This is a first draft of the patrolling system.

At the moment everything manually, the system lacks normal evaluation
of the move and the patrolling unit will not stop until its moves run
out. Also, at the moment, it is possible to patrol between two
waypoints only.

Further work will be carried out to transform the creation of
patrolling units to one line syntax.

data/ai/scenarios/scenario-lua-ai.cfg

@@ -164,7 +164,7 @@ Gs^Fp       , Gs^Fp       , Wwf         , Wwf         , Mm          , Rd
         [unit]
             x,y=16,5
             type="Wolf Rider"
-            generate_name=yes
+            name="Rark"
         [/unit]
 
         [unit]
@@ -296,26 +296,60 @@ function my_ai:stage_hello()
 end
 
 function my_ai:candidate_action_evaluation_hello()
-       wesnoth.message('hello from candidate action evaluation!')
+       --wesnoth.message('hello from candidate action evaluation!')
        return 42, {test=123}
 end
 
 function my_ai:candidate_action_execution_hello(cfg)
-       wesnoth.message('hello from candidate action execution!')
-       wesnoth.message('test value is ') -- .. cfg.test) -- ERROR: cfg.test is nil here
+      -- wesnoth.message('hello from candidate action execution!')
+       --wesnoth.message('test value is ') -- .. cfg.test) -- ERROR: cfg.test is nil here
        self:do_moves()
 end
 
 function my_ai:candidate_action_evaluation_hello2()
-       wesnoth.message('hello from second candidate action evaluation!')
+       --wesnoth.message('hello from second candidate action evaluation!')
        return 99
 end
 
 function my_ai:candidate_action_execution_hello2()
-       wesnoth.message('hello from second candidate action execution!')
+       --wesnoth.message('hello from second candidate action execution!')
        self:do_moves()
 end
 
+function my_ai:patrol_eval()
+	wesnoth.message('Considering to patrol, checking, whether everything is ok')
+	return 10000
+end
+
+function my_ai:patrol_gen(ai, n, w1, w2) -- n is the name of the unit, like Kiressh
+					  -- w1, w2 -- waypoint tables of form {x,y}
+	wesnoth.message("Creation of the patrol func")
+	local unit = wesnoth.get_units({name=n})[1]
+	
+	local x, y = unit.x, unit.y
+	local wpn = 1 --WayPoint Number - we have to remember which waypoint we are heading to
+
+	if (x == w1.x and y == w1.y) then
+		w1, w2 = w2, w2 -- if we are standing on the first waypoint, swap them
+	end
+
+	local waypoints = {w1, w2}	  -- this form might be just received from the args
+	wesnoth.message ("Eof creation")
+	return 
+		function()
+			--wesnoth.message(tostring(waypoints[1].x).."   YES")
+			wesnoth.message("Entering patrol execution code")
+			x, y = unit.x, unit.y
+			if (x == waypoints[wpn].x and y == waypoints[wpn].y) then
+				wpn = 3 - wpn -- hardcoded for two waypoints
+			end
+			ai.move(unit, waypoints[wpn].x, waypoints[wpn].y)
+		end
+
+end
+
+my_ai.patrol_exec = my_ai:patrol_gen(ai, "Rark", {x=16, y=15}, {x=16, y=5})
+
 
 function my_ai:do_moves()
 	--wesnoth.message('Passive leader: ', tostring(ai.get_passive_leader()))
@@ -335,11 +369,11 @@ function my_ai:do_moves()
 	--wesnoth.message('Leader goal' .. ai.get_leader_goal().x .. ' ' .. ai.get_leader_goal().y) -- fixed
 	--wesnoth.message('Avoid ex. ' .. #ai.get_avoid() .. ' ' ..ai.get_avoid()[1]["x"] .. " " .. ai.get_avoid()[1]["y"]) -- fixed?
 	--we	wesnoth.message('DSTSRC fun: ' .. #ai.get_dstsrc())
-	for k,v in pairs(ai.get_enemy_dstsrc()) do		
-		for i,l in ipairs(v) do
-			wesnoth.message("->" .. l.x .. " " .. l.y)
-		end
-	end
+	--for k,v in pairs(ai.get_enemy_dstsrc()) do		
+	---	for i,l in ipairs(v) do
+	--		wesnoth.message("->" .. l.x .. " " .. l.y)
+	--	end
+	--end
 	
        my_leader = wesnoth.get_units({side = 1, can_recruit=yes})[1].name
        
@@ -371,6 +405,12 @@ return my_ai
             [/engine]
             [stage]
                 name=testing_ai_default::candidate_action_evaluation_loop
+		[candidate_action]
+                    engine=lua
+                    name=patrol
+                    evaluation="return (...):patrol_eval()"
+                    execution="(...):patrol_exec()"
+                [/candidate_action]
                 [candidate_action]
                     engine=lua
                     name=first