Implement melee weapons

Add all melee weapons and handle dice expressions for damage. Generate
enchanted and cursed weapons. Add string representation for weapons.
Handle wielded and cursed weapons in actions.

game/action.py

@@ -137,6 +137,9 @@ def __init__(self, item: Item):
 
     def perform(self, actor: Actor, level: Level, log: MessageLog) -> bool:
         assert isinstance(actor, Player)
+        if self.item == actor.inventory.weapon_slot:
+            log.append("That's already in use.")
+            return False
         actor.inventory.weapon_slot = self.item
         log.append(f"You are now wielding {self.item}.")
         return True

game/combat.py

@@ -1,8 +1,8 @@
 from __future__ import annotations
 
-from dataclasses import dataclass, field
+from dataclasses import InitVar, dataclass, field
 
-from game.dice import roll
+from game.dice import parse_dice, roll
 from game.entity import Actor, Player
 from game.level import Level
 from game.messages import MessageLog
@@ -41,15 +41,21 @@ def ac(self) -> int:
         return self.base_ac - self.plus_ac
 
 
-@dataclass(frozen=True, slots=True)
+@dataclass(eq=False, slots=True, kw_only=True)
 class Weapon:
-    # weapon damage die
-    damage: int
+    # weapon damage dice
+    base_dmg: tuple[int, int] = field(init=False)
     # to hit bonus
     plus_hit: int = 0
     # damage bonus
     plus_dmg: int = 0
 
+    # damage dice expression
+    dmg_dice: InitVar[str]
+
+    def __post_init__(self, dmg_dice: str) -> None:
+        self.base_dmg = parse_dice(dmg_dice)
+
 
 def melee_attack(attacker: Actor, defender: Actor, level: Level, log: MessageLog) -> None:
     assert isinstance(attacker, Player) != isinstance(defender, Player)
@@ -63,10 +69,11 @@ def melee_attack(attacker: Actor, defender: Actor, level: Level, log: MessageLog
     thac0 = 21 - attacker.stats.hd
     hit = roll(1, d=20) + to_hit_bonus >= thac0 - armor_class
     if hit:
-        damage_die = attacker.stats.dmg
+        damage_dice = 1, attacker.stats.dmg
         if isinstance(attacker, Player) and attacker.inventory.weapon_slot:
-            damage_die = attacker.inventory.weapon_slot.weapon.damage
-        damage = roll(1, d=damage_die) + damage_bonus
+            damage_dice = attacker.inventory.weapon_slot.weapon.base_dmg
+        damage = roll(*damage_dice) + damage_bonus
+        damage = max(0, damage)
         defender.stats.hp = max(0, defender.stats.hp - damage)
         log.append(f"You hit the {defender.name}." if isinstance(attacker, Player)
                    else f"The {attacker.name} hits you.")

game/dice.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import random
+import re
 
 
 def roll(n: int, d: int) -> int:
@@ -13,3 +14,9 @@ def roll(n: int, d: int) -> int:
 
 def percent(p: int) -> bool:
     return random.randrange(100) < p
+
+
+def parse_dice(dice: str) -> tuple[int, int]:
+    assert re.match(r"^\d+d\d+$", dice)
+    n, d = dice.split('d')
+    return int(n), int(d)

game/entity.py

@@ -59,6 +59,12 @@ def __str__(self) -> str:
 class WeaponItem(Item):
     weapon: Weapon
 
+    def __str__(self) -> str:
+        if self.identified:
+            return f"a {self.weapon.plus_hit:+d},{self.weapon.plus_dmg:+d} {self.name}"
+        else:
+            return f"{article(self.name)} {self.name}"
+
 
 def article(noun: str) -> str:
     return "an" if noun[0] in 'aeiou' else "a"

game/game_loop.py

@@ -26,8 +26,14 @@ def new_game() -> tuple[Player, Level, MessageLog]:
     )
     inventory.add_item(armor)
     inventory.armor_slot = armor
-    weapon = WeaponItem(x=0, y=0, glyph=Glyph.WEAPON, name='+1,+1 mace',
-                        weapon=Weapon(plus_hit=1, plus_dmg=1, damage=9))
+    weapon = WeaponItem(
+        x=0,
+        y=0,
+        glyph=Glyph.WEAPON,
+        name="mace",
+        weapon=Weapon(plus_hit=+1, plus_dmg=+1, dmg_dice='2d4'),
+        identified=True,
+    )
     inventory.add_item(weapon)
     inventory.weapon_slot = weapon
     player = Player(

game/items.py

@@ -49,8 +49,11 @@ def spawn(self, x: int, y: int) -> Item:
 ]
 
 weapon_types = [
-    ItemType(1, Glyph.WEAPON, 'dagger', Weapon(damage=6)),
-    ItemType(1, Glyph.WEAPON, 'long sword', Weapon(damage=10)),
+    ItemType(1, Glyph.WEAPON, "mace", Weapon(dmg_dice='2d4')),
+    ItemType(1, Glyph.WEAPON, "longsword", Weapon(dmg_dice='3d4')),
+    ItemType(1, Glyph.WEAPON, "dagger", Weapon(dmg_dice='1d6')),
+    ItemType(1, Glyph.WEAPON, "two-handed sword", Weapon(dmg_dice='4d4')),
+    ItemType(1, Glyph.WEAPON, "spear", Weapon(dmg_dice='2d3')),
 ]
 
 
@@ -68,7 +71,7 @@ def get_item_types(self) -> tuple[list[ItemType], list[int]]:
     ItemCategory(27, potion_types),
     ItemCategory(27, scroll_types),
     ItemCategory(8, armor_types),
-    ItemCategory(9, weapon_types),
+    ItemCategory(8, weapon_types),
 ]
 
 

game/procgen.py

@@ -4,7 +4,7 @@
 import random
 
 from game.constants import Glyph, Tile
-from game.entity import ArmorItem, Item
+from game.entity import ArmorItem, Item, WeaponItem
 from game.items import get_item_categories
 from game.level import Level
 from game.monsters import eligible_monsters
@@ -266,6 +266,13 @@ def place_item(all_rooms: list[Room | Junction], level: Level) -> None:
             item.armor.plus_ac = -rng.randint(1, 3)
         elif r < 0.28:
             item.armor.plus_ac = +rng.randint(1, 3)
+    elif isinstance(item, WeaponItem):
+        r = rng.random()
+        if r < 0.10:
+            item.cursed = True
+            item.weapon.plus_hit = -rng.randint(1, 3)
+        elif r < 0.15:
+            item.weapon.plus_hit = +rng.randint(1, 3)
     level.entities.add(item)
 
 

game/state.py

@@ -74,6 +74,9 @@ def event(self, event: tcod.event.Event, player: Player, level: Level, log: Mess
             case Command.READ:
                 return UseItem(glyph=Glyph.SCROLL)
             case Command.WIELD:
+                if player.inventory.weapon_slot and player.inventory.weapon_slot.cursed:
+                    log.append("You can't. It appears to be cursed.")
+                    return Play()
                 return UseItem(glyph=Glyph.WEAPON)
             case Command.WEAR:
                 if player.inventory.armor_slot: