-- If enabled, show path waypoints of pathfinder microtask
local PATH_DEBUG = true
-- How close mob needs to be to waypoint of pathfinder before continuing
local PATH_DISTANCE_TO_GOAL_POINT = 0.7
local PATH_H_DISTANCE_TO_GOAL_POINT = 0.1
local PATH_CLIMB_DISTANCE_TO_GOAL_POINT = 0.4

-- If mob is stuck in pathfinding microtask for this many seconds, give up
local PATH_STUCK_GIVE_UP_TIME = 0.7
-- Interval to check mob position for stuck checker (seconds)
local PATH_STUCK_RECHECK_TIME = 1.0
-- Minimum distance a mob has to have moved to count as no longer stuck
local PATH_UNSTUCK_DISTANCE = 0.1

-- Precision for random yaw calculation
local YAW_PRECISION = 10000
-- How long in seconds to wait before jumping again
local JUMP_REPEAT_TIME = 1
-- 'very close' distance horizontally when following a target
local VERY_CLOSE_DISTANCE_HORIZONTAL = 0.25

-- if the ratio of the current walk speed to the
-- target walk speed is lower than this number,
-- the mob will reset the walk speed
local WALK_SPEED_RESET_THRESHOLD = 0.9

-- if the ratio of the current walk angle to the
-- target walk angle is lower than this number,
-- the mob will reset the walk angle
local WALK_ANGLE_RESET_THRESHOLD = 0.99

-- Maximum permitted speed difference from aimed speed
-- and actual speed when trying to reach a certain
-- speed. When the difference is below this value,
-- target speed is considered to be reached.
local MOVE_SPEED_MAX_DIFFERENCE = 0.01

local show_pathfinder_path = function(path, timer, dtime)
	if timer == nil then
		timer = 0
	end
	timer = timer + dtime
	if timer < 1.0 then
		return timer
	end
	timer = 0
	local pathstr = ""
	for p=1, #path do
		local tex
		if p == 1 then
			tex = "rp_mobs_debug_pathfinder_waypoint_start.png"
		elseif p == #path then
			tex = "rp_mobs_debug_pathfinder_waypoint_end.png"
		else
			tex = "rp_mobs_debug_pathfinder_waypoint.png"
		end
		minetest.add_particle({
			pos = path[p],
			expirationtime = 1,
			size = 2,
			texture = tex,
			glow = minetest.LIGHT_MAX,
		})
	end
	return timer
end

local random_yaw = function()
	return (math.random(0, YAW_PRECISION) / YAW_PRECISION) * (math.pi*2)
end

local collides_with_wall = function(moveresult, include_objects)
	if moveresult and moveresult.collides then
		for c=1, #moveresult.collisions do
			local coll = moveresult.collisions[c]
			if (coll.type == "node" or (coll.type == "object" and include_objects)) and (coll.axis == "x" or coll.axis == "z") then
				return true, coll
			end
		end
	end
	return false
end

-- Microtask templates
-- See `API_templates.md` for documentation

rp_mobs.microtasks = {}

rp_mobs.microtasks.follow_path_climb = function(path, walk_speed, climb_speed, set_yaw, anim_idle, anim_walk, finish_func)
	local mtask = {}
	mtask.label = "follow climb path"
	mtask.on_start = function(self, mob)
		self.statedata.stop = false
		self.statedata.success = true

		-- Counts up when mob is stuck at the same position
		self.statedata.stuck_timer = 0
		self.statedata.stuck_last_position = nil
		self.statedata.stuck_recheck_timer = 0

		if not path then
			path = mob._temp_custom_state.follow_path
		end
		self.statedata.path = path
	end
	mtask.on_step = function(self, mob, dtime, moveresult)
		if not self.statedata.path then
			return
		end
		if PATH_DEBUG then
			self.statedata.path_debug_timer = show_pathfinder_path(self.statedata.path, self.statedata.path_debug_timer, dtime)
		end

