# -*- coding: utf-8 -*-

"""user interface libraries

contains some functions designed to help implementation of cubicweb user interface

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

import csv

import re

from StringIO import StringIO

from logilab.mtconverter import xml_escape, html_unescape

from cubicweb.utils import ustrftime

def rql_for_eid(eid):

    """return the rql query necessary to fetch entity with the given eid.  This

    function should only be used to generate link with rql inside, not to give

    to cursor.execute (in which case you won't benefit from rql cache).

    :Parameters:

      - `eid`: the eid of the entity we should search

    :rtype: str

    :return: the rql query

    """

    return 'Any X WHERE X eid %s' % eid

def printable_value(req, attrtype, value, props=None, displaytime=True):

    """return a displayable value (i.e. unicode string)"""

    if value is None or attrtype == 'Bytes':

        return u''

    if attrtype == 'String':

        # don't translate empty value if you don't want strange results

        if props is not None and value and props.get('internationalizable'):

            return req._(value)

        return value

    if attrtype == 'Date':

        return ustrftime(value, req.property_value('ui.date-format'))

    if attrtype == 'Time':

        return ustrftime(value, req.property_value('ui.time-format'))

    if attrtype == 'Datetime':

        if not displaytime:

            return ustrftime(value, req.property_value('ui.date-format'))

        return ustrftime(value, req.property_value('ui.datetime-format'))

    if attrtype == 'Boolean':

        if value:

            return req._('yes')

        return req._('no')

    if attrtype == 'Float':

        value = req.property_value('ui.float-format') % value

    return unicode(value)

# text publishing #############################################################

try:

    from cubicweb.ext.rest import rest_publish # pylint: disable-msg=W0611

except ImportError:

    def rest_publish(entity, data):

        """default behaviour if docutils was not found"""

        return xml_escape(data)

TAG_PROG = re.compile(r'</?.*?>', re.U)

def remove_html_tags(text):

    """Removes HTML tags from text

    >>> remove_html_tags('<td>hi <a href="http://www.google.fr">world</a></td>')

    'hi world'

    >>>

    """

    return TAG_PROG.sub('', text)

REF_PROG = re.compile(r"<ref\s+rql=([\'\"])([^\1]*?)\1\s*>([^<]*)</ref>", re.U)

def _subst_rql(view, obj):

    delim, rql, descr = obj.groups()

    return u'<a href="%s">%s</a>' % (view.build_url(rql=rql), descr)

def html_publish(view, text):

    """replace <ref rql=''> links by <a href="...">"""

    if not text:

        return u''

    return REF_PROG.sub(lambda obj, view=view:_subst_rql(view, obj), text)

# fallback implementation, nicer one defined below if lxml is available

def soup2xhtml(data, encoding):

    # normalize line break

    # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1

    return u'\n'.join(data.splitlines())

# fallback implementation, nicer one defined below if lxml> 2.0 is available

def safe_cut(text, length):

    """returns a string of length <length> based on <text>, removing any html

    tags from given text if cut is necessary."""

    if text is None:

        return u''

    noenttext = html_unescape(text)

    text_nohtml = remove_html_tags(noenttext)

    # try to keep html tags if text is short enough

    if len(text_nohtml) <= length:

        return text

    # else if un-tagged text is too long, cut it

    return xml_escape(text_nohtml[:length] + u'...')

fallback_safe_cut = safe_cut

try:

    from lxml import etree

except (ImportError, AttributeError):

    # gae environment: lxml not availabel

    pass

else:

    def soup2xhtml(data, encoding):

        """tidy (at least try) html soup and return the result

        Note: the function considers a string with no surrounding tag as valid

              if <div>`data`</div> can be parsed by an XML parser

        """

        # normalize line break

        # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7.1

        data = u'\n'.join(data.splitlines())

        # XXX lxml 1.1 support still needed ?

        xmltree = etree.HTML('<div>%s</div>' % data)

        # NOTE: lxml 1.1 (etch platforms) doesn't recognize

        #       the encoding=unicode parameter (lxml 2.0 does), this is

        #       why we specify an encoding and re-decode to unicode later

        body = etree.tostring(xmltree[0], encoding=encoding)

        # remove <body> and </body> and decode to unicode

        return body[11:-13].decode(encoding)

    if hasattr(etree.HTML('<div>test</div>'), 'iter'):

        def safe_cut(text, length):

            """returns an html document of length <length> based on <text>,

            and cut is necessary.

