import re
from pathlib import Path


class CopybookPreprocessor:
    def __init__(self, paths=None):
        self.paths = paths or ["./copybooks"]

    def expand(self, text: str) -> str:
        def _rep(m):
            n = m.group(1).strip()
            for p in self.paths:
                for e in ("", ".cpy", ".cbl"):
                    f = Path(p) / f"{n}{e}"
                    if f.exists():
                        return f"      *> COPY {n}\n{f.read_text()}\n      *> END COPY {n}"
            return f"      *> COPY {n} NOT FOUND"
        return re.sub(r'^       COPY\s+(\w+(?:-\w+)?)\s*\.', _rep, text, flags=re.MULTILINE)