feat: extend abilities with tryHeal and tryRally

src/ai.lua

@@ -2,15 +2,38 @@
 -- resolves that monster's turn through game helpers, so all state mutation and
 -- rng use stays centralised and deterministic.
 
+local Status = require("status")
+local Infighting = require("infighting")
+
 local Ai = {}
 
-local AGGRO = { chase = 10, pack = 13, ranged = 12, flee = 8, erratic = 8 }
+local AGGRO = { chase = 10, pack = 13, ranged = 12, flee = 8, erratic = 8, tunnel = 10 }
 local DIRS = { { 1, 0 }, { -1, 0 }, { 0, 1 }, { 0, -1 } }
 
+-- A player-aligned ally standing adjacent to `monster` occupies its cell
+-- exactly the way a wall would for Game:stepMonsterToward's own pathfinding
+-- (blockedForMonster treats any occupied non-goal cell as impassable) - so a
+-- one-wide corridor an ally is plugging leaves every pursuit behaviour below
+-- with no route at all, and without this check they simply idle beside it
+-- forever rather than fighting the living combatant in their way. Resolves
+-- through Infighting.strike, the same generic monster-vs-any-creature combat
+-- infighting.lua already uses for rivalries and discord. Returns true once
+-- it has spent the monster's turn this way, so each caller can bail out at
+-- the same priority Game:playerAdjacent already has over closing distance.
+local function attackBlockingAlly(game, monster)
+  local ally = game:adjacentAlly(monster)
+  if not ally then return false end
+  Infighting.strike(game, monster, ally)
+  return true
+end
+
 local function chase(game, monster)
   if game:playerAdjacent(monster) then
     game:monsterMelee(monster)
-  elseif game:canSeePlayer(monster, AGGRO.chase) then
+    return
+  end
+  if attackBlockingAlly(game, monster) then return end
+  if game:canSeePlayer(monster, AGGRO.chase) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
   end
 end
@@ -20,6 +43,7 @@ local function pack(game, monster)
     game:monsterMelee(monster)
     return
   end
+  if attackBlockingAlly(game, monster) then return end
   if game:canSeePlayer(monster, AGGRO.pack) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
     return
@@ -39,6 +63,7 @@ local function ranged(game, monster)
     end
     return
   end
+  if attackBlockingAlly(game, monster) then return end
   if game:canSeePlayer(monster, AGGRO.ranged) then
     game:stepMonsterToward(monster, game.player.x, game.player.y)
   end
@@ -50,6 +75,14 @@ local function flee(game, monster)
   end
 end
 
+-- Shopkeepers idle unless game.lua has already flagged them hostile (a theft
+-- from their stock), at which point they behave exactly like a chaser.
+local function vend(game, monster)
+  if monster.hostile then
+    chase(game, monster)
+  end
+end
+
 local function erratic(game, monster)
   if game:playerAdjacent(monster) then
     game:monsterMelee(monster)
@@ -63,15 +96,45 @@ local function erratic(game, monster)
   end
 end
 
+-- A burrower: melee once adjacent, chase like anything else once it can see
+-- the player through open floor, otherwise claw straight through whatever
+-- rock stands between them (see Game:monsterDig, digging.lua) rather than
+-- idling the way a plain chaser out of sight would.
+local function tunnel(game, monster)
+  if game:playerAdjacent(monster) then
+    game:monsterMelee(monster)
+    return
+  end
+  if attackBlockingAlly(game, monster) then return end
+  if game:canSeePlayer(monster, AGGRO.tunnel) then
+    game:stepMonsterToward(monster, game.player.x, game.player.y)
+    return
+  end
+  game:monsterDig(monster, game.player.x, game.player.y)
+end
+
 Ai.behaviours = {
   chase = chase,
   pack = pack,
   ranged = ranged,
   flee = flee,
   erratic = erratic,
+  vend = vend,
+  tunnel = tunnel,
 }
 
+-- A confused monster gets the exact same chance each turn to have its own
+-- chosen direction overridden that Game:movePlayer rolls for the player - see
+-- status.lua's Status.CONFUSE_NUMERATOR/DENOMINATOR, shared by both sides so
+-- neither one confuses more reliably than the other. On a lucky roll (or once
+-- confusion wears off) `behaviour` below runs completely untouched.
 function Ai.act(game, monster)
+  if Status.has(monster, Status.CONFUSE)
+    and game.rng:chance(Status.CONFUSE_NUMERATOR, Status.CONFUSE_DENOMINATOR) then
+    local dir = DIRS[game.rng:range(1, #DIRS)]
+    game:moveMonster(monster, dir[1], dir[2])
+    return
+  end
   local behaviour = Ai.behaviours[monster.ai] or chase
   behaviour(game, monster)
 end