-- Mobs Api (9th August 2015)

local S = minetest.get_translator("mobs")

mobs = {}
mobs.mod = "redo"

-- Initial settings check

local damage_enabled = minetest.settings:get_bool("enable_damage") or false
local peaceful_only = minetest.settings:get_bool("only_peaceful_mobs") or false
local enable_blood = minetest.settings:get_bool("mobs_enable_blood") or false

mobs.protected = tonumber(minetest.settings:get("mobs_spawn_protected")) or 0
mobs.remove = minetest.settings:get_bool("remove_far_mobs") or false

local function is_too_near_spawn(pos)
   if minetest.is_singleplayer() or not minetest.settings:get_bool("mobs_safe_spawn") then
      return false
   end

   local sp = minetest.setting_get_pos("static_spawnpoint") or {x = 0, y = 0, z = 0}
   local rad = minetest.settings:get("static_spawn_radius") or 256

   return (vector.distance(pos, sp) < rad)
end

-- particle effects
local function effect(pos, amount, texture, max_size)
   minetest.add_particlespawner(
      {
         amount = amount,
         time = 0.25,
         minpos = pos,
         maxpos = pos,
         minvel = {x = -0, y = 2, z = -0},
         maxvel = {x = 2,  y = 6,  z = 2},
         minacc = {x = -4, y = -16, z = -4},
         maxacc = {x = 4, y = -4, z = 4},
         minexptime = 0.1,
         maxexptime = 1,
         minsize = 1,
         maxsize = (max_size or 2),
         texture = texture,
   })
end

-- on mob death drop items
local function check_for_death(self, hitter)
   local hp = self.object:get_hp()
   if hp > 0 then
      self.health = hp
      if self.sounds.damage ~= nil then
         minetest.sound_play(
	    self.sounds.damage,
	    {
               object = self.object,
               max_hear_distance = self.sounds.distance
         })
      end
      return false
   end
   local pos = self.object:get_pos()
   self.object:remove()
   local obj = nil
   for _,drop in ipairs(self.drops) do
      if math.random(1, drop.chance) == 1 then
         obj = minetest.add_item(pos, ItemStack(drop.name.." "..math.random(drop.min, drop.max)))
         if obj then
	    obj:set_velocity(
               {
                  x = math.random(-1, 1),
                  y = 5,
                  z = math.random(-1, 1)
            })
         end
      end
   end
   if self.sounds.death ~= nil then
      minetest.sound_play(
         self.sounds.death,
         {
	    object = self.object,
	    max_hear_distance = self.sounds.distance
      })
   end
   if self.on_die then
      self.on_die(self, pos, hitter)
   end
   return true
end

-- from TNT mod
local function calc_velocity(pos1, pos2, old_vel, power)
   local vel = vector.direction(pos1, pos2)
   vel = vector.normalize(vel)
   vel = vector.multiply(vel, power)
   local dist = vector.distance(pos1, pos2)
   dist = math.max(dist, 1)
   vel = vector.divide(vel, dist)
   vel = vector.add(vel, old_vel)
   return vel
end

-- modified from TNT mod
local function entity_physics(pos, radius)
   radius = radius * 2
   local objs = minetest.get_objects_inside_radius(pos, radius)
   local obj_pos, obj_vel, dist
   for _, obj in pairs(objs) do
      obj_pos = obj:get_pos()
      obj_vel = obj:get_velocity()
      dist = math.max(1, vector.distance(pos, obj_pos))
      if obj_vel ~= nil then
         obj:set_velocity(calc_velocity(pos, obj_pos, obj_vel, radius * 10))
      end
      local damage = (4 / dist) * radius
      obj:set_hp(obj:get_hp() - damage)
   end
end

