from lib import str_to_int
from collections import defaultdict


def part_1(data):
    rules = {}
    steps = None
    start_state = None
    current_state = None
    current_value = None
    for line in data.splitlines():
        if line.startswith("In state"):
            current_state = line[-2]
            rules[current_state] = {}
        elif "current value" in line:
            current_value = str_to_int(line)
            rules[current_state][current_value] = []
        elif "- Write the value" in line:
            rules[current_state][current_value].append(str_to_int(line))
        elif "- Move one slot to the right" in line:
            rules[current_state][current_value].append(1)
        elif "- Move one slot to the left" in line:
            rules[current_state][current_value].append(-1)
        elif "Continue with state" in line:
            rules[current_state][current_value].append(line[-2])
        elif "Begin in state" in line:
            start_state = line[-2]
        elif "checksum after" in line:
            steps = str_to_int(line)
        elif line.strip() == "":
            pass
        else:
            print(line)
            assert False

    assert type(steps) is int
    assert start_state is not None
    current_state = start_state
    tape = defaultdict(int)
    pos = 0
    for _ in range(steps):
        current_value = tape[pos]
        write_value, move, next_state = rules[current_state][current_value]
        tape[pos] = write_value
        pos += move
        current_state = next_state

    print(sum(tape.values()))


def main():
    with open("i25.txt") as f:
        data = f.read()
    part_1(data)


if __name__ == "__main__":
    main()