"""Gilded Rose Refactoring Kata."""
from __future__ import annotations

from abc import ABC, abstractmethod

AGED_BRIE: str = "Aged Brie"
BACKSTAGE_PASSES: str = "Backstage passes to a TAFKAL80ETC concert"
CONJURED: str = "Conjured"
MAX_QUALITY: int = 50
MIN_QUALITY: int = 0
SULFURAS: str = "Sulfuras, Hand of Ragnaros"
SULFURAS_QUALITY: int = 80

class ItemUpdateStrategy(ABC):
    """Abstract base class for item update strategies."""

    @abstractmethod
    def update_quality(self, item: Item) -> None:
        """Update the quality of the given item according to specific rules.

        Parameters
        ----------
        item : Item
            The item whose quality is to be updated.

        """
        pass

    @abstractmethod
    def update_sell_in(self, item: Item) -> None:
        """Update the sell_in of the given item according to specific rules.

        Parameters
        ----------
        item : Item
            The item whose sell_in is to be updated.

        """
        pass

class NormalItemStrategy(ItemUpdateStrategy):
    """Strategy for normal items that degrade in quality over time."""

    def update_quality(self, item: Item) -> None:
        """Decrease quality by 1 before sell date, by 2 after.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        degradation: int = 2 if item.sell_in < 0 else 1
        item.quality = max(MIN_QUALITY, item.quality - degradation)

    def update_sell_in(self, item: Item) -> None:
        """Decrease sell_in by 1 each day.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        item.sell_in -= 1


class AgedBrieStrategy(ItemUpdateStrategy):
    """Strategy for Aged Brie that increases in quality over time."""

    def update_quality(self, item: Item) -> None:
        """Increase quality by 1 before sell date, by 2 after.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        increase: int = 2 if item.sell_in < 0 else 1
        item.quality = min(MAX_QUALITY, item.quality + increase)

    def update_sell_in(self, item: Item) -> None:
        """Decrease sell_in by 1 each day.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        item.sell_in -= 1


class SulfurasStrategy(ItemUpdateStrategy):
    """Strategy for Sulfuras, a legendary item that never changes."""

    def update_quality(self, item: Item) -> None:
        """Sulfuras quality never changes.

        Parameters
        ----------
        item : Item
            The item to update (no actual change occurs).

        """
        pass

    def update_sell_in(self, item: Item) -> None:
        """Sulfuras never needs to be sold.

        Parameters
        ----------
        item : Item
            The item to update (no actual change occurs).

        """
        pass


class BackstagePassStrategy(ItemUpdateStrategy):
    """Strategy for Backstage passes with tiered quality appreciation."""

    def update_quality(self, item: Item) -> None:
        """Update quality based on days until concert.

        Quality increases by:
        - 1 when more than 10 days remain
        - 2 when 6-10 days remain
        - 3 when 1-5 days remain
        - drops to 0 after concert (sell_in < 0)

        Parameters
        ----------
        item : Item
            The item to update.

        """
        if item.sell_in < 0:
            item.quality = 0
        elif item.sell_in <= 5:
            item.quality = min(MAX_QUALITY, item.quality + 3)
        elif item.sell_in <= 10:
            item.quality = min(MAX_QUALITY, item.quality + 2)
        else:
            item.quality = min(MAX_QUALITY, item.quality + 1)

    def update_sell_in(self, item: Item) -> None:
        """Decrease sell_in by 1 each day.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        item.sell_in -= 1


class ConjuredItemStrategy(ItemUpdateStrategy):
    """Strategy for Conjured items that degrade twice as fast as normal items."""

    def update_quality(self, item: Item) -> None:
        """Decrease quality by 2 before sell date, by 4 after.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        degradation = 4 if item.sell_in < 0 else 2
        item.quality = max(MIN_QUALITY, item.quality - degradation)

    def update_sell_in(self, item: Item) -> None:
        """Decrease sell_in by 1 each day.