function mobs:register_mob(name, def)
   minetest.register_entity(
      name,
      {
	 stepheight = def.stepheight or 0.6,
	 name = name,
	 fly = def.fly,
	 fly_in = def.fly_in or "air",
	 owner = def.owner or "",
	 order = def.order or "",
	 on_die = def.on_die,
	 do_custom = def.do_custom,
	 jump_height = def.jump_height or 6,
	 jump_chance = def.jump_chance or 0,
	 rotate = math.rad(def.rotate or 0), --  0=front, 90=side, 180=back, 270=side2
	 lifetimer = def.lifetimer or 180, -- 3 minutes
	 hp_min = def.hp_min or 5,
	 hp_max = def.hp_max or 10,
	 physical = true,
	 collides_with_objects = def.collides_with_objects or true,
	 collisionbox = def.collisionbox,
	 visual = def.visual,
	 visual_size = def.visual_size or {x = 1, y = 1},
	 mesh = def.mesh,
	 makes_footstep_sound = def.makes_footstep_sound or false,
	 view_range = def.view_range or 5,
	 walk_velocity = def.walk_velocity or 1,
	 run_velocity = def.run_velocity or 2,
	 damage = def.damage,
	 light_damage = def.light_damage or 0,
	 water_damage = def.water_damage or 0,
	 lava_damage = def.lava_damage or 0,
	 fall_damage = def.fall_damage or 1,
	 fall_speed = def.fall_speed or -10, -- must be lower than -2 (default: -10)
	 drops = def.drops or {},
	 armor = def.armor,
	 on_rightclick = def.on_rightclick,
	 type = def.type,
	 explode_radius = def.explode_radius or 3,
	 attack_type = def.attack_type,
	 arrow = def.arrow,
	 shoot_interval = def.shoot_interval,
	 sounds = def.sounds or {},
	 animation = def.animation,
	 follow = def.follow or "",
	 jump = def.jump or true,
	 walk_chance = def.walk_chance or 50,
	 attacks_monsters = def.attacks_monsters or false,
	 group_attack = def.group_attack or false,
	 --fov = def.fov or 120,
	 passive = def.passive or false,
	 recovery_time = def.recovery_time or 0.5,
	 knock_back = def.knock_back or 3,
	 blood_amount = def.blood_amount or 5,
	 blood_texture = def.blood_texture or "mobs_blood.png",
	 shoot_offset = def.shoot_offset or 0,
	 floats = def.floats or 1, -- floats in water by default
	 replace_rate = def.replace_rate,
	 replace_what = def.replace_what,
	 replace_with = def.replace_with,
	 replace_offset = def.replace_offset or 0,
	 timer = 0,
	 env_damage_timer = 0, -- only if state = "attack"
	 attack = {player=nil, dist=nil},
	 state = "stand",
	 tamed = false,
	 pause_timer = 0,
	 horny = false,
	 hornytimer = 0,
	 child = false,
	 gotten = false,
	 health = 0,
	 on_replace = def.on_replace or nil,
	 on_spawn = def.on_spawn or nil,
	 check_fed = function(self, name, feed_count, breed) -- Check if a mob is fed
            self.food = (self.food or 0) + 1

            -- Make children grow quicker

            if self.child == true then
               self.hornytimer = self.hornytimer + 20
               return true
            end

            -- Feed and tame

            if self.food >= feed_count then
               self.food = 0

               if breed and self.hornytimer == 0 then
                  self.horny = true
               end

               self.gotten = false

               if (not self.tamed) and name ~= nil
               and ((not self.owner) or self.owner == "") then
                  self.owner = name
                  self.tamed = true

                  achievements.trigger_achievement(
                     minetest.get_player_by_name(name),
                     "best_friends_forever"
                  )
               end

               -- Make sound when fed so many times

               if self.sounds.random then
                  minetest.sound_play(
                     self.sounds.random,
                     {
                        object = self.object,
                        max_hear_distance = self.sounds.distance
                  })
               end
            end
         end,
	 do_attack = function(self, player, dist)
            if is_too_near_spawn(self.object:get_pos()) then return end

            if self.state ~= "attack" then
               if math.random(0,100) < 90
               and self.sounds.war_cry then
                  minetest.sound_play(
                     self.sounds.war_cry,
                     {
                        object = self.object,
                        max_hear_distance = self.sounds.distance
                  })
               end
               self.state = "attack"
               self.attack.player = player
               self.attack.dist = dist
            end
         end,
	 set_velocity = function(self, v)
            v = (v or 0)
            if def.drawtype
            and def.drawtype == "side" then
               self.rotate = math.rad(90)
            end

            local tmpyaw = self.object:get_yaw()
            local yaw = self.rotate

            if tmpyaw ~= tmpyaw then -- It's a nan value
               minetest.log("warning", "[mod:mobs] object:get_yaw() nan shim used")
            else
               yaw = yaw + tmpyaw
            end

