import streamlit as st
import plotly.graph_objects as go
from datetime import datetime
import pytz
from trading.journal import (
    create_trades_table, get_open_trades, get_trade_history,
    add_trade, update_trade, delete_trade, TradeEntry,
    get_open_trades_summary, get_current_prices, generate_position_id,
    get_position_summary, get_latest_portfolio_value, update_portfolio_value
)

def format_datetime(dt):
    """Format datetime for display"""
    if dt:
        return dt.strftime('%Y-%m-%d %H:%M')
    return ''

def plot_trade_history(trades):
    """Create a P/L chart using Plotly"""
    if not trades:
        return None
        
    # Prepare data
    dates = []
    pnl = []
    cumulative_pnl = 0
    
    for trade in trades:
        if trade['exit_price']:
            trade_pnl = (trade['exit_price'] - trade['entry_price']) * trade['shares']
            cumulative_pnl += trade_pnl
            dates.append(trade['exit_date'])
            pnl.append(cumulative_pnl)
    
    if not dates:
        return None
        
    # Create figure
    fig = go.Figure()
    fig.add_trace(
        go.Scatter(x=dates, y=pnl, mode='lines+markers',
                  name='Cumulative P/L',
                  line=dict(color='blue'),
                  hovertemplate='Date: %{x}<br>P/L: $%{y:.2f}<extra></extra>')
    )
    
    fig.update_layout(
        title='Cumulative Profit/Loss Over Time',
        xaxis_title='Date',
        yaxis_title='Cumulative P/L ($)',
        hovermode='x unified'
    )
    
    return fig

def trading_journal_page():
    st.header("Trading Journal")
    
    # Tabs for different journal functions
    tab1, tab2, tab3, tab4 = st.tabs(["Open Positions", "Add Trade", "Update Trade", "Trade History"])
    
    with tab1:
        st.subheader("Open Positions")
        open_trades = get_open_trades()
        open_summary = get_open_trades_summary()
        
        if open_summary:
            # Get current prices
            unique_tickers = list(set(summary['ticker'] for summary in open_summary))
            current_prices = get_current_prices(unique_tickers)
            
            total_portfolio_value = 0
            total_paper_pl = 0
            
            for summary in open_summary:
                with st.expander(f"{summary['ticker']} Summary"):
                    ticker = summary['ticker']
                    avg_entry = summary['avg_entry_price']
                    current_price = current_prices.get(ticker)
                    total_shares = summary['total_shares']
                    position_value = avg_entry * total_shares
                    
                    col1, col2 = st.columns(2)
                    with col1:
                        st.metric("Total Shares", f"{total_shares:,}")
                        st.metric("Average Entry", f"${avg_entry:.2f}")
                        st.metric("Position Value", f"${position_value:.2f}")
                    
                    with col2:
                        if current_price:
                            current_value = current_price * total_shares
                            paper_pl = (current_price - avg_entry) * total_shares
                            pl_percentage = (paper_pl / position_value) * 100
                            
                            st.metric("Current Price", f"${current_price:.2f}")
                            st.metric("Paper P/L", f"${paper_pl:.2f}", f"{pl_percentage:.2f}%")
                            
                            total_portfolio_value += current_value
                            total_paper_pl += paper_pl
            
            if total_portfolio_value > 0:
                st.markdown("---")
                st.subheader("Portfolio Summary")
                col1, col2 = st.columns(2)
                with col1:
                    st.metric("Total Portfolio Value", f"${total_portfolio_value:.2f}")
                with col2:
                    st.metric("Total P/L", f"${total_paper_pl:.2f}", 
                             f"{(total_paper_pl / (total_portfolio_value - total_paper_pl)) * 100:.2f}%")
    
    with tab2:
        st.subheader("Add New Trade")
        
        ticker = st.text_input("Ticker Symbol").upper()
        
        # Add direction selection
        direction = st.selectbox(
            "Direction",
            ["Buy", "Sell"],
            key="trade_direction"
        )
        
        if ticker:
            # Show existing positions for this ticker
            existing_positions = get_position_summary(ticker)
            if existing_positions:
                st.write(f"Existing {ticker} Positions:")
                for pos in existing_positions:
                    st.write(f"Position ID: {pos['position_id']}")
                    st.write(f"Total Shares: {pos['total_shares']}")
                    st.write(f"Average Entry: ${pos['avg_entry_price']:.2f}")
                
                if direction == "Sell":
                    position_id = st.selectbox(
                        "Select Position to Exit",
                        options=[pos['position_id'] for pos in existing_positions],
                        key="position_select"
                    )
                else:  # Buy
                    add_to_existing = st.checkbox("Add to existing position")
                    if add_to_existing:
                        position_id = st.selectbox(
                            "Select Position ID",
                            options=[pos['position_id'] for pos in existing_positions],
                            key="position_select"
                        )
                    else:
                        position_id = generate_position_id(ticker)
            else:
                if direction == "Sell":
                    st.error("No existing positions found for this ticker")
                    st.stop()
                position_id = generate_position_id(ticker)
        
            col1, col2 = st.columns(2)
            with col1:
                shares = st.number_input("Number of Shares", min_value=1, step=1)
                if direction == "Buy":
                    entry_price = st.number_input("Entry Price", min_value=0.01, step=0.01)
                else:
                    entry_price = st.number_input("Exit Price", min_value=0.01, step=0.01)
            
