from typing import Any, Iterator

from ..base import BaseSolver


class Solver(BaseSolver):
    def solve(self, input: str) -> Iterator[Any]:
        blocks: list[tuple[int, int]] = []
        frees: list[tuple[int, int]] = []

        contents_0: list[int | None] = [None for _ in range(sum(map(int, input)))]

        acc = 0
        for i, c in enumerate(input):
            if i % 2 == 0:
                for j in range(acc, acc + int(c)):
                    contents_0[j] = i // 2
                blocks.append((acc, int(c)))
            else:
                frees.append((acc, int(c)))
            acc += int(c)

        assert contents_0[-1] is not None

        contents = contents_0.copy()

        free_0 = next(i for i, c in enumerate(contents) if c is None)
        next_b = len(contents) - 1

        while free_0 < next_b:
            contents[free_0], contents[next_b] = contents[next_b], contents[free_0]

            free_0 += 1
            while free_0 < len(contents) and contents[free_0] is not None:
                free_0 += 1

            next_b -= 1
            while next_b >= 0 and contents[next_b] is None:
                next_b -= 1

        yield sum(i * c for i, c in enumerate(contents) if c is not None)

        contents = contents_0.copy()

        for block_start, block_length in self.progress.wrap(blocks[::-1]):
            try:
                i_free = next(
                    i_free
                    for i_free, (free_start, free_length) in enumerate(frees)
                    if free_start < block_start and free_length >= block_length
                )
            except StopIteration:
                continue

            free_start, free_length = frees[i_free]

            contents[free_start : free_start + block_length] = contents[
                block_start : block_start + block_length
            ]
            contents[block_start : block_start + block_length] = [None] * block_length

            if free_length == block_length:
                del frees[i_free]
            else:
                frees[i_free] = (free_start + block_length, free_length - block_length)

        yield sum(i * c for i, c in enumerate(contents) if c is not None)