import spaces
import os
import sys
import requests
import site

APP_DIR = os.path.dirname(os.path.abspath(__file__))
if APP_DIR not in sys.path:
    sys.path.insert(0, APP_DIR)
    print(f"✅ Added project root '{APP_DIR}' to sys.path.")

SAGE_PATCH_APPLIED = False

def apply_sage_attention_patch():
    global SAGE_PATCH_APPLIED
    if SAGE_PATCH_APPLIED:
        return "SageAttention patch already applied."

    try:
        from comfy import model_management
        import sageattention
        
        print("--- [Runtime Patch] sageattention package found. Applying patch... ---")
        model_management.sage_attention_enabled = lambda: True
        model_management.pytorch_attention_enabled = lambda: False
        
        SAGE_PATCH_APPLIED = True
        return "✅ Successfully enabled SageAttention."
    except ImportError:
        SAGE_PATCH_APPLIED = False
        msg = "--- [Runtime Patch] ⚠️ sageattention package not found. Continuing with default attention. ---"
        print(msg)
        return msg
    except Exception as e:
        SAGE_PATCH_APPLIED = False
        msg = f"--- [Runtime Patch] ❌ An error occurred while applying SageAttention patch: {e} ---"
        print(msg)
        return msg

@spaces.GPU
def dummy_gpu_for_startup():
    print("--- [GPU Startup] Dummy function for startup check initiated. ---")
    patch_result = apply_sage_attention_patch()
    print(f"--- [GPU Startup] {patch_result} ---")
    print("--- [GPU Startup] Startup check passed. ---")
    return "Startup check passed."

def handle_private_downloads():
    """
    Checks for a private_file_list.yaml, downloads required models using HF_TOKEN,
    and then clears the token from the environment.
    """
    import yaml
    from huggingface_hub import hf_hub_download
    from core.settings import (
        DIFFUSION_MODELS_DIR, TEXT_ENCODERS_DIR, VAE_DIR, CHECKPOINT_DIR, 
        LORA_DIR, CONTROLNET_DIR, MODEL_PATCHES_DIR, EMBEDDING_DIR
    )

    print("--- [Startup] Checking for private models to download... ---")
    private_list_path = os.path.join(APP_DIR, 'yaml', 'private_file_list.yaml')

    if not os.path.exists(private_list_path):
        print("--- [Startup] No private model list found. Skipping. ---")
        if 'HF_TOKEN' in os.environ:
             del os.environ['HF_TOKEN']
             print("--- [Startup] Cleared HF_TOKEN environment variable as it is no longer needed. ---")
             print(f"--- [Startup] Verifying HF_TOKEN after clearing: {os.environ.get('HF_TOKEN')}")
        return

    try:
        with open(private_list_path, 'r', encoding='utf-8') as f:
            private_files_config = yaml.safe_load(f)

        if not private_files_config or 'file' not in private_files_config:
            print("--- [Startup] Private model list is empty or malformed. Skipping. ---")
            return
        
        category_to_dir_map = {
            "diffusion_models": DIFFUSION_MODELS_DIR,
            "text_encoders": TEXT_ENCODERS_DIR,
            "vae": VAE_DIR,
            "checkpoints": CHECKPOINT_DIR,
            "loras": LORA_DIR,
            "controlnet": CONTROLNET_DIR,
            "model_patches": MODEL_PATCHES_DIR,
            "embeddings": EMBEDDING_DIR,
        }

        files_to_download = []
        for category, files in private_files_config.get('file', {}).items():
            dest_dir = category_to_dir_map.get(category)
            if not dest_dir:
                print(f"--- [Startup] ⚠️ Unknown category '{category}' in private_file_list.yaml. Skipping. ---")
                continue
            
            if isinstance(files, list):
                for file_info in files:
                    files_to_download.append((file_info, dest_dir))

        if not files_to_download:
            print("--- [Startup] No private models configured for download. ---")
            return

        print(f"--- [Startup] Found {len(files_to_download)} private model(s) to download. Using HF_TOKEN if available. ---")

        for file_info, dest_dir in files_to_download:
            filename = file_info.get("filename")
            repo_id = file_info.get("repo_id")
            repo_path = file_info.get("repository_file_path", filename)
            
            if not all([filename, repo_id]):
                print(f"--- [Startup] ⚠️ Skipping malformed entry in private_file_list.yaml: {file_info} ---")
                continue

