const opcodes = {
    0: { name: "HELLO", data: "JSON" },
    1: { name: "YOO", data: "JSON" },
    2: { name: "YOO_ACK", data: "JSON" },
    3: { name: "ACTION_CREATE_MESSAGE", data: "JSON" },
    4: { name: "EVENT_CREATE_MESSAGE", data: "JSON" },
    5: { name: "ACTION_UPDATE_STATUS", data: "JSON" },
    6: { name: "EVENT_CHANNEL_MEMBERS", data: "JSON" },
    7: { name: "ACTION_PING", data: "string" },
    21: { name: "ACTION_VOICE_REQUEST_SESSION", data: "JSON" },
    22: { name: "EVENT_VOICE_ASSIGN_SERVER", data: "JSON" },
    23: { name: "ACTION_VOICE_CONNECTION_REQUEST", data: "JSON" },
    24: { name: "EVENT_VOICE_CONNECTION_ANSWER", data: "JSON" },
    25: { name: "EVENT_RENEGOTIATE_REQUIRED", data: "JSON" },
    26: { name: "EVENT_TRACK_NOTIFICATION", data: "JSON" }
};

const opcodeSeparator = "@";

const parseMessage = (message) => {
    if (typeof message !== "string") throw new Error("msg: message not a string");
    const stringParts = message.split(opcodeSeparator);
    if (stringParts < 2) throw new Error("msg: message does not split into more than 2 parts");
    const components = [ stringParts.shift(), stringParts.join(opcodeSeparator) ];
    const op = parseInt(components[0]);
    if (isNaN(op)) throw new Error(`msg: message does not contain valid opcode: ${op}`);

    const opcodeData = opcodes[op];
    let data = components[1];
    if (!opcodeData) throw new Error(`msg: message contains unknown opcode ${op}`);
    if (opcodeData.data === "JSON") {
        data = JSON.parse(data);
    } else if (opcodeData.data === "string") {
        data = data.toString(); // NOTE: This isnt needed lol
    } else {
        throw new Error(`msg: invalid data type on opcode ${op}`);
    }

    return {
        opcode: op,
        data: data, 
        dataType: opcodeData.data,
        opcodeType: opcodeData.name || null
    };
};

const getOpcodeByName = (name) => {
    for (const [key, value] of Object.entries(opcodes)) if (value.name === name) return key;
};

const packet = (op, data) => {
    if (typeof op === "string") op = getOpcodeByName(op);
    return `${op}${opcodeSeparator}${JSON.stringify(data)}`;
};

module.exports = { opcodes, parseMessage, opcodeSeparator, getOpcodeByName, packet };