diachron/express/logging.ts

// internal-logging.ts

import { cli } from "./cli";

// FIXME: Move this to somewhere more appropriate
type AtLeastOne<T> = [T, ...T[]];

type MessageSource = "logging" | "diagnostic" | "user";

type Message = {
    // FIXME: number probably isn't what we want here
    timestamp?: number;
    source: MessageSource;

    text: AtLeastOne<string>;
};

const m1: Message = { timestamp: 123, source: "logging", text: ["foo"] };
const m2: Message = {
    timestamp: 321,
    source: "diagnostic",
    text: ["ok", "whatever"],
};

type FilterArgument = {
    limit?: number;
    before?: number;
    after?: number;

    // FIXME: add offsets to use instead of or in addition to before/after

    match?: (string | RegExp)[];
};

const loggerUrl = `http://${cli.logAddress.host}:${cli.logAddress.port}`;

const log = (message: Message) => {
    const payload = {
        timestamp: message.timestamp ?? Date.now(),
        source: message.source,
        text: message.text,
    };

    fetch(`${loggerUrl}/log`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify(payload),
    }).catch((err) => {
        console.error("[logging] Failed to send log:", err.message);
    });
};

const getLogs = async (filter: FilterArgument): Promise<Message[]> => {
    const params = new URLSearchParams();
    if (filter.limit) {
        params.set("limit", String(filter.limit));
    }
    if (filter.before) {
-        params.set("before", String(filter.before));
    }
    if (filter.after) {
        params.set("after", String(filter.after));
    }

    const url = `${loggerUrl}/logs?${params.toString()}`;
    const response = await fetch(url);
    return response.json();
};

// FIXME: there's scope for more specialized functions although they
// probably should be defined in terms of the basic ones here.

export { getLogs, log };