import os
import sys

def check_environment() -> None:
    """
    This function checks if required environment variables are set. It prints
    problem resolution guide and exits using `sys.exit(1)` on problem.
    """
    if "MATRIX_HOMESERVER" not in os.environ:
        print("Please set `MATRIX_HOMESERVER` environment variable!")
        print("P.S. use something like this in your shell:")
        print("    export MATRIX_HOMESERVER=\"https://matrix.server.net\"")
        sys.exit(1)
    if "MATRIX_USERNAME" not in os.environ:
        print("Please set `MATRIX_USERNAME` environment variable!")
        print("P.S. use something like this in your shell:")
        print("    export MATRIX_USERNAME=\"megakiller228\"")
        sys.exit(1)