_type="model", exist_ok=True)
        api.upload_folder(repo_id=new_repo_id, folder_path=output_dir, repo_type="model", token=hf_token)
        return f"https://huggingface.co/{new_repo_id}"
    elif target_type == "modelscope":
        api = ModelScopeApi()
        if modelscope_token:
            api.login(modelscope_token)
        api.push_model(model_id=new_repo_id, model_dir=output_dir)
        return f"https://modelscope.cn/models/{new_repo_id}"
    else:
        raise ValueError("Unknown target")

def process_and_upload_fp8(
    source_type,
    repo_url,
    safetensors_filename,
    fp8_format,
    lora_rank,
    architecture,
    target_type,
    new_repo_id,
    hf_token,
    modelscope_token,
    private_repo,
    progress=gr.Progress()
):
    if not re.match(r"^[a-zA-Z0-9._-]+/[a-zA-Z0-9._-]+$", new_repo_id):
        return None, "❌ Invalid repo ID format. Use 'username/model-name'.", ""
    if source_type == "huggingface" and not hf_token:
        return None, "❌ Hugging Face token required for source.", ""
    if target_type == "huggingface" and not hf_token:
        return None, "❌ Hugging Face token required for target.", ""
    
    # Validate lora_rank
    if lora_rank < 4:
        return None, "❌ LoRA rank must be at least 4.", ""
    
    temp_dir = None
    output_dir = tempfile.mkdtemp()
    try:
        progress(0.05, desc="Downloading model...")
        safetensors_path, temp_dir = download_safetensors_file(
            source_type, repo_url, safetensors_filename, hf_token, progress
        )
        
        progress(0.25, desc=f"Converting to FP8 with LoRA ({architecture})...")
        success, msg, stats = convert_safetensors_to_fp8_with_lora(
            safetensors_path, output_dir, fp8_format, lora_rank, architecture, progress
        )
        
        if not success:
            return None, f"❌ Conversion failed: {msg}", ""
        
        progress(0.9, desc="Uploading...")
        repo_url_final = upload_to_target(
            target_type, new_repo_id, output_dir, fp8_format, architecture, hf_token, modelscope_token, private_repo
        )
        
        base_name = os.path.splitext(safetensors_filename)[0]
        lora_filename = f"{base_name}-lora-r{lora_rank}-{architecture}.safetensors"
        fp8_filename = f"{base_name}-fp8-{fp8_format}.safetensors"
        
        readme = f"""---
library_name: diffusers
tags:
- fp8
- safetensors
- lora
- low-rank
- diffusion
- architecture-{architecture}
- converted-by-ai-toolkit
---
# FP8 Model with Low-Rank LoRA
- **Source**: `{repo_url}`
- **File**: `{safetensors_filename}`
- **FP8 Format**: `{fp8_format.upper()}`
- **LoRA Rank**: {lora_rank}
- **Architecture Target**: {architecture}
- **LoRA File**: `{lora_filename}`
- **FP8 File**: `{fp8_filename}`

## Architecture Distribution
"""
        
        # Add architecture stats to README if available
        if stats and 'architecture_distro' in stats:
            readme += "\n| Component | Layer Count |\n|-----------|------------|\n"
            for arch, count in stats['architecture_distro'].items():
                readme += f"| {arch.replace('_', ' ').title()} | {count} |\n"
        
        readme += f"""
## Usage (Inference)
```python
from safetensors.torch import load_file
import torch

# Load FP8 model
fp8_state = load_file("{fp8_filename}")
lora_state = load_file("{lora_filename}")

# Reconstruct approximate original weights
reconstructed = {{}}
for key in fp8_state:
    lora_a_key = f"lora_A.{{key}}"
    lora_b_key = f"lora_B.{{key}}"
    
    if lora_a_key in lora_state and lora_b_key in lora_state:
        A = lora_state[lora_a_key].to(torch.float32)
        B = lora_state[lora_b_key].to(torch.float32)
        
        # Handle different tensor dimensions
        if A.ndim == 2 and B.ndim == 2:
            lora_weight = B @ A
        elif A.ndim == 4 and B.ndim == 4:
            # For convolutional LoRA
            lora_weight = F.conv2d(fp8_state[key].to(torch.float32), 
                                  B, padding=1) + F.conv2d(fp8_state[key].to(torch.float32), 
                                  A, padding=1)
        else:
            # Fallback for mixed dimension cases
            lora_weight = B @ A.view(B.shape[1], -1)
            if lora_weight.shape != fp8_state[key].shape:
                lora_weight = lora_weight.view_as(fp8_state[key])
        
        reconstructed[key] = fp8_state[key].to(torch.float32) + lora_weight
    else:
        reconstructed[key] = fp8_state[key].to(torch.float32)
```