            """

            if text is None:

                return u''

            dom = etree.HTML(text)

            curlength = 0

            add_ellipsis = False

            for element in dom.iter():

                if curlength >= length:

                    parent = element.getparent()

                    parent.remove(element)

                    if curlength == length and (element.text or element.tail):

                        add_ellipsis = True

                else:

                    if element.text is not None:

                        element.text = cut(element.text, length - curlength)

                        curlength += len(element.text)

                    if element.tail is not None:

                        if curlength < length:

                            element.tail = cut(element.tail, length - curlength)

                            curlength += len(element.tail)

                        elif curlength == length:

                            element.tail = '...'

                        else:

                            element.tail = ''

            text = etree.tounicode(dom[0])[6:-7] # remove wrapping <body></body>

            if add_ellipsis:

                return text + u'...'

            return text

def text_cut(text, nbwords=30, gotoperiod=True):

    """from the given plain text, return a text with at least <nbwords> words,

    trying to go to the end of the current sentence.

    :param nbwords: the minimum number of words required

    :param gotoperiod: specifies if the function should try to go to

                       the first period after the cut (i.e. finish

                       the sentence if possible)

    Note that spaces are normalized.

    """

    if text is None:

        return u''

    words = text.split()

    text = u' '.join(words) # normalize spaces

    textlength = minlength = len(' '.join(words[:nbwords]))

    if gotoperiod:

        textlength = text.find('.', minlength) + 1

        if textlength == 0: # no period found

            textlength = minlength

    return text[:textlength]

def cut(text, length):

    """returns a string of a maximum length <length> based on <text>

    (approximatively, since if text has been  cut, '...' is added to the end of the string,

    resulting in a string of len <length> + 3)

    """

    if text is None:

        return u''

    if len(text) <= length:

        return text

    # else if un-tagged text is too long, cut it

    return text[:length] + u'...'

# HTML generation helper functions ############################################

HTML4_EMPTY_TAGS = frozenset(('base', 'meta', 'link', 'hr', 'br', 'param',

                              'img', 'area', 'input', 'col'))

def sgml_attributes(attrs):

    return u' '.join(u'%s="%s"' % (attr, xml_escape(unicode(value)))

                     for attr, value in sorted(attrs.items())

                     if value is not None)

def simple_sgml_tag(tag, content=None, escapecontent=True, **attrs):

    """generation of a simple sgml tag (eg without children tags) easier

    content and attri butes will be escaped

    """

    value = u'<%s' % tag

    if attrs:

        try:

            attrs['class'] = attrs.pop('klass')

        except KeyError:

            pass

        value += u' ' + sgml_attributes(attrs)

    if content:

        if escapecontent:

            content = xml_escape(unicode(content))

        value += u'>%s</%s>' % (content, tag)

    else:

        if tag in HTML4_EMPTY_TAGS:

            value += u' />'

        else:

            value += u'></%s>' % tag

    return value

def tooltipize(text, tooltip, url=None):

    """make an HTML tooltip"""

    url = url or '#'

    return u'<a href="%s" title="%s">%s</a>' % (url, tooltip, text)

def toggle_action(nodeid):

    """builds a HTML link that uses the js toggleVisibility function"""

    return u"javascript: toggleVisibility('%s')" % nodeid

def toggle_link(nodeid, label):

    """builds a HTML link that uses the js toggleVisibility function"""

    return u'<a href="%s">%s</a>' % (toggle_action(nodeid), label)

def ureport_as_html(layout):

    from logilab.common.ureports import HTMLWriter

    formater = HTMLWriter(True)

    stream = StringIO() #UStringIO() don't want unicode assertion

    formater.format(layout, stream)

    res = stream.getvalue()

    if isinstance(res, str):

        res = unicode(res, 'UTF8')

    return res

# traceback formatting ########################################################

import traceback

def rest_traceback(info, exception):

