import Toybox.Application;
import Toybox.Lang;
import Toybox.Time;

// Lightweight crash / diagnostic logger. Entries live in
// Application.Storage and are pruned with the same retention window
// as events so the watch storage never fills up.
module Logger {

    const KEY = "logs";
    const MAX_ENTRIES = 50;

    function log(msg as String) as Void {
        var raw = Application.Storage.getValue(KEY);
        var arr = (raw instanceof Array) ? raw : [];
        arr.add({
            "ts"  => Time.now().value(),
            "msg" => msg
        });
        if (arr.size() > MAX_ENTRIES) {
            arr = arr.slice(arr.size() - MAX_ENTRIES, arr.size());
        }
        Application.Storage.setValue(KEY, arr);
    }

    function getAll() as Array<Dictionary> {
        var raw = Application.Storage.getValue(KEY);
        return (raw instanceof Array) ? raw : [];
    }

    function pruneOld() as Void {
        var raw = Application.Storage.getValue(KEY);
        if (!(raw instanceof Array) || raw.size() == 0) {
            return;
        }
        var cutoff = Time.now().value() - Config.RETENTION_SEC;
        var kept = [];
        for (var i = 0; i < raw.size(); i++) {
            var d = raw[i] as Dictionary;
            var ts = d["ts"];
            if (ts != null && (ts as Number) >= cutoff) {
                kept.add(d);
            }
        }
        if (kept.size() != raw.size()) {
            Application.Storage.setValue(KEY, kept);
        }
    }
}