# coding: utf-8
"""Tests for conversions from markdown to other formats"""

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

import re
from copy import copy
from functools import partial

from ipython_genutils.py3compat import string_types

from ...tests.utils import onlyif_cmds_exist
from ...tests.base import TestsBase
from ..pandoc import convert_pandoc
from ..markdown import markdown2html

from jinja2 import Environment


class TestMarkdown(TestsBase):

    tests = [
        '*test',
        '**test',
        '*test*',
        '_test_',
        '__test__',
        '__*test*__',
        '**test**',
        '#test',
        '##test',
        'test\n----',
        'test [link](https://google.com/)',
    ]

    tokens = [
        '*test',
        '**test',
        'test',
        'test',
        'test',
        'test',
        'test',
        'test',
        'test',
        'test',
        ('test', 'https://google.com/'),
    ]

    @onlyif_cmds_exist('pandoc')
    def test_markdown2latex(self):
        """markdown2latex test"""
        for index, test in enumerate(self.tests):
            self._try_markdown(
                partial(
                    convert_pandoc, from_format='markdown', to_format='latex'),
                test, self.tokens[index])

    @onlyif_cmds_exist('pandoc')
    def test_markdown2latex_markup(self):
        """markdown2latex with markup kwarg test"""
        # This string should be passed through unaltered with pandoc's
        # markdown_strict reader
        s = '1) arabic number with parenthesis'
        self.assertEqual(convert_pandoc(s, 'markdown_strict', 'latex'), s)
        # This string should be passed through unaltered with pandoc's
        # markdown_strict+tex_math_dollars reader
        s = r'$\alpha$ latex math'
        # sometimes pandoc uses $math$, sometimes it uses \(math\)
        expected = re.compile(r'(\$|\\\()\\alpha(\$|\\\)) latex math')
        try:
            # py3
            assertRegex = self.assertRegex
        except AttributeError:
            # py2
            assertRegex = self.assertRegexpMatches
        assertRegex(
            convert_pandoc(s, 'markdown_strict+tex_math_dollars', 'latex'),
            expected)

    @onlyif_cmds_exist('pandoc')
    def test_pandoc_extra_args(self):
        # pass --no-wrap
        s = '\n'.join([
            "#latex {{long_line | md2l(['--wrap=none'])}}",
            "#rst {{long_line | md2r(['--columns', '5'])}}",
        ])
        long_line = ' '.join(['long'] * 30)
        env = Environment()
        env.filters.update({
            'md2l': lambda code, extra_args: convert_pandoc(
                code, from_format='markdown', to_format='latex',
                extra_args=extra_args),
            'md2r': lambda code, extra_args: convert_pandoc(
                code, from_format='markdown', to_format='rst',
                extra_args=extra_args),
        })
        tpl = env.from_string(s)
        rendered = tpl.render(long_line=long_line)
        _, latex, rst = rendered.split('#')

        self.assertEqual(latex.strip(), 'latex %s' % long_line)
        self.assertEqual(rst.strip(), 'rst %s' % long_line.replace(' ', '\n'))

    def test_markdown2html(self):
        """markdown2html test"""
        for index, test in enumerate(self.tests):
            self._try_markdown(markdown2html, test, self.tokens[index])

    def test_markdown2html_heading_anchors(self):
        for md, tokens in [('# test', ('<h1', '>test', 'id="test"',
                                       u'&#182;</a>', "anchor-link")),
                           ('###test head space',
                            ('<h3', '>test head space', 'id="test-head-space"',
                             u'&#182;</a>', "anchor-link"))]:
            self._try_markdown(markdown2html, md, tokens)

    def test_markdown2html_math(self):
        # Mathematical expressions not containing <, >, &
        # should be passed through unaltered
        # all the "<", ">", "&" must be escaped correctly
        cases = [(
            "\\begin{equation*}\n" +
            ("\\left( \\sum_{k=1}^n a_k b_k \\right)^2 "
             "\\leq \\left( \\sum_{k=1}^n a_k^2 \\right) "
             "\\left( \\sum_{k=1}^n b_k^2 \\right)\n") +
            "\\end{equation*}"),
            ("$$\n"
             "a = 1 *3* 5\n"
             "$$"),
            "$ a = 1 *3* 5 $",
            "$s_i = s_{i}\n$",
            "$a<b&b<lt$",
            "$a<b&lt;b>a;a-b<0$",
            "$<k'>$",
            "$$a<b&b<lt$$",
            "$$a<b&lt;b>a;a-b<0$$",
            "$$<k'>$$",
            ("$$x\n"
             "=\n"
             "2$$"),
            ("$$\n"
             "b =  \\left[\n"
             "P\\left(\\right)\n"
             "- (l_1\\leftrightarrow l_2\n)"
             "\\right]\n"
             "$$"),
            ("\\begin{equation*}\n"
             "x = 2 *55* 7\n"
             "\\end{equation*}"),
            """$
\\begin{tabular}{ l c r }
  1 & 2 & 3 \\
  4 & 5 & 6 \\
  7 & 8 & 9 \\
\\end{tabular}$"""]

