item.py

from bit_utils import read_bits, write_bits
from item_data import get_item_group, get_item_size_x, get_item_size_y, get_true_set_id, get_gem_quality, Rarity


# Item class, holding the various relevant item-related attributes and methods
class Item:
    def __init__(self, data):
        self.data = data  # The byte data
        self.code = self.get_item_code(data)  # Item code, i.e. "amu", "rng" etc
        self.rw = self.is_runeword(data)      # Is the item a runeword?
        self.simple = self.is_simple(data)    # Is the item "simple" (contains limited amount of data)
        self.rarity = self.get_rarity(data)   # Item rarity (normal, unique, rare, etc)
        self.set_id = self.get_set_id(data)   # Which set does item belong to?
        self.picture_id = self.get_picture_id(data)  # For jewels, rings/ammies etc, which picture does the item use
        self.group = get_item_group(self.code)     # What group does the item belong to (gloves, jewel, uber key, etc)
        self.x_size = get_item_size_x(self.code)   # How many horizontal slots does the item take
        self.y_size = get_item_size_y(self.code)   # How many vertical slots does the item take
        self.gem_quality = get_gem_quality(self.code)  # Quality of gem (none if not a gem)

    def set_position(self, x, y):
        # Modify item data and write new stash position
        self.data = write_bits(self.data, 65, 4, x)
        self.data = write_bits(self.data, 69, 4, y)

    def set_code(self, new_code):
        # Get new 3-letter item code and replace the old one
        for i in range(3):
            self.data = write_bits(self.data, 76 + i * 8, 8, ord(new_code[i]))
        self.data = write_bits(self.data, 100, 8, ord(' '))
        self.code = new_code

    @staticmethod
    def get_position(item):
        # Get position in stash
        x_pos = read_bits(item, 65, 4)
        y_pos = read_bits(item, 69, 4)
        return x_pos, y_pos

    @staticmethod
    def get_item_code(item):
        # Get the item code
        if Item.is_ear(item):  # Ears lack the bits that indicate item code, but they have a specific ear indicator
            return 'ear'
        item_code = ''
        for i in range(4):  # Reach each char individually
            char = chr(read_bits(item, 76 + i * 8, 8))
            if char != ' ':  # Item codes are 4 bytes long but most of them have a space as the last char which
                # should be ignored
                item_code += char
        return item_code

    @staticmethod
    def is_ear(item):
        return read_bits(item, 32, 1)

    @staticmethod
    def is_runeword(item):
        return read_bits(item, 42, 1)

    @staticmethod
    def is_simple(item):
        return read_bits(item, 37, 1)

    @staticmethod
    def get_rarity(item):
        if Item.is_simple(item):
            return None
        return Rarity(read_bits(item, 150, 4))

    @staticmethod
    def has_multiple_pictures(item):
        # Used to indicate whether an item can have multiple graphics (like rings, amulets, jewels etc)
        return read_bits(item, 154, 1)

    @staticmethod
    def get_picture_id(item):
        # Return id of picture for items with multiple pictures
        if Item.is_simple(item) or not Item.has_multiple_pictures(item):
            return None
        return read_bits(item, 155, 3)

    @staticmethod
    def is_class_specific(item):
        # The bits indicating if an item is class specific vary in location based on whether it has multiple pictures
        if Item.has_multiple_pictures(item):
            return read_bits(item, 158, 1)
        return read_bits(item, 155, 1)

    @staticmethod
    def num_filled_sockets(item):
        # Return number of socketed items in item
        if Item.is_ear(item) or Item.is_simple(item):
            return 0
        return read_bits(item, 108, 3)

    def get_set_id(self, item):
        # Get the set id of the item.
        if self.rarity is not Rarity.SET:  # First, make sure it's actually a set item
            return None
        # The relevant bit offset depends on whether the item has multiple graphics and/or is class specific
        offset = 156
        if self.has_multiple_pictures(item):
            offset += 3
        if self.is_class_specific(item):
            offset += 11
        # Once the set id is obtained, get the "true" set id from item_data.py
        # The set id as given in the item data actually indicates the specific item and not the set, i.e. Sigon parts
        # have different ids in the 35-40 range, Death's set is 47-49, etc. We want a single id for each set.
        return get_true_set_id(read_bits(item, offset, 12))