> **Note**: Requires PyTorch ≥ 2.1 for FP8 support. For best results, use the same architecture selection ({architecture}) during inference as was used during extraction.
"""
        
        with open(os.path.join(output_dir, "README.md"), "w") as f:
            f.write(readme)
        
        if target_type == "huggingface":
            HfApi(token=hf_token).upload_file(
                path_or_fileobj=os.path.join(output_dir, "README.md"),
                path_in_repo="README.md",
                repo_id=new_repo_id,
                repo_type="model",
                token=hf_token
            )
        
        progress(1.0, desc="✅ Done!")
        result_html = f"""
✅ Success!  
Model uploaded to: <a href="{repo_url_final}" target="_blank">{new_repo_id}</a>  
Includes: 
- FP8 model: `{fp8_filename}`
- LoRA weights: `{lora_filename}` (rank {lora_rank}, architecture: {architecture})

📊 Stats: {stats['layers_processed']}/{stats['layers_eligible']} eligible layers processed
"""
        return gr.HTML(result_html), "✅ FP8 + LoRA upload successful!", msg
    
    except Exception as e:
        error_msg = f"❌ Error: {str(e)}\n{traceback.format_exc()}"
        print(error_msg)
        return None, error_msg, ""
    
    finally:
        if temp_dir:
            shutil.rmtree(temp_dir, ignore_errors=True)
        shutil.rmtree(output_dir, ignore_errors=True)

with gr.Blocks(title="FP8 + LoRA Extractor (HF ↔ ModelScope)") as demo:
    gr.Markdown("# 🔄 Advanced FP8 Pruner with Architecture-Specific LoRA Extraction")
    gr.Markdown("Convert `.safetensors` → **FP8** + **targeted LoRA** weights for precision recovery. Supports Hugging Face ↔ ModelScope.")
    
    with gr.Row():
        with gr.Column():
            source_type = gr.Radio(["huggingface", "modelscope"], value="huggingface", label="Source")
            repo_url = gr.Textbox(label="Repo URL or ID", placeholder="https://huggingface.co/... or modelscope-id")
            safetensors_filename = gr.Textbox(label="Filename", placeholder="model.safetensors")
            
            with gr.Accordion("Advanced LoRA Settings", open=True):
                fp8_format = gr.Radio(["e4m3fn", "e5m2"], value="e5m2", label="FP8 Format")
                lora_rank = gr.Slider(minimum=4, maximum=256, step=4, value=64, label="LoRA Rank")
                
                architecture = gr.Dropdown(
                    choices=[
                        ("Auto-detect components", "auto"),
                        ("Text Encoder (embeddings, attention)", "text_encoder"),
                        ("UNet Transformers (attention blocks)", "unet_transformer"),
                        ("UNet Convolutions (resnets, downsampling)", "unet_conv"),
                        ("VAE (encoder/decoder)", "vae"),
                        ("All components", "all")
                    ],
                    value="auto",
                    label="Target Architecture",
                    info="Select which model components to apply LoRA to"
                )
            
            with gr.Accordion("Authentication", open=False):
                hf_token = gr.Textbox(label="Hugging Face Token", type="password")
                modelscope_token = gr.Textbox(label="ModelScope Token (optional)", type="password", visible=MODELScope_AVAILABLE)
        
        with gr.Column():
            target_type = gr.Radio(["huggingface", "modelscope"], value="huggingface", label="Target")
            new_repo_id = gr.Textbox(label="New Repo ID", placeholder="user/model-fp8-lora")
            private_repo = gr.Checkbox(label="Private Repository (HF only)", value=False)
            
            status_output = gr.Markdown()
            detailed_log = gr.Textbox(label="Processing Log", interactive=False, lines=10)
    
    convert_btn = gr.Button("🚀 Convert & Upload", variant="primary")
    repo_link_output = gr.HTML()
    
    convert_btn.click(
        fn=process_and_upload_fp8,
        inputs=[
            source_type,
            repo_url,
            safetensors_filename,
            fp8_format,
            lora_rank,
            architecture,
            target_type,
            new_repo_id,
            hf_token,
            modelscope_token,
            private_repo
        ],
        outputs=[repo_link_output, status_output, detailed_log],
        show_progress=True
    )
    
    gr.Examples(
        examples=[
            ["huggingface", "https://huggingface.co/Yabo/FramePainter/tree/main", "unet_diffusion_pytorch_model.safetensors", "e5m2", 64, "unet_transformer"],
            ["huggingface", "https://huggingface.co/stabilityai/sdxl-vae", "diffusion_pytorch_model.safetensors", "e4m3fn", 32, "vae"],
            ["huggingface", "https://huggingface.co/runwayml/stable-diffusion-v1-5/tree/main/text_encoder", "model.safetensors", "e5m2", 48, "text_encoder"]
        ],
        inputs=[source_type, repo_url, safetensors_filename, fp8_format, lora_rank, architecture],
        label="Example Conversions"
    )
    
    gr.Markdown("""
    ## 💡 Usage Tips
    
    - **For Text Encoders**: Use rank 32-64 with `text_encoder` architecture for optimal results.
    - **For UNet Attention**: Use `unet_transformer` with rank 64-128 for best quality preservation.
    - **For UNet Convolutions**: Use `unet_conv` with lower ranks (16-32) as convolutions compress better.
    - **For VAE**: Use `vae` architecture with rank 16-32.
    - **Auto Mode**: Let the tool analyze and target appropriate layers automatically.
    
    ⚠️ **Note**: Higher ranks produce better quality but larger LoRA files. Start with lower ranks and increase if needed.
    """)

demo.launch()