import gradio as gr
import os
from typing import List, Dict, Tuple
import json
import datetime

# Mock backend functions to simulate AWS Bedrock Agents
def validate_documents(files: List[str]) -> Tuple[str, str]:
    """Simulate Intake Agent: Check if all required docs are present."""
    if not files:
        return "❌ No documents uploaded", "error"
    
    required = ["ID", "Pay Stubs", "W-2", "Tax Returns", "Bank Statements", "Offer", "Insurance", "Title"]
    uploaded = [os.path.basename(f).split(".")[0] for f in files]
    missing = [doc for doc in required if doc not in uploaded]
    
    if missing:
        return f"⚠️ Missing documents: {', '.join(missing)}", "warning"
    return "✅ All documents validated successfully", "success"

def extract_data(files: List[str], ssn: str) -> Dict:
    """Simulate Extraction Agent: Extract data from documents."""
    if not files or not ssn:
        return {}
    
    return {
        "application_id": "APP-2024-001234",
        "ssn": ssn,
        "applicant_name": "John Doe",
        "monthly_income": 8500,
        "monthly_debts": 2100,
        "credit_score": 720,
        "property_value": 450000,
        "loan_amount": 360000,
        "insurance_coverage": "12_months",
        "title_status": "Clear",
        "employment_status": "Full-time",
        "years_employed": 3.5
    }

def analyze_data(data: Dict) -> Dict:
    """Simulate Credit/Capacity/Collateral/Compliance Agents: Analyze data."""
    if not data:
        return {}
    
    dti = (data["monthly_debts"] / data["monthly_income"]) * 100
    ltv = (data["loan_amount"] / data["property_value"]) * 100
    flags = []
    risk_level = "Low"
    
    if dti > 45:
        flags.append("High DTI Ratio")
        risk_level = "High"
    elif dti > 36:
        flags.append("Elevated DTI Ratio")
        risk_level = "Medium"
    
    if data["credit_score"] < 620:
        flags.append("Low Credit Score")
        risk_level = "High"
    elif data["credit_score"] < 680:
        flags.append("Fair Credit Score")
        if risk_level != "High":
            risk_level = "Medium"
    
    if ltv > 95:
        flags.append("High LTV Ratio")
        risk_level = "High"
    elif ltv > 80:
        flags.append("Elevated LTV Ratio")
        if risk_level == "Low":
            risk_level = "Medium"
    
    if "Clear" not in data["title_status"]:
        flags.append("Title Issues")
        risk_level = "High"
    
    status = "Ready for Approval" if not flags else "Requires Review"
    if risk_level == "High":
        status = "High Risk - Manual Review Required"
    
    return {
        "application_id": data["application_id"],
        "applicant_name": data["applicant_name"],
        "dti_ratio": round(dti, 2),
        "ltv_ratio": round(ltv, 2),
        "credit_score": data["credit_score"],
        "monthly_income": f"${data['monthly_income']:,}",
        "monthly_debts": f"${data['monthly_debts']:,}",
        "loan_amount": f"${data['loan_amount']:,}",
        "property_value": f"${data['property_value']:,}",
        "risk_level": risk_level,
        "flags": flags,
        "status": status,
        "processed_date": datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    }

def handle_conditions(additional_files: List[str], comments: str) -> str:
    """Simulate Conditions Agent: Process additional uploads."""
    if additional_files and comments.strip():
        file_names = [os.path.basename(f) for f in additional_files]
        return f"✅ Additional documentation received: {', '.join(file_names)}\n\n📝 Comments: {comments}\n\n⏳ Status: Under Review"
    elif additional_files:
        file_names = [os.path.basename(f) for f in additional_files]
        return f"✅ Additional files uploaded: {', '.join(file_names)}\n\n⚠️ Please provide comments for review"
    elif comments.strip():
        return f"📝 Comments noted: {comments}\n\n⚠️ Please upload supporting documents"
    return "❌ No additional files or comments provided"

def finalize_approval(decision: str, comments: str, analysis: Dict) -> str:
    """Simulate Final Approval Agent: Finalize decision."""
    if not analysis:
        return "❌ Error: No analysis data available. Please complete analysis first."
    
    app_id = analysis.get("application_id", "N/A")
    applicant = analysis.get("applicant_name", "N/A")
    timestamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    
    if decision == "Approve":
        if not analysis.get("flags", []):
            return f"""
🎉 **APPLICATION APPROVED** 

📋 **Application ID:** {app_id}
👤 **Applicant:** {applicant}
📅 **Decision Date:** {timestamp}
✅ **Status:** Clear to Close

