# -*- coding: utf-8 -*-
# -----------------------------------------------------------------------
# Copyright (c) 2009  Jendrik Seipp
#
# RedNotebook is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# RedNotebook is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with RedNotebook; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
# -----------------------------------------------------------------------

import logging
import os
import re
import sys

from gi.repository import GObject
from gi.repository import Pango

from rednotebook.external import txt2tags
from rednotebook.data import HASHTAG
from rednotebook.util import filesystem


# Linebreaks are only allowed at line ends
REGEX_LINEBREAK = r'\\\\[\s]*$'
REGEX_HTML_LINK = r'<a.*?>(.*?)</a>'

# pic [""/home/user/Desktop/RedNotebook pic"".png]
PIC_NAME = r'\S.*?\S|\S'
PIC_EXT = r'(?:png|jpe?g|gif|eps|bmp|svg)'
REGEX_PIC = re.compile(r'(\["")(%s)("")(\.%s)(\?\d+)?(\])' % (PIC_NAME, PIC_EXT), flags=re.I)

# named local link [my file.txt ""file:///home/user/my file.txt""]
# named link in web [heise ""http://heise.de""]
REGEX_NAMED_LINK = re.compile(r'(\[)(.*?)(\s"")(\S.*?\S)(""\])', flags=re.I)

ESCAPE_COLOR = r'XBEGINCOLORX\1XSEPARATORX\2XENDCOLORX'
COLOR_ESCAPED = r'XBEGINCOLORX(.*?)XSEPARATORX(.*?)XENDCOLORX'

TABLE_HEAD_BG = '#aaa'

CHARSET_UTF8 = '<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />'
PRINT_FUNCTION = '<script></script>'

CSS = """\
<style type="text/css">
    body {
        font-family: %(font)s;
    }
    <!-- Don't split last line between pages.
         This fix is only supported by Opera -->
    p {
        page-break-inside: avoid;
    }
    blockquote {
        margin: 1em 2em;
        border-left: 2px solid #999;
        font-style: oblique;
        padding-left: 1em;
    }
    blockquote:first-letter {
        margin: .2em .1em .1em 0;
        font-size: 160%%;
        font-weight: bold;
    }
    blockquote:first-line {
        font-weight: bold;
    }
    table {
        border-collapse: collapse;
    }
    td, th {
        <!--border: 1px solid #888;--> <!--Allow tables without borders-->
        padding: 3px 7px 2px 7px;
    }
    th {
        text-align: left;
        padding-top: 5px;
        padding-bottom: 4px;
        background-color: %(table_head_bg)s;
        color: #ffffff;
    }
    hr.heavy {
        height: 2px;
        background-color: black;
    }
</style>
"""

# MathJax
FORMULAS_SUPPORTED = True
MATHJAX_FILE = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js'

# Explicitly setting inlineMath: [ ['\\(','\\)'] ] doesn't work.
# Using defaults:
#       displayMath: [ ['$$','$$'], ['\[','\]'] ]
#       inlineMath:  [['\(','\)']]
MATHJAX_DELIMITERS = ['$$', '\\(', '\\)', r'\\[', '\\]']
MATHJAX = """\
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({{
    messageStyle: "none",
    config: ["MMLorHTML.js"],
    jax: ["input/TeX","input/MathML","output/HTML-CSS","output/NativeMML"],
    tex2jax: {{}},
    extensions: ["tex2jax.js","mml2jax.js","MathMenu.js","MathZoom.js"],
    TeX: {{
      extensions: ["AMSmath.js","AMSsymbols.js","noErrors.js","noUndefined.js"]
    }}
  }});
</script>
<script type="text/javascript" src="{MATHJAX_FILE}"></script>
""".format(**locals())


def convert_categories_to_markup(categories, with_category_title=True):
    # Only add Category title if the text is displayed
    if with_category_title:
        markup = '== %s ==\n' % _('Tags')
    else:
        markup = ''

    for category, entry_list in categories.items():
        markup += '- ' + category + '\n'
        for entry in entry_list:
            markup += '  - ' + entry + '\n'
    markup += '\n\n'
    return markup


def get_markup_for_day(day, with_text=True, with_tags=True, categories=None, date=None):
    '''
    Used for exporting days
    '''
    export_string = ''

