#  This file is part of ansi2html
#  Convert ANSI (terminal) colours and attributes to HTML
#  Copyright (C) 2012  Ralph Bean <rbean@redhat.com>
#  Copyright (C) 2013  Sebastian Pipping <sebastian@pipping.org>
#
#  Inspired by and developed off of the work by pixelbeat and blackjack.
#
#  This program 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 3 of
#  the License, or (at your option) any later version.
#
#  This program 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 this program.  If not, see
#  <http://www.gnu.org/licenses/>.

import re
import sys
import optparse
import pkg_resources

try:
    from collections import OrderedDict
except ImportError:
    from ordereddict import OrderedDict

from ansi2html.style import get_styles
import six
from six.moves import map
from six.moves import zip


ANSI_FULL_RESET = 0
ANSI_INTENSITY_INCREASED = 1
ANSI_INTENSITY_REDUCED = 2
ANSI_INTENSITY_NORMAL = 22
ANSI_STYLE_ITALIC = 3
ANSI_STYLE_NORMAL = 23
ANSI_BLINK_SLOW = 5
ANSI_BLINK_FAST = 6
ANSI_BLINK_OFF = 25
ANSI_UNDERLINE_ON = 4
ANSI_UNDERLINE_OFF = 24
ANSI_CROSSED_OUT_ON = 9
ANSI_CROSSED_OUT_OFF = 29
ANSI_VISIBILITY_ON = 28
ANSI_VISIBILITY_OFF = 8
ANSI_FOREGROUND_CUSTOM_MIN = 30
ANSI_FOREGROUND_CUSTOM_MAX = 37
ANSI_FOREGROUND_256 = 38
ANSI_FOREGROUND_DEFAULT = 39
ANSI_BACKGROUND_CUSTOM_MIN = 40
ANSI_BACKGROUND_CUSTOM_MAX = 47
ANSI_BACKGROUND_256 = 48
ANSI_BACKGROUND_DEFAULT = 49
ANSI_NEGATIVE_ON = 7
ANSI_NEGATIVE_OFF = 27


_template = six.u("""<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=%(output_encoding)s">
<style type="text/css">\n%(style)s\n</style>
</head>
<body class="body_foreground body_background" style="font-size: %(font_size)s;" >
<pre>
%(content)s
</pre>
</body>

</html>
""")


class _State(object):
    def __init__(self):
        self.reset()

    def reset(self):
        self.intensity = ANSI_INTENSITY_NORMAL
        self.style = ANSI_STYLE_NORMAL
        self.blink = ANSI_BLINK_OFF
        self.underline = ANSI_UNDERLINE_OFF
        self.crossedout = ANSI_CROSSED_OUT_OFF
        self.visibility = ANSI_VISIBILITY_ON
        self.foreground = (ANSI_FOREGROUND_DEFAULT, None)
        self.background = (ANSI_BACKGROUND_DEFAULT, None)
        self.negative = ANSI_NEGATIVE_OFF

    def adjust(self, ansi_code, parameter=None):
        if ansi_code in (ANSI_INTENSITY_INCREASED, ANSI_INTENSITY_REDUCED, ANSI_INTENSITY_NORMAL):
            self.intensity = ansi_code
        elif ansi_code in (ANSI_STYLE_ITALIC, ANSI_STYLE_NORMAL):
            self.style = ansi_code
        elif ansi_code in (ANSI_BLINK_SLOW, ANSI_BLINK_FAST, ANSI_BLINK_OFF):
            self.blink = ansi_code
        elif ansi_code in (ANSI_UNDERLINE_ON, ANSI_UNDERLINE_OFF):
            self.underline = ansi_code
        elif ansi_code in (ANSI_CROSSED_OUT_ON, ANSI_CROSSED_OUT_OFF):
            self.crossedout = ansi_code
        elif ansi_code in (ANSI_VISIBILITY_ON, ANSI_VISIBILITY_OFF):
            self.visibility = ansi_code
        elif ANSI_FOREGROUND_CUSTOM_MIN <= ansi_code <= ANSI_FOREGROUND_CUSTOM_MAX:
            self.foreground = (ansi_code, None)
        elif ansi_code == ANSI_FOREGROUND_256:
            self.foreground = (ansi_code, parameter)
        elif ansi_code == ANSI_FOREGROUND_DEFAULT:
            self.foreground = (ansi_code, None)
        elif ANSI_BACKGROUND_CUSTOM_MIN <= ansi_code <= ANSI_BACKGROUND_CUSTOM_MAX:
            self.background = (ansi_code, None)
        elif ansi_code == ANSI_BACKGROUND_256:
            self.background = (ansi_code, parameter)
        elif ansi_code == ANSI_BACKGROUND_DEFAULT:
            self.background = (ansi_code, None)
        elif ansi_code in (ANSI_NEGATIVE_ON, ANSI_NEGATIVE_OFF):
            self.negative = ansi_code

