# 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 mercurial import demandimport

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

from mercurial import util, encoding

from pygments import highlight

from pygments.util import ClassNotFound

from pygments.lexers import guess_lexer, guess_lexer_for_filename, TextLexer

from pygments.formatters import HtmlFormatter

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

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

def pygmentize(field, fctx, style, tmpl):

    # 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

    # 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])

    except (ClassNotFound, ValueError):

        try:

            lexer = guess_lexer(text[:1024])

        except (ClassNotFound, ValueError):

            lexer = TextLexer()

    formatter = HtmlFormatter(style=style)

    colorized = highlight(text, lexer, formatter)

    # strip wrapping div

    colorized = colorized[:colorized.find('\n</pre>')]

    colorized = colorized[colorized.find('<pre>')+5:]

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

                 for s in colorized.splitlines())

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

    oldl = tmpl.cache[field]

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

    tmpl.cache[field] = newl