    # Add date if it is not None and not the empty string
    if date:
        export_string += '= %s =\n\n' % date

    # Add text
    if with_text:
        export_string += day.text

    # Add Categories
    category_content_pairs = day.get_category_content_pairs()

    if with_tags and categories:
        categories = [word.lower() for word in categories]
        export_categories = dict((x, y) for (x, y) in category_content_pairs.items()
                                 if x.lower() in categories)
    elif with_tags and categories is None:
        # No restrictions
        export_categories = category_content_pairs
    else:
        # "Export no categories" selected
        export_categories = []

    if export_categories:
        export_string += '\n\n\n' + convert_categories_to_markup(
            export_categories, with_category_title=with_text)
    elif with_text:
        export_string += '\n\n'

    # Only return the string, when there is text or there are categories
    # We don't want to list empty dates
    if export_categories or with_text:
        export_string += '\n\n\n'
        return export_string

    return ''


def _get_config(target, options):

    config = {}

    # Set the configuration on the 'config' dict.
    config = txt2tags.ConfigMaster()._get_defaults()

    config['outfile'] = txt2tags.MODULEOUT  # results as list
    config['target'] = target

    # The Pre (and Post) processing config is a list of lists:
    # [ [this, that], [foo, bar], [patt, replace] ]
    config['postproc'] = []
    config['preproc'] = []
    config['style'] = []

    # Allow line breaks, r'\\\\' are 2 \ for regexes
    config['preproc'].append([REGEX_LINEBREAK, 'LINEBREAK'])

    # Highlight hashtags.
    if target == 'tex':
        config['preproc'].append([HASHTAG.pattern, r'\1{\2\3BEGININDEX\3ENDINDEX|color:red}'])
    else:
        config['preproc'].append([HASHTAG.pattern, r'\1{\2\3|color:red}'])

    # Escape color markup.
    config['preproc'].append([r'\{(.*?)\|color:(.+?)\}', ESCAPE_COLOR])

    if target in ['xhtml', 'html']:
        config['encoding'] = 'UTF-8'  # document encoding
        config['toc'] = 0
        config['css-sugar'] = 1

        # Fix encoding for export opened in firefox
        config['postproc'].append([r'<head>', '<head>' + CHARSET_UTF8])

        # Line breaks
        config['postproc'].append([r'LINEBREAK', '<br />'])

        # Apply image resizing
        config['postproc'].append([r'src=\"WIDTH(\d+)-', r'width="\1" src="'])

        # {{red text|color:red}} -> <span style="color:red">red text</span>
        config['postproc'].append([COLOR_ESCAPED, r'<span style="color:\2">\1</span>'])

    elif target == 'tex':
        config['encoding'] = 'utf8'
        config['preproc'].append(['€', 'Euro'])

        # Latex only allows whitespace and underscores in filenames if
        # the filename is surrounded by "...". This is in turn only possible
        # if the extension is omitted.
        config['preproc'].append([r'\[""', r'["""'])
        config['preproc'].append([r'""\.', r'""".'])

        scheme = 'file:///' if sys.platform == 'win32' else 'file://'

        # For images we have to omit the file:// prefix
        config['postproc'].append([r'includegraphics\{(.*)"%s' % scheme, r'includegraphics{"\1'])

        # Special handling for LOCAL file links (Omit scheme, add run:)
        # \htmladdnormallink{file.txt}{file:///home/user/file.txt}
        # -->
        # \htmladdnormallink{file.txt}{run:/home/user/file.txt}
        config['postproc'].append([r'htmladdnormallink\{(.*)\}\{%s(.*)\}' % scheme,
                                   r'htmladdnormallink{\1}{run:\2}'])

        # Line breaks
        config['postproc'].append([r'LINEBREAK', r'\\\\'])

        # Apply image resizing
        config['postproc'].append([r'includegraphics\{("?)WIDTH(\d+)-', r'includegraphics[width=\2px]{\1'])

