#!/usr/bin/env bash
# SUM Parts - compare early vs recent per-iteration speed in a running train log
#
# Separates "each iteration got slower" from "something between epochs got
# slower" (validation, checkpointing, dataloader restart).
set -uo pipefail

RUNROOT="$HOME/sum-parts/runs"
WORKDIR="${1:-$(cat "$RUNROOT/.latest" 2>/dev/null)}"
LOG="$WORKDIR/train.log"

[ -f "$LOG" ] || { echo "no train.log at ${WORKDIR:-<unset>}"; exit 1; }

echo "log: $LOG"
echo

echo "=== earliest 15 rate readings ==="
grep -oE '[0-9.]+(s/it|it/s)' "$LOG" | head -15 | tr '\n' ' '
echo
echo

echo "=== most recent 15 rate readings ==="
grep -oE '[0-9.]+(s/it|it/s)' "$LOG" | tail -15 | tr '\n' ' '
echo
echo

echo "=== Train Epoch progress lines (first / last) ==="
grep -oE 'Train Epoch \[[0-9]+/[0-9]+\] Loss [0-9.]+ Acc [0-9.]+' "$LOG" | head -3
echo "  ..."
grep -oE 'Train Epoch \[[0-9]+/[0-9]+\] Loss [0-9.]+ Acc [0-9.]+' "$LOG" | tail -3
echo

echo "=== log growth ==="
echo "  size      : $(du -h "$LOG" | cut -f1)"
echo "  last write: $(date -r "$LOG" '+%F %T')  (now $(date '+%F %T'))"