###############################################################################
#
# ChartScatter - A class for writing the Excel XLSX Scatter charts.
#
# Copyright 2013-2019, John McNamara, jmcnamara@cpan.org
#

from . import chart
from warnings import warn


class ChartScatter(chart.Chart):
    """
    A class for writing the Excel XLSX Scatter charts.


    """

    ###########################################################################
    #
    # Public API.
    #
    ###########################################################################

    def __init__(self, options=None):
        """
        Constructor.

        """
        super(ChartScatter, self).__init__()

        if options is None:
            options = {}

        self.subtype = options.get('subtype')

        if not self.subtype:
            self.subtype = 'marker_only'

        self.cross_between = 'midCat'
        self.horiz_val_axis = 0
        self.val_axis_position = 'b'
        self.smooth_allowed = True
        self.requires_category = True

        # Set the available data label positions for this chart type.
        self.label_position_default = 'right'
        self.label_positions = {
            'center': 'ctr',
            'right': 'r',
            'left': 'l',
            'above': 't',
            'below': 'b',
            # For backward compatibility.
            'top': 't',
            'bottom': 'b'}

    def combine(self, chart=None):
        """
        Create a combination chart with a secondary chart.

        Note: Override parent method to add a warning.

        Args:
            chart: The secondary chart to combine with the primary chart.

        Returns:
            Nothing.

        """
        if chart is None:
            return

        warn('Combined chart not currently supported with scatter chart '
             'as the primary chart')

    ###########################################################################
    #
    # Private API.
    #
    ###########################################################################

    def _write_chart_type(self, args):
        # Override the virtual superclass method with a chart specific method.
        # Write the c:scatterChart element.
        self._write_scatter_chart(args)

    ###########################################################################
    #
    # XML methods.
    #
    ###########################################################################

    def _write_scatter_chart(self, args):
        # Write the <c:scatterChart> element.

        if args['primary_axes']:
            series = self._get_primary_axes_series()
        else:
            series = self._get_secondary_axes_series()

        if not len(series):
            return

        style = 'lineMarker'
        subtype = self.subtype

        # Set the user defined chart subtype.
        if subtype == 'marker_only':
            style = 'lineMarker'

        if subtype == 'straight_with_markers':
            style = 'lineMarker'

        if subtype == 'straight':
            style = 'lineMarker'
            self.default_marker = {'type': 'none'}

        if subtype == 'smooth_with_markers':
            style = 'smoothMarker'

        if subtype == 'smooth':
            style = 'smoothMarker'
            self.default_marker = {'type': 'none'}

        # Add default formatting to the series data.
        self._modify_series_formatting()

        self._xml_start_tag('c:scatterChart')

        # Write the c:scatterStyle element.
        self._write_scatter_style(style)

        # Write the series elements.
        for data in series:
            self._write_ser(data)

        # Write the c:axId elements
        self._write_axis_ids(args)

        self._xml_end_tag('c:scatterChart')

    def _write_ser(self, series):
        # Over-ridden to write c:xVal/c:yVal instead of c:cat/c:val elements.
        # Write the <c:ser> element.

        index = self.series_index
        self.series_index += 1

        self._xml_start_tag('c:ser')

        # Write the c:idx element.
        self._write_idx(index)

        # Write the c:order element.
        self._write_order(index)

        # Write the series name.
        self._write_series_name(series)

        # Write the c:spPr element.
        self._write_sp_pr(series)

        # Write the c:marker element.
        self._write_marker(series.get('marker'))

        # Write the c:dPt element.
        self._write_d_pt(series.get('points'))

        # Write the c:dLbls element.
        self._write_d_lbls(series.get('labels'))

        # Write the c:trendline element.
        self._write_trendline(series.get('trendline'))

        # Write the c:errBars element.
        self._write_error_bars(series.get('error_bars'))

        # Write the c:xVal element.
        self._write_x_val(series)

        # Write the c:yVal element.
        self._write_y_val(series)

        # Write the c:smooth element.
        if 'smooth' in self.subtype and series['smooth'] is None:
            # Default is on for smooth scatter charts.
            self._write_c_smooth(True)
        else:
            self._write_c_smooth(series['smooth'])

        self._xml_end_tag('c:ser')

    def _write_plot_area(self):
        # Over-ridden to have 2 valAx elements for scatter charts instead
        # of catAx/valAx.
        #
        # Write the <c:plotArea> element.
        self._xml_start_tag('c:plotArea')

