"""
Custom Dash components for the interactive visualizer.

This module provides reusable UI components including the side panel,
navigation controls, and chart containers.
"""

from dash import html, dcc
import dash_bootstrap_components as dbc
import plotly.graph_objects as go
from plotly.subplots import make_subplots


def create_side_panel():
    """
    Create the side panel component for displaying hover information and controls.
    
    Returns:
        dash component: Side panel layout
    """
    return dbc.Card([
        dbc.CardHeader("Chart Information"),
        dbc.CardBody([
            html.Div(id="hover-info", children=[
                html.P("Hover over charts to see detailed information")
            ]),
            html.Hr(),
            html.Div([
                dbc.Button("Reset CVD", id="reset-cvd-btn", color="primary", className="me-2"),
                dbc.Button("Reset Zoom", id="reset-zoom-btn", color="secondary"),
            ])
        ])
    ], style={"height": "100vh"})


def create_chart_container():
    """
    Create the main chart container for the 4-subplot layout.
    
    Returns:
        dash component: Chart container with 4-subplot layout
    """
    return dcc.Graph(
        id="main-charts",
        figure=create_empty_subplot_layout(),
        style={"height": "100vh"},
        config={
            "displayModeBar": True,
            "displaylogo": False,
            "modeBarButtonsToRemove": ["select2d", "lasso2d"],
            "modeBarButtonsToAdd": ["resetScale2d"],
            "scrollZoom": True,  # Enable mouse wheel zooming
            "doubleClick": "reset+autosize"  # Double-click to reset zoom
        }
    )


def create_empty_subplot_layout():
    """
    Create empty 4-subplot layout matching existing visualizer structure.
    
    Returns:
        plotly.graph_objects.Figure: Empty figure with 4 subplots
    """
    fig = make_subplots(
        rows=4, cols=1,
        shared_xaxes=True,
        subplot_titles=["OHLC", "Volume", "Order Book Imbalance (OBI)", "Cumulative Volume Delta (CVD)"],
        vertical_spacing=0.02
    )
    
    # Configure layout to match existing styling
    fig.update_layout(
        height=800,
        showlegend=False,
        margin=dict(l=50, r=50, t=50, b=50),
        template="plotly_dark",  # Professional dark theme
        paper_bgcolor='rgba(0,0,0,0)',  # Transparent background
        plot_bgcolor='rgba(0,0,0,0)'    # Transparent plot area
    )
    
    # Configure synchronized zooming and panning
    configure_synchronized_axes(fig)
    
    return fig


def configure_synchronized_axes(fig):
    """
    Configure synchronized zooming and panning across all subplots.
    
    Args:
        fig: Plotly figure with subplots
    """
    # Enable dragmode for panning and zooming
    fig.update_layout(
        dragmode='zoom',
        selectdirection='h'  # Restrict selection to horizontal for time-based data
    )
    
    # Configure X-axes for synchronized behavior (already shared via make_subplots)
    # All subplots will automatically share zoom/pan on X-axis due to shared_xaxes=True
    
    # Configure individual Y-axes for better UX
    fig.update_yaxes(fixedrange=False, gridcolor='rgba(128,128,128,0.2)')  # Allow Y-axis zooming
    fig.update_xaxes(fixedrange=False, gridcolor='rgba(128,128,128,0.2)')  # Allow X-axis zooming
    
    # Enable crosshair cursor spanning all charts
    fig.update_layout(hovermode='x unified')
    fig.update_traces(hovertemplate='<extra></extra>')  # Clean hover labels
    
    return fig


def add_ohlc_trace(fig, ohlc_data: dict):
    """
    Add OHLC candlestick trace to the first subplot.
    
    Args:
        fig: Plotly figure with subplots
        ohlc_data: Dict with x, open, high, low, close arrays
    """
    candlestick = go.Candlestick(
        x=ohlc_data["x"],
        open=ohlc_data["open"],
        high=ohlc_data["high"], 
        low=ohlc_data["low"],
        close=ohlc_data["close"],
        name="OHLC"
    )
    
    fig.add_trace(candlestick, row=1, col=1)
    return fig


def add_volume_trace(fig, volume_data: dict):
    """
    Add Volume bar trace to the second subplot.
    
