"""
File upload component
"""

import dash
from dash import dcc, html
import dash_bootstrap_components as dbc


def create_upload_component():
    """
    Create the file upload component with drag-and-drop

    Returns:
        Dash component
    """
    return dbc.Card([
        dbc.CardHeader(html.H5("Data Input", className="mb-0")),
        dbc.CardBody([
            dcc.Upload(
                id='upload-data',
                children=html.Div([
                    html.I(className="fas fa-cloud-upload-alt fa-3x mb-3"),
                    html.H5('Drag and Drop or Click to Select File'),
                    html.P('Supported formats: CSV, Excel (max 100MB)', className='text-muted')
                ]),
                style={
                    'width': '100%',
                    'height': '150px',
                    'lineHeight': '150px',
                    'borderWidth': '2px',
                    'borderStyle': 'dashed',
                    'borderRadius': '10px',
                    'textAlign': 'center',
                    'backgroundColor': '#f8f9fa'
                },
                multiple=False
            ),
            html.Div(id='upload-status', className='mt-3'),
        ])
    ], className='mb-4')


def create_column_selector():
    """
    Create column mapping dropdowns with support for multivariate and covariate-informed forecasting

    Returns:
        Dash component
    """
    return dbc.Card([
        dbc.CardHeader(html.H5("Data Configuration", className="mb-0")),
        dbc.CardBody([
            # Forecasting Mode Selector
            dbc.Row([
                dbc.Col([
                    dbc.Label("Forecasting Mode", className="fw-bold"),
                    dcc.RadioItems(
                        id='forecasting-mode',
                        options=[
                            {'label': ' Univariate (Single target)', 'value': 'univariate'},
                            {'label': ' Multivariate (Multiple targets)', 'value': 'multivariate'},
                            {'label': ' Covariate-informed (With external variables)', 'value': 'covariate'}
                        ],
                        value='univariate',
                        className='mt-2',
                        labelStyle={'display': 'block', 'marginBottom': '8px'}
                    ),
                    html.Small("Chronos-2 supports all three modes with zero-shot learning",
                              className='text-muted')
                ], md=12),
            ], className='mb-3'),

            html.Hr(),

            # Column Selection
            dbc.Row([
                dbc.Col([
                    dbc.Label("Date/Timestamp Column"),
                    dcc.Dropdown(
                        id='date-column-dropdown',
                        placeholder='Select date column...',
                        clearable=False
                    )
                ], md=4),
                dbc.Col([
                    dbc.Label("Target Variable(s)"),
                    dcc.Dropdown(
                        id='target-column-dropdown',
                        placeholder='Select target column(s)...',
                        clearable=False,
                        multi=True  # Enable multi-select
                    ),
                    html.Small(id='target-help-text', className='text-muted')
                ], md=4),
                dbc.Col([
                    dbc.Label("ID Column (Optional)"),
                    dcc.Dropdown(
                        id='id-column-dropdown',
                        placeholder='Select ID column (optional)...',
                        clearable=True
                    ),
                    html.Small("For multiple time series", className='text-muted')
                ], md=4),
            ], className='mb-3'),

            # Covariate Selection (shown only for covariate-informed mode)
            html.Div([
                dbc.Row([
                    dbc.Col([
                        dbc.Label("Covariate Columns"),
                        dcc.Dropdown(
                            id='covariate-columns-dropdown',
                            placeholder='Select covariate column(s)...',
                            clearable=True,
                            multi=True
                        ),
                        html.Small("External variables that may influence the forecast",
                                  className='text-muted')
                    ], md=12),
                ], className='mb-3'),
            ], id='covariate-section', style={'display': 'none'}),

            html.Hr(),
            html.Div(id='data-preview-container', className='mt-3'),
            html.Div(id='data-quality-report', className='mt-3')
        ])
    ], className='mb-4', id='column-selector-card', style={'display': 'none'})


def create_sample_data_loader():
    """
    Create sample data loader component

    Returns:
        Dash component
    """
    return dbc.Card([
        dbc.CardBody([
            html.H6("Quick Start with Sample Data"),
            dbc.Row([
                dbc.Col([
                    dbc.Button(
                        "Weather Stations",
                        id='load-weather',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
                dbc.Col([
                    dbc.Button(
                        "Air Quality UCI",
                        id='load-airquality',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
                dbc.Col([
                    dbc.Button(
                        "Bitcoin Price",
                        id='load-bitcoin',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
            ]),
            dbc.Row([
                dbc.Col([
                    dbc.Button(
                        "S&P 500 Stock",
                        id='load-stock',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
                dbc.Col([
                    dbc.Button(
                        "Traffic Speeds",
                        id='load-traffic',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
                dbc.Col([
                    dbc.Button(
                        "Electricity Consumption",
                        id='load-electricity',
                        color='outline-primary',
                        size='sm',
                        className='w-100 mb-2'
                    ),
                ], md=4),
            ]),
        ])
    ], className='mb-4')


def format_upload_status(status: str, message: str, is_error: bool = False):
    """
    Format upload status message

