"""Read only the explicitly required workflow reference for canonical impl skills."""
from pathlib import Path

NAMES = {"gitea-issue-implementation", "gitea-issue-rework"}
REQUIRED = "Required reference: [workflow](references/workflow.md)"

def read_contract(path):
    path = Path(path)
    text = path.read_text(encoding="utf-8")
    if path.name == "SKILL.md" and path.parent.name in NAMES:
        if REQUIRED not in text:
            raise AssertionError("impl skill does not require its canonical workflow reference")
        reference = path.parent / "references/workflow.md"
        if reference.is_symlink() or not reference.is_file():
            raise AssertionError("canonical workflow reference missing or symlinked")
        text += "\n" + reference.read_text(encoding="utf-8")
    return text