app.py

import gradio as gr
from huggingface_hub import InferenceClient
from transformers import SynthIDTextWatermarkingConfig
import json

class SynthIDApp:
    def __init__(self):
        self.client = None
        self.watermarking_config = None
    
    def login(self, hf_token):
        """Initialize the inference client with authentication."""
        try:
            # Initialize the inference client
            self.client = InferenceClient(
                model="google/gemma-2b",
                token=hf_token
            )
            
            # Configure watermarking
            WATERMARK_KEYS = [654, 400, 836, 123, 340, 443, 597, 160, 57, 789]
            self.watermarking_config = SynthIDTextWatermarkingConfig(
                keys=WATERMARK_KEYS,
                ngram_len=5
            )
            
            # Test the connection
            _ = self.client.token_count("Test")
            return "Inference client initialized successfully!"
        except Exception as e:
            self.client = None
            self.watermarking_config = None
            return f"Error initializing client: {str(e)}"

    def apply_watermark(self, text):
        """Apply SynthID watermark to input text using the inference endpoint."""
        if not self.client:
            return text, "Error: Client not initialized. Please login first."
            
        try:
            # Convert watermarking config to dict for the API call
            watermark_dict = {
                "keys": self.watermarking_config.keys,
                "ngram_len": self.watermarking_config.ngram_len
            }
            
            # Make the API call with watermarking config
            response = self.client.text_generation(
                text,
                max_new_tokens=100,
                do_sample=True,
                temperature=0.7,
                top_p=0.9,
                watermarking_config=watermark_dict,
                return_full_text=False
            )
            
            watermarked_text = response
            return watermarked_text, "Watermark applied successfully!"
        except Exception as e:
            return text, f"Error applying watermark: {str(e)}"

    def analyze_text(self, text):
        """Analyze text characteristics."""
        try:
            total_words = len(text.split())
            avg_word_length = sum(len(word) for word in text.split()) / total_words if total_words > 0 else 0
            
            # Get token count if client is available
            token_info = ""
            if self.client:
                try:
                    token_count = self.client.token_count(text)
                    token_info = f"\n- Token count: {token_count}"
                except:
                    pass
            
            analysis = f"""Text Analysis:
- Total words: {total_words}
- Average word length: {avg_word_length:.2f}{token_info}

Note: This is a basic analysis. The official SynthID detector is not yet available in the public transformers package."""
            
            return analysis
        except Exception as e:
            return f"Error analyzing text: {str(e)}"

# Create Gradio interface
app_instance = SynthIDApp()

with gr.Blocks(title="SynthID Text Watermarking Tool") as app:
    gr.Markdown("# SynthID Text Watermarking Tool")
    gr.Markdown("Using Hugging Face Inference Endpoints for faster processing")
    
    # Login section
    with gr.Row():
        hf_token = gr.Textbox(
            label="Enter Hugging Face Token", 
            type="password",
            placeholder="hf_..."
        )
        login_status = gr.Textbox(label="Login Status")
    login_btn = gr.Button("Login")
    login_btn.click(app_instance.login, inputs=[hf_token], outputs=[login_status])
    
    with gr.Tab("Apply Watermark"):
        with gr.Row():
            input_text = gr.Textbox(
                label="Input Text", 
                lines=5,
                placeholder="Enter text to watermark..."
            )
            output_text = gr.Textbox(label="Watermarked Text", lines=5)
            status = gr.Textbox(label="Status")
        apply_btn = gr.Button("Apply Watermark")
        apply_btn.click(app_instance.apply_watermark, inputs=[input_text], outputs=[output_text, status])
    
    with gr.Tab("Analyze Text"):
        with gr.Row():
            analyze_input = gr.Textbox(
                label="Text to Analyze", 
                lines=5,
                placeholder="Enter text to analyze..."
            )
            analyze_result = gr.Textbox(label="Analysis Result", lines=5)
        analyze_btn = gr.Button("Analyze Text")
        analyze_btn.click(app_instance.analyze_text, inputs=[analyze_input], outputs=[analyze_result])
    
    gr.Markdown("""
    ### Instructions:
    1. Enter your Hugging Face token and click Login
    2. Once connected, you can use the tabs to apply watermarks or analyze text
    
    ### Notes:
    - This version uses Hugging Face's Inference Endpoints for faster processing
    - No model download required - everything runs in the cloud
    - The watermark is designed to be imperceptible to humans
    - This demo only implements watermark application
    - The official detector will be available in future releases
    - For production use, use your own secure watermark keys
    - Your token is never stored and is only used for API access
    """)

# Launch the app
if __name__ == "__main__":
    app.launch()