    Args:
        status: Status type ('success', 'error', 'info')
        message: Message to display
        is_error: Whether this is an error message

    Returns:
        Dash component
    """
    if is_error or status == 'error':
        return dbc.Alert([
            html.I(className="fas fa-exclamation-circle me-2"),
            message
        ], color='danger', dismissable=True)
    elif status == 'success':
        return dbc.Alert([
            html.I(className="fas fa-check-circle me-2"),
            message
        ], color='success', dismissable=True)
    elif status == 'warning':
        return dbc.Alert([
            html.I(className="fas fa-exclamation-triangle me-2"),
            message
        ], color='warning', dismissable=True)
    else:
        return dbc.Alert([
            html.I(className="fas fa-info-circle me-2"),
            message
        ], color='info', dismissable=True)


def create_data_preview_table(df, n_rows=10):
    """
    Create a data preview table

    Args:
        df: DataFrame to preview
        n_rows: Number of rows to show

    Returns:
        Dash component
    """
    if df is None or df.empty:
        return html.Div()

    return html.Div([
        html.H6("Data Preview"),
        dbc.Table.from_dataframe(
            df.head(n_rows),
            striped=True,
            bordered=True,
            hover=True,
            responsive=True,
            size='sm'
        ),
        html.P(
            f"Showing first {min(n_rows, len(df))} of {len(df)} rows",
            className='text-muted small'
        )
    ])


def create_quality_report(report: dict):
    """
    Create a data quality report display

    Args:
        report: Quality report dictionary

    Returns:
        Dash component
    """
    if not report:
        return html.Div()

    # Build warning messages if needed
    warnings = []
    if report.get('sampled', False):
        warnings.append(
            dbc.Alert(
                f"⚠️ Large dataset detected: Sampled from {report.get('original_points', 0):,} to {report.get('total_points', 0):,} rows (most recent data retained)",
                color="warning",
                className="mb-2"
            )
        )
    if report.get('duplicates_removed', 0) > 0:
        warnings.append(
            dbc.Alert(
                f"⚠️ Removed {report.get('duplicates_removed', 0):,} duplicate timestamps",
                color="info",
                className="mb-2"
            )
        )

    return dbc.Card([
        dbc.CardHeader(html.H6("Data Quality Report", className="mb-0")),
        dbc.CardBody([
            html.Div(warnings) if warnings else None,
            dbc.Row([
                dbc.Col([
                    html.Small("Total Points", className='text-muted'),
                    html.H6(f"{report.get('total_points', 0):,}")
                ], md=3),
                dbc.Col([
                    html.Small("Date Range", className='text-muted'),
                    html.H6(f"{report.get('date_range', {}).get('start', 'N/A')} to {report.get('date_range', {}).get('end', 'N/A')}",
                           style={'fontSize': '0.9rem'})
                ], md=3),
                dbc.Col([
                    html.Small("Frequency", className='text-muted'),
                    html.H6(report.get('frequency', 'Unknown'))
                ], md=2),
                dbc.Col([
                    html.Small("Missing Filled", className='text-muted'),
                    html.H6(str(report.get('missing_filled', 0)))
                ], md=2),
                dbc.Col([
                    html.Small("Outliers", className='text-muted'),
                    html.H6(str(report.get('outliers_detected', 0)))
                ], md=2),
            ]),
            html.Hr(),
            dbc.Row([
                dbc.Col([
                    html.Small("Mean", className='text-muted'),
                    html.P(f"{report.get('statistics', {}).get('mean', 0):.2f}")
                ], md=3),
                dbc.Col([
                    html.Small("Std Dev", className='text-muted'),
                    html.P(f"{report.get('statistics', {}).get('std', 0):.2f}")
                ], md=3),
                dbc.Col([
                    html.Small("Min", className='text-muted'),
                    html.P(f"{report.get('statistics', {}).get('min', 0):.2f}")
                ], md=3),
                dbc.Col([
                    html.Small("Max", className='text-muted'),
                    html.P(f"{report.get('statistics', {}).get('max', 0):.2f}")
                ], md=3),
            ])
        ])
    ], className='mt-3')