#!/usr/bin/env bash
# ─────────────────────────────────────────────────────────────────────────────
# gauntlet_run.sh — run a PER-ADVERSARY A/B gauntlet of N arms against MANY
# legacy opponents (the generalization test for the gun claims that have, until
# now, always been measured against the single opponent DrussGT).
#
#   tools/ab/gauntlet_run.sh \
#       --arms tools/ab/arms_gauntlet.txt \
#       --opponents tools/ab/opponents_gauntlet.txt \
#       --runs 3 --rounds 3 --conc 5 --outdir /tmp/ab/j117_gauntlet
#
# Difference from ab_run.sh: ab_run.sh hard-wires exactly ONE adversary
# (DrussGT, via run_bridge_battle's legacy default subject).  Here the SUBJECT
# is the frozen ModularBot itself (so the capture's `subject event counts` are
# ModularBot's own fire/hit/taken counts and `firstPlaces` is ModularBot's
# name-based round wins) and the ADVERSARY iterates over a list of legacy
# champ bot dirs from tools/robocode_shim/robots.json.
#
# For every (opponent, arm, run) it launches a real Tank Royale battle through
# tools/robocode_shim/run_bridge_battle.sh, each in its own process group with
# ephemeral ports and an isolated classic data dir.
#
# Arm file format (same as ab_run.sh):
#     name | ENV_VAR=value ENV_VAR2=value2 | optional label
#
# Opponent file format (one per line):
#     /tmp/tr_bots/<Name> | style-label       # or a bare Name (=> /tmp/tr_bots/)
#   Blank lines and #-comments ignored.
#
# Output layout (what gauntlet_analyze.py reads):
#     <outdir>/session.json
#     <outdir>/<opponent>/<arm>/run<N>.jsonl                    tick capture
#     <outdir>/<opponent>/<arm>/run<N>.jsonl.rounds.json        round boundaries
#     <outdir>/<opponent>/<arm>/run<N>.jsonl.results.json       cumulative scores
#     <outdir>/<opponent>/<arm>/run<N>.events.jsonl             fire/hit/death
#     <outdir>/<opponent>/<arm>/run<N>.battle.log               capture stdout
#     <outdir>/<opponent>/<arm>/run<N>.bot.stdout.log           ModularBot env
#
# Cleanup: every job runs in its own process group (setsid); on EXIT/INT/TERM
# this script SIGTERMs/SIGKILLs those groups and pkills anything referencing
# this session's outdir, so a Ctrl-C leaves no orphan battles.
# ─────────────────────────────────────────────────────────────────────────────
set -euo pipefail

REPO="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
RUN_BRIDGE="$REPO/tools/robocode_shim/run_bridge_battle.sh"

ARMS_FILE=""
OPP_FILE=""
RUNS=3
ROUNDS=3
CONC=4
OUTDIR=""
# A bot can fail to connect within the booter's 30 s window under load
# ("Only 1 of 2 bots started"), which is a FALSE NEGATIVE, not a real battle.
# Each job is retried until the capture shows real rows AND a subject counter
# line, so the analyzer never sees a phantom 0-0 run.
MAX_ATTEMPTS="${GAUNTLET_MAX_ATTEMPTS:-4}"

usage() {
  sed -n '2,45p' "${BASH_SOURCE[0]}" | sed 's/^# \{0,1\}//'
  exit "${1:-0}"
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --arms)      ARMS_FILE="$2"; shift 2;;
    --opponents) OPP_FILE="$2"; shift 2;;
    --runs)      RUNS="$2"; shift 2;;
    --rounds)    ROUNDS="$2"; shift 2;;
    --conc)      CONC="$2"; shift 2;;
    --outdir)    OUTDIR="$2"; shift 2;;
    -h|--help)   usage 0;;
    *) echo "unknown argument: $1" >&2; usage 1;;
  esac
done

[[ -n "$ARMS_FILE" ]] || { echo "ERROR: --arms <file> is required" >&2; usage 1; }
[[ -n "$OPP_FILE"  ]] || { echo "ERROR: --opponents <file> is required" >&2; usage 1; }
[[ -f "$ARMS_FILE" ]] || { echo "ERROR: arm file not found: $ARMS_FILE" >&2; exit 1; }
[[ -f "$OPP_FILE"  ]] || { echo "ERROR: opponent file not found: $OPP_FILE" >&2; exit 1; }
[[ -n "$OUTDIR" ]]    || { echo "ERROR: --outdir <dir> is required" >&2; exit 1; }
[[ "$OUTDIR" != "/" && "$OUTDIR" != "" ]] || { echo "ERROR: refusing outdir '$OUTDIR'" >&2; exit 1; }
OUTDIR="$(mkdir -p "$OUTDIR" && cd "$OUTDIR" && pwd)"