    def to_css_classes(self):
        css_classes = []

        def append_unless_default(output, value, default):
            if value != default:
                css_class = 'ansi%d' % value
                output.append(css_class)

        def append_color_unless_default(output, color, default, negative, neg_css_class):
            value, parameter = color
            if value != default:
                prefix = 'inv' if negative else 'ansi'
                css_class_index = str(value) \
                        if (parameter is None) \
                        else '%d-%d' % (value, parameter)
                output.append(prefix + css_class_index)
            elif negative:
                output.append(neg_css_class)

        append_unless_default(css_classes, self.intensity, ANSI_INTENSITY_NORMAL)
        append_unless_default(css_classes, self.style, ANSI_STYLE_NORMAL)
        append_unless_default(css_classes, self.blink, ANSI_BLINK_OFF)
        append_unless_default(css_classes, self.underline, ANSI_UNDERLINE_OFF)
        append_unless_default(css_classes, self.crossedout, ANSI_CROSSED_OUT_OFF)
        append_unless_default(css_classes, self.visibility, ANSI_VISIBILITY_ON)

        flip_fore_and_background = (self.negative == ANSI_NEGATIVE_ON)
        append_color_unless_default(css_classes, self.foreground, ANSI_FOREGROUND_DEFAULT, flip_fore_and_background, 'inv_background')
        append_color_unless_default(css_classes, self.background, ANSI_BACKGROUND_DEFAULT, flip_fore_and_background, 'inv_foreground')

        return css_classes


def linkify(line):
    for match in re.findall(r'https?:\/\/\S+', line):
        line = line.replace(match, '<a href="%s">%s</a>' % (match, match))

    return line


def _needs_extra_newline(text):
    if not text or text.endswith('\n'):
        return False
    return True


class CursorMoveUp(object):
    pass


class Ansi2HTMLConverter(object):
    """ Convert Ansi color codes to CSS+HTML

    Example:
    >>> conv = Ansi2HTMLConverter()
    >>> ansi = " ".join(sys.stdin.readlines())
    >>> html = conv.convert(ansi)
    """

    def __init__(self,
                 inline=False,
                 dark_bg=True,
                 font_size='normal',
                 linkify=False,
                 escaped=True,
                 markup_lines=False,
                 output_encoding='utf-8',
                 scheme='ansi2html'
                ):

        self.inline = inline
        self.dark_bg = dark_bg
        self.font_size = font_size
        self.linkify = linkify
        self.escaped = escaped
        self.markup_lines = markup_lines
        self.output_encoding = output_encoding
        self.scheme = scheme
        self._attrs = None

        if inline:
            self.styles = dict([(item.klass.strip('.'), item) for item in get_styles(self.dark_bg, self.scheme)])

        self.ansi_codes_prog = re.compile('\033\\[' '([\\d;]*)' '([a-zA-z])')

    def apply_regex(self, ansi):
        parts = self._apply_regex(ansi)
        parts = self._collapse_cursor(parts)
        parts = list(parts)