            local x = math.sin(yaw) * -v
            local z = math.cos(yaw) * v

            self.object:set_velocity({x = x, y = self.object:get_velocity().y, z = z})
         end,
	 get_velocity = function(self)
            local v = self.object:get_velocity()
            return (v.x ^ 2 + v.z ^ 2) ^ (0.5)
         end,
         in_fov = function(self,pos)
            -- checks if POS is in self's FOV
            local yaw = self.object:get_yaw() + self.rotate
            local vx = math.sin(yaw)
            local vz = math.cos(yaw)
            local ds = math.sqrt(vx ^ 2 + vz ^ 2)
            local ps = math.sqrt(pos.x ^ 2 + pos.z ^ 2)
            local d = { x = vx / ds, z = vz / ds }
            local p = { x = pos.x / ps, z = pos.z / ps }
            local an = ( d.x * p.x ) + ( d.z * p.z )

            a = math.deg( math.acos( an ) )

            if a > ( self.fov / 2 ) then
               return false
            else
               return true
            end
         end,
         set_animation = function(self, type)
            if not self.animation then
               return
            end

            if not self.animation.current then
               self.animation.current = ""
            end

            if type == "stand"
            and self.animation.current ~= "stand" then
               if self.animation.stand_start
                  and self.animation.stand_end
               and self.animation.speed_normal then
                  self.object:set_animation({
                        x = self.animation.stand_start,
                        y = self.animation.stand_end},
                     self.animation.speed_normal, 0)
                  self.animation.current = "stand"
               end
            elseif type == "walk"
            and self.animation.current ~= "walk"  then
               if self.animation.walk_start
                  and self.animation.walk_end
               and self.animation.speed_normal then
                  self.object:set_animation({
                        x = self.animation.walk_start,
                        y = self.animation.walk_end},
                     self.animation.speed_normal, 0)
                  self.animation.current = "walk"
               end
            elseif type == "run"
            and self.animation.current ~= "run"  then
               if self.animation.run_start
                  and self.animation.run_end
               and self.animation.speed_run then
                  self.object:set_animation({
                        x = self.animation.run_start,
                        y = self.animation.run_end},
                     self.animation.speed_run, 0)
                  self.animation.current = "run"
               end
            elseif type == "punch"
            and self.animation.current ~= "punch"  then
               if self.animation.punch_start
                  and self.animation.punch_end
               and self.animation.speed_normal then
                  self.object:set_animation({
                        x = self.animation.punch_start,
                        y = self.animation.punch_end},
                     self.animation.speed_normal, 0)
                  self.animation.current = "punch"
               end
            end
         end,
         on_step = function(self, dtime)

            if self.type == "monster"
            and peaceful_only then
               self.object:remove()
               return
            end

            -- if lifetimer run out and not npc; tamed or attacking then remove mob
            if self.type ~= "npc"
            and not self.tamed then
               self.lifetimer = self.lifetimer - dtime
               if self.lifetimer <= 0
               and self.state ~= "attack" then
                  minetest.log("action","lifetimer expired, removed "..self.name)
                  effect(self.object:get_pos(), 15, "tnt_smoke.png")
                  self.object:remove()
                  return
               end
            end

            -- check for mob drop/replace (used for chicken egg and sheep eating grass/wheat)
            if self.replace_rate
               and self.child == false
            and math.random(1, self.replace_rate) == 1 then
               local pos = self.object:get_pos()
               pos.y = pos.y + self.replace_offset
               if self.replace_what and self.object:get_velocity().y == 0 and #minetest.find_nodes_in_area(pos, pos, self.replace_what) > 0 then
                  --and self.state == "stand" then
                  if self.on_replace ~= nil then
                     self.on_replace(self, pos)
                  else
                     minetest.set_node(pos, {name = self.replace_with})
                  end
               end
            end

            local yaw = 0

            if not self.fly then
               -- floating in water (or falling)
               local pos = self.object:get_pos()
               local nod = minetest.get_node_or_nil(pos)
               if nod then nod = nod.name else nod = "default:dirt" end
               local nodef = minetest.registered_nodes[nod]

               local v = self.object:get_velocity()
               if v.y > 0.1 then
                  self.object:set_acceleration({
                        x = 0,
                        y= self.fall_speed,
                        z = 0
                  })
               end
               if nodef.groups.water then
                  if self.floats == 1 then
                     self.object:set_acceleration(
                        {
                           x = 0,
                           y = -self.fall_speed / (math.max(1, v.y) ^ 2),
                           z = 0
                     })
                  end
               else
                  self.object:set_acceleration(
                     {
                        x = 0,
                        y = self.fall_speed,
                        z = 0
                  })

