#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
This file is part of the web2py Web Framework
Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu>
License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html)
"""

import re
import cgi

__all__ = ['highlight']


class Highlighter(object):

    """
    Do syntax highlighting.
    """

    def __init__(
        self,
        mode,
        link=None,
        styles={},
        ):
        """
        Initialise highlighter:
            mode = language (PYTHON, WEB2PY,C, CPP, HTML, HTML_PLAIN)
        """

        mode = mode.upper()
        if link and link[-1] != '/':
            link = link + '/'
        self.link = link
        self.styles = styles
        self.output = []
        self.span_style = None
        if mode == 'WEB2PY':
            (mode, self.suppress_tokens) = ('PYTHON', [])
        elif mode == 'PYTHON':
            self.suppress_tokens = ['GOTOHTML']
        elif mode == 'CPP':
            (mode, self.suppress_tokens) = ('C', [])
        elif mode == 'C':
            self.suppress_tokens = ['CPPKEYWORD']
        elif mode == 'HTML_PLAIN':
            (mode, self.suppress_tokens) = ('HTML', ['GOTOPYTHON'])
        elif mode == 'HTML':
            self.suppress_tokens = []
        else:
            raise SyntaxError, 'Unknown mode: %s' % mode
        self.mode = mode

    def c_tokenizer(
        self,
        token,
        match,
        style,
        ):
        """
        Callback for C specific highlighting.
        """

        value = cgi.escape(match.group())
        self.change_style(token, style)
        self.output.append(value)

    def python_tokenizer(
        self,
        token,
        match,
        style,
        ):
        """
        Callback for python specific highlighting.
        """

        value = cgi.escape(match.group())
        if token == 'MULTILINESTRING':
            self.change_style(token, style)
            self.output.append(value)
            self.strMultilineString = match.group(1)
            return 'PYTHONMultilineString'
        elif token == 'ENDMULTILINESTRING':
            if match.group(1) == self.strMultilineString:
                self.output.append(value)
                self.strMultilineString = ''
                return 'PYTHON'
        if style and style[:5] == 'link:':
            self.change_style(None, None)
            (url, style) = style[5:].split(';', 1)
            if url == 'None' or url == '':
                self.output.append('<span style="%s">%s</span>'
                                    % (style, value))
            else:
                self.output.append('<a href="%s%s" style="%s">%s</a>'
                                    % (url, value, style, value))
        else:
            self.change_style(token, style)
            self.output.append(value)
        if token == 'GOTOHTML':
            return 'HTML'
        return None

    def html_tokenizer(
        self,
        token,
        match,
        style,
        ):
        """
        Callback for HTML specific highlighting.
        """

        value = cgi.escape(match.group())
        self.change_style(token, style)
        self.output.append(value)
        if token == 'GOTOPYTHON':
            return 'PYTHON'
        return None

