feat: extend classes with Classes.isValid and Classes.apply

src/classes.lua

@@ -0,0 +1,64 @@
+-- Player classes. A class is chosen once at character creation (Game.new
+-- options.class) and never changes; it grants a one-time stat or kit delta
+-- and, through skills.lua, gates which skills the player is allowed to spend
+-- points on. Classless play (no options.class given) is unaffected - every
+-- class delta is opt-in so existing unclassed games keep their exact stats.
+
+local Items = require("items")
+
+local Classes = {}
+
+Classes.order = { "fighter", "rogue", "mage", "ranger" }
+
+Classes.defs = {
+  fighter = {
+    name = "fighter",
+    apply = function(player)
+      player.maxHp = player.maxHp + 8
+      player.hp = player.hp + 8
+      player.attack = player.attack + 2
+      player.baseAttack = player.baseAttack + 2
+    end,
+  },
+  rogue = {
+    name = "rogue",
+    apply = function(player)
+      player.gold = player.gold + 15
+      player.attack = player.attack + 1
+      player.baseAttack = player.baseAttack + 1
+    end,
+  },
+  mage = {
+    name = "mage",
+    apply = function(player)
+      player.maxMana = player.maxMana + 8
+      player.mana = player.mana + 8
+      player.attack = player.attack - 1
+      player.baseAttack = player.baseAttack - 1
+    end,
+  },
+  ranger = {
+    name = "ranger",
+    apply = function(player)
+      Items.equipBow(Items.bow("shortbow", 3, 6), player)
+      player.inventory[#player.inventory + 1] = Items.ammo("arrow", 12)
+    end,
+  },
+}
+
+function Classes.isValid(key)
+  return Classes.defs[key] ~= nil
+end
+
+-- Applies the one-time delta for `key` to a freshly created player. Must run
+-- after the player's base stats, mana pool and starting inventory are all in
+-- place, since every delta is additive on top of whatever is already there.
+function Classes.apply(player, key)
+  local def = Classes.defs[key]
+  if not def then return false end
+  player.class = key
+  def.apply(player)
+  return true
+end
+
+return Classes