from tg.i18n import ugettext as _

from kallithea.lib import webutils

from kallithea.lib.utils2 import safe_str

from kallithea.lib.vcs.backends.base import EmptyChangeset

from kallithea.lib.vcs.exceptions import VCSError

from kallithea.lib.vcs.nodes import FileNode, SubModuleNode

log = logging.getLogger(__name__)

def _safe_id(idstring):

    r"""Make a string safe for including in an id attribute.

    The HTML spec says that id attributes 'must begin with

    a letter ([A-Za-z]) and may be followed by any number

    of letters, digits ([0-9]), hyphens ("-"), underscores

    ("_"), colons (":"), and periods (".")'. These regexps

    are slightly over-zealous, in that they remove colons

    and periods unnecessarily.

    Whitespace is transformed into underscores, and then

    anything which is not a hyphen or a character that

    matches \w (alphanumerics and underscore) is removed.

    """

    # Transform all whitespace to underscore

    idstring = re.sub(r'\s', "_", idstring)

    # Remove everything that is not a hyphen or a member of \w

    idstring = re.sub(r'(?!-)\W', "", idstring).lower()

    return idstring

def as_html(parsed_lines, table_class='code-difftable', line_class='line',

            old_lineno_class='lineno old', new_lineno_class='lineno new',

            no_lineno_class='lineno',

            code_class='code'):

    """

    Return given diff as html table with customized css classes

    """

    _html_empty = True

    _html = []

    _html.append('''<table class="%(table_class)s">\n''' % {

        'table_class': table_class

    })

    for file_info in parsed_lines:

        for chunk in file_info['chunks']:

            _html_empty = False

            for change in chunk:

                _html.append('''<tr class="%(lc)s %(action)s">\n''' % {

                    'lc': line_class,

                    'action': change['action']

                })

                if change['old_lineno'] or change['new_lineno']:

                    ###########################################################

                    # OLD LINE NUMBER

                    ###########################################################

                    anchor_old = "%(filename)s_o%(oldline_no)s" % {

                        'filename': _safe_id(file_info['filename']),

                        'oldline_no': change['old_lineno']

                    }

                    anchor_old_id = ''

                    if change['old_lineno']:

                        anchor_old_id = 'id="%s"' % anchor_old

                    _html.append('''\t<td %(a_id)s class="%(olc)s">''' % {

                        'a_id': anchor_old_id,

                        'olc': old_lineno_class,

                    })

                    _html.append('''<a href="%(url)s" data-pseudo-content="%(label)s"></a>''' % {

                        'label': change['old_lineno'],

                        'url': '#%s' % anchor_old,

                    })

                    _html.append('''</td>\n''')

                    ###########################################################

                    # NEW LINE NUMBER

                    ###########################################################

                    anchor_new = "%(filename)s_n%(newline_no)s" % {

                        'filename': _safe_id(file_info['filename']),

                        'newline_no': change['new_lineno']

                    }

                    anchor_new_id = ''

                    if change['new_lineno']:

                        anchor_new_id = 'id="%s"' % anchor_new

                    _html.append('''\t<td %(a_id)s class="%(nlc)s">''' % {

                        'a_id': anchor_new_id,

                        'nlc': new_lineno_class

                    })

                    _html.append('''<a href="%(url)s" data-pseudo-content="%(label)s"></a>''' % {

                        'label': change['new_lineno'],

                        'url': '#%s' % anchor_new,

                    })

                    _html.append('''</td>\n''')

                else:

                    ###########################################################

                    # NO LINE NUMBER

                    ###########################################################

                        'filename': _safe_id(file_info['filename']),

                    }

                    _html.append('''\t<td id="%(anchor)s" class="%(olc)s" colspan="2">''' % {

                        'anchor': anchor,

                        'olc': no_lineno_class,

                    })

                    _html.append('''</td>\n''')

                ###########################################################

                # CODE

                ###########################################################

                _html.append('''\t<td class="%(cc)s">''' % {

                    'cc': code_class,

                })