        for case in cases:
            result = markdown2html(case)
            # find the equation in the generated texts
            search_result = re.search(r"\$.*\$", result, re.DOTALL)
            if search_result is None:
                search_result = re.search(
                    "\\\\begin\\{equation.*\\}.*\\\\end\\{equation.*\\}",
                    result, re.DOTALL)
            math = search_result.group(0)
            # the resulting math part can not contain "<", ">" or
            # "&" not followed by "lt;", "gt;", or "amp;".
            self.assertNotIn("<", math)
            self.assertNotIn(">", math)
            # python 2.7 has assertNotRegexpMatches instead of assertNotRegex
            if not hasattr(self, 'assertNotRegex'):
                self.assertNotRegex = self.assertNotRegexpMatches
            self.assertNotRegex(math, "&(?![gt;|lt;|amp;])")
            # the result should be able to be unescaped correctly
            self.assertEquals(case, self._unescape(math))

    def test_markdown2html_math_mixed(self):
        """ensure markdown between inline and inline-block math works and
        test multiple LaTeX markup syntaxes.
        """
        case = """The entries of \\\\(C\\\\) are given by the exact formula:
$$
C_{ik} = \sum_{j=1}^n A_{ij} B_{jk},
$$
but you can _implement_ this computation in many ways.
$\approx 2mnp$ flops are needed for \\\\[ C_{ik} = \sum_{j=1}^n A_{ij} B_{jk} \\\\].
Also check empty math blocks work correctly:
$$$$
\\\\[\\\\]"""
        output_check = (case.replace("_implement_", "<em>implement</em>")
                            .replace("\\\\(", "$").replace("\\\\)", "$")
                            .replace("\\\\[", "$$").replace("\\\\]", "$$"))
        # these replacements are needed because we use $ and $$ in our html output
        self._try_markdown(markdown2html, case, output_check)

    def test_markdown2html_math_paragraph(self):
        """these should all parse without modification"""
        cases = [
            # https://github.com/ipython/ipython/issues/6724
            """Water that is stored in $t$, $s_t$, must equal the storage content of the previous stage,
$s_{t-1}$, plus a stochastic inflow, $I_t$, minus what is being released in $t$, $r_t$.
With $s_0$ defined as the initial storage content in $t=1$, we have""",
            # https://github.com/jupyter/nbviewer/issues/420
            """$C_{ik}$
$$
C_{ik} = \sum_{j=1}
$$
$C_{ik}$""",
            """$m$
$$
C = \begin{pmatrix}
          0 & 0 & 0 & \cdots & 0 & 0 & -c_0 \\
          0 & 0 & 0 & \cdots & 0 & 1 & -c_{m-1}
    \end{pmatrix}
$$
$x^m$""",
            """$r=\overline{1,n}$
$$ {\bf
b}_{i}^{r}(t)=(1-t)\,{\bf b}_{i}^{r-1}(t)+t\,{\bf b}_{i+1}^{r-1}(t),\:
 i=\overline{0,n-r}, $$
i.e. the $i^{th}$"""
        ]

        for case in cases:
            s = markdown2html(case)
            self.assertIn(case, self._unescape(s))

    @onlyif_cmds_exist('pandoc')
    def test_markdown2rst(self):
        """markdown2rst test"""

        #Modify token array for rst, escape asterisk
        tokens = copy(self.tokens)
        tokens[0] = r'\*test'
        tokens[1] = r'\**test'

        for index, test in enumerate(self.tests):
            self._try_markdown(
                partial(
                    convert_pandoc, from_format='markdown', to_format='rst'),
                test, tokens[index])

    def _try_markdown(self, method, test, tokens):
        results = method(test)
        if isinstance(tokens, string_types):
            self.assertIn(tokens, results)
        else:
            for token in tokens:
                self.assertIn(token, results)

    def _unescape(self, s):
        # undo cgi.escape() manually
        # We must be careful here for compatibility
        # html.unescape() is not availale on python 2.7
        # For more information, see:
        # https://wiki.python.org/moin/EscapingHtml
        s = s.replace("&lt;", "<")
        s = s.replace("&gt;", ">")
        s = s.replace("&amp;", "&")
        return s