        # Write the c:layout element.
        self._write_layout(self.plotarea.get('layout'), 'plot')

        # Write the subclass chart elements for primary and secondary axes.
        self._write_chart_type({'primary_axes': 1})
        self._write_chart_type({'primary_axes': 0})

        # Write c:catAx and c:valAx elements for series using primary axes.
        self._write_cat_val_axis({'x_axis': self.x_axis,
                                  'y_axis': self.y_axis,
                                  'axis_ids': self.axis_ids,
                                  'position': 'b',
                                  })

        tmp = self.horiz_val_axis
        self.horiz_val_axis = 1

        self._write_val_axis({'x_axis': self.x_axis,
                              'y_axis': self.y_axis,
                              'axis_ids': self.axis_ids,
                              'position': 'l',
                              })

        self.horiz_val_axis = tmp

        # Write c:valAx and c:catAx elements for series using secondary axes
        self._write_cat_val_axis({'x_axis': self.x2_axis,
                                  'y_axis': self.y2_axis,
                                  'axis_ids': self.axis2_ids,
                                  'position': 'b',
                                  })
        self.horiz_val_axis = 1
        self._write_val_axis({'x_axis': self.x2_axis,
                              'y_axis': self.y2_axis,
                              'axis_ids': self.axis2_ids,
                              'position': 'l',
                              })

        # Write the c:spPr element for the plotarea formatting.
        self._write_sp_pr(self.plotarea)

        self._xml_end_tag('c:plotArea')

    def _write_x_val(self, series):
        # Write the <c:xVal> element.
        formula = series.get('categories')
        data_id = series.get('cat_data_id')
        data = self.formula_data[data_id]

        self._xml_start_tag('c:xVal')

        # Check the type of cached data.
        data_type = self._get_data_type(data)

        # TODO. Can a scatter plot have non-numeric data.
        if data_type == 'str':
            # Write the c:numRef element.
            self._write_str_ref(formula, data, data_type)
        else:
            # Write the c:numRef element.
            self._write_num_ref(formula, data, data_type)

        self._xml_end_tag('c:xVal')

    def _write_y_val(self, series):
        # Write the <c:yVal> element.
        formula = series.get('values')
        data_id = series.get('val_data_id')
        data = self.formula_data[data_id]

        self._xml_start_tag('c:yVal')

        # Unlike Cat axes data should only be numeric.
        # Write the c:numRef element.
        self._write_num_ref(formula, data, 'num')

        self._xml_end_tag('c:yVal')

    def _write_scatter_style(self, val):
        # Write the <c:scatterStyle> element.
        attributes = [('val', val)]

        self._xml_empty_tag('c:scatterStyle', attributes)

    def _modify_series_formatting(self):
        # Add default formatting to the series data unless it has already been
        # specified by the user.
        subtype = self.subtype

        # The default scatter style "markers only" requires a line type.
        if subtype == 'marker_only':

            # Go through each series and define default values.
            for series in self.series:

                # Set a line type unless there is already a user defined type.
                if not series['line']['defined']:
                    series['line'] = {'width': 2.25,
                                      'none': 1,
                                      'defined': 1,
                                      }

    def _write_d_pt_point(self, index, point):
        # Write an individual <c:dPt> element. Override the parent method to
        # add markers.

        self._xml_start_tag('c:dPt')

        # Write the c:idx element.
        self._write_idx(index)

        self._xml_start_tag('c:marker')

        # Write the c:spPr element.
        self._write_sp_pr(point)

        self._xml_end_tag('c:marker')

        self._xml_end_tag('c:dPt')