		-- Check if mob is stuck
		local mobstuckpos = mob.object:get_pos()
		self.statedata.stuck_recheck_timer = self.statedata.stuck_recheck_timer + dtime
		if self.statedata.stuck_recheck_timer >= PATH_STUCK_RECHECK_TIME then
			if not self.statedata.stuck_last_position then
				self.statedata.stuck_last_position = mobstuckpos
			else
				local stuck_dist = vector.distance(mobstuckpos, self.statedata.stuck_last_position)
				local stuck_path_length = #self.statedata.path
				-- Mob didn't move much and did not advance the path since the last check, it seems we're stuck!
				if stuck_dist < PATH_UNSTUCK_DISTANCE and stuck_path_length == self.statedata.stuck_path_length then
					self.statedata.stuck_timer = self.statedata.stuck_timer + self.statedata.stuck_recheck_timer
				else
					self.statedata.stuck_timer = 0
				end
				-- Mob is stuck for too long. Give up and finish
				if self.statedata.stuck_timer > PATH_STUCK_GIVE_UP_TIME then
					self.statedata.stop = true
					self.statedata.success = false
					local vel = mob.object:get_velocity()
					vel.x = 0
					vel.z = 0
					mob.object:set_velocity(vel)
					minetest.log("verbose", "[rp_mobs] follow_path_climb: Mob at "..minetest.pos_to_string(mobstuckpos, 1).." stops due to being stuck")
					return
				end
				self.statedata.stuck_last_position = mobstuckpos
				self.statedata.stuck_path_length = #self.statedata.path
			end
			self.statedata.stuck_recheck_timer = 0
		end

		-- Get next target position
		local next_pos = self.statedata.path[1]
		local mob_pos = mob.object:get_pos()
		mob_pos = vector.add(mob_pos, mob._path_check_point or vector.zero())

		local next_pos_h = table.copy(next_pos)
		local mob_pos_h = table.copy(mob_pos)
		next_pos_h.y = 0
		mob_pos_h.y = 0

		if self.statedata.path[2] then
			local dist_mob_to_next = vector.distance(mob_pos, next_pos)
			local h_dist_mob_to_next = vector.distance(mob_pos_h, next_pos_h)

			local crossed = false
			if self.statedata.walkdir then
				local walkdir = {}
				walkdir.x = math.sign(next_pos.x - mob_pos.x)
				walkdir.z = math.sign(next_pos.z - mob_pos.z)
				crossed = self.statedata.walkdir.x ~= walkdir.x or self.statedata.walkdir.z ~= walkdir.z
			end

			if crossed or (dist_mob_to_next < PATH_CLIMB_DISTANCE_TO_GOAL_POINT and h_dist_mob_to_next < PATH_H_DISTANCE_TO_GOAL_POINT) then
				table.remove(self.statedata.path, 1)
				if #self.statedata.path == 0 then
					return
				end
				next_pos = self.statedata.path[1]

				self.statedata.walkdir = {}
				self.statedata.walkdir.x = math.sign(next_pos.x - mob_pos.x)
				self.statedata.walkdir.z = math.sign(next_pos.z - mob_pos.z)
			end
		end

		if set_yaw then
			local dir_to_next_pos = vector.direction(mob_pos, next_pos)
			local yaw = minetest.dir_to_yaw(dir_to_next_pos)
			mob.object:set_yaw(yaw)
		end

		local vel = mob.object:get_velocity()

		if math.abs(mob_pos.y - next_pos.y) < 0.05 then
			vel.y = 0
		elseif mob_pos.y < next_pos.y then
			vel.y = climb_speed
		else
			vel.y = -climb_speed
		end