                  -- fall damage
                  if self.fall_damage == 1
                  and self.object:get_velocity().y == 0 then
                     local d = (self.old_y or 0) - self.object:get_pos().y
                     if d > 5 then
                        self.object:set_hp(self.object:get_hp() - math.floor(d - 5))
                        effect(self.object:get_pos(), 5, "tnt_smoke.png")
                        check_for_death(self)
                     end
                     self.old_y = self.object:get_pos().y
                  end
               end
            end

            -- knockback timer
            if self.pause_timer > 0 then
               self.pause_timer = self.pause_timer - dtime
               if self.pause_timer < 1 then
                  self.pause_timer = 0
               end
               return
            end

            -- attack timer
            self.timer = self.timer + dtime
            if self.state ~= "attack" then
               if self.timer < 1 then
                  return
               end
               self.timer = 0
            end

            if self.sounds.random
            and math.random(1, 100) <= 1 then
               minetest.sound_play(
                  self.sounds.random,
                  {
                     object = self.object,
                     max_hear_distance = self.sounds.distance
               })
            end

            local do_env_damage = function(self)

               local pos = self.object:get_pos()
               local tod = minetest.get_timeofday()

               -- daylight above ground
               if self.light_damage ~= 0
                  and pos.y > 0
                  and tod > 0.2
                  and tod < 0.8
               and (minetest.get_node_light(pos) or 0) > 12 then
                  self.object:set_hp(self.object:get_hp() - self.light_damage)
                  effect(pos, 5, "tnt_smoke.png")
                  if check_for_death(self) then return end
               end

               pos.y = pos.y + self.collisionbox[2] -- foot level
               local nod = minetest.get_node_or_nil(pos)
               if not nod then return end
               local nodef = minetest.registered_nodes[nod.name]
               pos.y = pos.y + 1

               -- water
               if self.water_damage ~= 0
               and nodef.groups.water then
                  self.object:set_hp(self.object:get_hp() - self.water_damage)
                  effect(pos, 5, "bubble.png")
                  if check_for_death(self) then return end
               end

               -- lava or fire
               if self.lava_damage ~= 0
               and nodef.groups.lava then
                  self.object:set_hp(self.object:get_hp() - self.lava_damage)
                  effect(pos, 5, "mobs_flame.png", 8)
                  if check_for_death(self) then return end
               end

            end

            local do_jump = function(self)
               if self.fly then
                  return
               end

               self.jumptimer = (self.jumptimer or 0) + 1
               if self.jumptimer < 3 then
                  local pos = self.object:get_pos()
                  pos.y = (pos.y + self.collisionbox[2]) - 0.2
                  local nod = minetest.get_node(pos)
                  if not nod
                     or not minetest.registered_nodes[nod.name]
                  or minetest.registered_nodes[nod.name].walkable == false then
                     return
                  end
                  if self.direction then
                     pos.y = pos.y + 0.5
                     local nod = minetest.get_node_or_nil(
                        {
                           x = pos.x + self.direction.x,
                           y = pos.y,
                           z = pos.z + self.direction.z
                     })
                     if nod and nod.name and
                        (nod.name ~= "air"
                         or self.walk_chance == 0) then
                           local def = minetest.registered_items[nod.name]
                           if (def
                                  and def.walkable
                                  and not nod.name:find("fence"))
                           or self.walk_chance == 0 then
                              local v = self.object:get_velocity()
                              v.y = self.jump_height + 1
                              v.x = v.x * 2.2
                              v.z = v.z * 2.2
                              self.object:set_velocity(v)
                              if self.sounds.jump then
                                 minetest.sound_play(
                                    self.sounds.jump,
                                    {
                                       object = self.object,
                                       max_hear_distance = self.sounds.distance
                                 })
                              end
                           end
                     end
                  end
               else
                  self.jumptimer = 0
               end
            end

