from pathlib import Path

from click.testing import CliRunner

from markitect_tool.cli import main
from markitect_tool.literate import (
    discover_code_chunks,
    tangle_markdown,
    weave_markdown,
    write_tangle_files,
)


LITERATE_DOC = """# Literate Example

```python {#helpers}
def helper():
    return "ready"
```

```python {#main tangle="src/app.py"}
<<helpers>>

def main():
    return helper()
```
"""


def test_discover_code_chunks_with_references_and_targets():
    chunks = discover_code_chunks(LITERATE_DOC, source_path="example.md")

    assert [chunk.chunk_id for chunk in chunks] == ["helpers", "main"]
    assert chunks[1].target_path == "src/app.py"
    assert chunks[1].references == ["helpers"]


def test_tangle_expands_named_chunk_references():
    result = tangle_markdown(LITERATE_DOC, source_path="example.md")

    assert result.valid
    assert len(result.files) == 1
    assert result.files[0].path == "src/app.py"
    assert "def helper" in result.files[0].content
    assert "<<helpers>>" not in result.files[0].content
    assert result.provenance[0].operation == "literate.tangle"


def test_tangle_reports_missing_chunk_reference():
    markdown = """```python {#main tangle="src/app.py"}
<<missing>>
```
"""

    result = tangle_markdown(markdown, source_path="example.md")

    assert not result.valid
    assert result.diagnostics[0].code == "literate.missing_chunk"


def test_weave_appends_chunk_index():
    result = weave_markdown(LITERATE_DOC, source_path="example.md")

    assert "## Code Chunk Index" in result.markdown
    assert "`main` -> `src/app.py`; refs: `helpers`" in result.markdown


def test_write_tangle_files(tmp_path: Path):
    result = tangle_markdown(LITERATE_DOC, source_path="example.md")

    written = write_tangle_files(result, tmp_path)

    assert written == [str(tmp_path / "src" / "app.py")]
    assert "def main" in (tmp_path / "src" / "app.py").read_text(encoding="utf-8")


def test_mkt_tangle_and_weave(tmp_path: Path):
    source = tmp_path / "literate.md"
    output_dir = tmp_path / "out"
    woven = tmp_path / "woven.md"
    source.write_text(LITERATE_DOC, encoding="utf-8")
    runner = CliRunner()

    tangle_result = runner.invoke(main, ["tangle", str(source), "--output-dir", str(output_dir)])
    weave_result = runner.invoke(main, ["weave", str(source), "--output", str(woven)])

    assert tangle_result.exit_code == 0
    assert "files: 1" in tangle_result.output
    assert (output_dir / "src" / "app.py").exists()
    assert weave_result.exit_code == 0
    assert "## Code Chunk Index" in woven.read_text(encoding="utf-8")