import streamlit as st
import plotly.express as px
import pandas as pd
import google.generativeai as genai

def render_financial_dashboard(startup_data, cash_flow_df):
    """Render financial dashboard page."""
    st.title("Financial Dashboard")
    
    # Key metrics
    col1, col2, col3, col4 = st.columns(4)
    
    # Calculate runway
    runway_months, runway_df = calculate_runway(
        startup_data['cash'], 
        startup_data['burn_rate'], 
        startup_data['revenue'], 
        startup_data['growth_rate']
    )
    
    with col1:
        st.metric("Current Cash", f"${startup_data['cash']:,}")
    with col2:
        st.metric("Monthly Burn", f"${startup_data['burn_rate']:,}")
    with col3:
        st.metric("Monthly Revenue", f"${startup_data['revenue']:,}")
    with col4:
        st.metric("Runway", f"{runway_months} months")
    
    # Financial charts
    st.subheader("Financial Overview")
    
    tab1, tab2, tab3 = st.tabs(["Runway Projection", "Revenue vs. Expenses", "Burn Rate Trend"])
    
    with tab1:
        # Runway projection chart
        fig = px.line(runway_df.reset_index(), x='index', y='Cumulative_Cash', 
                     title="Cash Runway Projection",
                     labels={'index': 'Date', 'Cumulative_Cash': 'Remaining Cash'})
        fig.add_hline(y=0, line_dash="dash", line_color="red")
        fig.update_layout(height=400)
        st.plotly_chart(fig, use_container_width=True)
        
        # Get analysis from Gemini
        try:
            if setup_genai():
                with st.expander("AI Financial Analysis"):
                    analysis = get_runway_analysis(startup_data)
                    st.write(analysis)
        except Exception as e:
            st.error(f"Error generating AI analysis: {e}")
    
    with tab2:
        # Revenue vs Expenses chart
        rev_exp_df = cash_flow_df.copy()
        fig = px.bar(rev_exp_df, x='Month', y=['Revenue', 'Total_Expenses'],
                    title="Revenue vs. Expenses",
                    barmode='group',
                    labels={'value': 'Amount ($)', 'variable': 'Category'})
        fig.update_layout(height=400)
        st.plotly_chart(fig, use_container_width=True)
    
    with tab3:
        # Burn rate trend
        fig = px.line(cash_flow_df, x='Month', y='Net_Burn',
                     title="Monthly Net Burn Trend",
                     labels={'Net_Burn': 'Net Burn ($)'})
        fig.update_layout(height=400)
        st.plotly_chart(fig, use_container_width=True)
    
    # Expense breakdown
    st.subheader("Expense Breakdown")
    
    # Last month expenses
    last_month = cash_flow_df.iloc[-1]
    expense_categories = ['Payroll', 'Marketing', 'Office', 'Software', 'Travel', 'Legal', 'Misc']
    expense_values = [last_month[cat] for cat in expense_categories]
    
    fig = px.pie(values=expense_values, names=expense_categories, 
                title="Current Month Expense Breakdown")
    fig.update_layout(height=400)
    st.plotly_chart(fig, use_container_width=True)

def calculate_runway(initial_cash, monthly_burn, monthly_revenue, growth_rate, months=24):
    """Calculate runway based on current burn rate and revenue growth."""
    from datetime import datetime, timedelta
    import pandas as pd
    
    dates = [datetime.now() + timedelta(days=30*i) for i in range(months)]
    df = pd.DataFrame(index=dates, columns=['Cash', 'Revenue', 'Expenses', 'Net_Burn', 'Cumulative_Cash'])
    
    current_cash = initial_cash
    current_revenue = monthly_revenue
    df.iloc[0, df.columns.get_loc('Cash')] = current_cash
    df.iloc[0, df.columns.get_loc('Revenue')] = current_revenue
    df.iloc[0, df.columns.get_loc('Expenses')] = monthly_burn
    df.iloc[0, df.columns.get_loc('Net_Burn')] = monthly_burn - current_revenue
    df.iloc[0, df.columns.get_loc('Cumulative_Cash')] = current_cash
    
    runway_months = months
    for i in range(1, months):
        current_revenue = current_revenue * (1 + growth_rate)
        net_burn = monthly_burn - current_revenue
        current_cash = current_cash - net_burn
        
        df.iloc[i, df.columns.get_loc('Cash')] = current_cash
        df.iloc[i, df.columns.get_loc('Revenue')] = current_revenue
        df.iloc[i, df.columns.get_loc('Expenses')] = monthly_burn
        df.iloc[i, df.columns.get_loc('Net_Burn')] = net_burn
        df.iloc[i, df.columns.get_loc('Cumulative_Cash')] = current_cash
        
        if current_cash <= 0:
            runway_months = i
            break
    
    return runway_months, df

def get_runway_analysis(financial_data):
    """Get runway analysis using Gemini."""
    try:
        prompt = f"""
        You are a financial advisor for startups. Analyze this startup's financial data:
        - Current cash: ${financial_data['cash']}
        - Monthly burn rate: ${financial_data['burn_rate']}
        - Monthly revenue: ${financial_data['revenue']}
        - Monthly growth rate: {financial_data['growth_rate'] * 100}%

        Calculate and explain their runway, financial health, and recommendations in a concise paragraph.
        """
        
        model = genai.GenerativeModel('gemini-pro')
        response = model.generate_content(prompt)
        
        return response.text
    except Exception as e:
        return f"Error generating runway analysis: {e}"

def get_fundraising_readiness_analysis(financial_data):
    """Analyze startup's readiness for fundraising."""
    try:
        prompt = f"""
        You are a fundraising advisor for startups. Evaluate this startup's fundraising readiness:
        - Current cash: ${financial_data['cash']}
        - Monthly burn rate: ${financial_data['burn_rate']}
        - Monthly revenue: ${financial_data['revenue']}
        - Monthly growth rate: {financial_data['growth_rate'] * 100}%
        - Last funding: {financial_data.get('last_funding', 'Not specified')}
        - Company stage: {financial_data.get('stage', 'Not specified')}

        Provide insights on:
        1. Current runway and funding needs
        2. Attractiveness to potential investors
        3. Recommended fundraising strategy
        4. Key metrics to improve before fundraising

        Respond in a concise, actionable paragraph.
        """
        
        model = genai.GenerativeModel('gemini-pro')
        response = model.generate_content(prompt)
        
        return response.text
    except Exception as e:
        return f"Error generating fundraising readiness analysis: {e}"

def setup_genai():
    """Setup Google Generative AI"""
    try:
        import os
        import streamlit as st
        
        # Try getting API key from Streamlit secrets first
        if 'GOOGLE_API_KEY' in st.secrets:
            api_key = st.secrets['GOOGLE_API_KEY']
        # Fall back to environment variable
        elif 'GOOGLE_API_KEY' in os.environ:
            api_key = os.environ['GOOGLE_API_KEY']
        else:
            st.warning("Google API key not found. Using simulated AI responses.")
            return False
            
        genai.configure(api_key=api_key)
        return True
    except Exception as e:
        st.error(f"Error setting up Generative AI: {e}")
        return False