            -- environmental damage timer
            self.env_damage_timer = self.env_damage_timer + dtime
            if self.state == "attack"
            and self.env_damage_timer > 1 then
               self.env_damage_timer = 0
               do_env_damage(self)
            elseif self.state ~= "attack" then
               do_env_damage(self)
            end

            -- find someone to attack
            if self.type == "monster"
               and damage_enabled
            and self.state ~= "attack" then

               local s = self.object:get_pos()
               local p, sp, dist
               local player = nil
               local type = nil
               local obj = nil
               local min_dist = self.view_range + 1
               local min_player = nil

               for _,oir in ipairs(minetest.get_objects_inside_radius(s, self.view_range)) do

                  if oir:is_player() then
                     player = oir
                     type = "player"
                  else
                     obj = oir:get_luaentity()
                     if obj then
                        player = obj.object
                        type = obj.type
                     end
                  end

                  if type == "player"
                  or type == "npc" then
                     s = self.object:get_pos()
                     p = player:get_pos()
                     sp = s
                     p.y = p.y + 1
                     sp.y = sp.y + 1 -- aim higher to make looking up hills more realistic
                     dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
                     if dist < self.view_range then
                        -- and self.in_fov(self,p) then
                        -- choose closest player to attack
                        if minetest.line_of_sight(sp, p, 2) == true
                        and dist < min_dist then
                           min_dist = dist
                           min_player = player
                        end
                     end
                  end
               end
               -- attack player
               if min_player then
                  self.do_attack(self, min_player, min_dist)
               end
            end

            -- npc, find closest monster to attack
            local min_dist = self.view_range + 1
            local min_player = nil

            if self.type == "npc"
               and self.attacks_monsters
            and self.state ~= "attack" then
               local s = self.object:get_pos()
               local obj = nil
               for _, oir in pairs(minetest.get_objects_inside_radius(s,self.view_range)) do
                  obj = oir:get_luaentity()
                  if obj
                  and obj.type == "monster" then
                     -- attack monster
                     local p = obj.object:get_pos()
                     local dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
                     if dist < min_dist then
                        min_dist = dist
                        min_player = obj.object
                     end
                  end
               end
               if min_player then
                  self.do_attack(self, min_player, min_dist)
               end
            end

            -- horny animal can mate for 40 seconds, afterwards horny animal cannot mate again for 200 seconds
            if self.horny == true
               and self.hornytimer < 240
            and self.child == false then
               self.hornytimer = self.hornytimer + 1
               if self.hornytimer >= 240 then
                  self.hornytimer = 0
                  self.horny = false
               end
            end

            -- if animal is child take 240 seconds before growing into adult
            if self.child == true then
               self.hornytimer = self.hornytimer + 1
               if self.hornytimer > 240 then
                  self.child = false
                  self.hornytimer = 0
                  self.object:set_properties(
                     {
                        textures = self.base_texture,
                        mesh = self.base_mesh,
                        visual_size = self.base_size,
                        collisionbox = self.base_colbox,
                  })
               end
            end

            -- if animal is horny, find another same animal who is horny and mate
            if self.horny == true
            and self.hornytimer <= 40 then
               local pos = self.object:get_pos()
               effect({x = pos.x, y = pos.y + 0.5, z = pos.z}, 4, "heart.png")
               local ents = minetest.get_objects_inside_radius(pos, self.view_range)
               local num = 0
               local ent = nil
               for i,obj in ipairs(ents) do
                  ent = obj:get_luaentity()

                  -- check for same animal with different colour
                  local canmate = false
                  if ent then
                     if ent.name == self.name then
                        canmate = true
                     else
                        local entname = string.split(ent.name,":")
                        local selfname = string.split(self.name,":")
                        if entname[1] == selfname[1] then
                           entname = string.split(entname[2],"_")
                           selfname = string.split(selfname[2],"_")
                           if entname[1] == selfname[1] then
                              canmate = true
                           end
                        end
                     end
                  end