            dest_path = os.path.join(dest_dir, filename)
            if os.path.lexists(dest_path):
                print(f"--- [Startup] ✅ Model '{filename}' already exists. Skipping download. ---")
                continue
            
            print(f"--- [Startup] ⏳ Downloading '{filename}' from repo '{repo_id}'... ---")
            try:
                cached_path = hf_hub_download(repo_id=repo_id, filename=repo_path)
                os.makedirs(dest_dir, exist_ok=True)
                os.symlink(cached_path, dest_path)
                print(f"--- [Startup] ✅ Successfully downloaded and linked '{filename}'. ---")
            except Exception as e:
                print(f"--- [Startup] ❌ ERROR: Failed to download '{filename}': {e}")
                print("--- [Startup] ❌ Please ensure your HF_TOKEN is set correctly and has access to the repository. ---")

    finally:
        if 'HF_TOKEN' in os.environ:
            del os.environ['HF_TOKEN']
            print("--- [Startup] ✅ Cleared HF_TOKEN environment variable. ---")
            print(f"--- [Startup] Verifying HF_TOKEN after clearing: {os.environ.get('HF_TOKEN')}")
        else:
            print("--- [Startup] Note: HF_TOKEN environment variable was not set. Private downloads may fail without it. ---")

def main():
    from utils.app_utils import print_welcome_message
    from scripts import build_sage_attention

    print_welcome_message()
    
    # Handle downloads that require authentication first.
    handle_private_downloads()
    
    print("--- [Setup] Attempting to build and install SageAttention... ---")
    try:
        build_sage_attention.install_sage_attention()
        print("--- [Setup] ✅ SageAttention installation process finished. ---")
    except Exception as e:
        print(f"--- [Setup] ❌ SageAttention installation failed: {e}. Continuing with default attention. ---")


    print("--- [Setup] Reloading site-packages to detect newly installed packages... ---")
    try:
        site.main()
        print("--- [Setup] ✅ Site-packages reloaded. ---")
    except Exception as e:
        print(f"--- [Setup] ⚠️  Warning: Could not fully reload site-packages: {e} ---")

    from comfy_integration import setup as setup_comfyui
    from utils.app_utils import (
        build_preprocessor_model_map,
        build_preprocessor_parameter_map
    )
    from core import shared_state
    from core.settings import ALL_MODEL_MAP, ALL_FILE_DOWNLOAD_MAP

    def check_all_model_urls_on_startup():
        print("--- [Setup] Checking all model URL validity (one-time check) ---")
        for display_name, model_info in ALL_MODEL_MAP.items():
            _, components, _, _ = model_info
            if not components: continue
            
            for filename in components.values():
                download_info = ALL_FILE_DOWNLOAD_MAP.get(filename, {})
                repo_id = download_info.get('repo_id')
                if not repo_id: continue
                
                repo_file_path = download_info.get('repository_file_path', filename)
                url = f"https://huggingface.co/{repo_id}/resolve/main/{repo_file_path}"
                
                try:
                    response = requests.head(url, timeout=5, allow_redirects=True)
                    if response.status_code >= 400:
                        print(f"❌ Invalid URL for '{display_name}' component '{filename}': {url} (Status: {response.status_code})")
                        shared_state.INVALID_MODEL_URLS[display_name] = True
                        break 
                except requests.RequestException as e:
                    print(f"❌ URL check failed for '{display_name}' component '{filename}': {e}")
                    shared_state.INVALID_MODEL_URLS[display_name] = True
                    break
        print("--- [Setup] ✅ Finished checking model URLs. ---")

    print("--- Starting Application Setup ---")
    
    setup_comfyui.initialize_comfyui()

    check_all_model_urls_on_startup()
    
    print("--- Building ControlNet preprocessor maps ---")
    from core.generation_logic import build_reverse_map
    build_reverse_map()
    build_preprocessor_model_map()
    build_preprocessor_parameter_map()
    print("--- ✅ ControlNet preprocessor setup complete. ---")

    print("--- Environment configured. Proceeding with module imports. ---")
    from ui.layout import build_ui
    from ui.events import attach_event_handlers

    print(f"✅ Working directory is stable: {os.getcwd()}")

    demo = build_ui(attach_event_handlers)
        
    print("--- Launching Gradio Interface ---")
    demo.queue().launch(server_name="0.0.0.0", server_port=7860)


if __name__ == "__main__":
    main()