        # We want the plain latex formulas unescaped.
        # Allowed formulas: $$...$$, \[...\], \(...\)
        config['preproc'].append([r'\\\[\s*(.+?)\s*\\\]', r"BEGINEQUATION''\1''ENDEQUATION"])
        config['preproc'].append([r'\$\$\s*(.+?)\s*\$\$', r"BEGINEQUATION''\1''ENDEQUATION"])
        config['postproc'].append([r'BEGINEQUATION(.+)ENDEQUATION', r'$$\1$$'])
        config['preproc'].append([r'\\\(\s*(.+?)\s*\\\)', r"BEGINMATH''\1''ENDMATH"])
        config['postproc'].append([r'BEGINMATH(.+)ENDMATH', r'$\1$'])

        # Fix utf8 quotations - „, “ and ” cause problems compiling the latex document.
        config['postproc'].extend([[u'„', '"'], [u'”', '"'], [u'“', '"']])

        # Enable index.
        config['style'].append('makeidx')
        config['postproc'].append([r'BEGININDEX(.+?)ENDINDEX', r'\\index{\1}'])
        config['postproc'].append(['begin{document}', 'makeindex\n\\\\begin{document}'])
        config['postproc'].append(['end{document}', 'printindex\n\n\\\\end{document}'])

        config['postproc'].append([COLOR_ESCAPED, r'\\textcolor{\2}{\1}'])

    elif target == 'txt':
        # Line breaks
        config['postproc'].append([r'LINEBREAK', '\n'])

        # Apply image resizing ([WIDTH400-file:///pathtoimage.jpg])
        config['postproc'].append([r'\[WIDTH(\d+)-(.+)\]', r'[\2?\1]'])

    # Allow resizing images by changing
    # [filename.png?width] to [WIDTHwidth-filename.png]
    img_ext = r'png|jpe?g|gif|eps|bmp|svg'
    img_name = r'\S.*\S|\S'

    # Apply this prepoc only after the latex image quotes have been added
    config['preproc'].append([r'\[(%s\.(%s))\?(\d+)\]' % (img_name, img_ext), r'[WIDTH\3-\1]'])

    # Disable colors for all other targets.
    config['postproc'].append([COLOR_ESCAPED, r'\1'])

    # MathJax
    if options.pop('add_mathjax'):
        config['postproc'].append([r'</body>', MATHJAX + '</body>'])

    config['postproc'].append([r'</body>', PRINT_FUNCTION + '</body>'])

    # Custom css
    fonts = options.pop('font', 'sans-serif')
    if 'html' in target:
        css = CSS % {'font': fonts, 'table_head_bg': TABLE_HEAD_BG}
        config['postproc'].append([r'</head>', css + '</head>'])

    config.update(options)

    return config


def _convert_paths(txt, data_dir):
    def _convert_uri(uri):
        path = uri[len('file://'):] if uri.startswith('file://') else uri
        # Check if relative file exists and convert it if it does.
        if (not any(uri.startswith(proto) for proto in filesystem.REMOTE_PROTOCOLS) and
                not os.path.isabs(path)):
            path = os.path.join(data_dir, path)
            assert os.path.isabs(path), path
            if os.path.exists(path):
                uri = filesystem.get_local_url(path)
        return uri

    def _convert_pic_path(match):
        uri = _convert_uri(match.group(2) + match.group(4))
        # Reassemble picture markup.
        name, ext = os.path.splitext(uri)
        parts = [match.group(1), name, match.group(3), ext]
        if match.group(5) is not None:
            parts.append(match.group(5))
        parts.append(match.group(6))
        return ''.join(parts)

    def _convert_file_path(match):
        uri = _convert_uri(match.group(4))
        # Reassemble link markup
        parts = [match.group(i) for i in range(1, 6)]
        parts[3] = uri
        return ''.join(parts)

    txt = REGEX_PIC.sub(_convert_pic_path, txt)
    txt = REGEX_NAMED_LINK.sub(_convert_file_path, txt)
    return txt


def convert(txt, target, data_dir, headers=None, options=None):
    '''
    Code partly taken from txt2tags tarball
    '''
    options = options or {}

    # Only add MathJax code if there is a formula.
    options['add_mathjax'] = (
        FORMULAS_SUPPORTED and
        'html' in target and
        any(x in txt for x in MATHJAX_DELIMITERS))
    logging.debug('Add mathjax code: %s' % options['add_mathjax'])

