from __future__ import annotations

import tempfile
import unittest
from pathlib import Path

from techviz.document import build_context, canonicalize_document


class DocumentContextTests(unittest.TestCase):
    def test_extracts_current_and_neighbor_sections(self) -> None:
        text = """# Title

## Before

before fact

## Target

target fact

<!-- techviz:generate id=target -->

## After

after fact
"""
        with tempfile.TemporaryDirectory() as tmp:
            path = Path(tmp) / "doc.md"
            path.write_text(text, encoding="utf-8")
            context = build_context(path, marker_id="target")

        self.assertEqual(context["current_section"]["heading"]["text"], "Target")
        self.assertEqual(context["previous_section"]["heading"]["text"], "Before")
        self.assertEqual(context["next_section"]["heading"]["text"], "After")
        self.assertIn("target fact", context["numbered_context"])
        self.assertEqual(context["line_number_space"], "canonical-source-with-managed-blocks-collapsed")

    def test_generated_block_canonicalizes_to_original_marker(self) -> None:
        original = """# Title

## Target

fact

<!-- techviz:generate id=target -->

## After

more
"""
        rendered = """# Title

## Target

fact

<!-- techviz:begin id=target context-sha256=abc -->
<!-- techviz:generate id=target -->
![alt](target.svg)

<details><summary>Description</summary>Long description</details>
<!-- techviz:end id=target -->

## After

more
"""
        self.assertEqual(canonicalize_document(rendered), original)

        with tempfile.TemporaryDirectory() as tmp:
            original_path = Path(tmp) / "original.md"
            rendered_path = Path(tmp) / "rendered.md"
            original_path.write_text(original, encoding="utf-8")
            rendered_path.write_text(rendered, encoding="utf-8")
            original_context = build_context(original_path, marker_id="target")
            rendered_context = build_context(rendered_path, marker_id="target")
        self.assertEqual(original_context["document_sha256"], rendered_context["document_sha256"])
        self.assertEqual(original_context["numbered_context"], rendered_context["numbered_context"])

    def test_parent_preamble_is_trimmed_before_nested_target(self) -> None:
        with tempfile.TemporaryDirectory() as tmp:
            document = Path(tmp) / "nested.md"
            document.write_text(
                "# System\n\n"
                "## Parent\n\n"
                "Parent-level context.\n\n"
                "### Target\n\n"
                "Target details.\n\n"
                "<!-- techviz:generate id=nested -->\n\n"
                "### Following\n\n"
                "Following details.\n",
                encoding="utf-8",
            )
            context = build_context(document, marker_id="nested")
            previous = context["previous_section"]
            self.assertEqual(previous["heading"]["text"], "Parent")
            self.assertLess(previous["end_line"], context["current_section"]["start_line"])
            self.assertIn("Parent-level context.", previous["text"])
            self.assertNotIn("Target details.", previous["text"])
            self.assertEqual(context["next_section"]["heading"]["text"], "Following")


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