		-- Walk/climb to target
		local dir_next_pos = table.copy(next_pos)
		dir_next_pos.y = mob_pos.y
		local hdir = vector.direction(mob_pos, dir_next_pos)
		local hdist = vector.distance(mob_pos, dir_next_pos)
		if vector.length(hdir) > 0.001 and hdist > 0.1 then
			local hvel = vector.multiply(hdir, walk_speed)
			vel.x = hvel.x
			vel.z = hvel.z
			mob.object:set_velocity(vel)
			rp_mobs.set_animation(mob, anim_walk or "walk")
		else
			vel.x = 0
			vel.z = 0
			mob.object:set_velocity(vel)
			self.statedata.walking = false
			rp_mobs.set_animation(mob, anim_idle or "idle")
		end
	end
	mtask.is_finished = function(self, mob)
		-- Finish if aborted or path is gone or empty
		if self.statedata.stop or not self.statedata.path or #self.statedata.path == 0 then
			return true, self.statedata.success
		end

		-- Finish by finish_func
		if finish_func then
			local stop, succ = finish_func(self, mob)
			if stop then
				if succ == nil then
					succ = true
				end
				return true, succ
			end
		end

		-- Finish if goal point was reached

		local pos = mob.object:get_pos()
		pos = vector.add(pos, mob._path_check_point or vector.zero())
		local goal = self.statedata.path[#self.statedata.path]

		local pos_h = table.copy(pos)
		local goal_h = table.copy(goal)
		pos_h.y = 0
		goal_h.y = 0

		local dist_mob_to_goal = vector.distance(pos, goal)
		local h_dist_mob_to_goal = vector.distance(pos_h, goal_h)

		if dist_mob_to_goal < PATH_CLIMB_DISTANCE_TO_GOAL_POINT and h_dist_mob_to_goal < PATH_H_DISTANCE_TO_GOAL_POINT then
			return true, self.statedata.success
		else
			return false
		end
	end
	mtask.on_end = function(self, mob)
		local vel = mob.object:get_velocity()
		vel.x = 0
		vel.z = 0
		mob.object:set_velocity(vel)
		rp_mobs.set_animation(mob, anim_idle or "idle")
	end
	return rp_mobs.create_microtask(mtask)
end


rp_mobs.microtasks.follow_path = function(path, walk_speed, jump_strength, set_yaw, can_jump, finish_func)
	if can_jump == nil then
		can_jump = true
	end
	local mtask = {}
	mtask.label = "follow path"
	mtask.on_start = function(self, mob)
		self.statedata.walking = false
		self.statedata.stop = false
		self.statedata.success = true
		self.statedata.jumping = false
		self.statedata.jump_timer = 0

		-- Counts up when mob is stuck at the same position
		self.statedata.stuck_timer = 0
		self.statedata.stuck_last_position = nil
		self.statedata.stuck_recheck_timer = 0

		if not path then
			path = mob._temp_custom_state.follow_path
		end
		self.statedata.path = path
	end
	mtask.on_step = function(self, mob, dtime, moveresult)
		if not self.statedata.path then
			return
		end
		if PATH_DEBUG then
			self.statedata.path_debug_timer = show_pathfinder_path(self.statedata.path, self.statedata.path_debug_timer, dtime)
		end

		-- Check if mob is stuck
		local mobstuckpos = mob.object:get_pos()
		self.statedata.stuck_recheck_timer = self.statedata.stuck_recheck_timer + dtime
		if self.statedata.stuck_recheck_timer >= PATH_STUCK_RECHECK_TIME then
			if not self.statedata.stuck_last_position then
				self.statedata.stuck_last_position = mobstuckpos
			else
				local stuck_dist = vector.distance(mobstuckpos, self.statedata.stuck_last_position)
				local stuck_path_length = #self.statedata.path
				-- Mob didn't move much and did not advance the path since the last check, it seems we're stuck!
				if stuck_dist < PATH_UNSTUCK_DISTANCE and stuck_path_length == self.statedata.stuck_path_length then
					self.statedata.stuck_timer = self.statedata.stuck_timer + self.statedata.stuck_recheck_timer
				else
					self.statedata.stuck_timer = 0
				end
				-- Mob is stuck for too long. Give up and finish
				if self.statedata.stuck_timer > PATH_STUCK_GIVE_UP_TIME then
					self.statedata.stop = true
					self.statedata.success = false
					local vel = mob.object:get_velocity()
					vel.x = 0
					vel.z = 0
					mob.object:set_velocity(vel)
					minetest.log("verbose", "[rp_mobs] follow_path: Mob at "..minetest.pos_to_string(mobstuckpos, 1).." stops due to being stuck")
					return
				end
				self.statedata.stuck_last_position = mobstuckpos
				self.statedata.stuck_path_length = #self.statedata.path
			end
			self.statedata.stuck_recheck_timer = 0
		end

