from __future__ import annotations

import sys
import unittest
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from mech_workbench.probes.source import parse_source_layers, parse_source_position

class SourceHelperTests(unittest.TestCase):
    def test_parse_source_layers_range_and_list(self):
        self.assertEqual(parse_source_layers("15-17,20,16"), [15, 16, 17, 20])

    def test_parse_source_layers_rejects_descending_range(self):
        with self.assertRaises(ValueError):
            parse_source_layers("20-15")

    def test_parse_source_position_accepts_all_and_single_positions(self):
        self.assertEqual(parse_source_position("sweep"), "sweep")
        self.assertEqual(parse_source_position("all"), "all")
        self.assertEqual(parse_source_position("LAST"), "last")
        self.assertEqual(parse_source_position("-1"), "-1")

    def test_parse_source_position_rejects_unknown(self):
        with self.assertRaises(ValueError):
            parse_source_position("entity")

if __name__ == "__main__":
    unittest.main()