frc.py

import json
import time
import sys

configFile = "/boot/frc.json"
server = False
team = None

class CameraConfig: pass


def parseError(str):
    """Report parse error."""
    print("config error in '" + configFile + "': " + str, file=sys.stderr)

def readConfig():
    """Read configuration file."""
    global team
    global server

    # parse file
    try:
        with open(configFile, "rt", encoding="utf-8") as f:
            j = json.load(f)
    except OSError as err:
        print("could not open '{}': {}".format(configFile, err), file=sys.stderr)
        return False

    # top level must be an object
    if not isinstance(j, dict):
        parseError("must be JSON object")
        return False

    # team number
    try:
        team = j["team"]
    except KeyError:
        parseError("could not read team number")
        return False

    # ntmode (optional)
    if "ntmode" in j:
        str = j["ntmode"]
        if str.lower() == "client":
            server = False
        elif str.lower() == "server":
            server = True
        else:
            parseError("could not understand ntmode value '{}'".format(str))

    return True