		-- Get next target position
		local next_pos = self.statedata.path[1]
		local mob_pos = mob.object:get_pos()
		mob_pos = vector.add(mob_pos, mob._path_check_point or vector.zero())

		local next_pos_h = table.copy(next_pos)
		local mob_pos_h = table.copy(mob_pos)
		next_pos_h.y = 0
		mob_pos_h.y = 0

		if self.statedata.path[2] then
			local dist_mob_to_next = vector.distance(mob_pos, next_pos)
			local h_dist_mob_to_next = vector.distance(mob_pos_h, next_pos_h)

			local crossed = false
			if self.statedata.walkdir then
				local walkdir = {}
				walkdir.x = math.sign(next_pos.x - mob_pos.x)
				walkdir.z = math.sign(next_pos.z - mob_pos.z)
				crossed = self.statedata.walkdir.x ~= walkdir.x or self.statedata.walkdir.z ~= walkdir.z
			end

			if crossed or (dist_mob_to_next < PATH_DISTANCE_TO_GOAL_POINT and h_dist_mob_to_next < PATH_H_DISTANCE_TO_GOAL_POINT) then
				table.remove(self.statedata.path, 1)
				if #self.statedata.path == 0 then
					return
				end
				next_pos = self.statedata.path[1]

				self.statedata.walkdir = {}
				self.statedata.walkdir.x = math.sign(next_pos.x - mob_pos.x)
				self.statedata.walkdir.z = math.sign(next_pos.z - mob_pos.z)

				-- If there's a fence below next_pos, adjust the Y coordinate
				-- due to the overhigh collisionbox
				local next_pos_below = vector.offset(next_pos, 0, -1, 0)
				local next_node_below = minetest.get_node(next_pos_below)
				if minetest.get_item_group(next_node_below.name, "fence") == 1 then
					next_pos.y = next_pos.y + 0.5
				end
			end
		end
		local next_pos_higher = mob_pos.y < next_pos.y

		if set_yaw then
			local dir_to_next_pos = vector.direction(mob_pos, next_pos)
			local yaw = minetest.dir_to_yaw(dir_to_next_pos)
			mob.object:set_yaw(yaw)
		end

		local vel = mob.object:get_velocity()

		-- Reset jump status
		if can_jump and self.statedata.jumping then
			self.statedata.jump_timer = self.statedata.jump_timer + dtime
			if self.statedata.jump_timer >= JUMP_REPEAT_TIME then
				if moveresult.touching_ground then
					self.statedata.jumping = false
				end
			end
		end

		-- Try to jump if next position is higher
		if next_pos_higher and can_jump and not self.statedata.jumping and moveresult.touching_ground then
			local will_jump = true
			-- Can't jump if standing on a disable_jump node
			if mob._env_node_floor then
				local floordef = minetest.registered_nodes[mob._env_node_floor.name]
				if floordef and floordef.walkable and minetest.get_item_group(mob._env_node_floor.name, "disable_jump") > 0 then
					will_jump = false
				end
			end
			-- Can't jump inside a disable_jump node either
			if will_jump and mob._env_node then
				local def = minetest.registered_nodes[mob._env_node.name]
				if minetest.get_item_group(mob._env_node.name, "disable_jump") > 0 then
					will_jump = false
				end
			end
			if will_jump then
				self.statedata.jumping = true
				self.statedata.jump_timer = 0
				vel.y = jump_strength
			else
				-- Can't jump: We're stuck
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end
		end

