"""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.interfaces import IPrevNext

from cubicweb.selectors import (paginated_rset, sorted_rset,

                                primary_view, match_context_prop,

                                one_line_rset, implements)

from cubicweb.uilib import cut

from cubicweb.web.component import EntityVComponent, NavigationComponent

class PageNavigation(NavigationComponent):

    def call(self):

        """displays a resultset by page"""

        w = self.w

        req = self._cw

        rset = self.cw_rset

        page_size = self.page_size

        start = 0

        blocklist = []

        params = dict(req.form)

        self.clean_params(params)

        basepath = req.relative_path(includeparams=False)

        while start < rset.rowcount:

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

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

                                            self.index_display(start, stop)))

            start = stop + 1

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

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

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

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

        w(u'</div>')

    def index_display(self, start, stop):

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

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 == 'is':

                    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>')

class NextPrevNavigationComponent(EntityVComponent):

    __regid__ = 'prevnext'

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

    # itself

    title = _('contentnavigation_prevnext')

    help = _('contentnavigation_prevnext_description')

    __select__ = (one_line_rset() & primary_view()

                  & match_context_prop() & implements(IPrevNext))

    context = 'navbottom'

    order = 10

    def call(self, view=None):

        entity = self.cw_rset.get_entity(0, 0)

        previous = entity.previous_entity()

        next = entity.next_entity()

        if previous or next:

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

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

            if previous:

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

                self.w(self.previous_link(previous, textsize))

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

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

                                              % xml_escape(previous.absolute_url()))

            if next:

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

                self.w(self.next_link(next, textsize))

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

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

                                              % xml_escape(next.absolute_url()))

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

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

    def previous_link(self, previous, textsize):

        return u'<a href="%s" title="%s">&lt;&lt; %s</a>' % (

            xml_escape(previous.absolute_url()),

            self._cw._('i18nprevnext_previous'),

            xml_escape(cut(previous.dc_title(), textsize)))

    def next_link(self, next, textsize):

        return u'<a href="%s" title="%s">%s &gt;&gt;</a>' % (

            xml_escape(next.absolute_url()),

            self._cw._('i18nprevnext_next'),

            xml_escape(cut(next.dc_title(), textsize)))

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)

    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:

            url = xml_escape(req.build_url(__force_display=1, **params))

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

              % (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

#@deprecated (see below)

def limit_rset_using_paged_nav(self, req, rset, w, forcedisplay=False,

                               show_all_option=True, page_size=None):

    if not (forcedisplay or req.form.get('__force_display') is not None):

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

View.pagination = deprecated('[3.2] .pagination is deprecated, use paginate')(

    limit_rset_using_paged_nav)

limit_rset_using_paged_nav = deprecated('[3.6] limit_rset_using_paged_nav is deprecated, use do_paginate')(

    limit_rset_using_paged_nav)