    """return a ReST formated traceback"""

    res = [u'Traceback\n---------\n::\n']

    for stackentry in traceback.extract_tb(info[2]):

        res.append(u'\tFile %s, line %s, function %s' % tuple(stackentry[:3]))

        if stackentry[3]:

            res.append(u'\t  %s' % stackentry[3].decode('utf-8', 'replace'))

    res.append(u'\n')

    try:

        res.append(u'\t Error: %s\n' % exception)

    except:

        pass

    return u'\n'.join(res)

def html_traceback(info, exception, title='',

                   encoding='ISO-8859-1', body=''):

    """ return an html formatted traceback from python exception infos.

    """

    tcbk = info[2]

    stacktb = traceback.extract_tb(tcbk)

    strings = []

    if body:

        strings.append(u'<div class="error_body">')

        # FIXME

        strings.append(body)

        strings.append(u'</div>')

    if title:

        strings.append(u'<h1 class="error">%s</h1>'% xml_escape(title))

    try:

        strings.append(u'<p class="error">%s</p>' % xml_escape(str(exception)).replace("\n","<br />"))

    except UnicodeError:

        pass

    strings.append(u'<div class="error_traceback">')

    for index, stackentry in enumerate(stacktb):

        strings.append(u'<b>File</b> <b class="file">%s</b>, <b>line</b> '

                       u'<b class="line">%s</b>, <b>function</b> '

                       u'<b class="function">%s</b>:<br/>'%(

            xml_escape(stackentry[0]), stackentry[1], xml_escape(stackentry[2])))

        if stackentry[3]:

            string = xml_escape(stackentry[3]).decode('utf-8', 'replace')

            strings.append(u'&nbsp;&nbsp;%s<br/>\n' % (string))

        # add locals info for each entry

        try:

            local_context = tcbk.tb_frame.f_locals

            html_info = []

            chars = 0

            for name, value in local_context.iteritems():

                value = xml_escape(repr(value))

                info = u'<span class="name">%s</span>=%s, ' % (name, value)

                line_length = len(name) + len(value)

                chars += line_length

                # 150 is the result of *years* of research ;-) (CSS might be helpful here)

                if chars > 150:

                    info = u'<br/>' + info

                    chars = line_length

                html_info.append(info)

            boxid = 'ctxlevel%d' % index

            strings.append(u'[%s]' % toggle_link(boxid, '+'))

            strings.append(u'<div id="%s" class="pycontext hidden">%s</div>' %

                           (boxid, ''.join(html_info)))

            tcbk = tcbk.tb_next

        except Exception:

            pass # doesn't really matter if we have no context info

    strings.append(u'</div>')

    return '\n'.join(strings)

# csv files / unicode support #################################################

class UnicodeCSVWriter:

    """proxies calls to csv.writer.writerow to be able to deal with unicode"""

    def __init__(self, wfunc, encoding, **kwargs):

        self.writer = csv.writer(self, **kwargs)

        self.wfunc = wfunc

        self.encoding = encoding

    def write(self, data):

        self.wfunc(data)

    def writerow(self, row):

        csvrow = []

        for elt in row:

            if isinstance(elt, unicode):

                csvrow.append(elt.encode(self.encoding))

            else:

                csvrow.append(str(elt))

        self.writer.writerow(csvrow)

    def writerows(self, rows):

        for row in rows:

            self.writerow(row)

# some decorators #############################################################

class limitsize(object):

    def __init__(self, maxsize):

        self.maxsize = maxsize

    def __call__(self, function):

        def newfunc(*args, **kwargs):

            ret = function(*args, **kwargs)

            if isinstance(ret, basestring):

                return ret[:self.maxsize]

            return ret

        return newfunc

def htmlescape(function):

    def newfunc(*args, **kwargs):

        ret = function(*args, **kwargs)

        assert isinstance(ret, basestring)

        return xml_escape(ret)

    return newfunc