"""Tests for parent/child delimiter splitting."""

from __future__ import annotations

import tempfile
import unittest
from pathlib import Path

from rag_cut.models import Block, BlockType, SplitConfig, SplitMode
from rag_cut.pipeline import chunk_document
from rag_cut.splitters.parent_child import split_by_parent_child


def p(text: str) -> Block:
    return Block(type=BlockType.PARAGRAPH, text=text)


class ParentChildSplitTest(unittest.TestCase):
    def test_parent_and_child_chunks_are_linked(self) -> None:
        blocks = [p("Intro A##Detail A1###Detail A2##Intro B###Detail B1")]
        groups = split_by_parent_child(
            blocks,
            SplitConfig(
                mode=SplitMode.PARENT_CHILD,
                parent_delimiter="##",
                child_delimiter="###",
                max_chunk_size=2000,
                child_max_size=500,
                overlap=0,
            ),
        )

        parents = [g for g in groups if g.meta.get("is_section_parent")]
        children = [g for g in groups if g.meta.get("is_sub_chunk")]
        self.assertGreaterEqual(len(parents), 2)
        self.assertGreaterEqual(len(children), 2)
        self.assertTrue(all(g.meta.get("retrieval") is False for g in parents))
        self.assertTrue(all(g.meta.get("retrieval") is True for g in children))
        self.assertTrue(all(g.meta.get("parent_section_id") for g in children))

    def test_requires_parent_delimiter(self) -> None:
        with self.assertRaises(ValueError):
            split_by_parent_child(
                [p("hello")],
                SplitConfig(mode=SplitMode.PARENT_CHILD, parent_delimiter=None),
            )

    def test_pipeline_persists_parent_chunk_ids(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            source = Path(tmp) / "pc.md"
            source.write_text(
                "Alpha parent##A1 child###A2 child##Beta parent###B1 child",
                encoding="utf-8",
            )
            result = chunk_document(
                source,
                config=SplitConfig(
                    mode=SplitMode.PARENT_CHILD,
                    parent_delimiter="##",
                    child_delimiter="###",
                    max_chunk_size=2000,
                    child_max_size=400,
                    overlap=0,
                ),
                storage_root=Path(tmp) / "storage",
            )

        self.assertEqual(result.split_mode, SplitMode.PARENT_CHILD)
        self.assertEqual(result.split_config.get("chunk_strategy"), "parent_child_delimiter")
        parents = [c for c in result.chunks if c.meta.get("is_section_parent")]
        children = [c for c in result.chunks if c.meta.get("is_sub_chunk")]
        self.assertTrue(parents)
        self.assertTrue(children)
        for child in children:
            self.assertIn("parent_chunk_id", child.meta)
            self.assertIsInstance(child.meta["parent_chunk_id"], int)


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