import sys
import os
import json

CONSTRUCTED_CONFIG_FILE = "/tmp/runner-config.json"


def main() -> str:
    try:
        config = {
            "registration_token": os.environ["SEMAPHORE_RUNNER_REGISTRATION_TOKEN"],
            "config_file": os.getenv(
                "SEMAPHORE_RUNNER_CONFIG_FILE", "/semaphore/runner.json"
            ),
            "api_url": os.environ["SEMAPHORE_RUNNER_API_URL"],
            "max_parallel_tasks": int(
                os.getenv("SEMAPHORE_RUNNER_MAX_PARALLEL_TASKS", "1")
            ),
        }
    except KeyError as err:
        print(f"Missing required configuration value {err}", file=sys.stderr)
        sys.exit(1)

    with open(CONSTRUCTED_CONFIG_FILE, "w") as outfile:
        json.dump(config, outfile, indent=4)

    sys.exit(0)


if __name__ == "__main__":
    main()