📦 **Next Steps:**
- Closing package will be generated automatically
- Borrower will be contacted within 24 hours
- Expected closing date: {(datetime.datetime.now() + datetime.timedelta(days=14)).strftime("%Y-%m-%d")}

💬 **Comments:** {comments if comments.strip() else 'Standard approval - all criteria met'}
"""
        else:
            return f"""
✅ **APPLICATION APPROVED WITH CONDITIONS**

📋 **Application ID:** {app_id}
👤 **Applicant:** {applicant}
📅 **Decision Date:** {timestamp}
⚠️ **Conditions:** {', '.join(analysis['flags'])}

📋 **Required Actions:**
- Address flagged conditions before closing
- Submit additional documentation if required
- Schedule manual review if needed

💬 **Comments:** {comments}
"""
    else:  # Reject
        return f"""
❌ **APPLICATION REJECTED**

📋 **Application ID:** {app_id}
👤 **Applicant:** {applicant}
📅 **Decision Date:** {timestamp}

🚫 **Rejection Reasons:**
{chr(10).join([f"• {flag}" for flag in analysis.get('flags', ['Manual rejection'])])}

📞 **Next Steps:**
- Applicant will be contacted within 48 hours
- Adverse action notice will be sent
- Reapplication possible after addressing issues

💬 **Comments:** {comments}
"""

# Custom CSS for production-grade styling
custom_css = """
/* Global Styles */
.gradio-container {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif !important;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%) !important;
    min-height: 100vh;
}

.main {
    background: rgba(255, 255, 255, 0.95) !important;
    border-radius: 20px !important;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1) !important;
    margin: 20px !important;
    padding: 0 !important;
}

/* Header Styling */
.header-section {
    background: linear-gradient(90deg, #1e3c72 0%, #2a5298 100%) !important;
    color: white !important;
    padding: 30px !important;
    border-radius: 20px 20px 0 0 !important;
    margin-bottom: 0 !important;
    text-align: center !important;
}

.header-section h1 {
    margin: 0 !important;
    font-size: 2.5rem !important;
    font-weight: 700 !important;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3) !important;
}

.header-section p {
    margin: 10px 0 0 0 !important;
    font-size: 1.1rem !important;
    opacity: 0.9 !important;
}

/* Section Styling */
.section-card {
    background: white !important;
    border-radius: 15px !important;
    padding: 25px !important;
    margin: 20px !important;
    box-shadow: 0 8px 25px rgba(0,0,0,0.1) !important;
    border: 1px solid rgba(0,0,0,0.05) !important;
    transition: all 0.3s ease !important;
}

.section-card:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 12px 35px rgba(0,0,0,0.15) !important;
}

.section-title {
    color: #2c3e50 !important;
    font-size: 1.5rem !important;
    font-weight: 600 !important;
    margin-bottom: 20px !important;
    padding-bottom: 10px !important;
    border-bottom: 3px solid #3498db !important;
    display: flex !important;
    align-items: center !important;
    gap: 10px !important;
}

/* Button Styling */
.btn-primary {
    background: linear-gradient(45deg, #667eea, #764ba2) !important;
    border: none !important;
    border-radius: 10px !important;
    padding: 12px 30px !important;
    font-weight: 600 !important;
    font-size: 1rem !important;
    transition: all 0.3s ease !important;
    text-transform: uppercase !important;
    letter-spacing: 0.5px !important;
}

.btn-primary:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4) !important;
}

.btn-success {
    background: linear-gradient(45deg, #56ab2f, #a8e6cf) !important;
    border: none !important;
    border-radius: 10px !important;
    padding: 12px 30px !important;
    font-weight: 600 !important;
}

.btn-danger {
    background: linear-gradient(45deg, #ff416c, #ff4b2b) !important;
    border: none !important;
    border-radius: 10px !important;
    padding: 12px 30px !important;
    font-weight: 600 !important;
}

/* Input Styling */
input, textarea, select {
    border-radius: 8px !important;
    border: 2px solid #e1e8ed !important;
    padding: 12px !important;
    font-size: 1rem !important;
    transition: all 0.3s ease !important;
}

input:focus, textarea:focus, select:focus {
    border-color: #667eea !important;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1) !important;
    outline: none !important;
}

/* Status Messages */
.status-success {
    background: linear-gradient(45deg, #56ab2f, #a8e6cf) !important;
    color: white !important;
    padding: 15px !important;
    border-radius: 10px !important;
    font-weight: 600 !important;
}

.status-warning {
    background: linear-gradient(45deg, #f7971e, #ffd200) !important;
    color: #333 !important;
    padding: 15px !important;
    border-radius: 10px !important;
    font-weight: 600 !important;
}

.status-error {
    background: linear-gradient(45deg, #ff416c, #ff4b2b) !important;
    color: white !important;
    padding: 15px !important;
    border-radius: 10px !important;
    font-weight: 600 !important;
}