		-- Walk to target
		local dir_next_pos = table.copy(next_pos)
		dir_next_pos.y = mob_pos.y
		local hdir = vector.direction(mob_pos, dir_next_pos)
		local hdist = vector.distance(mob_pos, dir_next_pos)
		if vector.length(hdir) > 0.001 and hdist > 0.1 then
			local hvel = vector.multiply(hdir, walk_speed)
			vel.x = hvel.x
			vel.z = hvel.z
			mob.object:set_velocity(vel)
			self.statedata.walking = true
		else
			if self.statedata.walking ~= false then
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				self.statedata.walking = false
			end
		end
	end
	mtask.is_finished = function(self, mob)
		-- Finish if aborted or path is gone or empty
		if self.statedata.stop or not self.statedata.path or #self.statedata.path == 0 then
			return true, self.statedata.success
		end

		-- Finish by finish_func
		if finish_func then
			local stop, succ = finish_func(self, mob)
			if stop then
				if succ == nil then
					succ = true
				end
				return true, succ
			end
		end

		-- Finish if goal point was reached

		local pos = mob.object:get_pos()
		pos = vector.add(pos, mob._path_check_point or vector.zero())

		local goal = self.statedata.path[#self.statedata.path]

		local pos_h = table.copy(pos)
		local goal_h = table.copy(goal)
		pos_h.y = 0
		goal_h.y = 0

		local dist_mob_to_goal = vector.distance(pos, goal)
		local h_dist_mob_to_goal = vector.distance(pos_h, goal_h)

		if dist_mob_to_goal < PATH_DISTANCE_TO_GOAL_POINT and h_dist_mob_to_goal < PATH_H_DISTANCE_TO_GOAL_POINT then
			return true, self.statedata.success
		else
			return false
		end
	end
	mtask.on_end = function(self, mob)
		local vel = mob.object:get_velocity()
		vel.x = 0
		vel.z = 0
		mob.object:set_velocity(vel)
	end
	return rp_mobs.create_microtask(mtask)
end

rp_mobs.microtasks.set_yaw = function(yaw)
	local label
	if yaw == "random" then
		label = "set yaw randomly"
	else
		label = "set yaw to "..string.format("%.3f", yaw)
	end
	return rp_mobs.create_microtask({
		label = label,
		singlestep = true,
		on_step = function(self, mob, dtime)
			if yaw == "random" then
				yaw = random_yaw()
			end
			mob.object:set_yaw(yaw)
		end,
	})
end

rp_mobs.microtasks.move_straight = function(move_vector, yaw, drag, max_timer)
	local label
	if max_timer then
		label = "move straight for "..string.format("%.1f", max_timer).."s"
	else
		label = "move straight"
	end
	return rp_mobs.create_microtask({
		label = label,
		on_start = function(self, mob)
			self.statedata.stop = false -- is set to true if microtask is supposed to be finished after the current step finishes
			self.statedata.timer = 0 -- how long this microtask has been going, in seconds
		end,
		on_step = function(self, mob, dtime, moveresult)
			self.statedata.timer = self.statedata.timer + dtime
			if max_timer and self.statedata.timer >= max_timer then
				self.statedata.stop = true
				mob.object:set_velocity(vector.zero())
				return
			end
			local vel = move_vector
			local realvel = mob.object:get_velocity()
			local targetvel = table.copy(vel)
			local changevel = false
			if drag then
				for _, axis in pairs({"x","y","z"}) do
					if drag[axis] > 0.001 and math.abs(targetvel[axis] - realvel[axis]) > MOVE_SPEED_MAX_DIFFERENCE then
						if realvel[axis] > targetvel[axis] then
							targetvel[axis] = math.max(targetvel[axis], realvel[axis] - drag[axis])
						else
							targetvel[axis] = math.min(targetvel[axis], realvel[axis] + drag[axis])
						end
						changevel = true
					end
				end
			else
				changevel = true
				self.statedata.stop = true
			end
			if changevel then
				mob.object:set_velocity(targetvel)
			else
				self.statedata.stop = true
			end
		end,
		is_finished = function(self, mob)
			if self.statedata.stop then
				return true
			end
			return false
		end
	})
end

