import sys
import unittest
from pathlib import Path

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

from stages.alignment_edits import AlignmentHeuristicEngine
from stages.asr_whisper import AsrWord


def _words(tokens: list[str], step: float = 0.2) -> list[AsrWord]:
    out: list[AsrWord] = []
    start = 0.0
    for token in tokens:
        out.append(
            AsrWord(
                text=token,
                start_s=start,
                end_s=start + 0.1,
                prob=0.9,
            )
        )
        start += step
    return out


class AlignmentHeuristicEngineTests(unittest.TestCase):
    def test_returns_original_when_no_words_available(self):
        engine = AlignmentHeuristicEngine()

        result = engine.apply("hello world", [])

        self.assertEqual(result.draft_text, "hello world")
        self.assertEqual(result.applied_count, 0)
        self.assertEqual(result.decisions, [])

    def test_applies_i_mean_tail_correction(self):
        engine = AlignmentHeuristicEngine()
        words = _words(["set", "alarm", "for", "6", "i", "mean", "7"])

        result = engine.apply("set alarm for 6 i mean 7", words)

        self.assertEqual(result.draft_text, "set alarm for 7")
        self.assertEqual(result.applied_count, 1)
        self.assertTrue(any(item.rule_id == "cue_correction" for item in result.decisions))

    def test_preserves_literal_i_mean_context(self):
        engine = AlignmentHeuristicEngine()
        words = _words(["write", "exactly", "i", "mean", "this", "sincerely"])

        result = engine.apply("write exactly i mean this sincerely", words)

        self.assertEqual(result.draft_text, "write exactly i mean this sincerely")
        self.assertEqual(result.applied_count, 0)
        self.assertGreaterEqual(result.skipped_count, 1)

    def test_collapses_exact_restart_repetition(self):
        engine = AlignmentHeuristicEngine()
        words = _words(["please", "send", "it", "please", "send", "it"])

        result = engine.apply("please send it please send it", words)

        self.assertEqual(result.draft_text, "please send it")
        self.assertEqual(result.applied_count, 1)
        self.assertTrue(any(item.rule_id == "restart_repeat" for item in result.decisions))


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