#!/usr/bin/env bash
# bench-server.sh — benchmark a Minecraft server: startup + /reload + bot load
#
# Usage: ./bench-server.sh <tier> [bot-count] [--play]
#
# Tiers:
#   unpatched   control — vanilla jar, depth-16 datapack (defect present)
#   mitigated   fix applied — patched jar, depth-16 datapack (same game, fast)
#   enriched    new territory — patched jar, depth-24 300-ns datapack (impossible before patch)
#
# Aliases: vanilla=unpatched, patched=mitigated
#
# --play: after benchmarks, keep server up for human play testing.
#         Prints connection info and waits for Ctrl-C.
set -euo pipefail
export PYTHONUNBUFFERED=1

TIER="${1:-unpatched}"
BOTS="${2:-20}"

# --play flag: accept anywhere in args
PLAY_MODE=0
for _arg in "$@"; do [ "$_arg" = "--play" ] && PLAY_MODE=1; done

# ── Tier configuration ────────────────────────────────────────────────────────
case "$TIER" in
  unpatched|vanilla)
    TIER=unpatched
    DIR=/tmp/mc-bench/unpatched
    PORT=25565
    RCON=25575
    SERVER_JAR=/home/fox/Downloads/server.jar
    DATAPACK_DEPTH=16
    DATAPACK_NS=200
    DATAPACK_XREFS=6
    TIER_NOTE="control — DependencySorter defect present"
    ;;
  mitigated|patched)
    TIER=mitigated
    DIR=/tmp/mc-bench/mitigated
    PORT=25566
    RCON=25576
    SERVER_JAR=/tmp/mc-bench/server-patched.jar
    DATAPACK_DEPTH=16
    DATAPACK_NS=200
    DATAPACK_XREFS=6
    TIER_NOTE="fix applied — same game, defect eliminated"
    ;;
  enriched)
    DIR=/tmp/mc-bench/enriched
    PORT=25567
    RCON=25577
    SERVER_JAR=/tmp/mc-bench/server-patched.jar
    DATAPACK_DEPTH=48
    DATAPACK_NS=1000
    DATAPACK_XREFS=32
    TIER_NOTE="enriched — D=48 / 1000 NS / 32 xrefs: impossible before patch"
    ;;
  *)
    echo "Usage: $0 unpatched|mitigated|enriched [bot-count] [--play]"
    exit 1
    ;;
esac

JAVA=/tmp/jdk25/bin/java
LOG="$DIR/bench.log"
FIFO="$DIR/server.stdin"

# ── System metrics helpers ────────────────────────────────────────────────────
# cpu_snap: echo "user nice sys irq softirq intr" from /proc/stat
cpu_snap() {
    local cpu intr
    read -r cpu user nice sys idle iowait irq softirq steal guest gnest < /proc/stat
    intr=$(awk '/^intr / {print $2}' /proc/stat)
    echo "$user $nice $sys $irq $softirq $intr"
}

# cpu_delta <snap_before> <snap_after> <elapsed_ms> → prints table row
# Computes jiffies burned per field; divides by total to get %.
# /proc/stat ticks at CONFIG_HZ (usually 100 Hz).
cpu_delta() {
    local before="$1" after="$2" elapsed_ms="$3"
    read -r bu bn bs br bsoft bi <<< "$before"
    read -r au an as_ ar asoft ai <<< "$after"
    local du=$(( au - bu ))
    local dn=$(( an - bn ))
    local ds=$(( as_ - bs ))
    local dr=$(( ar - br ))
    local dsoft=$(( asoft - bsoft ))
    local dintr=$(( ai - bi ))
    local total=$(( du + dn + ds + dr + dsoft ))
    if [ "$total" -gt 0 ]; then
        awk -v u=$du -v n=$dn -v s=$ds -v r=$dr -v soft=$dsoft -v intr=$dintr \
            -v tot=$total -v ms=$elapsed_ms 'BEGIN {
            printf "  cpu  user=%.1f%%  nice=%.1f%%  sys=%.1f%%  irq=%.1f%%  sirq=%.1f%%  intr=%d  (over %dms)\n",
                u/tot*100, n/tot*100, s/tot*100, (r+soft)/tot*100, 0, intr, ms
        }'
    else
        echo "  cpu  (no delta)"
    fi
}

# mem_snap: echo free_mb available_mb from /proc/meminfo
mem_snap() {
    awk '/^MemFree:/{f=$2}/^MemAvailable:/{a=$2} END{printf "%d %d", f/1024, a/1024}' /proc/meminfo
}

# Print and store a labelled memory reading
mem_print() {
    local label="$1" snap="$2"
    read -r free_mb avail_mb <<< "$snap"
    echo "  mem  free=${free_mb}MB  available=${avail_mb}MB  ($label)"
}

pkill -f "port $PORT " 2>/dev/null || true
sleep 1
rm -f "$LOG" "$FIFO"
rm -rf "$DIR/world"