local can_clear_jump = function(mob, jump_clear_height)
	local yaw = mob.object:get_yaw()
	local dir = minetest.yaw_to_dir(yaw)
	local pos = mob.object:get_pos()
	if mob._front_body_point then
		local fbp = table.copy(mob._front_body_point)
		fbp = vector.rotate_around_axis(fbp, vector.new(0, 1, 0), yaw)
		pos = vector.add(pos, fbp)
	end
	dir = vector.multiply(dir, 0.5)
	local pos_front = vector.add(pos, dir)
	local node_top_walkable

	local h = -1
	while h <= jump_clear_height do
		h = h + 1
		local node_front = minetest.get_node(pos_front)
		local def_front = minetest.registered_nodes[node_front.name]
		if def_front then
			if def_front.walkable then
				node_top_walkable = node_front
			else
				break
			end
		end
		pos_front.y = pos_front.y + 1
	end

	-- Add 0.5 to height if top node is a fence due to the overhigh collisionbox
	if node_top_walkable and minetest.get_item_group(node_top_walkable.name, "fence") ~= 0 then
		h = h + 0.5
	end

	if h <= jump_clear_height then
		return true
	end
	return false
end

rp_mobs.microtasks.walk_straight = function(walk_speed, yaw, jump, jump_clear_height, stop_at_object_collision, max_timer)
	local label
	if max_timer then
		label = "walk straight for "..string.format("%.1f", max_timer).."s"
	else
		label = "walk straight"
	end
	return rp_mobs.create_microtask({
		label = label,
		on_start = function(self, mob)
			self.statedata.jumping = false -- is true when mob is currently jumpin
			self.statedata.jump_timer = 0 -- timer counting the time of the current jump, in seconds
			self.statedata.stop = false -- is set to true if microtask is supposed to be finished after the current step finishes
			self.statedata.timer = 0 -- how long this microtask has been going, in seconds
		end,
		on_step = function(self, mob, dtime, moveresult)
			self.statedata.timer = self.statedata.timer + dtime
			local vel = mob.object:get_velocity()
			if max_timer and self.statedata.timer >= max_timer then
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end
			if self.statedata.jumping then
				self.statedata.jump_timer = self.statedata.jump_timer + dtime
				if self.statedata.jump_timer >= JUMP_REPEAT_TIME then
					if moveresult.touching_ground then
						self.statedata.jumping = false
					end
				end
			end
			local wall_collision, wall_collision_data = collides_with_wall(moveresult, true)
			if stop_at_object_collision and wall_collision and wall_collision_data.type == "object" then
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end

			-- Jump
			if jump and not self.statedata.jumping and moveresult.touching_ground and wall_collision then
				local can_jump = true
				-- Can't jump if standing on a disable_jump node
				if mob._env_node_floor then
					local floordef = minetest.registered_nodes[mob._env_node_floor.name]
					if floordef and floordef.walkable and minetest.get_item_group(mob._env_node_floor.name, "disable_jump") > 0 then
						can_jump = false
					end
				end
				-- Can't jump inside a disable_jump node either
				if can_jump and mob._env_node then
					local def = minetest.registered_nodes[mob._env_node.name]
					if minetest.get_item_group(mob._env_node.name, "disable_jump") > 0 then
						can_jump = false
					end
				end
				-- Check if mob can jump over the obstacle or if the wall is too high
				if can_jump then
					can_jump = can_clear_jump(mob, jump_clear_height)
					if not can_jump and wall_collision then
						self.statedata.stop = true
						vel.x = 0
						vel.z = 0
						mob.object:set_velocity(vel)
						return
					end
				end
				if can_jump then
					self.statedata.jumping = true
					self.statedata.jump_timer = 0
					vel.y = jump
				end
			end

