import argparse
import codeowners
import os

def find_codeowners_path(p):
    """Searches the folder containing the path 'p' and all parents until
       a CODEOWNERS file is found.  Returns 'None' if no file is found."""
    head, tail = os.path.split(p)
    if tail == '':
        return None
    co_path = os.path.join(head, 'CODEOWNERS')
    if os.path.exists(co_path):
        return os.path.normpath(co_path)
    else:
        return find_codeowners_path(head)

def make_relative(root, path):
    """Converts a path to a unix-style path relative to the root folder"""
    p = os.path.normpath(os.path.abspath(path))
    abs_root = os.path.abspath(root)
    prefix = os.path.commonprefix([abs_root, p])
    if prefix != abs_root:
        raise Exception(f'{p} does not exist under the root folder {abs_root}')
    relpath = os.path.relpath(p, abs_root)
    return relpath.replace('\\', '/')

def describe_owners(file_path):
    co_path = find_codeowners_path(file_path)
    if co_path:
        owners = get_owners(co_path)
        rel_path = make_relative(os.path.split(co_path)[0], file_path)
        results = owners.of(rel_path)
        if len(results) == 0:
            print(f'"{file_path}",none,"No matching entries in CODEOWNERS"')
        else:
            for result in results:
                print(f'"{file_path}",{result[0].lower()},"{result[1]}"')
    else:
        print(f'"{file_path}",none,"Unable to find CODEOWNERS file"')

def get_owners(co_path):
    """Get a CodeOwners object for the specified CODEOWNERS file path"""
    with open(co_path, "rt") as f:
        # process the file to remove leading /'s which don't seem to be handled properly by the
        # codeowners python module.
        contents = []
        for line in f.readlines():
            stripped_line = line.strip()
            if stripped_line.startswith('/'):
                stripped_line = stripped_line[1:]
            contents.append(stripped_line)
        processed = "\n".join(contents)
        
        return codeowners.CodeOwners(processed)

def main():
    parser = argparse.ArgumentParser(description="Show user/team ownership information for specified files")
    parser.add_argument("files", nargs='+')
    args = parser.parse_args()

    print('file,owner_type,owner')
    for file in args.files:
        describe_owners(file)

if __name__ == "__main__":
    main()