    Args:
        fig: Plotly figure with subplots
        volume_data: Dict with x (timestamps) and y (volumes) arrays
    """
    volume_bar = go.Bar(
        x=volume_data["x"],
        y=volume_data["y"],
        name="Volume",
        marker_color='rgba(158, 185, 243, 0.7)',  # Blue with transparency
        showlegend=False,
        hovertemplate="Volume: %{y}<extra></extra>"
    )
    
    fig.add_trace(volume_bar, row=2, col=1)
    return fig


def add_obi_trace(fig, obi_data: dict):
    """
    Add OBI line trace to the third subplot.
    
    Args:
        fig: Plotly figure with subplots
        obi_data: Dict with timestamp and obi arrays
    """
    obi_line = go.Scatter(
        x=obi_data["timestamp"],
        y=obi_data["obi"],
        mode='lines',
        name="OBI",
        line=dict(color='blue', width=2),
        showlegend=False,
        hovertemplate="OBI: %{y:.3f}<extra></extra>"
    )
    
    # Add horizontal reference line at y=0
    fig.add_hline(y=0, line=dict(color='gray', dash='dash', width=1), row=3, col=1)
    fig.add_trace(obi_line, row=3, col=1)
    return fig


def add_cvd_trace(fig, cvd_data: dict):
    """
    Add CVD line trace to the fourth subplot.
    
    Args:
        fig: Plotly figure with subplots
        cvd_data: Dict with timestamp and cvd arrays
    """
    cvd_line = go.Scatter(
        x=cvd_data["timestamp"],
        y=cvd_data["cvd"],
        mode='lines',
        name="CVD",
        line=dict(color='red', width=2),
        showlegend=False,
        hovertemplate="CVD: %{y:.1f}<extra></extra>"
    )
    
    fig.add_trace(cvd_line, row=4, col=1)
    return fig


def create_populated_chart(ohlc_data, metrics_data):
    """
    Create a chart container with real data populated.
    
    Args:
        ohlc_data: List of OHLC tuples or None
        metrics_data: List of Metric objects or None
        
    Returns:
        dcc.Graph component with populated data
    """
    from data_adapters import format_ohlc_for_plotly, format_volume_for_plotly, format_metrics_for_plotly
    
    # Create base subplot layout
    fig = create_empty_subplot_layout()
    
    # Add real data if available
    if ohlc_data:
        # Format OHLC data
        ohlc_formatted = format_ohlc_for_plotly(ohlc_data)
        volume_formatted = format_volume_for_plotly(ohlc_data)
        
        # Add OHLC trace
        fig = add_ohlc_trace(fig, ohlc_formatted)
        
        # Add Volume trace
        fig = add_volume_trace(fig, volume_formatted)
    
    if metrics_data:
        # Format metrics data
        metrics_formatted = format_metrics_for_plotly(metrics_data)
        
        # Add OBI and CVD traces
        if metrics_formatted["obi"]["x"]:  # Check if we have OBI data
            obi_data = {
                "timestamp": metrics_formatted["obi"]["x"],
                "obi": metrics_formatted["obi"]["y"]
            }
            fig = add_obi_trace(fig, obi_data)
        if metrics_formatted["cvd"]["x"]:  # Check if we have CVD data
            cvd_data = {
                "timestamp": metrics_formatted["cvd"]["x"],
                "cvd": metrics_formatted["cvd"]["y"]
            }
            fig = add_cvd_trace(fig, cvd_data)
    
    return dcc.Graph(
        id="main-charts",
        figure=fig,
        style={"height": "100vh"},
        config={
            "displayModeBar": True,
            "displaylogo": False,
            "modeBarButtonsToRemove": ["select2d", "lasso2d"],
            "modeBarButtonsToAdd": ["pan2d", "zoom2d", "zoomIn2d", "zoomOut2d", "resetScale2d"],
            "scrollZoom": True,
            "doubleClick": "reset+autosize"
        }
    )