#!/usr/bin/env python3
import chess
import chess.engine
import time
import sys

# Path to the Stockfish executable
STOCKFISH_PATH = "/home/tun08104/senior_design/stockfish_dwld/stockfish/src/stockfish"

# Path to your custom NNUE file
MY_NNUE_PATH = sys.argv[1]

# Stockfish skill levels (0–20)
EASY_SKILL = 2
INTERMEDIATE_SKILL = 10
STRONG_SKILL = 20  # Default Stockfish strength

# Time control per move (seconds)
MOVE_TIME = 0.05

# Games to play
GAMES = 20

# Opponent difficulty selection: "easy", "intermediate", "strong"
OPPONENT = "intermediate"  


# =====================
# INTERNAL SETUP
# =====================

def make_engine(nnue_path=None, skill=None):
    """Create a Stockfish engine with optional NNUE override + skill level."""
    engine = chess.engine.SimpleEngine.popen_uci(STOCKFISH_PATH)

    if nnue_path is not None:
        engine.configure({"EvalFile": nnue_path})

    if skill is not None:
        engine.configure({"Skill Level": skill})

    return engine


def play_game(engine_white, engine_black, move_time):
    """Play a single game and return result: 1 = white win, 0 = draw, -1 = black win."""
    board = chess.Board()

    while not board.is_game_over():
        engine = engine_white if board.turn == chess.WHITE else engine_black

        try:
            result = engine.play(board, chess.engine.Limit(time=move_time))
        except Exception as e:
            print("Engine crashed or timed out:", e)
            return 0

        if result.move is None:
            break

        board.push(result.move)

    outcome = board.outcome()

    if outcome is None:
        return 0

    if outcome.winner is True:
        return 1
    elif outcome.winner is False:
        return -1
    else:
        return 0


def main():
    print("Launching engines...")
    # Decide opponent skill
    if OPPONENT == "easy":
        opp_skill = EASY_SKILL
    elif OPPONENT == "intermediate":
        opp_skill = INTERMEDIATE_SKILL
    else:
        opp_skill = STRONG_SKILL

    # Custom NNUE engine
    my_engine = make_engine(nnue_path=MY_NNUE_PATH, skill=20)

    # Opponent Stockfish engine
    opp_engine = make_engine(nnue_path=None, skill=opp_skill)

    print(f"Opponent skill level = {opp_skill}")
    print(f"Testing over {GAMES} games...\n")

    scores = {"win": 0, "loss": 0, "draw": 0}

    for i in range(1, GAMES + 1):
        print(f"=== Game {i} ===")

        # Alternate colors every game
        if i % 2 == 1:
            white = my_engine
            black = opp_engine
            my_color = "White"
        else:
            white = opp_engine
            black = my_engine
            my_color = "Black"

        result = play_game(white, black, MOVE_TIME)

        # Interpret score from my_engine perspective
        if result == 1 and my_color == "White":
            scores["win"] += 1
            print("My NNUE wins")
        elif result == -1 and my_color == "Black":
            scores["win"] += 1
            print("My NNUE wins")
        elif result == 0:
            scores["draw"] += 1
            print("Draw")
        else:
            scores["loss"] += 1
            print("My NNUE loses")

    # Shut down engines
    my_engine.quit()
    opp_engine.quit()

    # Summary
    print("\n===== FINAL SCORE =====")
    print(f"Wins:   {scores['win']}")
    print(f"Draws:  {scores['draw']}")
    print(f"Losses: {scores['loss']}")
    print("=======================")

    score = scores["win"] + 0.5 * scores["draw"]
    print(f"Score: {score}/{GAMES}")
    print("=======================")


if __name__ == "__main__":
    main()