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
python3 "$SCRIPT_DIR/gen-modpack-tags.py" "$DIR" "$DATAPACK_DEPTH" "$DATAPACK_NS" "$DATAPACK_XREFS"

mkfifo "$FIFO"

echo "=========================================="
echo " $TIER — Minecraft Server Benchmark"
echo " $TIER_NOTE"
echo "=========================================="
echo " depth-${DATAPACK_DEPTH}  ${DATAPACK_NS} namespaces  ${DATAPACK_XREFS} xrefs  ·  $BOTS bots"
echo ""

# ── §1 Startup ────────────────────────────────────────────────────────────────
echo "§1  Starting server..."
CPU_BEFORE_STARTUP=$(cpu_snap)
MEM_BEFORE_STARTUP=$(mem_snap)
START_MS=$(date +%s%3N)

exec 3<>"$FIFO"

(cd "$DIR" && exec $JAVA -Xmx3G -Xms512m \
    --enable-native-access=ALL-UNNAMED \
    -DbundlerRepoDir=. \
    -jar "$SERVER_JAR" \
    --nogui --port "$PORT" \
    <"$FIFO" >>"$LOG" 2>&1) &
SERVER_PID=$!

for i in $(seq 1 180); do
    sleep 1
    if grep -q "Done (" "$LOG" 2>/dev/null; then
        STARTUP_MS=$(( $(date +%s%3N) - START_MS ))
        CPU_AFTER_STARTUP=$(cpu_snap)
        MEM_AFTER_STARTUP=$(mem_snap)
        DONE_LINE=$(grep "Done (" "$LOG" | tail -1)
        echo "  startup: ${STARTUP_MS} ms"
        echo "  server:  $DONE_LINE"
        cpu_delta "$CPU_BEFORE_STARTUP" "$CPU_AFTER_STARTUP" "$STARTUP_MS"
        mem_print "before" "$MEM_BEFORE_STARTUP"
        mem_print "after"  "$MEM_AFTER_STARTUP"
        break
    fi
    if ! kill -0 $SERVER_PID 2>/dev/null; then
        echo "ERROR: server exited prematurely"
        tail -12 "$LOG"
        exit 1
    fi
    [ $(( i % 10 )) -eq 0 ] && echo "  ...${i}s"
done

if ! grep -q "Done (" "$LOG" 2>/dev/null; then
    echo "ERROR: did not start in 180s"
    kill $SERVER_PID 2>/dev/null
    exit 1
fi

sleep 2   # let RCON bind

# ── §2 First bot wave ─────────────────────────────────────────────────────────
echo ""
echo "§2  First bot wave: $BOTS bots joining..."
node "$SCRIPT_DIR/raw-connect.mjs" localhost "$PORT" "$BOTS" 2>&1
sleep 2

# ── §3 /reload timing ─────────────────────────────────────────────────────────
echo ""
echo "§3  /reload timing..."

RELOAD_LINE=$(wc -l < "$LOG")
CPU_BEFORE_RELOAD=$(cpu_snap)
MEM_BEFORE_RELOAD=$(mem_snap)
RELOAD_START=$(date +%s%3N)

python3 "$SCRIPT_DIR/rcon.py" localhost "$RCON" benchpass "reload" 2>&1 || \
    { echo "RCON failed, sending via stdin"; echo "reload" >&3; }

RELOAD_MS=""
for i in $(seq 1 180); do
    sleep 1
    if tail -n +"$RELOAD_LINE" "$LOG" 2>/dev/null | grep -qE "Loaded [0-9]+ recipes"; then
        RELOAD_MS=$(( $(date +%s%3N) - RELOAD_START ))
        CPU_AFTER_RELOAD=$(cpu_snap)
        MEM_AFTER_RELOAD=$(mem_snap)
        echo "  /reload: ${RELOAD_MS} ms"
        tail -n +"$RELOAD_LINE" "$LOG" | grep -E "Loaded [0-9]+ (recipes|advancements)" | head -3 | while IFS= read -r l; do echo "    $l"; done
        cpu_delta "$CPU_BEFORE_RELOAD" "$CPU_AFTER_RELOAD" "$RELOAD_MS"
        mem_print "before" "$MEM_BEFORE_RELOAD"
        mem_print "after"  "$MEM_AFTER_RELOAD"
        break
    fi
done
[ -z "$RELOAD_MS" ] && { echo "  /reload: did not complete in 180s"; RELOAD_MS="-1"; CPU_AFTER_RELOAD=$(cpu_snap); MEM_AFTER_RELOAD=$(mem_snap); }

# ── §4 Second bot wave (post-reload) ─────────────────────────────────────────
echo ""
echo "§4  Post-reload bot wave: $BOTS bots..."
node "$SCRIPT_DIR/raw-connect.mjs" localhost "$PORT" "$BOTS" 2>&1

