import copy

program = []

with open("8 - input", 'r') as file:
    lines = file.readlines()
    for line in lines:
        line = line.strip("\n")

        #Instruction nop +346
        program.append\
        (
                [line.split(" ")[0],            #   string "nop"
                 line.split(" ")[1][0],         #   string "+"
                 int(line.split(" ")[1][1:])]   #   integer 346
        )


def execute(index, instruction, acc, printLog=False):
    spacer = "\t"
    if index < 10:
        spacer = spacer * 2

    if instruction[0] == "nop":
        if printLog:
            print(f"[{index}]{spacer}{instruction[0]}")

        return index + 1, acc   #   For nop instruction, we just move to the next instruction, acc has not been modified but we return it.

    elif instruction[0] == "acc":
        if printLog:
            print(f"[{index}]{spacer}{instruction[0]} with arg {instruction[1]}{instruction[2]}", end="")

        if instruction[1] == "+":
            acc += instruction[2]   #   Add argument of instruction to acc

        elif instruction[1] == "-":
            acc -= instruction[2]   #   Subtract argument of instruction to acc

        if printLog:
            print(f", global acc: {acc}")

        return index + 1, acc   #   With acc instruction, we go to the next instruction in the program

    elif instruction[0] == "jmp":
        if printLog:
            print(f"[{index}]{spacer}{instruction[0]} {instruction[1]}{instruction[2]}", end="")

        if instruction[1] == "+":   #   We're jumping forward
            if printLog:
                print(f", jmping to {index + instruction[2]}")
            return index + instruction[2], acc  #   Return the next index to run, current index + the argument of the instruction, acc has not been modified

        elif instruction[1] == "-": #   We're jumping backwards
            if printLog:
                print(f", jmping to {index - instruction[2]}")
            return index - instruction[2], acc  #   Return the next index to run, current index - the argument of the instruction, acc has not been modified

    else:
        print(f"{instruction} not valid!")  #   You have misspelled an instruction
        exit(1)

def runProgram(_program, printLog = False):
    acc = 0
    index = 0
    executedInstructions = []
    while True:
        if index >= len(program) or index < 0:      #   Program is about to run code outside of the inputted program
            result = (acc, index, "Out of bounds")  #   Return current value of the acc variable, and the index the program stopped at and the errorcode
            return result

        instruction = _program[index]               #   Get the current instruction
        #print(f"\n{executedInstructions}")
        if index not in executedInstructions:       #   No infinte loops allowed
            executedInstructions.append(index)      #   Note that we have already run this instruction
            index, acc = execute(index, instruction, acc, printLog) #   Execute the instruction and get the next instruction index, and the calculated value of acc
        else:
            result = (acc, index, "Infinite loop")  #   As we said - No fun allowed!
            return result


print(runProgram(program))  #   Run the original program
print()

# part 2
programBak = copy.deepcopy(program)     #   Our program list is a list of a list, if we would've used = or list.copy(), python would've given us only references
triedInstructions = []
for i in range(0, len(program)):
    program = copy.deepcopy(programBak) #   We only want to change one (1) nop/jmp instruction at a time so we need to use a fresh, original program each time

    if i not in triedInstructions:      #   We only want to try each instruction once
        if program[i][0] == "nop":
            program[i][0] = "jmp"
            #print(f"Switched instruction {programBak[i]} at {i} to {program[i]}")
            triedInstructions.append(i) #   Note the instruction we've tried

        elif program[i][0] == "jmp":
            program[i][0] = "nop"
            #print(f"Switched instruction {programBak[i]} at {i} to {program[i]}")
            triedInstructions.append(i)

        else:
            continue    #   We only need to run the program if we've modified a jmp or nop instruction

        result = runProgram(program)
        if result[2] == "Out of bounds":    #   We are looking for an out of bounds error
            print(result)
            exit(0)

print("Never got errorcode 'Out of bounds'")
exit(1)