"""Tests for text chunking."""

import unittest
from unittest.mock import patch

from converter import config
from converter.chunking import split_into_chunks


class ChunkSizeDefaultTests(unittest.TestCase):
    """Guard the request-size setting: each API call is one model
    generation, and the servers silently truncate audio when a single
    generation runs too long (~2.5 min faster backend, ~11 min Gradio
    demo), so the default chunk size must stay well inside that budget.
    There is no hard ceiling beyond CHUNK_SIZE; users raising it accept
    the truncation risk themselves."""

    def test_default_chunk_size_within_single_generation_budget(self):
        self.assertLessEqual(config.CHUNK_SIZE, 300)

    def test_default_chunk_size_is_positive(self):
        self.assertGreaterEqual(config.CHUNK_SIZE, 1)


class RequestSizeTests(unittest.TestCase):
    def test_oversized_chunk_size_is_honored(self):
        # No clamping: whatever size is configured (or requested) is used.
        text = " ".join(f"word{i}" for i in range(30)) + "."
        chunks = split_into_chunks(text, max_words=5000)
        self.assertEqual(len(chunks), 1)
        self.assertEqual(len(chunks[0].split()), 30)

    def test_default_uses_runtime_config_chunk_size(self):
        # The default resolves config.CHUNK_SIZE at call time, so
        # patching the config changes the default split size.
        sentences = " ".join(
            f"S{i} " + " ".join(["word"] * 8) + "." for i in range(60))
        with patch.object(config, "CHUNK_SIZE", 120):
            chunks = split_into_chunks(sentences)
        self.assertGreater(len(chunks), 1)
        self.assertTrue(all(len(chunk.split()) <= 120 for chunk in chunks))


class SplitIntoChunksTests(unittest.TestCase):
    def test_empty_input(self):
        self.assertEqual(split_into_chunks(""), [])
        self.assertEqual(split_into_chunks("   \n  "), [])

    def test_short_text_single_chunk(self):
        self.assertEqual(split_into_chunks("One short sentence."), ["One short sentence."])

    def test_respects_word_limit_across_sentences(self):
        # 10 sentences of 9 words each = 90 words total
        sentences = [f"S{i} " + " ".join(["word"] * 8) + "." for i in range(10)]
        chunks = split_into_chunks(" ".join(sentences), max_words=25)
        self.assertGreater(len(chunks), 1)
        self.assertTrue(all(len(c.split()) <= 25 for c in chunks))
        self.assertEqual(sum(len(c.split()) for c in chunks), 90)

    def test_long_sentence_split_keeps_punctuation(self):
        # 10 clauses of 5 words each, joined by comma+space
        sentence = ", ".join([" ".join(["w"] * 5) for _ in range(10)]) + "."
        chunks = split_into_chunks(sentence, max_words=12)
        self.assertGreater(len(chunks), 1)
        self.assertTrue(all(len(c.split()) <= 12 for c in chunks))
        self.assertIn(",", chunks[0])  # commas retained for TTS prosody

    def test_clause_split_never_breaks_numbers(self):
        # Regression: the clause split used to fire at every comma even
        # without whitespace, mutating "1,000,000" into "1, 000, 000".
        sentence = ("There were exactly 1,000,000 soldiers marching at 12:30, "
                    + "and they kept marching onward " * 30) + "endlessly."
        chunks = split_into_chunks(sentence, max_words=25)
        self.assertGreater(len(chunks), 1)
        joined = " ".join(chunks)
        self.assertIn("1,000,000", joined)
        self.assertIn("12:30", joined)
        self.assertNotIn("1, 000", joined)
        self.assertNotIn("000, 000", joined)
        self.assertNotIn("12: 30", joined)

    def test_clause_split_requires_whitespace_after_punctuation(self):
        # Run-on clauses without spaces after commas have no clause split
        # point, so the last-resort word-boundary split fires instead.
        # Tokens themselves (and numbers like "1,000,000") stay intact.
        sentence = ",".join([" ".join(["w"] * 5) for _ in range(10)]) + "."
        chunks = split_into_chunks(sentence, max_words=12)
        self.assertGreater(len(chunks), 1)
        self.assertTrue(all(len(chunk.split()) <= 12 for chunk in chunks))
        tokens = sentence.replace(",", " , ").split()
        rejoined = " ".join(chunks).replace(",", " , ").split()
        self.assertEqual(rejoined, tokens)

    def test_single_oversized_sentence_is_word_split(self):
        # A punctuation-free sentence longer than the limit is split at word
        # boundaries so no single request exceeds the configured size.
        sentence = " ".join(["word"] * 30) + "."
        chunks = split_into_chunks(sentence, max_words=10)
        self.assertGreater(len(chunks), 1)
        self.assertTrue(all(len(chunk.split()) <= 10 for chunk in chunks))
        self.assertEqual(sum(len(chunk.split()) for chunk in chunks), 30)

    def test_word_split_never_breaks_number_tokens(self):
        # Numbers and other punctuation-bearing tokens are single words and
        # must never be broken apart by the last-resort word split.
        sentence = ("There were exactly 1,000,000 soldiers marching at 12:30 "
                    "and " + "they kept marching onward " * 20) + "endlessly."
        chunks = split_into_chunks(sentence, max_words=10)
        self.assertGreater(len(chunks), 1)
        joined = " ".join(chunks)
        self.assertIn("1,000,000", joined)
        self.assertIn("12:30", joined)
        self.assertNotIn("1, 000", joined)
        self.assertNotIn("12: 30", joined)


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