/*
    Calendar - Save (merge) an array of events (used for ICS import).
    POST: eventsData (JSON array string)
*/
requirelib("filelib");

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

var incoming;
try {
    incoming = JSON.parse(eventsData);
} catch (e) {
    sendJSONResp({ error: "Invalid events data" });
}

if (incoming && Array.isArray(incoming)) {
    // 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) {}
    }

    // Build index of existing events by id
    var idx = {};
    for (var i = 0; i < events.length; i++) {
        idx[events[i].id] = i;
    }

    var added = 0;
    var ts = new Date().getTime();
    for (var j = 0; j < incoming.length; j++) {
        var ev = incoming[j];
        if (!ev.id || ev.id === "") {
            ev.id = "ev_" + (ts + j).toString(36) + Math.random().toString(36).slice(2, 7);
        }
        if (idx[ev.id] !== undefined) {
            events[idx[ev.id]] = ev;
        } else {
            events.push(ev);
            added++;
        }
    }

    filelib.writeFile(evPath, JSON.stringify(events));
    sendJSONResp({ ok: true, added: added, total: events.length });
}