                _html.append('''\n\t\t<div class="add-bubble"><div>&nbsp;</div></div><pre>%(code)s</pre>\n''' % {

                    'code': change['line']

                })

                _html.append('''\t</td>''')

                _html.append('''\n</tr>\n''')

    _html.append('''</table>''')

    if _html_empty:

        return None

    return ''.join(_html)

def wrap_to_table(html):

    """Given a string with html, return it wrapped in a table, similar to what

    as_html returns."""

    return '''\

              <table class="code-difftable">

                <tr class="line">

                <td class="lineno new"></td>

                <td class="code"><pre>%s</pre></td>

                </tr>

              </table>''' % html

def html_diff(filenode_old, filenode_new, diff_limit=None,

                ignore_whitespace=True, line_context=3):

    """

    Returns a file diff as HTML wrapped into a table.

    Checks for diff_limit and presents a message if the diff is too big.

    """

    if filenode_old is None:

        filenode_old = FileNode(filenode_new.path, '', EmptyChangeset())

    op = None

    a_path = filenode_old.path # default, might be overriden by actual rename in diff

    if filenode_old.is_binary or filenode_new.is_binary:

        html_diff = wrap_to_table(_('Binary file'))

                        stats['binary'] = True

                        stats['ops'][NEW_FILENODE] = 'new file'

                    elif head['a_file'] and not head['b_file']:

                        op = 'removed'

                        stats['binary'] = True

                        stats['ops'][DEL_FILENODE] = 'deleted file'

                # it's not ADD not DELETE

                if op is None:

                    op = 'modified'

                    stats['binary'] = True

                    stats['ops'][MOD_FILENODE] = 'modified file'

            # a real non-binary diff

            if head['a_file'] or head['b_file']:

                chunks, added, deleted = _parse_lines(diff_lines)

                stats['binary'] = False

                stats['added'] = added

                stats['deleted'] = deleted

                # explicit mark that it's a modified file

                if op == 'modified':

                    stats['ops'][MOD_FILENODE] = 'modified file'

            else:  # Git binary patch (or empty diff)

                # Git binary patch

                if head['bin_patch']:

                    stats['ops'][BIN_FILENODE] = 'binary diff not shown'

                chunks = []

            if op == 'removed' and chunks:

                # a way of seeing deleted content could perhaps be nice - but

                # not with the current UI

                chunks = []

            # show helpful additional texts for mode change and renaming, but not for plain 'modified file'

            msgs = [

                {

                    'old_lineno': '',

                    'new_lineno': '',

                    'action': 'context',

                    'line': msg,

                }

                for op_, msg in stats['ops'].items()

                if op_ != MOD_FILENODE

            ]

            if msgs:

                chunks.insert(0, msgs)

            _files.append({

                'old_filename':     head['a_path'],

                'filename':         head['b_path'],

                'old_revision':     head['a_blob_id'],

                'new_revision':     head['b_blob_id'],

                'chunks':           chunks,

                'operation':        op,

                'stats':            stats,

            })

        if not html:

            return _files

        for diff_data in _files:

            for chunk in diff_data['chunks']:

                for change in chunk:

                    change['line'] = _escaper(change['line'])

                # highlight inline changes when one del is followed by one add

                lineiter = iter(chunk)

                try:

                    peekline = next(lineiter)

                    while True:

                        # find a first del line

                        while peekline['action'] != 'del':

                            peekline = next(lineiter)

                        delline = peekline

                        peekline = next(lineiter)

                        # if not followed by add, eat all following del lines

                        if peekline['action'] != 'add':

                            while peekline['action'] == 'del':

                                peekline = next(lineiter)

                            continue

                        # found an add - make sure it is the only one

                        addline = peekline

                        try:

                            peekline = next(lineiter)

                        except StopIteration:

                            # add was last line - ok

                            _highlight_inline_diff(delline, addline)

                            raise

                        if peekline['action'] != 'add':

                            # there was only one add line - ok

                            _highlight_inline_diff(delline, addline)

                except StopIteration:

                    pass

        return _files