from collections import defaultdict
from matplotlib.font_manager import FontProperties
from matplotlib.table import Table as mpl_Table

import param

from ..element import ItemTable, Table
from .element import ElementPlot
from ..core.options import Store
from ..core.util import safe_unicode


class TablePlot(ElementPlot):
    """
    A TablePlot can plot both TableViews and ViewMaps which display
    as either a single static table or as an animated table
    respectively.
    """

    border = param.Number(default=0.05, bounds=(0.0, 0.5), doc="""
        The fraction of the plot that should be empty around the
        edges.""")

    float_precision = param.Integer(default=3, doc="""
        The floating point precision to use when printing float
        numeric data types.""")

    max_value_len = param.Integer(default=20, doc="""
        The maximum allowable string length of a value shown in any
        table cell. Any strings longer than this length will be
        truncated.""")

    max_font_size = param.Integer(default=12, doc="""
        The largest allowable font size for the text in each table
        cell.""")

    max_rows = param.Integer(default=15, doc="""
        The maximum number of Table rows before the table is
        summarized.""")

    font_types = param.Dict(default={'heading': FontProperties(weight='bold',
                                                               family='DejaVu Sans')},
       doc="""The font style used for heading labels used for emphasis.""")

    style_opts = ['alpha', 'sketch_params']

    # Disable computing plot bounds from data.
    apply_databounds = False

    def __init__(self, table, **params):
        super(TablePlot, self).__init__(table, **params)
        self.cell_values = self._format_table()


    def _format_table(self):
        cell_values = defaultdict(dict)
        for key in self.keys:
            frame = self._get_frame(key)
            if frame is None:
                continue

            # Mapping from the cell coordinates to the dictionary key.
            summarize = frame.rows > self.max_rows
            half_rows = self.max_rows/2
            rows = min([self.max_rows, frame.rows])
            for row in range(rows):
                adjusted_row = row
                for col in range(frame.cols):
                    if summarize and row == half_rows:
                        cell_text = "..."
                    else:
                        if summarize and row > half_rows:
                            adjusted_row = (frame.rows - self.max_rows + row)
                        value = frame.pprint_cell(adjusted_row, col)
                        cell_text = self.pprint_value(value)
                    cell_values[key][(row, col)] = cell_text
        return cell_values


    def pprint_value(self, value):
        """
        Generate the pretty printed representation of a value for
        inclusion in a table cell.
        """
        if isinstance(value, float):
            formatter = '{:.%df}' % self.float_precision
            formatted = formatter.format(value)
        elif isinstance(value, str):
            formatted = safe_unicode(value)
        else:
            formatted = str(value)

        if len(formatted) > self.max_value_len:
            return formatted[:(self.max_value_len-3)]+'...'
        else:
            return formatted


    def __call__(self, ranges=None):
        element = self.map.last
        axis = self.handles['axis']

        axis.set_axis_off()
        size_factor = (1.0 - 2*self.border)
        table = mpl_Table(axis, bbox=[self.border, self.border,
                                      size_factor, size_factor])

        width = size_factor / element.cols
        height = size_factor / element.rows

        summarize = element.rows > self.max_rows
        half_rows = self.max_rows/2
        rows = min([self.max_rows, element.rows])
        for row in range(rows):
            adjusted_row = row
            for col in range(element.cols):
                if summarize and row > half_rows:
                    adjusted_row = (element.rows - self.max_rows + row)
                cell_value = self.cell_values[self.keys[-1]][(row, col)]
                cellfont = self.font_types.get(element.cell_type(adjusted_row,col), None)
                font_kwargs = dict(fontproperties=cellfont) if cellfont else {}
                table.add_cell(row, col, width, height, text=cell_value,  loc='center',
                               **font_kwargs)

        table.set_fontsize(self.max_font_size)
        table.auto_set_font_size(True)
        axis.add_table(table)

        self.handles['table'] = table

        return self._finalize_axis(self.keys[-1])


    def update_handles(self, axis, view, key, ranges=None):
        table = self.handles['table']

        for coords, cell in table.get_celld().items():
            value = self.cell_values[key][coords]
            cell.set_text_props(text=value)

        # Resize fonts across table as necessary
        table.set_fontsize(self.max_font_size)
        table.auto_set_font_size(True)

Store.registry.update({ItemTable: TablePlot,
                       Table: TablePlot})