                  if ent
                     and canmate == true
                     and ent.horny == true
                  and ent.hornytimer <= 40 then
                     num = num + 1
                  end
                  if num > 1 then
                     self.hornytimer = 41
                     ent.hornytimer = 41
                     minetest.after(
                        7,
                        function(dtime)
                           local mob = minetest.add_entity(pos, self.name)
                           local ent2 = mob:get_luaentity()
                           local textures = self.base_texture
                           if def.child_texture then
                              textures = def.child_texture[1]
                           end
                           mob:set_properties({
                                 textures = textures,
                                 visual_size = {
                                    x = self.base_size.x / 2,
                                    y = self.base_size.y / 2
                                 },
                                 collisionbox = {
                                    self.base_colbox[1] / 2,
                                    self.base_colbox[2] / 2,
                                    self.base_colbox[3] / 2,
                                    self.base_colbox[4] / 2,
                                    self.base_colbox[5] / 2,
                                    self.base_colbox[6] / 2
                                 },
                           })
                           ent2.child = true
                           ent2.tamed = true
                           --ent2.following = ent -- follow mother
                     end)
                     num = 0
                     break
                  end
               end
            end

            -- find player to follow
            if (self.follow ~= "" or self.order == "follow") and not self.following and self.state ~= "attack" then
               local s, p, dist
               for _,player in pairs(minetest.get_connected_players()) do
                  s = self.object:get_pos()
                  p = player:get_pos()
                  dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
                  if dist < self.view_range then
                     self.following = player
                     break
                  end
               end
            end

            -- custom function (defined in mob lua file)
            if self.do_custom then
               self.do_custom(self)
            end

            if self.type == "npc"
               and self.order == "follow"
            and self.state ~= "attack" then
               -- npc stop following player if not owner
               if self.following
                  and self.type == "npc"
                  and self.owner
               and self.owner ~= self.following:get_player_name() then
                  self.following = nil
               end
            else
               -- stop following player if not holding specific item
               if self.following
                  and self.following.is_player
               and self.following:get_wielded_item():get_name() ~= self.follow then
                  self.following = nil
               end
            end

            -- follow player or mob
            if self.following then
               local s = self.object:get_pos()
               local p

               if self.following.is_player
               and self.following:is_player() then
                  p = self.following:get_pos()
               elseif self.following.object then
                  p = self.following.object:get_pos()
               end

               if p then
                  local dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
                  if dist > self.view_range then
                     self.following = nil
                  else
                     local vec = {x = p.x - s.x, y = p.y - s.y, z = p.z - s.z}
                     yaw = (math.atan(vec.z / vec.x) + math.pi / 2) - self.rotate
                     if p.x > s.x then
                        yaw = yaw + math.pi
                     end
                     self.object:set_yaw(yaw)

                     -- anyone but standing npc's can move along
                     if dist > 2 and self.order ~= "stand" then
                        if (self.jump and self.get_velocity(self) <= 0.5 and self.object:get_velocity().y == 0) or (self.object:get_velocity().y == 0 and self.jump_chance > 0) then
                           self.direction = {
                              x = math.sin(yaw) * -1,
                              y = -20,
                              z = math.cos(yaw)
                           }
                           do_jump(self)
                        end
                        self.set_velocity(self, self.walk_velocity)
                        if self.walk_chance ~= 0 then
                           self:set_animation("walk")
                        end
                     else
                        self.set_velocity(self, 0)
                        self:set_animation("stand")
                     end
                     return
                  end
               end
            else
               self:set_animation("stand")
            end

            if self.state == "stand" then
               -- randomly turn
               if math.random(1, 4) == 1 then
                  -- if there is a player nearby look at them
                  local lp = nil
                  local s = self.object:get_pos()

                  if self.type == "npc" then
                     local o = minetest.get_objects_inside_radius(self.object:get_pos(), 3)

                     local yaw = 0
                     for _,o in ipairs(o) do
                        if o:is_player() then
                           lp = o:get_pos()
                           break
                        end
                     end
                  end

                  if lp ~= nil then
                     local vec = {x = lp.x - s.x, y = lp.y - s.y, z = lp.z - s.z}
                     yaw = (math.atan(vec.z / vec.x) + math.pi / 2) - self.rotate
                     if lp.x > s.x then
                        yaw = yaw + math.pi
                     end
                  else
                     yaw = self.object:get_yaw() + ((math.random(0, 360) - 180) / 180 * math.pi)
                  end
                  self.object:set_yaw(yaw)
               end

               self.set_velocity(self, 0)
               self.set_animation(self, "stand")

               -- npc's ordered to stand stay standing
               if self.type == "npc"
               and self.order == "stand" then
                  self.set_velocity(self, 0)
                  self.state = "stand"
                  self:set_animation("stand")
               else
                  if self.walk_chance ~= 0 and math.random(1, 100) <= self.walk_chance then
                     self.set_velocity(self, self.walk_velocity)
                     self.state = "walk"
                     self.set_animation(self, "walk")
                  end

