"""
The node's WebRTC transport, as source text, for the hub tests that check a
client contract against what the node actually sends.

Read from the tree rather than imported, so these tests keep working in a
checkout without the node installed. The file set is derived — the transport
is `webrtc_server.py` and whatever has been split out of it under
`transport/webrtc/` — so that code moving between those files does not leave a
test reading a file its subject has left. The node suite's `node_source.py`
draws the same line and holds it with `test_node_source_scope.py`.
"""

import ast
from pathlib import Path

# parents[2] is `packages/`: the tests live at packages/meshbay-hub/tests/. A
# wrong index here does not fail anything — every test using it skips, which
# is worse than not having them: a green run that measured nothing. That
# happened once.
TRANSPORT = (Path(__file__).resolve().parents[2] / "meshbay-node" / "src"
             / "meshbay_node" / "transport")
SERVER = TRANSPORT / "webrtc_server.py"


def available() -> bool:
    return SERVER.exists()


def webrtc_files() -> list[Path]:
    files = [SERVER]
    package = TRANSPORT / "webrtc"
    if package.is_dir():
        files += sorted(p for p in package.rglob("*.py")
                        if "__pycache__" not in p.parts)
    return files


def webrtc_source() -> str:
    return "\n".join(p.read_text(encoding="utf-8") for p in webrtc_files())


def method(name: str) -> str:
    """The text of one method of a class in the transport, found by name."""
    found = []
    for path in webrtc_files():
        text = path.read_text(encoding="utf-8")
        for node in ast.walk(ast.parse(text)):
            if isinstance(node, ast.ClassDef):
                for member in node.body:
                    if isinstance(member, (ast.FunctionDef, ast.AsyncFunctionDef)) \
                            and member.name == name:
                        found.append(ast.get_source_segment(text, member, padded=True))
    assert len(found) == 1, f"{name}: expected one definition, found {len(found)}"
    return found[0]