#!/usr/bin/env bash
# build.sh - Unified build wrapper (Phase 7 + Pool TLS) with discoverable help
#
# Quick use:
#   ./build.sh bench_pool_tls_hakmem        # Recommended target
#   ./build.sh help                         # Show usage/hints/ENV
#   ./build.sh verify bench_pool_tls_hakmem # Check freshness
#
# Notes:
# - Flags are pinned to avoid drift (see below). You can pass extra make flags via
#   EXTRA_MAKEFLAGS, e.g. EXTRA_MAKEFLAGS="HAKMEM_DEBUG_VERBOSE=1" ./build.sh <target>
# - Arena ENV (Pool TLS): HAKMEM_POOL_TLS_ARENA_MB_INIT/MAX/GROWTH_LEVELS
# - See also: docs/BUILDING_QUICKSTART.md

set -euo pipefail

FLAVOR="release"
if [[ $# -gt 0 && ( "$1" == "release" || "$1" == "debug" ) ]]; then
  FLAVOR="$1"; shift
fi
TARGET="${1:-bench_mid_large_mt_hakmem}"

usage() {
  cat <<'USAGE'
=========================================
 HAKMEM Build Script (help)
=========================================
Usage:
  ./build.sh <target>
  ./build.sh help            # Show this help
  ./build.sh list            # Show common targets
  ./build.sh verify <bin>    # Verify binary freshness

Common targets (curated):
  - bench_random_mixed_hakmem
  - bench_pool_tls_hakmem
  - bench_mid_large_mt_hakmem
  - larson_hakmem

Pinned build flags (by default):
  POOL_TLS_PHASE1=1 HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 PREWARM_TLS=1 POOL_TLS_PREWARM=1 POOL_TLS_BIND_BOX=1

Extra flags (optional):
  Use environment var EXTRA_MAKEFLAGS, e.g.:
    EXTRA_MAKEFLAGS="HAKMEM_DEBUG_VERBOSE=1" ./build.sh bench_pool_tls_hakmem
    EXTRA_MAKEFLAGS="HAKMEM_TINY_SAFE_FREE=1" ./build.sh bench_random_mixed_hakmem

Pool TLS Arena ENV (A/B friendly):
  export HAKMEM_POOL_TLS_ARENA_MB_INIT=2   # default 1
  export HAKMEM_POOL_TLS_ARENA_MB_MAX=16   # default 8
  export HAKMEM_POOL_TLS_ARENA_GROWTH_LEVELS=4  # default 3

Verify & perf tips:
  make print-flags
  ./verify_build.sh <bin>
  perf stat -e cycles,instructions,branches,branch-misses,cache-misses -r 3 -- ./<bin> ...
  strace -e trace=mmap,madvise,munmap -c ./<bin> ...
USAGE
}

list_targets() {
  cat <<'LIST'
Common build targets:
  bench_random_mixed_hakmem    # Tiny 1T mixed
  bench_pool_tls_hakmem        # Pool TLS (8–52KB)
  bench_mid_large_mt_hakmem    # Mid-Large MT (8–32KB)
  larson_hakmem                # Larson mixed
  bench_random_mixed_system    # glibc baseline
  bench_pool_tls_system        # glibc baseline (PoolTLS workload)
  bench_mid_large_mt_system    # glibc baseline (Mid-Large workload)
LIST
}

if [[ "${TARGET}" == "help" || "${TARGET}" == "-h" || "${TARGET}" == "--help" ]]; then
  usage
  exit 0
fi

if [[ "${TARGET}" == "list" ]]; then
  list_targets
  exit 0
fi

if [[ "${TARGET}" == "verify" ]]; then
  BIN="${2:-}"
  if [[ -z "${BIN}" ]]; then
    echo "Usage: ./build.sh verify <binary>" >&2
    exit 2
  fi
  ./verify_build.sh "${BIN}"
  exit 0
fi

echo "========================================="
echo " HAKMEM Build Script"
echo " Flavor: ${FLAVOR}"
echo " Target: ${TARGET}"
echo " Flags:  POOL_TLS_PHASE1=${POOL_TLS_PHASE1:-0} POOL_TLS_PREWARM=${POOL_TLS_PREWARM:-0} POOL_TLS_BIND_BOX=${POOL_TLS_BIND_BOX:-0} DISABLE_MINCORE=${DISABLE_MINCORE:-0} HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 PREWARM_TLS=1 ${EXTRA_MAKEFLAGS:-}"
echo "========================================="