                  -- jumping mobs only
                  --					if self.jump and math.random(1, 100) <= self.jump_chance then
                  --						self.direction = {x = 0, y = 0, z = 0}
                  --						do_jump(self)
                  --						self.set_velocity(self, self.walk_velocity)
                  --					end
               end

            elseif self.state == "walk" then
               local s = self.object:get_pos()
               local lp = minetest.find_node_near(s, 1, {"group:water"})

               -- water swimmers cannot move out of water
               if self.fly and self.fly_in == "default:water_source" and not lp then
                  self.set_velocity(self, 0)
                  self.state = "flop" -- change to undefined state so nothing more happens
                  self:set_animation("stand")
                  return
               end
               -- if water nearby then turn away
               if lp then
                  local vec = {x = lp.x - s.x, y = lp.y - s.y, z = lp.z - s.z}
                  yaw = math.atan(vec.z / vec.x) + 3 * math.pi / 2 - self.rotate
                  if lp.x > s.x then
                     yaw = yaw + math.pi
                  end
                  self.object:set_yaw(yaw)

                  -- otherwise randomly turn
               elseif math.random(1, 100) <= 30 then
                  self.object:set_yaw(self.object:get_yaw() + ((math.random(0, 360) - 180) / 180 * math.pi))
               end
               if self.jump and self.get_velocity(self) <= 0.5 and self.object:get_velocity().y == 0 then
                  self.direction = {
                     x = math.sin(yaw) * -1,
                     y = -20,
                     z = math.cos(yaw)
                  }
                  do_jump(self)
               end

               self:set_animation("walk")
               self.set_velocity(self, self.walk_velocity)
               if math.random(1, 100) <= 30 then
                  self.set_velocity(self, 0)
                  self.state = "stand"
                  self:set_animation("stand")
               end

               -- exploding mobs
            elseif self.state == "attack" and self.attack_type == "explode" then
               if not self.attack.player
               or not self.attack.player:is_player() then
                  self.state = "stand"
                  self:set_animation("stand")
                  self.timer = 0
                  self.blinktimer = 0
                  return
               end
               local s = self.object:get_pos()
               local p = self.attack.player:get_pos()
               local dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
               if dist > self.view_range or self.attack.player:get_hp() <= 0 then
                  self.state = "stand"
                  self.v_start = false
                  self.set_velocity(self, 0)
                  self.timer = 0
                  self.blinktimer = 0
                  self.attack = {player = nil, dist = nil}
                  self:set_animation("stand")
                  return
               else
                  self:set_animation("walk")
                  self.attack.dist = dist
               end

               local vec = {x = p.x - s.x, y = p.y - s.y, z = p.z - s.z}
               yaw = math.atan(vec.z / vec.x) + math.pi / 2 - self.rotate
               if p.x > s.x then
                  yaw = yaw+math.pi
               end
               self.object:set_yaw(yaw)
               if self.attack.dist > 3 then
                  if not self.v_start then
                     self.v_start = true
                     self.set_velocity(self, self.run_velocity)
                     self.timer = 0
                     self.blinktimer = 0
                  else
                     self.timer = 0
                     self.blinktimer = 0
                     if self.get_velocity(self) <= 0.5 and self.object:get_velocity().y == 0 then
                        local v = self.object:get_velocity()
                        v.y = 5
                        self.object:set_velocity(v)
                     end
                     self.set_velocity(self, self.run_velocity)
                  end
                  self:set_animation("run")
               else
                  self.set_velocity(self, 0)
                  self.timer = self.timer + dtime
                  self.blinktimer = (self.blinktimer or 0) + dtime
                  if self.blinktimer > 0.2 then
                     self.blinktimer = 0
                     if self.blinkstatus then
                        self.object:settexturemod("")
                     else
                        self.object:settexturemod("^[brighten")
                     end
                     self.blinkstatus = not self.blinkstatus
                  end
                  if self.timer > 3 then
                     local pos = vector.round(self.object:get_pos())
                     entity_physics(pos, 3) -- hurt player/mobs caught in blast area
                     if minetest.find_node_near(pos, 1, {"group:water"}) or minetest.is_protected(pos, "") then
                        self.object:remove()
                        if self.sounds.explode ~= "" then
                           minetest.sound_play(self.sounds.explode, {
                                                  pos = pos,
                                                  gain = 1.0,
                                                  max_hear_distance = 16
                           })
                        end
                        effect(pos, 15, "tnt_smoke.png", 5)
                        return
                     end

