#!/usr/bin/env bash
#
# crafty_egtb -- thin wrapper so match_play.py's Engine class (which always
# spawns its path with hardcoded TYPHOON flags, "--hash 256m --cpus 1
# --logfile -" -- see match_play.py's engine_args) can drive Crafty instead.
# Crafty speaks xboard protocol natively (Engine sends "xboard" at startup,
# per match_play.py's own comments), so unlike stockfish_xboard this needs
# no PolyGlot adapter -- but it also can't take typhoon's command-line
# flags, so (same pattern as stockfish_xboard) every argument this script
# is called with is deliberately DISCARDED.
#
# Crafty's own Syzygy/Fathom-based EGTB support reads the exact same
# .rtbw/.rtbz files typhoon and stockfish_xboard point at (confirmed
# 2026-10-18 via `strings crafty`: message strings "SYZYGY EGTB access
# enabled, %d piece TBs found" / "Could not find %s.rtbw"). There is no
# command-line flag or environment variable for this, despite a
# `CRAFTY_TB_PATH` string existing in the binary (tried, confirmed it does
# nothing) -- the ONLY way is two separate interactive commands:
#   tbpath <dir>   -- just records the directory, no confirmation output
#   egtb           -- actually TOGGLES probing on; THIS is what prints
#                      "SYZYGY EGTB access enabled, N piece TBs found" and
#                      is required in addition to tbpath, not instead of it.
# Verified against a KBNK (bishop+knight mate) position: `go` without these
# two commands searches ~877K/656K nodes per move; with them, depth 0
# instantly returns "Won ... <EGTB>" in the PV.
#
# Since these are interactive commands (not args or env), they're injected
# by piping them in ahead of whatever xboard/match_play.py writes to stdin
# next -- `cat` with two input sources (this script's own heredoc, then
# stdin) concatenates them for Crafty to read as one continuous stream, the
# same way a human would type tbpath/egtb first and then start playing.
#
# Override via env vars if needed:
#   CRAFTY_BIN   defaults to "crafty" (resolved via PATH, i.e.
#                /usr/local/bin/crafty on this box -- NOT any older
#                ~/programming/chess/crafty-25.2/crafty build, see
#                eval_tune/compare_vs_crafty.py's comments on why that
#                distinction matters)
#   SYZYGY_PATH  defaults to /zscratch/egtb (same default typhoon's
#                --egtbpath and stockfish_xboard's SYZYGY_PATH use). Set to
#                "" to disable TB probing entirely (skips tbpath/egtb).

set -e

CRAFTY_BIN="${CRAFTY_BIN:-crafty}"
SYZYGY_PATH="${SYZYGY_PATH:-/zscratch/egtb}"

if [ -n "$SYZYGY_PATH" ]; then
    { printf 'tbpath %s\negtb\n' "$SYZYGY_PATH"; cat; } | exec stdbuf -oL "$CRAFTY_BIN"
else
    exec stdbuf -oL "$CRAFTY_BIN" < /dev/stdin
fi