    all_styles = {
        'C': (c_tokenizer, (
            ('COMMENT', re.compile(r'//.*\r?\n'),
             'color: green; font-style: italic'),
            ('MULTILINECOMMENT', re.compile(r'/\*.*?\*/', re.DOTALL),
             'color: green; font-style: italic'),
            ('PREPROCESSOR', re.compile(r'\s*#.*?[^\\]\s*\n',
             re.DOTALL), 'color: magenta; font-style: italic'),
            ('PUNC', re.compile(r'[-+*!&|^~/%\=<>\[\]{}(),.:]'),
             'font-weight: bold'),
            ('NUMBER',
             re.compile(r'0x[0-9a-fA-F]+|[+-]?\d+(\.\d+)?([eE][+-]\d+)?|\d+'),
             'color: red'),
            ('KEYWORD', re.compile(r'(sizeof|int|long|short|char|void|'
              + r'signed|unsigned|float|double|'
              + r'goto|break|return|continue|asm|'
              + r'case|default|if|else|switch|while|for|do|'
              + r'struct|union|enum|typedef|'
              + r'static|register|auto|volatile|extern|const)(?![a-zA-Z0-9_])'),
             'color:#185369; font-weight: bold'),
            ('CPPKEYWORD',
             re.compile(r'(class|private|protected|public|template|new|delete|'
              + r'this|friend|using|inline|export|bool|throw|try|catch|'
              + r'operator|typeid|virtual)(?![a-zA-Z0-9_])'),
             'color: blue; font-weight: bold'),
            ('STRING', re.compile(r'r?u?\'(.*?)(?<!\\)\'|"(.*?)(?<!\\)"'),
             'color: #FF9966'),
            ('IDENTIFIER', re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*'),
             None),
            ('WHITESPACE', re.compile(r'[   \r\n]+'), 'Keep'),
            )),
        'PYTHON': (python_tokenizer, (
            ('GOTOHTML', re.compile(r'\}\}'), 'color: red'),
            ('PUNC', re.compile(r'[-+*!|&^~/%\=<>\[\]{}(),.:]'),
             'font-weight: bold'),
            ('NUMBER',
             re.compile(r'0x[0-9a-fA-F]+|[+-]?\d+(\.\d+)?([eE][+-]\d+)?|\d+'
             ), 'color: red'),
            ('KEYWORD',
             re.compile(r'(def|class|break|continue|del|exec|finally|pass|'
              + r'print|raise|return|try|except|global|assert|lambda|'
              + r'yield|for|while|if|elif|else|and|in|is|not|or|import|'
              + r'from|True|False)(?![a-zA-Z0-9_])'),
             'color:#185369; font-weight: bold'),
            ('WEB2PY',
             re.compile(r'(request|response|session|cache|redirect|local_import|HTTP|TR|XML|URL|BEAUTIFY|A|BODY|BR|B|CAT|CENTER|CODE|DIV|EM|EMBED|FIELDSET|LEGEND|FORM|H1|H2|H3|H4|H5|H6|IFRAME|HEAD|HR|HTML|I|IMG|INPUT|LABEL|LI|LINK|MARKMIN|MENU|META|OBJECT|OL|ON|OPTION|P|PRE|SCRIPT|SELECT|SPAN|STYLE|TABLE|THEAD|TBODY|TFOOT|TAG|TD|TEXTAREA|TH|TITLE|TT|T|UL|XHTML|IS_SLUG|IS_STRONG|IS_LOWER|IS_UPPER|IS_ALPHANUMERIC|IS_DATETIME|IS_DATETIME_IN_RANGE|IS_DATE|IS_DATE_IN_RANGE|IS_DECIMAL_IN_RANGE|IS_EMAIL|IS_EXPR|IS_FLOAT_IN_RANGE|IS_IMAGE|IS_INT_IN_RANGE|IS_IN_SET|IS_IPV4|IS_LIST_OF|IS_LENGTH|IS_MATCH|IS_EQUAL_TO|IS_EMPTY_OR|IS_NULL_OR|IS_NOT_EMPTY|IS_TIME|IS_UPLOAD_FILENAME|IS_URL|CLEANUP|CRYPT|IS_IN_DB|IS_NOT_IN_DB|DAL|Field|SQLFORM|SQLTABLE|xmlescape|embed64)(?![a-zA-Z0-9_])'
             ), 'link:%(link)s;text-decoration:None;color:#FF5C1F;'),
            ('MAGIC', re.compile(r'self|None'),
             'color:#185369; font-weight: bold'),
            ('MULTILINESTRING', re.compile(r'r?u?(\'\'\'|""")'),
             'color: #FF9966'),
            ('STRING', re.compile(r'r?u?\'(.*?)(?<!\\)\'|"(.*?)(?<!\\)"'
             ), 'color: #FF9966'),
            ('IDENTIFIER', re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*'),
             None),
            ('COMMENT', re.compile(r'\#.*\r?\n'),
             'color: green; font-style: italic'),
            ('WHITESPACE', re.compile(r'[   \r\n]+'), 'Keep'),
            )),
        'PYTHONMultilineString': (python_tokenizer,
                                  (('ENDMULTILINESTRING',
                                  re.compile(r'.*?("""|\'\'\')',
                                  re.DOTALL), 'color: darkred'), )),
        'HTML': (html_tokenizer, (
            ('GOTOPYTHON', re.compile(r'\{\{'), 'color: red'),
            ('COMMENT', re.compile(r'<!--[^>]*-->|<!>'),
             'color: green; font-style: italic'),
            ('XMLCRAP', re.compile(r'<![^>]*>'),
             'color: blue; font-style: italic'),
            ('SCRIPT', re.compile(r'<script .*?</script>', re.IGNORECASE
              + re.DOTALL), 'color: black'),
            ('TAG', re.compile(r'</?\s*[a-zA-Z0-9]+'),
             'color: darkred; font-weight: bold'),
            ('ENDTAG', re.compile(r'/?>'),
             'color: darkred; font-weight: bold'),
            )),
        }

