import tempfile
import unittest
from pathlib import Path

from rag.preview import preview_document


class PreviewTests(unittest.TestCase):
    def test_previews_manually_selected_strategy_with_custom_config(self):
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "faq.md"
            path.write_text("Q: 什么是净值？\nA: 基金单位价值。", encoding="utf-8")

            preview = preview_document(path, strategy="qa_pair", chunk_size=64, chunk_overlap=4)

            self.assertEqual(preview["strategy"], "qa_pair")
            self.assertEqual(preview["actual_strategy"], "qa_pair")
            self.assertEqual(len(preview["chunks"]), 1)
            self.assertEqual(preview["chunks"][0]["section_title"], None)

    def test_rejects_auto_strategy(self):
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "faq.md"
            path.write_text("普通文本", encoding="utf-8")

            with self.assertRaises(ValueError):
                preview_document(path, strategy="auto")

    def test_preview_reports_chapter_fallback(self):
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "notice.md"
            path.write_text("没有标题的普通文本", encoding="utf-8")

            preview = preview_document(path, strategy="chapter_semantic")

            self.assertEqual(preview["actual_strategy"], "default")
            self.assertTrue(preview["degraded"])
            self.assertTrue(preview["warning"])

    def test_preview_exposes_cleaning_warnings_and_uses_cleaned_text(self):
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "notice.md"
            path.write_text("\ufeff第一段\r\n\r\n\r\n第二段\t内容", encoding="utf-8")

            preview = preview_document(path, strategy="default")

            self.assertTrue(preview["cleaning_changed"])
            self.assertTrue(preview["cleaning_warnings"])
            self.assertEqual(preview["chunks"][0]["text"], "第一段")
            self.assertEqual(preview["chunks"][1]["text"], "第二段 内容")


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