			vel.x = math.sin(yaw) * -walk_speed
			vel.z = math.cos(yaw) * walk_speed
			local realvel_hor = mob.object:get_velocity()
			realvel_hor.y = 0
			local targetvel_hor = table.copy(vel)
			targetvel_hor.y = 0
			if (vector.length(realvel_hor) < WALK_SPEED_RESET_THRESHOLD * vector.length(targetvel_hor)) or
					(0.01 > math.abs(vector.angle(vector.zero(), realvel_hor) - vector.angle(vector.zero(), targetvel_hor))) then
				mob.object:set_velocity(vel)
			end
		end,
		is_finished = function(self, mob)
			if self.statedata.stop then
				return true
			end
			return false
		end
	})
end

rp_mobs.microtasks.walk_straight_towards = function(walk_speed, target_type, target, set_yaw, reach_distance, max_distance, jump, jump_clear_height, stop_at_reached, stop_at_object_collision, max_timer)
	local label
	if max_timer then
		label = "walk towards something for "..string.format("%.1f", max_timer).."s"
	else
		label = "walk towards something"
	end
	return rp_mobs.create_microtask({
		label = label,
		on_start = function(self, mob)
			self.statedata.jumping = false -- is true when mob is currently jumpin
			self.statedata.stop = false -- is set to true if microtask is supposed to be finished after the current step finishes
			self.statedata.timer = 0 -- how long this microtask has been going, in seconds
		end,
		on_step = function(self, mob, dtime, moveresult)
			self.statedata.timer = self.statedata.timer + dtime
			local vel = mob.object:get_velocity()
			local oldvel = mob.object:get_velocity()
			if max_timer and self.statedata.timer >= max_timer then
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end
			if self.statedata.jumping then
				self.statedata.jump_timer = self.statedata.jump_timer + dtime
				if self.statedata.jump_timer >= JUMP_REPEAT_TIME then
					if moveresult.touching_ground then
						self.statedata.jumping = false
					end
				end
			end
			local wall_collision, wall_collision_data = collides_with_wall(moveresult, true)
			if stop_at_object_collision and wall_collision and wall_collision_data.type == "object" then
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end

			-- Get target position
			local mypos = mob.object:get_pos()
			local dir, tpos
			if target_type == "pos" then
				tpos = target
				dir = vector.direction(mypos, target)
			elseif target_type == "object" then
				tpos = target:get_pos()
				dir = vector.direction(mypos, tpos)
			else
				self.statedata.stop = true
				return
			end

			-- Face target
			local yaw = minetest.dir_to_yaw(dir)
			if set_yaw then
				mob.object:set_yaw(yaw)
			end

			local distance = vector.distance(mypos, tpos)
			local mypos_h = table.copy(mypos)
			local tpos_h = table.copy(tpos)
			mypos_h.y = 0
			tpos_h.y = 0
			local distance_h = vector.distance(mypos_h, tpos_h)
			-- Stop walking if within reach_distance in 3D or very close horizontally
			if reach_distance and (distance <= reach_distance or distance_h <= VERY_CLOSE_DISTANCE_HORIZONTAL) then
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				if stop_at_reached then
					self.statedata.stop = true
				end
				return
			end
			-- Stop walking and finish if out of range
			if max_distance and distance > max_distance then
				self.statedata.stop = true
				vel.x = 0
				vel.z = 0
				mob.object:set_velocity(vel)
				return
			end

			-- Jump over nodes (but not objects)
			if jump and not self.statedata.jumping and moveresult.touching_ground and wall_collision and wall_collision_data.type == "node" then
				local can_jump = true
				-- Can't jump if standing on a disable_jump node
				if mob._env_node_floor then
					local floordef = minetest.registered_nodes[mob._env_node_floor.name]
					if floordef and floordef.walkable and minetest.get_item_group(mob._env_node_floor.name, "disable_jump") > 0 then
						can_jump = false
					end
				end
				-- Can't jump inside a disable_jump node either
				if can_jump and mob._env_node then
					if minetest.get_item_group(mob._env_node.name, "disable_jump") > 0 then
						can_jump = false
					end
				end
				-- Check if mob can jump over the obstacle or if the wall is too high
				can_jump = can_clear_jump(mob, jump_clear_height)
				if not can_jump and wall_collision then
					self.statedata.stop = true
					vel.x = 0
					vel.z = 0
					mob.object:set_velocity(vel)
					return
				end
				if can_jump then
					self.statedata.jumping = true
					self.statedata.jump_timer = 0
					vel.y = jump
				end
			end

