import chess.pgn

PGN_PATH = 'test.pgn'
NODES = 800

def average_time_per_move(pgn_file):
        pgn = open(pgn_file, encoding="utf-8-sig")
        stats = {} #format {engine_name : [total_time, nr_of_samples]}
        while True:
            game = chess.pgn.read_game(pgn)
            if game is None:
                break
            white_engine = game.headers['White']
            black_engine = game.headers['Black']
            engines = [white_engine, black_engine]

            for engine in engines:
                if engine not in stats.keys():
                    stats[engine] = [0.0, 0]
            node = game
            ply_nr = 0
            while not node.is_end():
                next_node = node.variations[0]
                engine = engines[ply_nr % 2]
                comment = node.comment
                if comment != 'book' and comment != '':
                    used_time = float(comment.split(' ')[1][:-1])
                    stats[engine][0] += used_time
                    stats[engine][1] += 1
                node = next_node
                ply_nr += 1

            #calculate average time used for move
            stats_final = {eng: stats[eng][0]/(stats[eng][1] if stats[eng][1]!= 0 else 1) for eng in stats.keys()}
            return(stats_final)

stats = average_time_per_move(PGN_PATH)
nodes_per_move = 800

for engine in stats.keys():
    print(engine, NODES/stats[engine])