# Always clean to avoid stale objects when toggling flags
make clean >/dev/null 2>&1 || true

# Phase 7 + Pool TLS defaults (pinned) + user extras
# Default: Target-specific Pool TLS settings
# - Mid-Large targets (8-34KB workloads) → Pool TLS ON (critical for performance)
# - Tiny targets (≤1KB workloads) → Pool TLS OFF (avoid TLS overhead for short benchmarks)
case "${TARGET}" in
  bench_mid_large_mt_hakmem|bench_pool_tls_hakmem|bench_mid_large_mt_system|bench_pool_tls_system|larson_hakmem|larson_mi|larson_system)
    POOL_TLS_PHASE1_DEFAULT=${POOL_TLS_PHASE1:-1}  # ON for Mid-Large and mixed workloads
    ;;
  *)
    POOL_TLS_PHASE1_DEFAULT=${POOL_TLS_PHASE1:-0}  # OFF for Tiny-focused benchmarks
    ;;
esac
POOL_TLS_PREWARM_DEFAULT=${POOL_TLS_PREWARM:-0}
POOL_TLS_BIND_BOX_DEFAULT=${POOL_TLS_BIND_BOX:-0}
DISABLE_MINCORE_DEFAULT=${DISABLE_MINCORE:-0}

MAKE_ARGS=(
  BUILD_FLAVOR=${FLAVOR} \
  POOL_TLS_PHASE1=${POOL_TLS_PHASE1_DEFAULT} \
  POOL_TLS_PREWARM=${POOL_TLS_PREWARM_DEFAULT} \
  POOL_TLS_BIND_BOX=${POOL_TLS_BIND_BOX_DEFAULT} \
  DISABLE_MINCORE=${DISABLE_MINCORE_DEFAULT} \
  HEADER_CLASSIDX=1 \
  AGGRESSIVE_INLINE=1 \
  PREWARM_TLS=1 \
)

# Apply debug flavor extras (non-invasive): verbose + safe-free optional
if [[ "${FLAVOR}" == "debug" ]]; then
  MAKE_ARGS+=(HAKMEM_DEBUG_VERBOSE=1)
  MAKE_ARGS+=(BUILD_RELEASE_DEFAULT=0)  # Disable release mode for debug builds
  # Uncomment to enable extra safety by default for debug runs (may slow hot path)
  # MAKE_ARGS+=(HAKMEM_TINY_SAFE_FREE=1)
else
  MAKE_ARGS+=(BUILD_RELEASE_DEFAULT=1)  # Enable release mode for release builds
fi

# Append user-provided extras and target
if [[ -n "${EXTRA_MAKEFLAGS:-}" ]]; then
  # shellcheck disable=SC2206
  MAKE_ARGS+=(${EXTRA_MAKEFLAGS})
fi
MAKE_ARGS+=("${TARGET}")

make "${MAKE_ARGS[@]}"

echo ""
echo "========================================="
echo " ✅ Build successful"
echo " Run: ./${TARGET}"
echo "-----------------------------------------"
# Place artifacts under out/<flavor>/
OUTDIR="out/${FLAVOR}"
mkdir -p "${OUTDIR}"
if [[ -x "./${TARGET}" ]]; then
  cp -f "./${TARGET}" "${OUTDIR}/${TARGET}"
  echo " Saved: ${OUTDIR}/${TARGET}"
fi
echo " Tip: ./build.sh help  # flags, ENV, targets"
echo "========================================="