/* Progress Indicators */
.step-indicator {
    display: flex !important;
    justify-content: space-between !important;
    margin: 20px 0 !important;
    position: relative !important;
}

.step {
    background: #e1e8ed !important;
    border-radius: 50% !important;
    width: 40px !important;
    height: 40px !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    font-weight: bold !important;
    color: #666 !important;
    z-index: 2 !important;
}

.step.active {
    background: linear-gradient(45deg, #667eea, #764ba2) !important;
    color: white !important;
}

.step.completed {
    background: linear-gradient(45deg, #56ab2f, #a8e6cf) !important;
    color: white !important;
}

/* JSON Display Enhancement */
.json-display {
    background: #f8f9fa !important;
    border: 1px solid #e9ecef !important;
    border-radius: 10px !important;
    padding: 20px !important;
    font-family: 'Monaco', 'Consolas', monospace !important;
    max-height: 400px !important;
    overflow-y: auto !important;
}

/* File Upload Styling */
.file-upload {
    border: 2px dashed #667eea !important;
    border-radius: 10px !important;
    padding: 30px !important;
    text-align: center !important;
    background: rgba(102, 126, 234, 0.05) !important;
    transition: all 0.3s ease !important;
}

.file-upload:hover {
    background: rgba(102, 126, 234, 0.1) !important;
    border-color: #5a67d8 !important;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main {
        margin: 10px !important;
    }
    
    .section-card {
        margin: 10px !important;
        padding: 20px !important;
    }
    
    .header-section h1 {
        font-size: 2rem !important;
    }
}
"""

# Gradio Interface
with gr.Blocks(css=custom_css, title="Mortgage Underwriting System", theme=gr.themes.Soft()) as app:
    
    # Header Section
    with gr.Row():
        with gr.Column():
            gr.HTML("""
            <div class="header-section">
                <h1>🏠 Mortgage Underwriting Automation</h1>
                <p>Intelligent Document Processing & Risk Assessment Platform</p>
            </div>
            """)
    
    # Progress Indicator
    with gr.Row():
        with gr.Column():
            gr.HTML("""
            <div class="section-card">
                <div class="step-indicator">
                    <div class="step active">1</div>
                    <div class="step">2</div>
                    <div class="step">3</div>
                    <div class="step">4</div>
                </div>
                <div style="text-align: center; margin-top: 10px; color: #666;">
                    <strong>Document Upload</strong> → Data Analysis → Conditions → Final Approval
                </div>
            </div>
            """)
    
    # Section 1: Document Upload
    with gr.Row():
        with gr.Column():
            gr.HTML('<div class="section-card">')
            gr.HTML('<div class="section-title">📄 Document Upload & Validation</div>')
            
            with gr.Row():
                with gr.Column(scale=2):
                    files_input = gr.File(
                        label="Required Documents",
                        file_count="multiple",
                        file_types=[".pdf", ".png", ".jpg", ".jpeg"],
                        elem_classes=["file-upload"]
                    )
                    gr.HTML("""
                    <div style="background: #f8f9fa; padding: 15px; border-radius: 8px; margin: 10px 0;">
                        <strong>📋 Required Documents Checklist:</strong><br>
                        • Government-issued ID<br>
                        • Recent Pay Stubs (2-3 months)<br>
                        • W-2 Forms (2 years)<br>
                        • Tax Returns (2 years)<br>
                        • Bank Statements (3 months)<br>
                        • Purchase Offer/Contract<br>
                        • Insurance Documentation<br>
                        • Property Title Information
                    </div>
                    """)
                
                with gr.Column(scale=1):
                    ssn_input = gr.Textbox(
                        label="Social Security Number",
                        placeholder="XXX-XX-XXXX",
                        type="password"
                    )
                    validate_btn = gr.Button("🔍 Validate Documents", variant="primary", size="lg")
                    validate_output = gr.Textbox(
                        label="Validation Status",
                        interactive=False,
                        lines=2
                    )
            
            gr.HTML('</div>')
    
    # Section 2: Data Extraction and Analysis
    with gr.Row():
        with gr.Column():
            gr.HTML('<div class="section-card">')
            gr.HTML('<div class="section-title">🔍 Automated Analysis & Risk Assessment</div>')
            
            with gr.Row():
                with gr.Column():
                    extract_btn = gr.Button("⚡ Extract Data & Analyze Risk", variant="primary", size="lg")
                    
                    with gr.Row():
                        with gr.Column():
                            analysis_output = gr.JSON(
                                label="📊 Comprehensive Analysis Results",
                                elem_classes=["json-display"]
                            )
                        
