#!/usr/bin/env bash
# Phase 6 local platform gate: fixed-buffer recv + SEND_ZC echo integrity.
set -euo pipefail
ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
ECHO="${1:-$ROOT/build/naut_echo}"
PORT="${NAUT_ECHO_PORT:-39127}"
LOG="$(mktemp /tmp/naut_echo_scale.XXXXXX)"
cleanup() {
  [ -n "${server:-}" ] && kill -TERM "$server" 2>/dev/null || true
  [ -n "${server:-}" ] && wait "$server" 2>/dev/null || true
  rm -f "$LOG"
}
trap cleanup EXIT

NAUT_SQPOLL=1 "$ECHO" "$PORT" >"$LOG" 2>&1 &
server=$!
for _ in $(seq 1 100); do
  grep -q "echo listening" "$LOG" && break
  kill -0 "$server" 2>/dev/null || {
    echo "FAIL: echo server exited"; cat "$LOG"; exit 1;
  }
  sleep 0.05
done
grep -q "echo listening" "$LOG" || {
  echo "FAIL: echo server did not listen"; cat "$LOG"; exit 1;
}

BYTES=$((256 * 1024 * 1024))
CONNS=8
python3 "$ROOT/tests/integration/echo_client.py" "$PORT" "$BYTES" "$CONNS"
kill -TERM "$server"
wait "$server"
server=""
grep -q "bytes echoed" "$LOG" || {
  echo "FAIL: echo server did not shut down cleanly"; cat "$LOG"; exit 1;
}
grep "bytes echoed" "$LOG"

# Server-side accounting must match exactly: every byte the client sent was
# echoed back, and no connection was dropped mid-stream. (A truncated echo is
# also caught client-side, but asserting the count here makes a server-side
# drop a hard, deterministic failure rather than a timing-dependent one.)
echoed=$(grep -oE '[0-9]+ bytes echoed' "$LOG" | grep -oE '^[0-9]+')
if [ "$echoed" != "$BYTES" ]; then
  echo "FAIL: echoed $echoed bytes, expected $BYTES (a connection was dropped)"
  cat "$LOG"; exit 1
fi
conns=$(grep -oE '[0-9]+ conns' "$LOG" | grep -oE '^[0-9]+')
if [ "$conns" != "$CONNS" ]; then
  echo "FAIL: served $conns connections, expected $CONNS"; cat "$LOG"; exit 1
fi

# Report whether the SQPOLL path was actually exercised (it falls back cleanly
# where the kernel/privileges disallow it — informational, not a failure).
if grep -q "sqpoll" "$LOG"; then
  echo "PASS: io_uring SQPOLL fixed-buffer/SEND_ZC echo path is byte-correct"
else
  echo "PASS: io_uring echo path byte-correct (SQPOLL unavailable, used fallback)"
fi