# highlight.py - highlight extension implementation file

#

#  Copyright 2007-2009 Adam Hupp <adam@hupp.org> and others

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

#

# The original module was split in an interface and an implementation

# file to defer pygments loading and speedup extension setup.

from __future__ import absolute_import

import pygments

import pygments.formatters

import pygments.lexers

import pygments.util

from mercurial import demandimport

demandimport.ignore.extend(['pkgutil', 'pkg_resources', '__main__'])

from mercurial import (

    encoding,

    util,

)

highlight = pygments.highlight

ClassNotFound = pygments.util.ClassNotFound

guess_lexer = pygments.lexers.guess_lexer

guess_lexer_for_filename = pygments.lexers.guess_lexer_for_filename

TextLexer = pygments.lexers.TextLexer

HtmlFormatter = pygments.formatters.HtmlFormatter

SYNTAX_CSS = ('\n<link rel="stylesheet" href="{url}highlightcss" '

              'type="text/css" />')

def pygmentize(field, fctx, style, tmpl, guessfilenameonly=False):

    # append a <link ...> to the syntax highlighting css

    old_header = tmpl.load('header')

    if SYNTAX_CSS not in old_header:

        new_header = old_header + SYNTAX_CSS

        tmpl.cache['header'] = new_header

    text = fctx.data()

    if util.binary(text):

        return

    # str.splitlines() != unicode.splitlines() because "reasons"

    for c in "\x0c\x1c\x1d\x1e":

        if c in text:

            text = text.replace(c, '')

    # Pygments is best used with Unicode strings:

    # <http://pygments.org/docs/unicode/>

    text = text.decode(encoding.encoding, 'replace')

    # To get multi-line strings right, we can't format line-by-line

    try:

        lexer = guess_lexer_for_filename(fctx.path(), text[:1024],

                                         stripnl=False)

    except (ClassNotFound, ValueError):

        # guess_lexer will return a lexer if *any* lexer matches. There is

        # no way to specify a minimum match score. This can give a high rate of

        # false positives on files with an unknown filename pattern.

        if guessfilenameonly:

            return

        try:

            lexer = guess_lexer(text[:1024], stripnl=False)

        except (ClassNotFound, ValueError):

            # Don't highlight unknown files

            return

    # Don't highlight text files

    if isinstance(lexer, TextLexer):

        return

    formatter = HtmlFormatter(nowrap=True, style=style)

    colorized = highlight(text, lexer, formatter)

    coloriter = (s.encode(encoding.encoding, 'replace')

                 for s in colorized.splitlines())

    tmpl.filters['colorize'] = lambda x: next(coloriter)

    oldl = tmpl.cache[field]

    newl = oldl.replace('line|escape', 'line|colorize')

    tmpl.cache[field] = newl