app.py

import gradio as gr
import difflib
import re

def clean_and_tokenize(text):
    # Normalize whitespaces
    return re.findall(r'\b\w+\b|[^\w\s]', text)

def calculate_drift_metrics(text_a, text_b):
    words_a = text_a.split()
    words_b = text_b.split()
    
    set_a = set(words_a)
    set_b = set(words_b)
    
    # Jaccard similarity
    union = len(set_a.union(set_b))
    intersection = len(set_a.intersection(set_b))
    jaccard_sim = (intersection / union) * 100 if union > 0 else 100.0
    
    # SequenceMatcher
    matcher = difflib.SequenceMatcher(None, words_a, words_b)
    ratio = matcher.ratio() * 100
    
    # Edits breakdown
    opcodes = matcher.get_opcodes()
    insertions = 0
    deletions = 0
    replacements = 0
    
    for tag, i1, i2, j1, j2 in opcodes:
        if tag == 'insert':
            insertions += (j2 - j1)
        elif tag == 'delete':
            deletions += (i2 - i1)
        elif tag == 'replace':
            replacements += max(i2 - i1, j2 - j1)
            
    drift_percent = 100 - ratio
    
    return {
        "jaccard": round(jaccard_sim, 2),
        "similarity": round(ratio, 2),
        "drift": round(drift_percent, 2),
        "insertions": insertions,
        "deletions": deletions,
        "replacements": replacements,
        "words_a": len(words_a),
        "words_b": len(words_b)
    }

def generate_word_diff(text_a, text_b):
    # Clean texts
    words_a = text_a.splitlines()
    words_b = text_b.splitlines()
    
    # We will generate a beautiful side-by-side or inline HTML diff
    # difflib.HtmlDiff is nice, but we want a highly premium custom HTML view
    diff = difflib.HtmlDiff(wrapcolumn=60)
    html_table = diff.make_table(words_a, words_b, context=True, numlines=3)
    
    # Style the table to fit our glowing dark theme
    styled_html = f"""
    <style>
        .diff_table {{ font-family: 'Inter', monospace; font-size: 13px; border-collapse: collapse; width: 100%; color: #e2e8f0; background: #0f172a; border-radius: 8px; overflow: hidden; }}
        .diff_header {{ background: #1e293b; color: #94a3b8; font-weight: 600; padding: 8px; border-bottom: 2px solid #334155; }}
        td.diff_header {{ text-align: right; background: #1e293b; color: #64748b; padding: 4px 8px; user-select: none; width: 40px; border-right: 1px solid #334155; }}
        .diff_next {{ display: none; }}
        .diff_add {{ background-color: rgba(16, 185, 129, 0.25) !important; color: #34d399 !important; text-decoration: none; }}
        .diff_chg {{ background-color: rgba(245, 158, 11, 0.25) !important; color: #fbbf24 !important; text-decoration: none; }}
        .diff_sub {{ background-color: rgba(239, 68, 68, 0.25) !important; color: #f87171 !important; text-decoration: line-through; }}
        td {{ padding: 4px 12px; word-break: break-all; white-space: pre-wrap; }}
        tr:hover td {{ background: #1e293b; }}
    </style>
    <div style="overflow-x: auto; border-radius: 8px; border: 1px solid #334155;">
        {html_table}
    </div>
    """
    return styled_html

def handle_compare(text_a, file_a, text_b, file_b):
    # Retrieve values
    final_a = text_a
    if file_a is not None:
        try:
            with open(file_a.name, 'r', encoding='utf-8', errors='ignore') as f:
                final_a = f.read()
        except Exception as e:
            final_a = f"Error reading File A: {str(e)}"
            
    final_b = text_b
    if file_b is not None:
        try:
            with open(file_b.name, 'r', encoding='utf-8', errors='ignore') as f:
                final_b = f.read()
        except Exception as e:
            final_b = f"Error reading File B: {str(e)}"
            
    if not final_a.strip() and not final_b.strip():
        return "<div style='color: #ef4444; padding: 1rem;'>Please enter or upload text for both versions to compare.</div>", ""
        
