/*
    Calendar - Save (create or update) a single event.
    POST: eventData (JSON string of event object)
*/
requirelib("filelib");

var evPath = "user:/Document/Calendar/events.json";

var ev;
try {
    ev = JSON.parse(eventData);
} catch (e) {
    sendJSONResp({ error: "Invalid event data" });
}

if (ev) {
    // Ensure the event has an id
    if (!ev.id || ev.id === "") {
        var ts    = new Date().getTime();
        ev.id = "ev_" + ts.toString(36) + Math.random().toString(36).slice(2, 7);
    }

    // Read existing events
    var events = [];
    if (filelib.fileExists(evPath)) {
        try {
            var raw    = filelib.readFile(evPath);
            var parsed = JSON.parse(raw);
            if (Array.isArray(parsed)) events = parsed;
        } catch (e) {}
    }

    // Upsert
    var found = false;
    for (var i = 0; i < events.length; i++) {
        if (events[i].id === ev.id) {
            events[i] = ev;
            found = true;
            break;
        }
    }
    if (!found) events.push(ev);

    filelib.writeFile(evPath, JSON.stringify(events));
    sendJSONResp({ ok: true, id: ev.id });
}