    def highlight(self, data):
        """
        Syntax highlight some python code.
        Returns html version of code.
        """

        i = 0
        mode = self.mode
        while i < len(data):
            for (token, o_re, style) in Highlighter.all_styles[mode][1]:
                if not token in self.suppress_tokens:
                    match = o_re.match(data, i)
                    if match:
                        if style:
                            new_mode = \
                                Highlighter.all_styles[mode][0](self,
                                    token, match, style
                                     % dict(link=self.link))
                        else:
                            new_mode = \
                                Highlighter.all_styles[mode][0](self,
                                    token, match, style)
                        if new_mode != None:
                            mode = new_mode
                        i += max(1, len(match.group()))
                        break
            else:
                self.change_style(None, None)
                self.output.append(data[i])
                i += 1
        self.change_style(None, None)
        return ''.join(self.output).expandtabs(4)

    def change_style(self, token, style):
        """
        Generate output to change from existing style to another style only.
        """

        if token in self.styles:
            style = self.styles[token]
        if self.span_style != style:
            if style != 'Keep':
                if self.span_style != None:
                    self.output.append('</span>')
                if style != None:
                    self.output.append('<span style="%s">' % style)
                self.span_style = style


def highlight(
    code,
    language,
    link='/examples/globals/vars/',
    counter=1,
    styles={},
    highlight_line=None,
    attributes={},
    ):
    if not 'CODE' in styles:
        code_style = """
        font-size: 11px;
        font-family: Bitstream Vera Sans Mono,monospace;
        background-color: transparent;
        margin: 0;
        padding: 5px;
        border: none;
        overflow: auto;
        white-space: pre !important;\n"""
    else:
        code_style = styles['CODE']
    if not 'LINENUMBERS' in styles:
        linenumbers_style = """
        font-size: 11px;
        font-family: Bitstream Vera Sans Mono,monospace;
        background-color: transparent;
        margin: 0;
        padding: 5px;
        border: none;
        color: #A0A0A0;\n"""
    else:
        linenumbers_style = styles['LINENUMBERS']
    if not 'LINEHIGHLIGHT' in styles:
        linehighlight_style = "background-color: #EBDDE2;"
    else:
        linehighlight_style = styles['LINEHIGHLIGHT']

    if language and language.upper() in ['PYTHON', 'C', 'CPP', 'HTML',
            'WEB2PY']:
        code = Highlighter(language, link, styles).highlight(code)
    else:
        code = cgi.escape(code)
    lines = code.split('\n')

    if counter is None:
        linenumbers = [''] * len(lines)
    elif isinstance(counter, str):
        linenumbers = [cgi.escape(counter)] * len(lines)
    else:
        linenumbers = [str(i + counter) + '.' for i in
                               xrange(len(lines))]

    if highlight_line:
        if counter and not isinstance(counter, str):
            lineno = highlight_line - counter
        else:
            lineno = highlight_line
        if lineno<len(lines):
            lines[lineno] = '<div style="%s">%s</div>' % (linehighlight_style, lines[lineno])
            linenumbers[lineno] = '<div style="%s">%s</div>' % (linehighlight_style, linenumbers[lineno])

    code = '<br/>'.join(lines)
    numbers = '<br/>'.join(linenumbers)

    items = attributes.items()
    fa = ' '.join([key[1:].lower() for (key, value) in items if key[:1]
                   == '_' and value == None] + ['%s="%s"'
                   % (key[1:].lower(), str(value).replace('"', "'"))
                  for (key, value) in attributes.items() if key[:1]
                   == '_' and value])
    if fa:
        fa = ' ' + fa
    return '<table%s><tr valign="top"><td style="width:40px; text-align: right;"><pre style="%s">%s</pre></td><td><pre style="%s">%s</pre></td></tr></table>'\
         % (fa, linenumbers_style, numbers, code_style, code)


if __name__ == '__main__':
    import sys
    argfp = open(sys.argv[1])
    data = argfp.read()
    argfp.close()
    print '<html><body>' + highlight(data, sys.argv[2])\
         + '</body></html>'