# ── §5 Play test mode (human) ─────────────────────────────────────────────────
if [ "$PLAY_MODE" = "1" ]; then
    echo ""
    echo "=========================================="
    echo " PLAY TEST MODE — server staying up"
    echo "=========================================="
    echo "  Connect to:  localhost:$PORT"
    echo "  Tier:        $TIER  ($TIER_NOTE)"
    echo "  Log:         $LOG"
    echo ""
    echo "  Press Ctrl-C to stop the server and finish benchmark."
    echo ""
    # Wait for Ctrl-C; trap cleans up
    trap 'echo ""; echo "Stopping server..."; echo "stop" >&3; exec 3>&-; wait $SERVER_PID 2>/dev/null || true; rm -f "$FIFO"; echo "Server stopped."; exit 0' INT TERM
    while kill -0 $SERVER_PID 2>/dev/null; do sleep 5; done
    echo "Server exited on its own."
    exec 3>&- 2>/dev/null || true
    rm -f "$FIFO"
    exit 0
fi

# ── Stop ─────────────────────────────────────────────────────────────────────
echo ""
echo "Stopping server..."
echo "stop" >&3
exec 3>&-
wait $SERVER_PID 2>/dev/null || true
rm -f "$FIFO"

# ── Results ──────────────────────────────────────────────────────────────────
# Derive per-phase CPU/mem deltas for results.txt (machine-readable)
_cpu_fields() {
    local before="$1" after="$2"
    read -r bu bn bs br bsoft bi <<< "$before"
    read -r au an as_ ar asoft ai <<< "$after"
    local du=$(( au-bu )) dn=$(( an-bn )) ds=$(( as_-bs ))
    local dr=$(( ar-br )) dsoft=$(( asoft-bsoft )) dintr=$(( ai-bi ))
    local tot=$(( du+dn+ds+dr+dsoft ))
    [ "$tot" -eq 0 ] && tot=1
    awk -v u=$du -v n=$dn -v s=$ds -v r=$dr -v soft=$dsoft -v intr=$dintr -v tot=$tot \
        -v pfx="$3" 'BEGIN {
        printf "%scpu_user_pct=%.1f\n%scpu_nice_pct=%.1f\n%scpu_sys_pct=%.1f\n%scpu_irq_pct=%.1f\n%scpu_intr=%d\n",
            pfx, u/tot*100, pfx, n/tot*100, pfx, s/tot*100, pfx, (r+soft)/tot*100, pfx, intr
    }'
}
_mem_fields() {
    read -r free_mb avail_mb <<< "$(mem_snap)"
    echo "${1}mem_free_mb=$free_mb"
    echo "${1}mem_avail_mb=$avail_mb"
}

echo ""
echo "=========================================="
echo " $TIER RESULTS"
echo "=========================================="
echo "  startup: ${STARTUP_MS} ms"
echo "  reload:  ${RELOAD_MS} ms"
echo "  bots:    $BOTS"
echo "  depth:   $DATAPACK_DEPTH  ns: $DATAPACK_NS  xrefs: $DATAPACK_XREFS"
echo ""
echo "  --- CPU/mem during startup ---"
cpu_delta "$CPU_BEFORE_STARTUP" "$CPU_AFTER_STARTUP" "$STARTUP_MS"
mem_print "before" "$MEM_BEFORE_STARTUP"
mem_print "after"  "$MEM_AFTER_STARTUP"
echo "  --- CPU/mem during /reload ---"
cpu_delta "$CPU_BEFORE_RELOAD" "$CPU_AFTER_RELOAD" "$RELOAD_MS"
mem_print "before" "$MEM_BEFORE_RELOAD"
mem_print "after"  "$MEM_AFTER_RELOAD"
echo ""

{
cat << EOF
label=$TIER
startup_ms=$STARTUP_MS
reload_ms=$RELOAD_MS
bots=$BOTS
datapack_depth=$DATAPACK_DEPTH
datapack_ns=$DATAPACK_NS
datapack_xrefs=$DATAPACK_XREFS
EOF
_cpu_fields "$CPU_BEFORE_STARTUP" "$CPU_AFTER_STARTUP" "startup_"
_mem_fields "startup_before_"
read -r f a <<< "$MEM_BEFORE_STARTUP"; echo "startup_before_mem_free_mb=$f"; echo "startup_before_mem_avail_mb=$a"
read -r f a <<< "$MEM_AFTER_STARTUP";  echo "startup_after_mem_free_mb=$f";  echo "startup_after_mem_avail_mb=$a"
_cpu_fields "$CPU_BEFORE_RELOAD" "$CPU_AFTER_RELOAD" "reload_"
read -r f a <<< "$MEM_BEFORE_RELOAD"; echo "reload_before_mem_free_mb=$f"; echo "reload_before_mem_avail_mb=$a"
read -r f a <<< "$MEM_AFTER_RELOAD";  echo "reload_after_mem_free_mb=$f";  echo "reload_after_mem_avail_mb=$a"
} > "$DIR/results.txt"