"""Tests for RSTExporter"""

# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.

import io
import re

import nbformat
from nbformat import v4

from .base import ExportersTestsBase
from ..rst import RSTExporter
from ...tests.utils import onlyif_cmds_exist


class TestRSTExporter(ExportersTestsBase):
    """Tests for RSTExporter"""

    exporter_class = RSTExporter
    should_include_raw = ['rst']

    def test_constructor(self):
        """
        Can a RSTExporter be constructed?
        """
        RSTExporter()


    @onlyif_cmds_exist('pandoc')
    def test_export(self):
        """
        Can a RSTExporter export something?
        """
        (output, resources) = RSTExporter().from_filename(self._get_notebook())
        assert len(output) > 0

    @onlyif_cmds_exist('pandoc')
    def test_empty_code_cell(self):
        """No empty code cells in rst"""
        nbname = self._get_notebook()
        with io.open(nbname, encoding='utf8') as f:
            nb = nbformat.read(f, 4)

        exporter = self.exporter_class()

        (output, resources) = exporter.from_notebook_node(nb)
        # add an empty code cell
        nb.cells.append(
            v4.new_code_cell(source="")
        )
        (output2, resources) = exporter.from_notebook_node(nb)
        # adding an empty code cell shouldn't change output
        self.assertEqual(output.strip(), output2.strip())

    @onlyif_cmds_exist('pandoc')
    def test_png_metadata(self):
        """
        Does RSTExporter treat pngs with width/height metadata correctly?
        """
        (output, resources) = RSTExporter().from_filename(
            self._get_notebook(nb_name="pngmetadata.ipynb"))
        assert len(output) > 0
        check_for_png = re.compile(
            r'.. image::.*?\n\s+(.*?)\n\s*\n',
            re.DOTALL)
        result = check_for_png.search(output)
        assert result is not None
        attr_string = result.group(1)
        assert ':width:' in attr_string
        assert ':height:' in attr_string
        assert 'px' in attr_string