        Parameters
        ----------
        item : Item
            The item to update.

        """
        item.sell_in -= 1

class ItemStrategyFactory:
    """Factory for creating appropriate item update strategies.

    Maps item names to their corresponding update strategies.
    Centralizes the logic for determining which strategy to use.
    """

    def __init__(self) -> None:
        """Initialize the factory with strategy instances."""
        self._normal = NormalItemStrategy()
        self._aged_brie = AgedBrieStrategy()
        self._sulfuras = SulfurasStrategy()
        self._backstage = BackstagePassStrategy()
        self._conjured = ConjuredItemStrategy()

    def get_strategy(self, item_name: str) -> ItemUpdateStrategy:
        """Return the appropriate strategy for the given item name.

        Parameters
        ----------
        item_name : str
            The name of the item.

        Returns
        -------
        ItemUpdateStrategy
            The strategy instance for updating this item type.

        """
        if item_name == SULFURAS:
            return self._sulfuras
        elif item_name == AGED_BRIE:
            return self._aged_brie
        elif item_name == BACKSTAGE_PASSES:
            return self._backstage
        elif item_name.startswith(CONJURED):
            return self._conjured
        else:
            return self._normal

class GildedRose:
    """Manages inventory quality updates for the Gilded Rose inn.

    Updates item quality and sell_in values acording to specific business rules:
    - Normal items degrade in quality over time
    - "Aged Brie" increases in quality as it ages
    - "Sulfuras" is a legendary item that never changes
    - "Backstage passes" increase in quality as concert approaches, drop to 0 after
    - Quality is never negative and never exceeds 50 (except Sulfuras at 80)

    Goblin will throw a tantrum if the Item class is modified.
    """

    def __init__(self, items: list[Item]) -> None:
        """Initialize the GildedRose with a list of items.

        Parameters
        ----------
        items : list[Item]
            The list of items in the inventory.

        """
        self.items = items

    def update_quality(self) -> None:
        """Update quality and sell_in for all items according to the business rules."""
        for item in self.items:
            if item.name != "Aged Brie" and item.name != "Backstage passes to a TAFKAL80ETC concert":
                if item.quality > 0:
                    if item.name != "Sulfuras, Hand of Ragnaros":
                        item.quality = item.quality - 1
            else:
                if item.quality < 50:
                    item.quality = item.quality + 1
                    if item.name == "Backstage passes to a TAFKAL80ETC concert":
                        if item.sell_in < 11:
                            if item.quality < 50:
                                item.quality = item.quality + 1
                        if item.sell_in < 6:
                            if item.quality < 50:
                                item.quality = item.quality + 1
            if item.name != "Sulfuras, Hand of Ragnaros":
                item.sell_in = item.sell_in - 1
            if item.sell_in < 0:
                if item.name != "Aged Brie":
                    if item.name != "Backstage passes to a TAFKAL80ETC concert":
                        if item.quality > 0:
                            if item.name != "Sulfuras, Hand of Ragnaros":
                                item.quality = item.quality - 1
                    else:
                        item.quality = item.quality - item.quality
                else:
                    if item.quality < 50:
                        item.quality = item.quality + 1


class Item:
    """Represents an item in the Gilded Rose inventory.

    This class must not be modidied cuz Goblin said so.
    """

    def __init__(self, name: str, sell_in: int, quality: int) -> None:
        """Initialize an item in the Gilded Rose inventory.

        Parameters
        ----------
        name : str
            The item's name, which determines its update behavior.
        sell_in : int
            Number of days remaining to sell the item.
        quality : int
            Current quality value (0-50 for normal items, 80 for Sulfuras).

        """
        self.name = name
        self.sell_in = sell_in
        self.quality = quality

    def __repr__(self) -> str:
        """Return a string representation of the item.

        Returns
        -------
        str
            A string describing the item with its name, sell_in, and quality.

        """
        return f"{self.name}, {self.sell_in}, {self.quality}"