Micro AIs: add check for valid move and error message

This now checks whether the move intended to be done with ai.move is
possible and display an error message if it is not.

data/ai/lua/ai_helper.lua

@@ -144,7 +144,7 @@ function ai_helper.checked_attack(ai, attacker, defender, weapon)
     ai.attack(attacker, defender, weapon)
 end
 
-function ai_helper.checked_move_full(ai, unit, x, y)
+function ai_helper.checked_move_core(ai, unit, x, y, move_type)
     local check = ai.check_move(unit, x, y)
 
     if (not check.ok) then
@@ -153,12 +153,24 @@ function ai_helper.checked_move_full(ai, unit, x, y)
         -- E_AMBUSHED = 2005
         -- E_NOT_REACHED_DESTINATION = 2007
         if (check.status ~= 2001) and (check.status ~= 2005) and (check.status ~= 2007) then
-            ai_helper.checked_action_error('ai.move_full', check.status)
+            ai_helper.checked_action_error(move_type, check.status)
             return
         end
     end
 
-    ai.move_full(unit, x, y)
+    if (move_type == 'ai.move_full') then
+        ai.move_full(unit, x, y)
+    else
+        ai.move(unit, x, y)
+    end
+end
+
+function ai_helper.checked_move_full(ai, unit, x, y)
+    ai_helper.checked_move_core(ai, unit, x, y, 'ai.move_full')
+end
+
+function ai_helper.checked_move(ai, unit, x, y)
+    ai_helper.checked_move_core(ai, unit, x, y, 'ai.move')
 end
 
 ----- General functionality and maths helper functions ------
@@ -1041,7 +1053,7 @@ function ai_helper.move_unit_out_of_way(ai, unit, cfg)
 
     if (max_rating > -9e99) then
         --W.message { speaker = unit.id, message = 'Moving out of way' }
-        ai.move(unit, best_hex[1], best_hex[2])
+        ai_helper.checked_move(ai, unit, best_hex[1], best_hex[2])
     end
 end
 

data/ai/micro_ais/cas/ca_big_animals.lua

@@ -82,7 +82,7 @@ function ca_big_animals:execution(ai, cfg)
         --AH.put_labels(reach_map)
 
         if (best_hex[1] ~= unit.x) or (best_hex[2] ~= unit.y) then
-            ai.move(unit, best_hex[1], best_hex[2])  -- partial move only
+            AH.checked_move(ai, unit, best_hex[1], best_hex[2])  -- partial move only
         else  -- If animal did not move, we need to stop it (also delete the goal)
             ai.stopunit_moves(unit)
             unit.variables.goal_x = nil

data/ai/micro_ais/cas/ca_bottleneck_move.lua

@@ -497,7 +497,7 @@ function ca_bottleneck_move:execution(ai, cfg, self)
         --print("Moving unit:",self.data.unit.id, self.data.unit.x, self.data.unit.y, " ->", best_hex[1], best_hex[2], " -- turn:", wesnoth.current.turn)
 
         if (self.data.unit.x ~= self.data.hex[1]) or (self.data.unit.y ~= self.data.hex[2]) then  -- test needed for level-up move
-            ai.move(self.data.unit, self.data.hex[1], self.data.hex[2])   -- don't want full move, as this might be stepping out of the way
+            AH.checked_move(ai, self.data.unit, self.data.hex[1], self.data.hex[2])   -- don't want full move, as this might be stepping out of the way
         end
 
