#!/usr/bin/env bash
set -euo pipefail

# Compare memory efficiency (Max RSS) between HAKMEM and System on tiny-hot bench.
# - Runs selected sizes/batches with /usr/bin/time -v and parses Maximum resident set size (KB).
# - Optionally toggles HAKMEM_TINY_FLUSH_ON_EXIT to evaluate exit-time trimming.
# Output: bench_results/memory_eff_YYYYMMDD_HHMMSS/results.csv
# Usage: scripts/run_memory_efficiency.sh [cycles]

ROOT_DIR=$(cd "$(dirname "$0")/.." && pwd)
cd "$ROOT_DIR"

cycles=${1:-60000}

if [[ ! -x /usr/bin/time ]]; then
  echo "[error] /usr/bin/time not found. Install 'time' package." >&2
  exit 1
fi

echo "[build] perf_main benches (no bench-only macros)"
make -s perf_main >/dev/null

TS=$(date +%Y%m%d_%H%M%S)
OUTDIR="bench_results/memory_eff_${TS}"
mkdir -p "$OUTDIR"
CSV="$OUTDIR/results.csv"
echo "allocator,size,batch,cycles,flush_on_exit,max_rss_kb,elapsed_ms" > "$CSV"

sizes=(32 64 128)
batches=(100)

run_case() {
  local alloc="$1"; shift
  local size="$1"; shift
  local batch="$1"; shift
  local cyc="$1"; shift
  local flush="$1"; shift
  local bin
  if [[ "$alloc" == "hakmem" ]]; then bin=./bench_tiny_hot_hakmem; else bin=./bench_tiny_hot_system; fi
  local tmp_log="$OUTDIR/tmp_${alloc}_${size}_${batch}_${cyc}_${flush}.log"
  local tmp_out="$OUTDIR/tmp_${alloc}_${size}_${batch}_${cyc}_${flush}.out"
  if [[ "$alloc" == "hakmem" ]]; then
    HAKMEM_TINY_FLUSH_ON_EXIT="$flush" /usr/bin/time -v "$bin" "$size" "$batch" "$cyc" >"$tmp_out" 2>"$tmp_log" || true
  else
    /usr/bin/time -v "$bin" "$size" "$batch" "$cyc" >"$tmp_out" 2>"$tmp_log" || true
  fi
  local rss=$(sed -n 's/^\s*Maximum resident set size (kbytes): \([0-9]\+\).*/\1/p' "$tmp_log" | tail -1)
  local elapsed=$(sed -n 's/^\s*Elapsed (wall clock) time (h:mm:ss or m:ss): \(.*\)/\1/p' "$tmp_log" | tail -1)
  # convert elapsed to ms (best-effort; handles m:ss or h:mm:ss)
  local ms=0
  if [[ -n "$elapsed" ]]; then
    local e1="" e2="" e3=""
    IFS=: read -r e1 e2 e3 <<<"$elapsed" || true
    if [[ -n "$e3" ]]; then
      # h:m:s
      ms=$(( (10#${e1}*3600 + 10#${e2}*60) * 1000 ))
      ms=$(( ms + (10#${e3%.*})*1000 ))
    else
      # m:s
      ms=$(( (10#${e1}*60) * 1000 ))
      ms=$(( ms + (10#${e2%.*})*1000 ))
    fi
  fi
  echo "$alloc,$size,$batch,$cyc,$flush,${rss:-},${ms:-}" >> "$CSV"
}

for s in "${sizes[@]}"; do
  for b in "${batches[@]}"; do
    echo "[run] SYSTEM size=$s batch=$b cycles=$cycles"
    run_case system "$s" "$b" "$cycles" 0
    echo "[run] HAKMEM (flush=0) size=$s batch=$b cycles=$cycles"
    run_case hakmem "$s" "$b" "$cycles" 0
    echo "[run] HAKMEM (flush=1) size=$s batch=$b cycles=$cycles"
    run_case hakmem "$s" "$b" "$cycles" 1
  done
done

echo "[done] CSV: $CSV"
sed -n '1,40p' "$CSV" || true