        if self.linkify:
            parts = [linkify(part) for part in parts]

        combined = "".join(parts)

        if self.markup_lines:
            combined = "\n".join([
                """<span id="line-%i">%s</span>""" % (i, line)
                for i, line in enumerate(combined.split('\n'))
            ])

        return combined

    def _apply_regex(self, ansi):
        if self.escaped:
            specials = OrderedDict([
                ('&', '&amp;'),
                ('<', '&lt;'),
                ('>', '&gt;'),
            ])
            for pattern, special in specials.items():
                ansi = ansi.replace(pattern, special)

        state = _State()
        inside_span = False
        last_end = 0  # the index of the last end of a code we've seen
        for match in self.ansi_codes_prog.finditer(ansi):
            yield ansi[last_end:match.start()]
            last_end = match.end()

            params, command = match.groups()

            if command not in 'mMA':
                continue

            # Special cursor-moving code.  The only supported one.
            if command == 'A':
                yield CursorMoveUp
                continue

            try:
                params = list(map(int, params.split(';')))
            except ValueError:
                params = [ANSI_FULL_RESET]

            # Find latest reset marker
            last_null_index = None
            skip_after_index = -1
            for i, v in enumerate(params):
                if i <= skip_after_index:
                    continue

                if v == ANSI_FULL_RESET:
                    last_null_index = i
                elif v in (ANSI_FOREGROUND_256, ANSI_BACKGROUND_256):
                    skip_after_index = i + 2

            # Process reset marker, drop everything before
            if last_null_index is not None:
                params = params[last_null_index + 1:]
                if inside_span:
                    inside_span = False
                    yield '</span>'
                state.reset()

                if not params:
                    continue

            # Turn codes into CSS classes
            skip_after_index = -1
            for i, v in enumerate(params):
                if i <= skip_after_index:
                    continue

                if v in (ANSI_FOREGROUND_256, ANSI_BACKGROUND_256):
                    try:
                        parameter = params[i + 2]
                    except IndexError:
                        continue
                    skip_after_index = i + 2
                else:
                    parameter = None
                state.adjust(v, parameter=parameter)

            if inside_span:
                yield '</span>'
                inside_span = False

            css_classes = state.to_css_classes()
            if not css_classes:
                continue

            if self.inline:
                style = [self.styles[klass].kw for klass in css_classes if
                         klass in self.styles]
                yield '<span style="%s">' % "; ".join(style)
            else:
                yield '<span class="%s">' % " ".join(css_classes)
            inside_span = True

        yield ansi[last_end:]
        if inside_span:
            yield '</span>'
            inside_span = False

    def _collapse_cursor(self, parts):
        """ Act on any CursorMoveUp commands by deleting preceding tokens """

        final_parts = []
        for part in parts:

            # Throw out empty string tokens ("")
            if not part:
                continue

            # Go back, deleting every token in the last 'line'
            if part == CursorMoveUp:
                final_parts.pop()
                while '\n' not in final_parts[-1]:
                    final_parts.pop()

                continue

            # Otherwise, just pass this token forward
            final_parts.append(part)

        return final_parts

    def prepare(self, ansi='', ensure_trailing_newline=False):
        """ Load the contents of 'ansi' into this object """

        body = self.apply_regex(ansi)

        if ensure_trailing_newline and _needs_extra_newline(body):
            body += '\n'

        self._attrs = {
            'dark_bg': self.dark_bg,
            'font_size': self.font_size,
            'body': body,
        }

        return self._attrs

    def attrs(self):
        """ Prepare attributes for the template """
        if not self._attrs:
            raise Exception("Method .prepare not yet called.")
        return self._attrs

    def convert(self, ansi, full=True, ensure_trailing_newline=False):
        attrs = self.prepare(ansi, ensure_trailing_newline=ensure_trailing_newline)
        if not full:
            return attrs["body"]
        else:
            return _template % {
                'style' : "\n".join(map(str, get_styles(self.dark_bg, self.scheme))),
                'font_size' : self.font_size,
                'content' :  attrs["body"],
                'output_encoding' : self.output_encoding,
            }

