"""
rearrange a list of crates one by one according to given instructions
"""


import re
from string import ascii_letters

instruction_pattern = re.compile(r'(\d+)')

class CrateMover9000:
    def __init__(self, plan:str) -> None:
        self.numstacks = len(instruction_pattern.findall(plan.pop()))
        self.stacks = [[] for _ in range(self.numstacks)]

        for i in range(len(plan)):
            layer = f"{plan.pop():<{self.numstacks*4}}"
            crates = layer[1::4]
            for j, crate in enumerate(crates):
                if crate in ascii_letters:
                    self.stacks[j].append(crate)

    def move(self, instruction:str) -> None:
        num, source, target = [int(s) for s in instruction_pattern.findall(instruction)]
        for _ in range(num):
            self.stacks[target-1].append(self.stacks[source-1].pop())

    def shuffle(self, insttructions:str) -> None:
        for line in instructions:
            self.move(line)


    def show(self) -> None:
        for i, stack in enumerate(self.stacks):
            print(i+1,*stack)
        print("")

    def top_crates(self) -> str:
        s = ''
        for stack in self.stacks:
            s += stack[-1]
        return s

text = """
    [D]
[N] [C]
[Z] [M] [P]
 1   2   3

move 1 from 2 to 1
move 3 from 1 to 3
move 2 from 2 to 1
move 1 from 1 to 2
"""

with open('2022/5/crane.txt') as filein:
    text = filein.read()

plan, instructions = [t.splitlines(keepends=False) for t in text.split('\n\n')]

crane = CrateMover9000(plan)
crane.show()
crane.shuffle(instructions)
crane.show()
print("top message:", crane.top_crates())

"""
now rearrange a list of crates  in batches according to given instructions
"""

class CrateMover9001(CrateMover9000):
    def __init__(self, plan: str) -> None:
        super().__init__(plan)

    def move(self, instruction: str) -> None:
        num, source, target = [int(s) for s in instruction_pattern.findall(instruction)]
        self.stacks[target-1] += self.stacks[source-1][-num:]
        self.stacks[source-1] = self.stacks[source-1][:-num]

plan, instructions = [t.splitlines(keepends=False) for t in text.split('\n\n')]
crane = CrateMover9001(plan)
crane.shuffle(instructions)
crane.show()
print("top message:", crane.top_crates())