#!/usr/bin/env bash
# make_twin.sh — #54 mirror-twin sparring partner generator.
#
# Builds a self-contained `SacTwin` bot dir inside the sample-bots archive so
# RunTraining.java resolves it like any sample bot ($SAMPLE_BOTS_DIR/<name>).
# The twin is the SAME binary as SAC_LSTM_Bot but with:
#   - distinct identity  (SacTwin.json; SACLSTM_BOT_JSON overrides the baked-in
#     src json — loadBotInfo gives json total precedence over env, #49 lesson)
#   - its OWN weights dir, seeded from a FROZEN copy of weights/sac_best.zip
#     (no checkpoint write races with the main bot)
#   - its OWN round_counter.txt (main liveness guard untouched)
#
# Re-running resets the twin to the frozen baseline (reproducible opponent).
#
# Usage: ./make_twin.sh [target-archive-dir]
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
TARGET="${1:-${SAMPLE_BOTS_DIR:-/home/davide/Projects/tank-royale/sample-bots/java/build/archive}}/SacTwin"
BIN="$SCRIPT_DIR/SAC_LSTM_Bot"          # nimble build -d:release output
SEED="$SCRIPT_DIR/weights/sac_best.zip" # frozen baseline

[ -x "$BIN" ]   || { echo ">>> $BIN missing — run 'nimble build -d:release' first"; exit 1; }
[ -f "$SEED" ]  || { echo ">>> $SEED missing — need at least one eval'd checkpoint"; exit 1; }

mkdir -p "$TARGET/weights"
cp "$BIN" "$TARGET/SAC_LSTM_Bot"

cat > "$TARGET/SacTwin.json" <<EOF
{
  "name": "SacTwin",
  "version": "0.1.0",
  "authors": ["Davide Cappellini"],
  "description": "Mirror-twin sparring partner of SAC_LSTM_Bot (#54), generated by make_twin.sh — own weights dir, frozen seed",
  "homepage": "",
  "countryCodes": ["IT"],
  "gameTypes": ["classic", "melee", "1v1"],
  "platform": "Nim",
  "programmingLang": "Nim"
}
EOF

cat > "$TARGET/SacTwin.sh" <<'EOF'
#!/bin/sh
# Twin launcher (#54): identity + weights fully decoupled from the main bot.
DIR="$(cd "$(dirname "$0")" && pwd)"
export SACLSTM_BOT_JSON="$DIR/SacTwin.json"
export SACLSTM_WEIGHTS_PATH="$DIR/weights/sac_latest.zip"
exec "$DIR/SAC_LSTM_Bot"
EOF
chmod +x "$TARGET/SacTwin.sh" "$TARGET/SAC_LSTM_Bot"

cp "$SEED" "$TARGET/weights/sac_latest.zip"
cp "$SEED" "$TARGET/weights/sac_best.zip"
echo 0 > "$TARGET/weights/round_counter.txt"
echo ">>> twin ready: $TARGET (seeded from $(stat -c %y "$SEED" | cut -d. -f1) snapshot of sac_best.zip)"