    # Turn relative paths into absolute paths.
    txt = _convert_paths(txt, data_dir)

    # The body text must be a list.
    txt = txt.split('\n')

    # Set the three header fields
    if headers is None:
        if target == 'tex':
            # LaTeX requires a title if \maketitle is used
            headers = ['RedNotebook', '', '']
        else:
            headers = ['', '', '']

    config = _get_config(target, options)

    # Let's do the conversion
    try:
        headers = txt2tags.doHeader(headers, config)
        body, toc = txt2tags.convert(txt, config)
        footer = txt2tags.doFooter(config)
        toc = txt2tags.toc_tagger(toc, config)
        toc = txt2tags.toc_formatter(toc, config)
        full_doc = headers + toc + body + footer
        finished = txt2tags.finish_him(full_doc, config)
        result = '\n'.join(finished)
    # Txt2tags error, show the messsage to the user
    except txt2tags.error as msg:
        logging.error(msg)
        result = msg
    # Unknown error, show the traceback to the user
    except Exception:
        result = (
            '<b>Error</b>: This day contains invalid '
            '<a href="http://txt2tags.org/markup.html">txt2tags markup</a>. '
            'You can help us fix this by submitting a bugreport in the '
            '<a href="https://code.google.com/p/txt2tags/issues/list">'
            'txt2tags bugtracker</a>. Please append the day\'s text to the issue.')
        logging.error('Invalid markup:\n%s' % txt2tags.getUnknownErrorMessage())
    return result


def convert_to_pango(txt, headers=None, options=None):
    '''
    Code partly taken from txt2tags tarball
    '''
    original_txt = txt

    # Here is the marked body text, it must be a list.
    txt = txt.split('\n')

    # Set the three header fields
    if headers is None:
        headers = ['', '', '']

    config = txt2tags.ConfigMaster()._get_defaults()

    config['outfile'] = txt2tags.MODULEOUT  # results as list
    config['target'] = 'xhtml'

    config['preproc'] = []
    # We need to escape the ampersand here, otherwise "&amp;" would become
    # "&amp;amp;"
    config['preproc'].append([r'&amp;', '&'])

    # Allow line breaks
    config['postproc'] = []
    config['postproc'].append([REGEX_LINEBREAK, '\n'])

    if options is not None:
        config.update(options)

    # Let's do the conversion
    try:
        body, toc = txt2tags.convert(txt, config)
        full_doc = body
        finished = txt2tags.finish_him(full_doc, config)
        result = ''.join(finished)

    # Txt2tags error, show the messsage to the user
    except txt2tags.error as msg:
        logging.error(msg)
        result = msg

    # Unknown error, show the traceback to the user
    except Exception:
        result = txt2tags.getUnknownErrorMessage()
        logging.error(result)

    # remove unwanted paragraphs
    result = result.replace('<p>', '').replace('</p>', '')

    logging.log(5, 'Converted "%s" text to "%s" txt2tags markup' %
                (repr(original_txt), repr(result)))

    # Remove unknown tags (<a>)
    def replace_links(match):
        """Return the link name."""
        return match.group(1)
    result = re.sub(REGEX_HTML_LINK, replace_links, result)

    try:
        Pango.parse_markup(result, -1, "0")
        # result is valid pango markup, return the markup.
        return result
    except GObject.GError:
        # There are unknown tags in the markup, return the original text
        logging.debug('There are unknown tags in the markup: %s' % result)
        return original_txt


def convert_from_pango(pango_markup):
    original_txt = pango_markup
    replacements = dict((
        ('<b>', '**'), ('</b>', '**'),
        ('<i>', '//'), ('</i>', '//'),
        ('<s>', '--'), ('</s>', '--'),
        ('<u>', '__'), ('</u>', '__'),
        ('&amp;', '&'),
        ('&lt;', '<'), ('&gt;', '>'),
        ('\n', r'\\'),
    ))
    for orig, repl in replacements.items():
        pango_markup = pango_markup.replace(orig, repl)

    logging.log(5, 'Converted "%s" pango to "%s" txt2tags' %
                (repr(original_txt), repr(pango_markup)))
    return pango_markup