# ── prerequisites ────────────────────────────────────────────────────────────
ROBOCODE_JAR="${ROBOCODE_JAR:-/tmp/robocode/install/libs/robocode.jar}"
RUNNER_JAR="${TR_RUNNER_JAR:-/home/davide/Projects/tank-royale/runner/examples/lib/robocode-tankroyale-runner.jar}"
BOT_API_JAR="${TR_BOT_API_JAR:-$HOME/Downloads/sample-bots-java-1.0.2/lib/robocode-tankroyale-bot-api-1.0.2.jar}"

missing=0
for f in "$ROBOCODE_JAR" "$RUNNER_JAR" "$BOT_API_JAR"; do
  if [[ ! -f "$f" ]]; then echo "ERROR: missing prerequisite: $f" >&2; missing=1; fi
done
command -v nim >/dev/null 2>&1 || { echo "ERROR: nim not on PATH" >&2; missing=1; }
command -v git >/dev/null 2>&1 || { echo "ERROR: git not on PATH" >&2; missing=1; }
[[ -f "$RUN_BRIDGE" ]] || { echo "ERROR: missing $RUN_BRIDGE" >&2; missing=1; }
(( missing == 0 )) || { echo "ERROR: prerequisites missing — not starting a broken session" >&2; exit 1; }

# ── parse the arm file into parallel arrays ──────────────────────────────────
trim() { local s="$1"; s="${s#"${s%%[![:space:]]*}"}"; s="${s%"${s##*[![:space:]]}"}"; printf '%s' "$s"; }

ARM_NAMES=(); ARM_ENVS=(); ARM_LABELS=()
while IFS= read -r line || [[ -n "$line" ]]; do
  [[ -z "${line//[[:space:]]/}" ]] && continue
  [[ "$line" =~ ^[[:space:]]*# ]] && continue
  name="$(trim "${line%%|*}")"
  rest="${line#*|}"
  if [[ "$line" == *"|"* ]]; then
    envspec="$(trim "${rest%%|*}")"
    label="$(trim "${rest#*|}")"
  else
    envspec=""; label=""
  fi
  [[ -n "$name" ]] || { echo "ERROR: arm with empty name in $ARMS_FILE" >&2; exit 1; }
  ARM_NAMES+=("$name"); ARM_ENVS+=("$envspec"); ARM_LABELS+=("$label")
done < "$ARMS_FILE"
(( ${#ARM_NAMES[@]} > 0 )) || { echo "ERROR: no arms parsed from $ARMS_FILE" >&2; exit 1; }
dupes="$(printf '%s\n' "${ARM_NAMES[@]}" | sort | uniq -d)"
[[ -z "$dupes" ]] || { echo "ERROR: duplicate arm name(s): $dupes" >&2; exit 1; }

# ── parse the opponent file ──────────────────────────────────────────────────
OPP_DIRS=(); OPP_NAMES=(); OPP_STYLES=()
while IFS= read -r line || [[ -n "$line" ]]; do
  [[ -z "${line//[[:space:]]/}" ]] && continue
  [[ "$line" =~ ^[[:space:]]*# ]] && continue
  dir="$(trim "${line%%|*}")"
  style=""
  if [[ "$line" == *"|"* ]]; then style="$(trim "${line#*|}")"; fi
  [[ "$dir" == */* ]] || dir="/tmp/tr_bots/$dir"
  [[ -d "$dir" ]] || { echo "ERROR: opponent bot dir not found: $dir" >&2; exit 1; }
  nm="$(basename "$dir")"
  OPP_DIRS+=("$dir"); OPP_NAMES+=("$nm"); OPP_STYLES+=("$style")
done < "$OPP_FILE"
(( ${#OPP_NAMES[@]} > 0 )) || { echo "ERROR: no opponents parsed from $OPP_FILE" >&2; exit 1; }

# ── fresh session dir ────────────────────────────────────────────────────────
rm -rf "$OUTDIR"
mkdir -p "$OUTDIR"
WORK="$OUTDIR/.work"; mkdir -p "$WORK"