         -- If this is a move for a level-up attack, do the attack also

data/ai/micro_ais/cas/ca_forest_animals_move.lua

@@ -98,7 +98,7 @@ function ca_forest_animals_move:execution(ai, cfg)
                 local rand = math.random(#reachable_terrain)
                 -- This is not a full move, as running away might happen next
                 if (unit.x ~= reachable_terrain[rand][1]) or (unit.y ~= reachable_terrain[rand][2]) then
-                    ai.move(unit, reachable_terrain[rand][1], reachable_terrain[rand][2])
+                    AH.checked_move(ai, unit, reachable_terrain[rand][1], reachable_terrain[rand][2])
                 end
             else  -- or if no close reachable terrain was found, move toward the closest
                 local locs = wesnoth.get_locations(wander_terrain)
@@ -114,7 +114,7 @@ function ca_forest_animals_move:execution(ai, cfg)
                     local next_hop = AH.next_hop(unit, x, y)
                     --print(next_hop[1], next_hop[2])
                     if (unit.x ~= next_hop[1]) or (unit.y ~= next_hop[2]) then
-                        ai.move(unit, next_hop[1], next_hop[2])
+                        AH.checked_move(ai, unit, next_hop[1], next_hop[2])
                     end
                 end
             end

data/ai/micro_ais/cas/ca_hang_out.lua

@@ -132,7 +132,7 @@ function ca_hang_out:execution(ai, cfg, self)
         end
     else
         -- Otherwise move unit and mark as having been used
-        ai.move(best_unit, best_hex[1], best_hex[2])
+        AH.checked_move(ai, best_unit, best_hex[1], best_hex[2])
         best_unit.variables.mai_hangout_moved = true
     end
 end

data/ai/micro_ais/cas/ca_herding_herd_sheep.lua

@@ -86,7 +86,7 @@ function ca_herding_herd_sheep:execution(ai, cfg)
         ai.stopunit_moves(best_dog)
     else
         --print('Dog moving to herd sheep')
-        ai.move(best_dog, best_hex[1], best_hex[2])  -- partial move only
+        AH.checked_move(ai, best_dog, best_hex[1], best_hex[2])  -- partial move only
     end
 end
 

data/ai/micro_ais/cas/ca_herding_sheep_move.lua

@@ -43,7 +43,7 @@ function ca_herding_sheep_move:execution(ai, cfg)
     if herding_area:get(x, y) or (not dogs[1]) or ((x == sheep.x) and (y == sheep.y)) then
         AH.movefull_stopunit(ai, sheep, x, y)
     else
-        ai.move(sheep, x, y)
+        AH.checked_move(ai, sheep, x, y)
     end
 end
 

data/ai/micro_ais/cas/ca_hunter.lua

@@ -113,7 +113,7 @@ function ca_hunter:execution(ai, cfg)
         --AH.put_labels(reach_map)
 
         if (best_hex[1] ~= unit.x) or (best_hex[2] ~= unit.y) then
-            ai.move(unit, best_hex[1], best_hex[2])  -- partial move only
+            AH.checked_move(ai, unit, best_hex[1], best_hex[2])  -- partial move only
         else  -- If hunter did not move, we need to stop it (also delete the goal)
             ai.stopunit_moves(unit)
             unit.variables.goal_x, unit.variables.goal_y = nil, nil

data/ai/micro_ais/cas/ca_messenger_move.lua

@@ -58,7 +58,7 @@ function ca_messenger_move:execution(ai, cfg, self)
     --print(next_hop[1], next_hop[2])
 
     if next_hop and ((next_hop[1] ~= messenger.x) or (next_hop[2] ~= messenger.y)) then
-        ai.move(messenger, next_hop[1], next_hop[2])
+        AH.checked_move(ai, messenger, next_hop[1], next_hop[2])
     else
         ai.stopunit_moves(messenger)
     end

data/ai/micro_ais/cas/ca_patrol.lua

@@ -119,7 +119,7 @@ function ca_patrol:execution(ai, cfg, self)
             local x, y = wesnoth.find_vacant_tile(self.data[patrol.id..'_x'], self.data[patrol.id..'_y'], patrol)
             local nh = AH.next_hop(patrol, x, y)
             if nh and ((nh[1] ~= patrol.x) or (nh[2] ~= patrol.y)) then
-                ai.move(patrol, nh[1], nh[2])
+                AH.checked_move(ai, patrol, nh[1], nh[2])
             else
                 ai.stopunit_moves(patrol)
             end