#!/usr/bin/env python3

# For various reasons we need the contents of certain files to be
# duplicated in two places, for example stdlib/2/builtins.pyi and
# stdlib/2/__builtin__.pyi must be identical.  In the past we used
# symlinks but that doesn't always work on Windows, so now you must
# manually update both files, and this test verifies that they are
# identical.  The list below indicates which sets of files must match.

import filecmp
import os

consistent_files = [
    {"stdlib/2/builtins.pyi", "stdlib/2/__builtin__.pyi"},
    {"stdlib/2and3/threading.pyi", "stdlib/2and3/_dummy_threading.pyi"},
]


def main():
    files = [os.path.join(root, file) for root, dir, files in os.walk(".") for file in files]
    no_symlink = "You cannot use symlinks in typeshed, please copy {} to its link."
    for file in files:
        _, ext = os.path.splitext(file)
        if ext == ".pyi" and os.path.islink(file):
            raise ValueError(no_symlink.format(file))
    for file1, *others in consistent_files:
        f1 = os.path.join(os.getcwd(), file1)
        for file2 in others:
            f2 = os.path.join(os.getcwd(), file2)
            if not filecmp.cmp(f1, f2):
                raise ValueError(
                    "File {f1} does not match file {f2}. Please copy it to {f2}\n"
                    "Run either:\ncp {f1} {f2}\nOr:\ncp {f2} {f1}".format(f1=file1, f2=file2)
                )


if __name__ == "__main__":
    main()