    def produce_headers(self):
        return '<style type="text/css">\n%(style)s\n</style>\n' % {
            'style' : "\n".join(map(str, get_styles(self.dark_bg, self.scheme)))
        }


def main():
    """
    $ ls --color=always | ansi2html > directories.html
    $ sudo tail /var/log/messages | ccze -A | ansi2html > logs.html
    $ task burndown | ansi2html > burndown.html
    """

    version_str = pkg_resources.get_distribution('ansi2html').version
    parser = optparse.OptionParser(
        usage=main.__doc__,
        version="%%prog %s" % version_str)
    parser.add_option(
        "-p", "--partial", dest="partial",
        default=False, action="store_true",
        help="Process lines as them come in.  No headers are produced.")
    parser.add_option(
        "-i", "--inline", dest="inline",
        default=False, action="store_true",
        help="Inline style without headers or template.")
    parser.add_option(
        "-H", "--headers", dest="headers",
        default=False, action="store_true",
        help="Just produce the <style> tag.")
    parser.add_option(
        "-f", '--font-size', dest='font_size', metavar='SIZE',
        default="normal",
        help="Set the global font size in the output.")
    parser.add_option(
        "-l", '--light-background', dest='light_background',
        default=False, action="store_true",
        help="Set output to 'light background' mode.")
    parser.add_option(
        "-a", '--linkify', dest='linkify',
        default=False, action="store_true",
        help="Transform URLs into <a> links.")
    parser.add_option(
        "-u", '--unescape', dest='escaped',
        default=True, action="store_false",
        help="Do not escape XML tags found in the input.")
    parser.add_option(
        "-m", '--markup-lines', dest="markup_lines",
        default=False, action="store_true",
        help="Surround lines with <span id='line-n'>..</span>.")
    parser.add_option(
        '--input-encoding', dest='input_encoding', metavar='ENCODING',
        default='utf-8',
        help="Specify input encoding")
    parser.add_option(
        '--output-encoding', dest='output_encoding', metavar='ENCODING',
        default='utf-8',
        help="Specify output encoding")
    parser.add_option(
        '-s', '--scheme', dest='scheme', metavar='SCHEME',
        default='ansi2html',
        help="Specify color palette scheme [ansi2html, xterm, xterm-bright]")

    opts, args = parser.parse_args()

    conv = Ansi2HTMLConverter(
        inline=opts.inline,
        dark_bg=not opts.light_background,
        font_size=opts.font_size,
        linkify=opts.linkify,
        escaped=opts.escaped,
        markup_lines=opts.markup_lines,
        output_encoding=opts.output_encoding,
        scheme=opts.scheme,
    )

    def _read(input_bytes):
        if six.PY3:
            # This is actually already unicode.  How to we explicitly decode in
            # python3?  I don't know the answer yet.
            return input_bytes
        else:
            return input_bytes.decode(opts.input_encoding)

    def _print(output_unicode, end='\n'):
        if hasattr(sys.stdout, 'buffer'):
            output_bytes = (output_unicode + end).encode(opts.output_encoding)
            sys.stdout.buffer.write(output_bytes)
        elif not six.PY3:
            sys.stdout.write((output_unicode + end).encode(opts.output_encoding))
        else:
            sys.stdout.write(output_unicode + end)

    # Produce only the headers and quit
    if opts.headers:
        _print(conv.produce_headers(), end='')
        return

    full = not bool(opts.partial or opts.inline)
    if six.PY3:
        output = conv.convert("".join(sys.stdin.readlines()), full=full, ensure_trailing_newline=True)
        _print(output, end='')
    else:
        output = conv.convert(six.u("").join(
            map(_read, sys.stdin.readlines())
        ), full=full, ensure_trailing_newline=True)
        _print(output, end='')
