# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

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

#

# This file is part of CubicWeb.

#

# CubicWeb is free software: you can redistribute it and/or modify it under the

# terms of the GNU Lesser General Public License as published by the Free

# Software Foundation, either version 2.1 of the License, or (at your option)

# any later version.

#

# CubicWeb 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 Lesser General Public License for more

# details.

#

# You should have received a copy of the GNU Lesser General Public License along

# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.

"""navigation components definition for CubicWeb web client"""

__docformat__ = "restructuredtext en"

_ = unicode

from rql.nodes import VariableRef, Constant

from logilab.mtconverter import xml_escape

from logilab.common.deprecation import deprecated

from cubicweb.selectors import (paginated_rset, sorted_rset,

                                adaptable, implements)

from cubicweb.uilib import cut

from cubicweb.view import EntityAdapter, implements_adapter_compat

from cubicweb.web.component import EmptyComponent, EntityCtxComponent, NavigationComponent

class PageNavigation(NavigationComponent):

    def call(self):

        """displays a resultset by page"""

        params = dict(self._cw.form)

        self.clean_params(params)

        basepath = self._cw.relative_path(includeparams=False)

        self.w(u'<div class="pagination">')

        self.w(self.previous_link(basepath, params))

        self.w(u'[ %s ]' %

               u' | '.join(self.iter_page_links(basepath, params)))

        self.w(u'  %s' % self.next_link(basepath, params))

        self.w(u'</div>')

    def index_display(self, start, stop):

        return u'%s - %s' % (start+1, stop+1)

    def iter_page_links(self, basepath, params):

        rset = self.cw_rset

        page_size = self.page_size

        start = 0

        while start < rset.rowcount:

            stop = min(start + page_size - 1, rset.rowcount - 1)

            yield self.page_link(basepath, params, start, stop,

                                 self.index_display(start, stop))

            start = stop + 1

class PageNavigationSelect(PageNavigation):

    """displays a resultset by page as PageNavigationSelect but in a <select>,

    better when there are a lot of results.

    """

    __select__ = paginated_rset(4)

    page_link_templ = u'<option value="%s" title="%s">%s</option>'

    selected_page_link_templ = u'<option value="%s" selected="selected" title="%s">%s</option>'

    def call(self):

        params = dict(self._cw.form)

        self.clean_params(params)

        basepath = self._cw.relative_path(includeparams=False)

        w = self.w

        w(u'<div class="pagination">')

        w(self.previous_link(basepath, params))

        w(u'<select onchange="javascript: document.location=this.options[this.selectedIndex].value">')

        for option in self.iter_page_links(basepath, params):

            w(option)

        w(u'</select>')

        w(u'  %s' % self.next_link(basepath, params))

        w(u'</div>')

class SortedNavigation(NavigationComponent):

    """sorted navigation apply if navigation is needed (according to page size)

    and if the result set is sorted

    """

    __select__ = paginated_rset() & sorted_rset()

    # number of considered chars to build page links

    nb_chars = 5

    def display_func(self, rset, col, attrname):

        if attrname is not None:

            def index_display(row):

                if not rset[row][col]: # outer join

                    return u''

                entity = rset.get_entity(row, col)

                return entity.printable_value(attrname, format='text/plain')

        elif self._cw.vreg.schema.eschema(rset.description[0][col]).final:

            def index_display(row):

                return unicode(rset[row][col])

        else:

            def index_display(row):

                return rset.get_entity(row, col).view('text')

        return index_display

    def call(self):

        """displays links to navigate accross pages of a result set

        Displayed result is done according to a variable on which the sort

        is done, and looks like:

        [ana - cro] | [cro - ghe] | ... | [tim - zou]

        """

        w = self.w

        rset = self.cw_rset

        page_size = self.page_size

        rschema = self._cw.vreg.schema.rschema

        # attrname = the name of attribute according to which the sort

        # is done if any

        for sorterm in rset.syntax_tree().children[0].orderby:

            if isinstance(sorterm.term, Constant):

                col = sorterm.term.value - 1

                index_display = self.display_func(rset, col, None)

                break

            var = sorterm.term.get_nodes(VariableRef)[0].variable

            col = None

            for ref in var.references():

                rel = ref.relation()

                if rel is None:

                    continue

                attrname = rel.r_type

                if attrname in ('is', 'has_text'):

                    continue

                if not rschema(attrname).final:

                    col = var.selected_index()

                    attrname = None

                if col is None:

                    # final relation or not selected non final relation

                    if var is rel.children[0]:

                        relvar = rel.children[1].children[0].get_nodes(VariableRef)[0]

                    else:

                        relvar = rel.children[0].variable

                    col = relvar.selected_index()

                if col is not None:

                    break

            else:

                # no relation but maybe usable anyway if selected

                col = var.selected_index()

                attrname = None

            if col is not None:

                index_display = self.display_func(rset, col, attrname)

                break

        else:

            # nothing usable found, use the first column

            index_display = self.display_func(rset, 0, None)

        blocklist = []

        params = dict(self._cw.form)

        self.clean_params(params)

        start = 0

        basepath = self._cw.relative_path(includeparams=False)

        while start < rset.rowcount:

            stop = min(start + page_size - 1, rset.rowcount - 1)

            cell = self.format_link_content(index_display(start), index_display(stop))

            blocklist.append(self.page_link(basepath, params, start, stop, cell))

            start = stop + 1

        self.write_links(basepath, params, blocklist)

    def format_link_content(self, startstr, stopstr):

        text = u'%s - %s' % (startstr.lower()[:self.nb_chars],

                             stopstr.lower()[:self.nb_chars])

        return xml_escape(text)

    def write_links(self, basepath, params, blocklist):

        self.w(u'<div class="pagination">')

        self.w(u'%s ' % self.previous_link(basepath, params))

        self.w(u'[ %s ]' % u' | '.join(blocklist))

        self.w(u' %s' % self.next_link(basepath, params))

        self.w(u'</div>')

from cubicweb.interfaces import IPrevNext

class IPrevNextAdapter(EntityAdapter):

    """interface for entities which can be linked to a previous and/or next

    entity

    """

    __needs_bw_compat__ = True

    __regid__ = 'IPrevNext'

    __select__ = implements(IPrevNext, warn=False) # XXX for bw compat, else should be abstract

    @implements_adapter_compat('IPrevNext')

    def next_entity(self):

        """return the 'next' entity"""

        raise NotImplementedError

    @implements_adapter_compat('IPrevNext')

    def previous_entity(self):

        """return the 'previous' entity"""

        raise NotImplementedError

class NextPrevNavigationComponent(EntityCtxComponent):

    __regid__ = 'prevnext'

    # register msg not generated since no entity implements IPrevNext in cubicweb

    # itself

    help = _('ctxcomponents_prevnext_description')

    __select__ = EntityCtxComponent.__select__ & adaptable('IPrevNext')

    context = 'navbottom'

    order = 10

    @property

    def prev_icon(self):

        return '<img src="%s"/>' % xml_escape(self._cw.data_url('go_prev.png'))

    @property

    def next_icon(self):

        return '<img src="%s"/>' % xml_escape(self._cw.data_url('go_next.png'))

    def init_rendering(self):

        adapter = self.entity.cw_adapt_to('IPrevNext')

        self.previous = adapter.previous_entity()

        self.next = adapter.next_entity()

        if not (self.previous or self.next):

            raise EmptyComponent()

    def render_body(self, w):

        w(u'<div class="prevnext">')

        self.prevnext(w)

        w(u'</div>')

        w(u'<div class="clear"></div>')

    def prevnext(self, w):

        if self.previous:

            self.prevnext_entity(w, self.previous, 'prev')

        if self.next:

            self.prevnext_entity(w, self.next, 'next')

    def prevnext_entity(self, w, entity, type):

        textsize = self._cw.property_value('navigation.short-line-size')

        content = xml_escape(cut(entity.dc_title(), textsize))

        if type == 'prev':

            title = self._cw._('i18nprevnext_previous')

            icon = self.prev_icon

            cssclass = u'previousEntity left'

            content = icon + content

        else:

            title = self._cw._('i18nprevnext_next')

            icon = self.next_icon

            cssclass = u'nextEntity right'

            content = content + '  ' + icon

        self.prevnext_div(w, type, cssclass, entity.absolute_url(),

                          title, content)

    def prevnext_div(self, w, type, cssclass, url, title, content):

        w(u'<div class="%s">' % cssclass)

        w(u'<a href="%s" title="%s">%s</a>' % (xml_escape(url),

                                               xml_escape(title),

                                               content))

        w(u'</div>')

        self._cw.html_headers.add_raw('<link rel="%s" href="%s" />' % (

              type, xml_escape(url)))

def do_paginate(view, rset=None, w=None, show_all_option=True, page_size=None):

    """write pages index in w stream (default to view.w) and then limit the result

    set (default to view.rset) to the currently displayed page

    """

    req = view._cw

    if rset is None:

        rset = view.cw_rset

    if w is None:

        w = view.w

    nav = req.vreg['components'].select_or_none(

        'navigation', req, rset=rset, page_size=page_size, view=view)

    if nav:

        if w is None:

            w = view.w

        # get boundaries before component rendering

        start, stop = nav.page_boundaries()

        nav.render(w=w)

        params = dict(req.form)

        nav.clean_params(params)

        # make a link to see them all

        if show_all_option:

            basepath = req.relative_path(includeparams=False)

            params['__force_display'] = 1

            url = nav.page_url(basepath, params)

            w(u'<div><a href="%s">%s</a></div>\n'

              % (xml_escape(url), req._('show %s results') % len(rset)))

        rset.limit(offset=start, limit=stop-start, inplace=True)

def paginate(view, show_all_option=True, w=None, page_size=None, rset=None):

    """paginate results if the view is paginable and we're not explictly told to

    display everything (by setting __force_display in req.form)

    """

    if view.paginable and not view._cw.form.get('__force_display'):

        do_paginate(view, rset, w, show_all_option, page_size)

# monkey patch base View class to add a .paginate([...])

# method to be called to write pages index in the view and then limit the result

# set to the current page

from cubicweb.view import View

View.do_paginate = do_paginate

View.paginate = paginate