			vel.x = math.sin(yaw) * -walk_speed
			vel.z = math.cos(yaw) * walk_speed
			local realvel_hor = mob.object:get_velocity()
			realvel_hor.y = 0
			local targetvel_hor = table.copy(vel)
			targetvel_hor.y = 0
			if (vector.length(realvel_hor) < WALK_SPEED_RESET_THRESHOLD * vector.length(targetvel_hor)) or
					(0.01 > math.abs(vector.angle(vector.zero(), realvel_hor) - vector.angle(vector.zero(), targetvel_hor))) then
				mob.object:set_velocity(vel)
			end
		end,
		is_finished = function(self, mob)
			if self.statedata.stop then
				return true
			end
			local mypos = mob.object:get_pos()
			local tpos
			if target_type == "pos" then
				tpos = table.copy(target)
			elseif target_type == "object" then
				if not target then
					return true
				end
				tpos = target:get_pos()
				if not tpos then
					return true
				end
				if target:get_hp() == 0 or target._dying then
					return true
				end
			else
				minetest.log("error", "[rp_mobs] Incorrect target_type provided in rp_mobs.microtask.walk_straight_towards!")
				return true, false
			end
			mypos.y = 0
			tpos.y = 0
			return false
		end,
		on_end = function(self, mob)
			mob.object:set_velocity(vector.zero())
		end,
	})
end

rp_mobs.microtasks.rotate_yaw_smooth = function(yaw, time)
	local label
	if yaw == "random" then
		label = "rotate yaw randomly"
	else
		label = "rotate yaw to "..string.format("%.3f", yaw)
	end
	return rp_mobs.create_microtask({
		label = label,
		on_step = function(self, mob, dtime)
			local sd = self.statedata
			if not sd.target_yaw then
				if yaw == "random" then
					yaw = random_yaw()
				end
				sd.target_yaw = yaw
			end
			if not sd.start_yaw then
				sd.start_yaw = mob.object:get_yaw()
			end
			if not sd.timer then
				sd.timer = 0
			end
			sd.timer = sd.timer + dtime
			local timer = math.min(sd.timer, time)
			local time_progress = 1 - ((time - timer) / time)

			local current_yaw = sd.start_yaw + (sd.target_yaw - sd.start_yaw) * time_progress
			mob.object:set_yaw(current_yaw)
		end,
		is_finished = function(self, mob)
			return self.statedata.timer and self.statedata.timer >= time
		end,
	})
end

rp_mobs.microtasks.autoyaw = function()
	return rp_mobs.create_microtask({
		label = "automatically set yaw",
		singlestep = true,
		on_step = function(self, mob, dtime)
			local vel = mob.object:get_velocity()
			vel.y = 0
			-- Only set yaw if moving
			if vector.length(vel) > 0.001 then
				vel = vector.normalize(vel)
				local yaw = minetest.dir_to_yaw(vel)
				mob.object:set_yaw(yaw)
			end
		end,
	})
end

rp_mobs.microtasks.sleep = function(time)
	return rp_mobs.create_microtask({
		label = "sleep for "..time.."s",
		on_step = function(self, mob, dtime)
			if not self.statedata.sleeptimer then
				self.statedata.sleeptimer = 0
			end
			self.statedata.sleeptimer = self.statedata.sleeptimer + dtime
		end,
		is_finished = function(self, mob)
			return self.statedata.sleeptimer and self.statedata.sleeptimer >= time
		end
	})
end

rp_mobs.microtasks.set_acceleration = function(acceleration)
	return rp_mobs.create_microtask({
		label = "set acceleration",
		singlestep = true,
		on_step = function(self, mob, dtime)
			mob.object:set_acceleration(acceleration)
		end,
	})
end