Function eval_time_bucket

nodedb-query/src/functions/datetime.rs:190–221

`time_bucket(interval, timestamp)` — truncate a millisecond timestamp to the start of the given interval bucket. Accepts two argument orders (both common in SQL): - `time_bucket('1 hour', timestamp_col)` — interval first - `time_bucket(timestamp_col, '1 hour')` — timestamp first The interval is a string like `'1h'`, `'5m'`, `'1 hour'`, `'30 seconds'`. The timestamp is an integer (epoch milliseco

(args: &[Value])

/// The interval is a string like `'1h'`, `'5m'`, `'1 hour'`, `'30 seconds'`.
/// The timestamp is an integer (epoch milliseconds).
fn eval_time_bucket(args: &[Value]) -> Value {
    if args.len() < 2 {
        return Value::Null;
    }

    // Detect which arg is the interval string and which is the timestamp.
    let (interval_ms, timestamp_ms) = match (&args[0], &args[1]) {
        // time_bucket('1 hour', timestamp)
        (Value::String(s), ts_val) => {
            let interval = parse_interval_to_ms(s);
            let ts = value_to_timestamp_ms(ts_val);
            (interval, ts)
        }
        // time_bucket(timestamp, '1 hour')
        (ts_val, Value::String(s)) => {
            let interval = parse_interval_to_ms(s);
            let ts = value_to_timestamp_ms(ts_val);
            (interval, ts)
        }
        // time_bucket(3600, timestamp) — interval as integer seconds
        (Value::Integer(interval_secs), ts_val) => {
            let ts = value_to_timestamp_ms(ts_val);
            (Some((*interval_secs) * 1000), ts)
        }
        _ => return Value::Null,
    };

    match (interval_ms, timestamp_ms) {
        (Some(i), Some(ts)) if i > 0 => Value::Integer((ts / i) * i),
        _ => Value::Null,
    }
}

fn value_to_timestamp_ms(v: &Value) -> Option<i64> {
    match v {