# ── build ONE frozen bot from HEAD ───────────────────────────────────────────
COMMIT="$(git -C "$REPO" rev-parse HEAD)"
FROZEN_DIR="$OUTDIR/frozen/ModularBot"
FROZEN_BIN="$FROZEN_DIR/ModularBot_bin"
FROZEN_JSON="$FROZEN_DIR/ModularBot.json"
mkdir -p "$FROZEN_DIR"
BUILDDIR="$WORK/head"
mkdir -p "$BUILDDIR"
echo "[gauntlet] exporting HEAD ($COMMIT) -> $BUILDDIR"
git -C "$REPO" archive HEAD | tar -x -C "$BUILDDIR"

echo "[gauntlet] building frozen ModularBot (nim c -d:release)…"
( cd "$BUILDDIR/ModularBot_garage" && \
  nim c -d:release --nimcache:"$OUTDIR/nimcache" --out:"$FROZEN_BIN" src/ModularBot.nim )
[[ -x "$FROZEN_BIN" ]] || { echo "ERROR: frozen build failed" >&2; exit 1; }
BINSHA="$(sha256sum "$FROZEN_BIN" | awk '{print $1}')"
echo "[gauntlet] frozen binary sha256=$BINSHA"

cat > "$FROZEN_JSON" <<'JSON'
{
  "name": "ModularBot",
  "version": "0.1.0",
  "authors": ["Davide Cappellini"],
  "description": "frozen A/B build of ModularBot (gauntlet_run.sh)",
  "homepage": "",
  "countryCodes": ["IT"],
  "gameTypes": ["classic", "1v1"],
  "platform": "Nim",
  "programmingLang": "Nim"
}
JSON

# ── session.json ─────────────────────────────────────────────────────────────
json_esc() { printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g'; }
{
  printf '{\n'
  printf '  "commit": "%s",\n' "$COMMIT"
  printf '  "binary_sha256": "%s",\n' "$BINSHA"
  printf '  "binary": "frozen/ModularBot/ModularBot_bin",\n'
  printf '  "rounds": %d,\n' "$ROUNDS"
  printf '  "runs": %d,\n' "$RUNS"
  printf '  "conc": %d,\n' "$CONC"
  printf '  "timestamp": "%s",\n' "$(date -Is)"
  printf '  "outdir": "%s",\n' "$(json_esc "$OUTDIR")"
  printf '  "arms": [\n'
  for i in "${!ARM_NAMES[@]}"; do
    printf '    {"name": "%s", "env": "%s", "label": "%s"}' \
      "$(json_esc "${ARM_NAMES[$i]}")" "$(json_esc "${ARM_ENVS[$i]}")" "$(json_esc "${ARM_LABELS[$i]}")"
    (( i + 1 < ${#ARM_NAMES[@]} )) && printf ',' || true
    printf '\n'
  done
  printf '  ],\n'
  printf '  "opponents": [\n'
  for i in "${!OPP_NAMES[@]}"; do
    printf '    {"name": "%s", "dir": "%s", "style": "%s"}' \
      "$(json_esc "${OPP_NAMES[$i]}")" "$(json_esc "${OPP_DIRS[$i]}")" "$(json_esc "${OPP_STYLES[$i]}")"
    (( i + 1 < ${#OPP_NAMES[@]} )) && printf ',' || true
    printf '\n'
  done
  printf '  ]\n}\n'
} > "$OUTDIR/session.json"

# ── one job (run in its own process group) ───────────────────────────────────
# exported so the detached `bash -c` subshell can call it; config via env
export REPO RUN_BRIDGE ROUNDS OUTDIR WORK FROZEN_BIN FROZEN_JSON

gauntlet_run_one() {
  local opponent_dir="$1" opponent="$2" arm="$3" run="$4" envspec="$5"
  local dir="$OUTDIR/$opponent/$arm"
  local work="$WORK/$opponent/$arm/run$run"
  local botdir="$work/bots/ModularBot"
  mkdir -p "$dir" "$botdir" "$work/data"

  cp "$FROZEN_JSON" "$botdir/ModularBot.json"
  cat > "$botdir/ModularBot.sh" <<SH
#!/bin/sh
cd "\$(dirname "\$0")"
exec ./ModularBot_bin > "$dir/run$run.bot.stdout.log" 2> "$dir/run$run.bot.stderr.log"
SH
  chmod +x "$botdir/ModularBot.sh"
  ln -sf "$FROZEN_BIN" "$botdir/ModularBot_bin"

  local attempt=0
  while :; do
    attempt=$((attempt + 1))
    rm -f "$dir/run$run.jsonl" "$dir/run$run.jsonl.rounds.json" \
          "$dir/run$run.jsonl.results.json" "$dir/run$run.events.jsonl" \
          "$dir/run$run.status" "$dir/run$run.bot.stdout.log" "$dir/run$run.bot.stderr.log"