                        with gr.Column():
                            gr.HTML("""
                            <div style="background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: white; padding: 20px; border-radius: 10px;">
                                <h3 style="margin: 0 0 15px 0;">🎯 Risk Assessment Criteria</h3>
                                <div style="background: rgba(255,255,255,0.1); padding: 15px; border-radius: 8px;">
                                    <strong>📈 DTI Ratio:</strong> ≤ 45% (Optimal: ≤ 36%)<br>
                                    <strong>💳 Credit Score:</strong> ≥ 620 (Preferred: ≥ 680)<br>
                                    <strong>🏘️ LTV Ratio:</strong> ≤ 95% (Conventional: ≤ 80%)<br>
                                    <strong>📋 Documentation:</strong> Complete & Verified<br>
                                    <strong>🏢 Employment:</strong> Stable Income History
                                </div>
                            </div>
                            """)
            
            gr.HTML('</div>')
    
    # Section 3: Conditional Requirements
    with gr.Row():
        with gr.Column():
            gr.HTML('<div class="section-card">')
            gr.HTML('<div class="section-title">📎 Additional Documentation & Conditions</div>')
            
            with gr.Row():
                with gr.Column():
                    additional_files = gr.File(
                        label="Upload Additional Documents",
                        file_count="multiple",
                        file_types=[".pdf", ".png", ".jpg", ".jpeg"],
                        elem_classes=["file-upload"]
                    )
                    condition_comments = gr.Textbox(
                        label="Underwriter Comments & Instructions",
                        placeholder="Provide detailed comments about additional requirements...",
                        lines=4
                    )
                    condition_btn = gr.Button("📤 Submit Additional Documentation", variant="secondary", size="lg")
                
                with gr.Column():
                    condition_output = gr.Textbox(
                        label="📋 Conditions Status",
                        interactive=False,
                        lines=6
                    )
                    
                    gr.HTML("""
                    <div style="background: #fff3cd; border: 1px solid #ffeaa7; padding: 15px; border-radius: 8px; color: #856404;">
                        <strong>💡 Common Additional Requirements:</strong><br>
                        • Gift Letter (for down payment assistance)<br>
                        • Employment Verification Letter<br>
                        • Asset Verification Documents<br>
                        • Property Appraisal Report<br>
                        • Explanation Letters (for credit items)<br>
                        • Homeowner's Insurance Proof
                    </div>
                    """)
            
            gr.HTML('</div>')
    
    # Section 4: Final Decision
    with gr.Row():
        with gr.Column():
            gr.HTML('<div class="section-card">')
            gr.HTML('<div class="section-title">⚖️ Final Underwriting Decision</div>')
            
            with gr.Row():
                with gr.Column():
                    approve_radio = gr.Radio(
                        choices=["Approve", "Reject"],
                        label="📋 Underwriting Decision",
                        info="Select final decision based on comprehensive analysis"
                    )
                    approval_comments = gr.Textbox(
                        label="💬 Decision Comments & Rationale",
                        placeholder="Provide detailed reasoning for the decision...",
                        lines=4
                    )
                    approve_btn = gr.Button("✅ Submit Final Decision", variant="primary", size="lg")
                
                with gr.Column():
                    final_output = gr.Textbox(
                        label="🏆 Final Approval Status",
                        interactive=False,
                        lines=12,
                        elem_classes=["status-display"]
                    )
            
            gr.HTML('</div>')
    
    # Footer
    with gr.Row():
        with gr.Column():
            gr.HTML("""
            <div style="text-align: center; padding: 20px; color: #666; background: rgba(0,0,0,0.05); border-radius: 0 0 20px 20px;">
                <p>🔒 Secure • 🤖 AI-Powered • ⚡ Real-time Processing</p>
                <p><small>© 2024 Mortgage Underwriting Automation Platform | Version 2.0</small></p>
            </div>
            """)
    
    # Event Handlers
    validate_btn.click(
        fn=lambda files: validate_documents(files)[0],
        inputs=files_input,
        outputs=validate_output
    )
    
    extract_btn.click(
        fn=lambda files, ssn: analyze_data(extract_data(files, ssn)),
        inputs=[files_input, ssn_input],
        outputs=analysis_output
    )
    
    condition_btn.click(
        fn=handle_conditions,
        inputs=[additional_files, condition_comments],
        outputs=condition_output
    )
    
    approve_btn.click(
        fn=finalize_approval,
        inputs=[approve_radio, approval_comments, analysis_output],
        outputs=final_output
    )

if __name__ == "__main__":
    app.launch(
        server_name="0.0.0.0",
        server_port=7860,
        share=False,
        show_error=True,
        favicon_path=None,
        ssl_verify=False,
        debug=True
    )