#!/usr/bin/env bash
# Reports per-run, for foundation suite, -j 4:
#   - wall      : total `flutter test` invocation time
#   - first     : compile time for the first test file (cache miss)
#   - subseq    : average compile time per subsequent file (cache hit / miss)
#   - total     : sum of all per-file compile times
#
# The "subseq" and "total" rows are the ones the PR moves; "wall" is dominated
# by test execution and is reported for completeness.

set -euo pipefail

FLUTTER_ROOT="${FLUTTER_ROOT:-$(pwd)}"
FLUTTER="$FLUTTER_ROOT/bin/flutter"
TARGET="$FLUTTER_ROOT/packages/flutter/test/foundation/"
RUNS="${RUNS:-3}"

cd "$FLUTTER_ROOT/packages/flutter"

bench_one() {
  local name="$1" log
  log=$(mktemp)
  local start end ms
  start=$(date +%s%N)
  "$FLUTTER" test -j 4 -v "$TARGET" >"$log" 2>&1
  end=$(date +%s%N)
  ms=$(( (end - start) / 1000000 ))

  local compiles n first sum rest_avg
  compiles=$(grep -oP 'Compiling .+ took \K\d+(?=ms)' "$log" || true)
  n=$(echo "$compiles" | grep -c . || true)
  first=$(echo "$compiles" | head -1)
  sum=$(echo "$compiles" | awk '{s+=$1} END{print s+0}')
  rest_avg=0
  if [[ "$n" -gt 1 ]]; then
    rest_avg=$(echo "$compiles" | tail -n +2 | awk '{s+=$1} END{print int(s/NR)}')
  fi
  printf "  %-8s wall=%5dms  first=%4dms  subseq=%3dms (n=%d)  total=%5dms\n" \
    "$name" "$ms" "$first" "$rest_avg" "$((n-1))" "$sum"
  rm -f "$log"
}

echo "Foundation suite (32 files, ~220 tests), -j 4, $RUNS runs + 1 warmup"
echo "Commit: $(cd "$FLUTTER_ROOT" && git rev-parse --short HEAD) ($(cd "$FLUTTER_ROOT" && git status --porcelain | wc -l) modified files)"
bench_one "warmup"
for i in $(seq 1 "$RUNS"); do
  bench_one "run_$i"
done