    local rc=0
    # shellcheck disable=SC2086  # envspec is intentionally word-split
    env $envspec \
        SHIM_BOTDIR="$botdir" \
        SHIM_BOT_NAME="ModularBot" \
        SHIM_DATA="$work/data" \
        TR_EVENTS_OUT="$dir/run$run.events.jsonl" \
        timeout 900 "$RUN_BRIDGE" "$opponent_dir" "$ROUNDS" "$dir/run$run.jsonl" \
        > "$dir/run$run.battle.log" 2>&1 || rc=$?
    echo "$rc" > "$dir/run$run.status"

    # liveness: a real battle has captured rows and a subject counter line
    if grep -q "subject event counts" "$dir/run$run.battle.log" 2>/dev/null \
       && grep -Eq "rows=[1-9]" "$dir/run$run.battle.log" 2>/dev/null; then
      break
    fi
    if (( attempt >= MAX_ATTEMPTS )); then
      echo "[gauntlet] WARNING: ${opponent}/${arm} run${run} never started after ${attempt} attempts" >&2
      break
    fi
    sleep $((attempt * 2))
  done
  echo "$attempt" > "$dir/run$run.attempts"
  return 0
}
export -f gauntlet_run_one

# ── cleanup: kill this session's children ────────────────────────────────────
JOB_PIDS=()
cleanup() {
  local rc=$?
  trap - EXIT INT TERM
  for p in "${JOB_PIDS[@]:-}"; do
    [[ -n "$p" ]] || continue
    kill -TERM -- "-$p" 2>/dev/null || kill -TERM "$p" 2>/dev/null || true
  done
  sleep 0.5
  for p in "${JOB_PIDS[@]:-}"; do
    [[ -n "$p" ]] || continue
    kill -KILL -- "-$p" 2>/dev/null || true
  done
  pkill -f "[r]un_bridge_battle.sh.*$OUTDIR" 2>/dev/null || true
  pkill -f "[r]obocode_shim.TrBattleCapture.*$OUTDIR" 2>/dev/null || true
  exit "$rc"
}
trap cleanup EXIT INT TERM

# ── launch the jobs, K at a time ─────────────────────────────────────────────
NJOBS=$(( ${#OPP_NAMES[@]} * ${#ARM_NAMES[@]} * RUNS ))
echo "[gauntlet] session: ${#OPP_NAMES[@]} opponents × ${#ARM_NAMES[@]} arms × $RUNS runs = $NJOBS battles, rounds=$ROUNDS, conc=$CONC"
echo "[gauntlet] outdir:  $OUTDIR"
RUNNING=0
for oi in "${!OPP_NAMES[@]}"; do
  for ai in "${!ARM_NAMES[@]}"; do
    for (( r=1; r<=RUNS; r++ )); do
      setsid bash -c 'gauntlet_run_one "$1" "$2" "$3" "$4" "$5"' _ \
        "${OPP_DIRS[$oi]}" "${OPP_NAMES[$oi]}" "${ARM_NAMES[$ai]}" "$r" "${ARM_ENVS[$ai]}" &
      JOB_PIDS+=("$!")
      RUNNING=$((RUNNING + 1))
      if (( RUNNING >= CONC )); then
        wait -n || true
        RUNNING=$((RUNNING - 1))
      fi
    done
  done
done
wait || true

JOB_PIDS=()

# ── aggregate status ─────────────────────────────────────────────────────────
FAILED=0
for oi in "${!OPP_NAMES[@]}"; do
  for ai in "${!ARM_NAMES[@]}"; do
    for (( r=1; r<=RUNS; r++ )); do
      st="$(cat "$OUTDIR/${OPP_NAMES[$oi]}/${ARM_NAMES[$ai]}/run$r.status" 2>/dev/null || echo 999)"
      if [[ "$st" != "0" ]]; then
        echo "[gauntlet] FAIL ${OPP_NAMES[$oi]}/${ARM_NAMES[$ai]} run$r (rc=$st)" >&2
        FAILED=$((FAILED + 1))
      fi
    done
  done
done

echo "[gauntlet] done: $(( NJOBS - FAILED )) ok, $FAILED failed"
echo "[gauntlet] analyze with: python3 $REPO/tools/ab/gauntlet_analyze.py $OUTDIR"
(( FAILED == 0 )) || exit 1