"""csv export views

"""

__docformat__ = "restructuredtext en"

from cubicweb.schema import display_name

from cubicweb.uilib import UnicodeCSVWriter

from cubicweb.view import EntityView, AnyRsetView

class CSVMixIn(object):

    """mixin class for CSV views"""

    templatable = False

    content_type = "text/comma-separated-values"

    binary = True # avoid unicode assertion

    csv_params = {'dialect': 'excel',

                  'quotechar': '"',

                  'delimiter': ';',

                  'lineterminator': '\n'}

    def set_request_content_type(self):

        """overriden to set a .csv filename"""

        self._cw.set_content_type(self.content_type, filename='cubicwebexport.csv')

    def csvwriter(self, **kwargs):

        params = self.csv_params.copy()

        params.update(kwargs)

        return UnicodeCSVWriter(self.w, self._cw.encoding, **params)

class CSVRsetView(CSVMixIn, AnyRsetView):

    """dumps raw result set in CSV"""

    __regid__ = 'csvexport'

    title = _('csv export')

    def call(self):

        writer = self.csvwriter()

        writer.writerow(self.columns_labels())

        rset, descr = self.cw_rset, self.cw_rset.description

        eschema = self._cw.vreg.schema.eschema

        for rowindex, row in enumerate(rset):

            csvrow = []

            for colindex, val in enumerate(row):

                etype = descr[rowindex][colindex]

                if val is not None and not eschema(etype).final:

                    # csvrow.append(val) # val is eid in that case

                    content = self._cw.view('textincontext', rset,

                                            row=rowindex, col=colindex)

                else:

                    content = self._cw.view('final', rset,

                                            format='text/plain',

                                            row=rowindex, col=colindex)

                csvrow.append(content)

            writer.writerow(csvrow)

class CSVEntityView(CSVMixIn, EntityView):

    """dumps rset's entities (with full set of attributes) in CSV

    the generated CSV file will have a table per entity type found in the

    resultset. ('table' here only means empty lines separation between table

    contents)

    """

    __regid__ = 'ecsvexport'

    title = _('csv entities export')

    def call(self):

        req = self._cw

        rows_by_type = {}

        writer = self.csvwriter()

        rowdef_by_type = {}

        for index in xrange(len(self.cw_rset)):

            entity = self.cw_rset.complete_entity(index)

            if entity.e_schema not in rows_by_type:

                rowdef_by_type[entity.e_schema] = [rs for rs, at in entity.e_schema.attribute_definitions()

                                                   if at != 'Bytes']

                rows_by_type[entity.e_schema] = [[display_name(req, rschema.type)

                                                  for rschema in rowdef_by_type[entity.e_schema]]]

            rows = rows_by_type[entity.e_schema]

            rows.append([entity.printable_value(rs.type, format='text/plain')

                         for rs in rowdef_by_type[entity.e_schema]])

        for rows in rows_by_type.itervalues():

            writer.writerows(rows)

            # use two empty lines as separator

            writer.writerows([[], []])