from abc import ABC, abstractmethod
from pathlib import Path
from typing import Any, Generic, TypeVar
from urllib.request import Request, urlopen
from html.parser import HTMLParser
from importlib import import_module

T1 = TypeVar("T1")
T2 = TypeVar("T2")


class CodeExtractor(HTMLParser):
    def __init__(self) -> None:
        super().__init__()
        self.inpre = False
        self.incode = False
        self.code: list[str] = []

    def handle_starttag(self, tag: str, attrs: list[tuple[str, str | None]]) -> None:
        if tag == "code":
            self.incode = True
        elif tag == "pre":
            self.inpre = True

    def handle_endtag(self, tag: str) -> None:
        if tag == "code":
            self.incode = False
        elif tag == "pre":
            self.inpre = False

    def handle_data(self, data: str) -> None:
        if self.incode and self.inpre:
            self.code.append(data)


class Aoc2(ABC, Generic[T1, T2]):
    def __init__(self, year: int, day: int):
        self._year = year
        self._day = day

        with open(".session", encoding="utf8") as f:
            self._session = f.read().strip()

    @abstractmethod
    def part1(self, inpt: T1) -> Any:
        ...

    @abstractmethod
    def part2(self, inpt: T2) -> Any:
        ...

    @abstractmethod
    def parseinput1(self, inpt: str) -> T1:
        ...

    @abstractmethod
    def parseinput2(self, inpt: str) -> T2:
        ...

    def dl_with_cache(self, url: str, cachefilepath: Path) -> str:
        cachefilepath.parent.mkdir(parents=True, exist_ok=True)

        if cachefilepath.exists():
            return cachefilepath.read_text()

        request = Request(url, headers={"Cookie": f"session={self._session}"})
        with urlopen(request) as response:
            inpt: str = response.read().decode()

        cachefilepath.write_text(inpt)
        return inpt

    def get_data_for_day(self) -> str:
        return self.dl_with_cache(
            f"https://adventofcode.com/{self._year}/day/{self._day}/input",
            Path("aoc_cache") / str(self._year) / f"day{self._day}_input",
        )

    def get_examples_for_day(self) -> list[str]:
        site = self.dl_with_cache(
            f"https://adventofcode.com/{self._year}/day/{self._day}",
            Path("aoc_cache") / str(self._year) / f"day{self._day}_site",
        )
        code_extractor = CodeExtractor()
        code_extractor.feed(site)
        return code_extractor.code

    def run_example_1(self, ex_nr: int = 0) -> str:
        inpt = self.get_examples_for_day()[ex_nr]
        return str(self.part1(self.parseinput1(inpt)))

    def run_example_2(self, ex_nr: int = -1) -> str:
        inpt = self.get_examples_for_day()[ex_nr]
        return str(self.part2(self.parseinput2(inpt)))

    def run_1(self) -> str:
        inpt = self.get_data_for_day()
        return str(self.part1(self.parseinput1(inpt)))

    def run_2(self) -> str:
        inpt = self.get_data_for_day()
        return str(self.part2(self.parseinput2(inpt)))

    def run(self) -> None:
        print("Example:\t", end="")
        print(f"{self.run_example_1()}\t", end="")
        print(f"{self.run_example_2()}")

        print("Real input:\t", end="")
        print(f"{self.run_1()}\t", end="")
        print(f"{self.run_2()}")


class Aoc(Generic[T1], Aoc2[T1, T1]):
    def parseinput(self, inpt: str) -> T1:
        raise NotImplementedError

    def parseinput1(self, inpt: str) -> T1:
        return self.parseinput(inpt)

    def parseinput2(self, inpt: str) -> T1:
        return self.parseinput(inpt)

    def part2(self, inpt: T1) -> Any:
        return self.part1(inpt)


def main():
    days = [
        import_module(file.stem)
        for file in Path(".").iterdir()
        if file.name.endswith(".py") and file.name.startswith("day")
    ]
    for day in days:
        print(f"Running {day.__name__}")
        day.main()
        print()


if __name__ == "__main__":
    main()