#!/usr/bin/env python3

from typing import TextIO
import itertools

circuit: dict[str, int] = {}


class Continue(Exception):
    pass


def part1(instructions: TextIO) -> int:
    ins: list[str] = []

    # process all instructions into a list
    for l in instructions:
        ins.append(l.strip())

    # repeat until the list is empty
    while len(ins) != 0:
        for connection in ins:
            cpart = connection.split()
            # print(cpart, sep="")
            cpart.remove("->")

            # Exclude the destination
            try:
                # possibles = list(itertools.filterfalse(str.isupper, cpart))[:-1]
                for p in range(len(cpart) - 1):
                    if not cpart[p].isnumeric() and not cpart[p].isupper():
                        if cpart[p] in circuit:
                            # Get the value?
                            # This error can be ignored, lol
                            cpart[p] = circuit[cpart[p]]
                        else:
                            # We can't do anything for this
                            raise Continue
            except Continue:
                continue

            # assignment
            if len(cpart) == 2:
                circuit[cpart[1]] = int(cpart[0])
            elif "NOT" in cpart:
                circuit[cpart[-1]] = (
                    ~int(cpart[1]) & 0xFFFF
                )  # see notes for why you can't just use ~
            elif "AND" in cpart:
                circuit[cpart[-1]] = int(cpart[0]) & int(cpart[2])
            elif "OR" in cpart:
                circuit[cpart[-1]] = int(cpart[0]) | int(cpart[2])
            elif "LSHIFT" in cpart:
                circuit[cpart[-1]] = int(cpart[0]) << int(cpart[2])
            elif "RSHIFT" in cpart:
                circuit[cpart[-1]] = int(cpart[0]) >> int(cpart[2])

            ins.remove(connection)

    # print(circuit)
    return circuit["a"]


def part2(f: TextIO):
    circuit["b"] = circuit["a"]

    for k in list(circuit.keys()):
        if k != "b":
            del circuit[k]

    return part1(f)


if __name__ == "__main__":
    with open("day07.txt", "r") as f:
        print(part1(f))

    with open("day07.txt", "r") as f:
        print(part2(f))