    # Calculate stats
    stats = calculate_drift_metrics(final_a, final_b)
    
    # HTML stats card
    stats_html = f"""
    <div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 1rem; margin-bottom: 1.5rem;">
        <div style="background: #1e293b; border: 1px solid #334155; border-radius: 8px; padding: 1rem; text-align: center;">
            <div style="font-size: 0.8rem; color: #94a3b8; font-weight: 500; text-transform: uppercase; letter-spacing: 0.05em;">Document Similarity</div>
            <div style="font-size: 2rem; font-weight: 700; color: #10b981; margin-top: 0.25rem;">{stats['similarity']}%</div>
        </div>
        <div style="background: #1e293b; border: 1px solid #334155; border-radius: 8px; padding: 1rem; text-align: center;">
            <div style="font-size: 0.8rem; color: #94a3b8; font-weight: 500; text-transform: uppercase; letter-spacing: 0.05em;">Lexical Drift Spread</div>
            <div style="font-size: 2rem; font-weight: 700; color: #ef4444; margin-top: 0.25rem;">{stats['drift']}%</div>
        </div>
        <div style="background: #1e293b; border: 1px solid #334155; border-radius: 8px; padding: 1rem; text-align: center;">
            <div style="font-size: 0.8rem; color: #94a3b8; font-weight: 500; text-transform: uppercase; letter-spacing: 0.05em;">Word Additions</div>
            <div style="font-size: 2rem; font-weight: 700; color: #3b82f6; margin-top: 0.25rem;">+{stats['insertions']}</div>
        </div>
        <div style="background: #1e293b; border: 1px solid #334155; border-radius: 8px; padding: 1rem; text-align: center;">
            <div style="font-size: 0.8rem; color: #94a3b8; font-weight: 500; text-transform: uppercase; letter-spacing: 0.05em;">Word Deletions</div>
            <div style="font-size: 2rem; font-weight: 700; color: #f43f5e; margin-top: 0.25rem;">-{stats['deletions']}</div>
        </div>
    </div>
    <div style="background: #1e293b; border: 1px solid #334155; border-radius: 8px; padding: 1rem; margin-bottom: 1.5rem; color: #cbd5e1;">
        <h4 style="margin: 0 0 0.5rem 0; color: #e2e8f0;">Provenance Analysis Summary</h4>
        <p style="margin: 0; font-size: 0.95rem; line-height: 1.5;">
            Version A contains <strong>{stats['words_a']}</strong> words, and Version B contains <strong>{stats['words_b']}</strong> words. 
            There are <strong>{stats['replacements']}</strong> words modified in place. 
            The vocabulary overlap index (Jaccard similarity) is <strong>{stats['jaccard']}%</strong>.
            This indicates a <strong>{"high" if stats['drift'] > 30 else "moderate" if stats['drift'] > 10 else "minimal"} degree of document mutation</strong> over successive drafts.
        </p>
    </div>
    """
    
    # Generate interactive table
    diff_table = generate_word_diff(final_a, final_b)
    
    return stats_html, diff_table

# Setup CSS styling for premium look
custom_css = """
body, .gradio-container { background-color: #0b0f19 !important; font-family: 'Inter', sans-serif !important; }
h1, h2, h3 { color: #f8fafc !important; }
.gr-button-primary { background: linear-gradient(135deg, #059669 0%, #10b981 100%) !important; border: none !important; }
.gr-button-primary:hover { opacity: 0.9 !important; }
"""

# App Interface
with gr.Blocks(theme=gr.themes.Soft(primary_hue="emerald", secondary_hue="slate"), css=custom_css) as demo:
    gr.HTML("""
    <div style="text-align: center; margin-bottom: 2rem; border-bottom: 1px solid #1e293b; padding-bottom: 1.5rem;">
        <h1 style="font-size: 2.2rem; font-weight: 800; background: linear-gradient(135deg, #10b981 0%, #3b82f6 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent;">📊 Version Diffing & Provenance Auditor</h1>
        <p style="color: #94a3b8; font-size: 1.1rem; margin-top: 0.5rem;">Audit the evolution of policies, legislative bills, manuscripts, or transcripts with statistical drift analytics.</p>
    </div>
    """)
    
    with gr.Row():
        with gr.Column(scale=1):
            gr.Markdown("### 📜 Original Version (Draft A)")
            text_input_a = gr.Textbox(label="Paste Text A", placeholder="Enter original draft here...", lines=10)
            file_input_a = gr.File(label="Or Upload Text File A", file_types=[".txt"])
            
        with gr.Column(scale=1):
            gr.Markdown("### 📝 New Version (Draft B)")
            text_input_b = gr.Textbox(label="Paste Text B", placeholder="Enter revised draft here...", lines=10)
            file_input_b = gr.File(label="Or Upload Text File B", file_types=[".txt"])
            
    compare_btn = gr.Button("🔍 Audit Document Drift & Generate Diff Table", variant="primary")
    
    gr.Markdown("### 📈 Analytical Provenance Dashboard & Drift Metrics")
    stats_output = gr.HTML(value="<div style='color: #64748b;'>Submit documents above to calculate version changes.</div>")
    
    gr.Markdown("### 🔍 Color-Coded Structural Difference View")
    diff_output = gr.HTML(value="<div style='color: #64748b;'>Visual diff will render here. Green represents additions, red represents deletions, and yellow represents replacements.</div>")
    
    # Wiring events
    compare_btn.click(
        fn=handle_compare,
        inputs=[text_input_a, file_input_a, text_input_b, file_input_b],
        outputs=[stats_output, diff_output]
    )

if __name__ == "__main__":
    demo.launch()