            with col2:
                if direction == "Buy":
                    target_price = st.number_input("Target Price", min_value=0.01, step=0.01)
                    stop_loss = st.number_input("Stop Loss", min_value=0.01, step=0.01)
                    strategy = st.text_input("Strategy")
                else:
                    exit_reason = st.text_area("Exit Reason", key="exit_reason")
                
                order_type = st.selectbox("Order Type", ["Market", "Limit"], key="add_trade_order_type")
            
            entry_date = st.date_input("Entry Date")
            entry_time = st.time_input("Entry Time")
            
            if direction == "Buy":
                followed_rules = st.checkbox("Followed Trading Rules")
                entry_reason = st.text_area("Entry Reason", key="add_trade_reason")
            
            notes = st.text_area("Notes", key="add_trade_notes")
            
            if st.button("Add Trade"):
                try:
                    entry_datetime = datetime.combine(entry_date, entry_time)
                    entry_datetime = pytz.timezone('US/Pacific').localize(entry_datetime)
                    
                    trade = TradeEntry(
                        ticker=ticker,
                        entry_date=entry_datetime,
                        shares=shares,
                        entry_price=entry_price,
                        target_price=target_price if direction == "Buy" else None,
                        stop_loss=stop_loss if direction == "Buy" else None,
                        strategy=strategy if direction == "Buy" else None,
                        order_type=order_type,
                        position_id=position_id,
                        followed_rules=followed_rules if direction == "Buy" else None,
                        entry_reason=entry_reason if direction == "Buy" else None,
                        exit_reason=exit_reason if direction == "Sell" else None,
                        notes=notes,
                        direction=direction.lower()
                    )
                    
                    add_trade(trade)
                    st.success("Trade added successfully!")
                    st.query_params(rerun=True)
                except Exception as e:
                    st.error(f"Error adding trade: {str(e)}")
    
    with tab3:
        st.subheader("Update Trade")
        open_trades = get_open_trades()
        
        if open_trades:
            trade_id = st.selectbox(
                "Select Trade to Update",
                options=[t['id'] for t in open_trades],
                format_func=lambda x: f"{next(t['ticker'] for t in open_trades if t['id'] == x)} - {x}",
                key="trade_select"
            )
            
            trade = next(t for t in open_trades if t['id'] == trade_id)
            
            col1, col2 = st.columns(2)
            with col1:
                new_shares = st.number_input("Shares", value=trade['shares'])
                new_entry = st.number_input("Entry Price", value=float(trade['entry_price']))
                new_target = st.number_input("Target Price", value=float(trade['target_price']))
            
            with col2:
                new_stop = st.number_input("Stop Loss", value=float(trade['stop_loss']))
                new_strategy = st.text_input("Strategy", value=trade['strategy'])
                new_order_type = st.selectbox("Order Type", ["Market", "Limit"], 
                                            index=0 if trade['order_type'] == "Market" else 1,
                                            key="update_trade_order_type")
            
            # Add date and time fields
            entry_date = st.date_input(
                "Entry Date", 
                value=trade['entry_date'].date(),
                key="update_entry_date"
            )
            entry_time = st.time_input(
                "Entry Time", 
                value=trade['entry_date'].time(),
                key="update_entry_time"
            )
            
            new_notes = st.text_area("Notes", 
                                    value=trade['notes'] if trade['notes'] else "",
                                    key="update_trade_notes")
            
            if st.button("Update Trade"):
                try:
                    # Combine date and time into datetime
                    entry_datetime = datetime.combine(entry_date, entry_time)
                    entry_datetime = pytz.timezone('US/Pacific').localize(entry_datetime)
                    
                    updates = {
                        'entry_date': entry_datetime,
                        'shares': new_shares,
                        'entry_price': new_entry,
                        'target_price': new_target,
                        'stop_loss': new_stop,
                        'strategy': new_strategy,
                        'order_type': new_order_type,
                        'notes': new_notes
                    }
                    
                    update_trade(trade_id, updates)
                    st.success("Trade updated successfully!")
                    st.query_params(rerun=True)
                except Exception as e:
                    st.error(f"Error updating trade: {str(e)}")
        else:
            st.info("No open trades to update")
    
    with tab4:
        st.subheader("Trade History")
        history = get_trade_history()
        
        if history:
            # Add P/L chart
            fig = plot_trade_history(history)
            if fig:
                st.plotly_chart(fig, use_container_width=True)
            
            for trade in history:
                with st.expander(f"{trade['ticker']} - {format_datetime(trade['entry_date'])}"):
                    profit_loss = (trade['exit_price'] - trade['entry_price']) * trade['shares'] if trade['exit_price'] else None
                    
                    col1, col2 = st.columns(2)
                    with col1:
                        st.metric("Entry Price", f"${trade['entry_price']:.2f}")
                        st.metric("Shares", trade['shares'])
                        if profit_loss:
                            st.metric("P/L", f"${profit_loss:.2f}")
                    
                    with col2:
                        if trade['exit_price']:
                            st.metric("Exit Price", f"${trade['exit_price']:.2f}")
                            st.metric("Exit Date", format_datetime(trade['exit_date']))
                    
                    st.text(f"Strategy: {trade['strategy']}")
                    if trade['notes']:
                        st.text(f"Notes: {trade['notes']}")
        else:
            st.info("No trade history found")