from pathlib import Path

import pytest
from click.testing import CliRunner

from markitect_tool.cli import main
from markitect_tool.core import parse_markdown
from markitect_tool.reference import (
    ReferenceContext,
    ReferenceResolutionError,
    load_namespaces,
    parse_reference,
    resolve_reference,
)


def test_parse_reference_splits_namespace_fragment_and_selector():
    address = parse_reference("std:clauses/payment.md#section:fees::blocks[type=code]")

    assert address.namespace == "std"
    assert address.address == "clauses/payment.md"
    assert address.fragment == "section:fees"
    assert address.selector == "blocks[type=code]"


def test_load_namespaces_accepts_optional_colon_suffix():
    namespaces = load_namespaces({"namespaces": {"std:": "./standard", "src": "../src"}})

    assert namespaces == {"std": "./standard", "src": "../src"}


def test_resolve_path_reference_returns_document_unit(tmp_path: Path):
    context_file = tmp_path / "context.md"
    target_file = tmp_path / "target.md"
    context_file.write_text("# Context\n", encoding="utf-8")
    target_file.write_text("---\nid: target-doc\ntitle: Target\n---\n\n# Target\n\nBody.", encoding="utf-8")
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    resolution = resolve_reference("target.md", context=context)

    assert resolution.target_path == str(target_file.resolve())
    assert len(resolution.units) == 1
    assert resolution.units[0].kind == "document"
    assert resolution.units[0].unit_id == "target-doc"
    assert "# Target" in resolution.units[0].text


def test_resolve_namespace_reference_and_explicit_section_id(tmp_path: Path):
    standard = tmp_path / "standard"
    standard.mkdir()
    context_file = tmp_path / "context.md"
    clause_file = standard / "clauses.md"
    context_file.write_text(
        "---\nnamespaces:\n  std: ./standard\n---\n\n# Context\n",
        encoding="utf-8",
    )
    clause_file.write_text(
        "# Clauses\n\n## Payment Terms {#payment-terms}\n\nPay within 30 days.\n",
        encoding="utf-8",
    )
    document = parse_markdown(context_file.read_text(encoding="utf-8"), source_path=str(context_file))
    context = ReferenceContext.from_document(document, root=tmp_path)

    resolution = resolve_reference("std:clauses.md#section:payment-terms", context=context)

    assert resolution.units[0].kind == "section"
    assert resolution.units[0].unit_id == "payment-terms"
    assert resolution.units[0].name == "Payment Terms"
    assert "Pay within 30 days" in resolution.units[0].text


def test_resolve_selector_reference_uses_existing_query_engine(tmp_path: Path):
    standard = tmp_path / "standard"
    standard.mkdir()
    context_file = tmp_path / "context.md"
    source_file = standard / "clauses.md"
    context_file.write_text(
        "---\nnamespaces:\n  std: ./standard\n---\n\n# Context\n",
        encoding="utf-8",
    )
    source_file.write_text(
        "# Clauses\n\n## Warranty\n\nWarranty text.\n\n## Liability\n\nLiability text.\n",
        encoding="utf-8",
    )
    context = ReferenceContext.from_document(parse_markdown(context_file.read_text(encoding="utf-8"), str(context_file)), root=tmp_path)

    resolution = resolve_reference("std:clauses.md::sections[heading=Warranty]", context=context)

    assert [unit.kind for unit in resolution.units] == ["section"]
    assert resolution.units[0].name == "Warranty"
    assert "Liability" not in resolution.units[0].text


def test_resolve_pathless_fragment_uses_current_document(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text("# Context\n\n## Overview\n\nUseful local context.\n", encoding="utf-8")
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    resolution = resolve_reference("#overview", context=context)

    assert resolution.target_path == str(context_file.resolve())
    assert resolution.units[0].kind == "section"
    assert resolution.units[0].unit_id == "overview"
    assert "Useful local context" in resolution.units[0].text


def test_resolve_named_region_by_id_and_tag(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text(
        """# Context

<!-- mkt:region id="overview" tags="reuse summary" -->
Reusable region text.
<!-- /mkt:region -->
""",
        encoding="utf-8",
    )
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    by_id = resolve_reference("#region:overview", context=context)
    by_tag = resolve_reference("#tag:summary", context=context)

    assert by_id.units[0].kind == "region"
    assert by_id.units[0].text == "Reusable region text."
    assert by_tag.units[0].unit_id == "overview"


def test_resolve_fenced_block_by_id(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text(
        """# Context

```python {#load-config tags="code setup" tangle="src/config.py"}
def load_config():
    return {}
```
""",
        encoding="utf-8",
    )
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    resolution = resolve_reference("#fence:load-config", context=context)

    assert resolution.units[0].kind == "fenced_block"
    assert resolution.units[0].unit_id == "load-config"
    assert resolution.units[0].metadata["language"] == "python"
    assert resolution.units[0].metadata["attrs"]["tangle"] == "src/config.py"
    assert "def load_config" in resolution.units[0].text


def test_resolve_line_range_fragment(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text("# Context\n\nLine A\nLine B\nLine C\n", encoding="utf-8")
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    resolution = resolve_reference("#line:3-4", context=context)

    assert resolution.units[0].kind == "line_range"
    assert resolution.units[0].span.line_start == 3
    assert resolution.units[0].text == "Line A\nLine B"


def test_resolve_rejects_unknown_namespace(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text("# Context\n", encoding="utf-8")
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    with pytest.raises(ReferenceResolutionError, match="Unknown namespace"):
        resolve_reference("missing:doc.md", context=context)


def test_resolve_rejects_paths_outside_root(tmp_path: Path):
    context_file = tmp_path / "context.md"
    context_file.write_text("# Context\n", encoding="utf-8")
    context = ReferenceContext(root=tmp_path, current_path=context_file)

    with pytest.raises(ReferenceResolutionError, match="escapes root"):
        resolve_reference("../outside.md", context=context)


def test_mkt_ref_resolve_outputs_text(tmp_path: Path):
    context_file = tmp_path / "context.md"
    target_file = tmp_path / "target.md"
    context_file.write_text("# Context\n", encoding="utf-8")
    target_file.write_text("# Target\n\n## Decision\n\nChosen.", encoding="utf-8")

    result = CliRunner().invoke(
        main,
        ["ref", "resolve", str(context_file), "target.md#decision", "--root", str(tmp_path)],
    )

    assert result.exit_code == 0
    assert "1 unit(s)" in result.output
    assert "section decision" in result.output
    assert "Decision" in result.output