# Get everything! handles every single possible select query required
# by the app..
# note: field_map is not the nicest thing in the world..
# it should be replaced by something wiser sometime!
def query(g, params, tables, query_fields=None, query_op='ilike', what='*',
          join=None, where=None, field_map=None, group_by=None, order_by=None,
          include_total=True, debug=False):
    if query_fields is None:
        query_fields = ()
    if join is None:
        join = {}
    if where is None:
        where = {}
    if field_map is None:
        field_map = {}
    assert query_fields.__class__ is tuple
    cursor = g.db.cursor()
    if 'sort' in params:
        assert order_by is None
        sort_args = json.loads(params['sort'])
        order_by = ','.join(['%s %s' % (field_map.get(sa['property'],
                                                      sa['property']),
                                        sa['direction']) for sa in sort_args])

    # todo: put that somewhere that makes more sense
    comp_op_map = {'lt': '<', 'gt': '>', 'le': '<=', 'ge': '>=', 'eq': '='}

    if params.get('filter', '').strip():
        for filter_arg in json.loads(params['filter']):
            f = filter_arg['field']
            if filter_arg['type'] == 'string':
                s = set(['%%%s%%' % v for v in filter_arg['value'].split()])
                where[(field_map.get(f, f), 'ilike', 'unaccent')] = s
            elif filter_arg['type'] == 'list':
                where[field_map.get(f, f)] = tuple(filter_arg['value'])
            else:
                fav = filter_arg['value']
                where[(field_map.get(f, f),
                       comp_op_map[filter_arg.get('comparison', 'eq')])] = fav

    if params.get('query', '').strip():
        # autocomplete query
        if query_op.lower() in ['ilike', 'like']:
            # this is needed because the concat operator (||)
            # doesn't work with null values
            query_fields = ["coalesce(%s::text, '')" % ff
                            for ff in query_fields]
            s = set(['%%%s%%' % v for v in params['query'].split()])
            where[('||'.join(query_fields), query_op, 'unaccent')] = s
        # exact field query: assumes only 1 field,
        # because there is only 1 query value
        else:
            assert len(query_fields) == 1
            where[(query_fields[0], query_op)] = params['query']

    json_out = {'success': True}
    if include_total and not debug:
        json_out['total'] = pg.count(cursor, tables, what=what, join=join,
                                     where=where, group_by=group_by,
                                     debug_assert=False)
    json_out['rows'] = pg.select(cursor, tables, what=what, join=join,
                                 where=where, offset=params.get('start', None),
                                 limit=params.get('limit', None) or None,
                                 group_by=group_by, order_by=order_by,
                                 debug_assert=debug)
    return json_out