1# Parser for test templates
2#
3# Copyright (c) 2021 Virtuozzo International GmbH.
4#
5# This program is free software; you can redistribute it and/or modify
6# it under the terms of the GNU General Public License as published by
7# the Free Software Foundation; either version 2 of the License, or
8# (at your option) any later version.
9#
10# This program is distributed in the hope that it will be useful,
11# but WITHOUT ANY WARRANTY; without even the implied warranty of
12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13# GNU General Public License for more details.
14#
15# You should have received a copy of the GNU General Public License
16# along with this program.  If not, see <http://www.gnu.org/licenses/>.
17#
18
19import itertools
20from lark import Lark
21
22grammar = """
23start: ( text | column_switch | row_switch )+
24
25column_switch: "{" text ["|" text]+ "}"
26row_switch: "[" text ["|" text]+ "]"
27text: /[^|{}\[\]]+/
28"""
29
30parser = Lark(grammar)
31
32class Templater:
33    def __init__(self, template):
34        self.tree = parser.parse(template)
35
36        c_switches = []
37        r_switches = []
38        for x in self.tree.children:
39            if x.data == 'column_switch':
40                c_switches.append([el.children[0].value for el in x.children])
41            elif x.data == 'row_switch':
42                r_switches.append([el.children[0].value for el in x.children])
43
44        self.columns = list(itertools.product(*c_switches))
45        self.rows = list(itertools.product(*r_switches))
46
47    def gen(self, column, row):
48        i = 0
49        j = 0
50        result = []
51
52        for x in self.tree.children:
53            if x.data == 'text':
54                result.append(x.children[0].value)
55            elif x.data == 'column_switch':
56                result.append(column[i])
57                i += 1
58            elif x.data == 'row_switch':
59                result.append(row[j])
60                j += 1
61
62        return ''.join(result)
63