                     self.object:remove()

                     pos.y = pos.y - 1

                     tnt.explode(pos, self.explode_radius, self.sounds.explode)
                  end
               end
               -- end of exploding mobs

            elseif self.state == "attack"
            and self.attack_type == "dogfight" then
               if not self.attack.player or not self.attack.player:get_pos() then
                  self.state = "stand"
                  self:set_animation("stand")
                  return
               end
               local s = self.object:get_pos()
               local p = self.attack.player:get_pos()
               local dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5

               -- fly bit modified from BlockMens creatures mod
               if self.fly
               and dist > 2 then

                  local nod = minetest.get_node_or_nil(s)
                  local p1 = s
                  local me_y = math.floor(p1.y)
                  local p2 = p
                  local p_y = math.floor(p2.y + 1)
                  local v = self.object:get_velocity()
                  if nod
                  and nod.name == self.fly_in then
                     if me_y < p_y then
                        self.object:set_velocity({
                              x = v.x,
                              y = 1 * self.walk_velocity,
                              z = v.z
                        })
                     elseif me_y > p_y then
                        self.object:set_velocity({
                              x = v.x,
                              y = -1 * self.walk_velocity,
                              z = v.z
                        })
                     end
                  else
                     if me_y < p_y then
                        self.object:set_velocity({
                              x = v.x,
                              y = 0.01,
                              z = v.z
                        })
                     elseif me_y > p_y then
                        self.object:set_velocity({
                              x = v.x,
                              y = -0.01,
                              z = v.z
                        })
                     end
                  end

               end
               -- end fly bit

               if dist > self.view_range or self.attack.player:get_hp() <= 0 then
                  self.state = "stand"
                  self.set_velocity(self, 0)
                  self.attack = {player = nil, dist = nil}
                  self:set_animation("stand")
                  return
               else
                  self.attack.dist = dist
               end

               local vec = {x = p.x - s.x, y = p.y - s.y, z = p.z - s.z}
               yaw = (math.atan(vec.z / vec.x) + math.pi / 2) - self.rotate
               if p.x > s.x then
                  yaw = yaw + math.pi
               end
               self.object:set_yaw(yaw)
               -- attack distance is 2 + half of mob width so the bigger mobs can attack (like slimes)
               if self.attack.dist > ((-self.collisionbox[1] + self.collisionbox[4]) / 2) + 2 then
                  -- jump attack
                  if (self.jump and self.get_velocity(self) <= 0.5 and self.object:get_velocity().y == 0) or (self.object:get_velocity().y == 0 and self.jump_chance > 0) then
                     self.direction = {
                        x = math.sin(yaw) * -1,
                        y = -20,
                        z = math.cos(yaw)
                     }
                     do_jump(self)
                  end
                  self.set_velocity(self, self.run_velocity)
                  self:set_animation("run")
               else
                  self.set_velocity(self, 0)
                  self:set_animation("punch")
                  if self.timer > 1 then
                     self.timer = 0
                     local p2 = p
                     local s2 = s
                     p2.y = p2.y + 1.5
                     s2.y = s2.y + 1.5
                     if minetest.line_of_sight(p2, s2) == true then
                        if self.sounds.attack then
                           minetest.sound_play(
                              self.sounds.attack,
                              {
                                 object = self.object,
                                 max_hear_distance = self.sounds.distance
                           })
                        end
                        self.attack.player:punch(
                           self.object,
                           1.0,
                           {
                              full_punch_interval=1.0,
                              damage_groups = {fleshy=self.damage}
                           }, vec)
                        if self.attack.player:get_hp() <= 0 then
                           self.state = "stand"
                           self:set_animation("stand")
                        end
                     end
                  end
               end

            elseif self.state == "attack"
            and self.attack_type == "shoot" then

               local s = self.object:get_pos()
               local p = self.attack.player:get_pos()
               if not p then
                  self.state = "stand"
                  return
               end
               p.y = p.y - .5
               s.y = s.y + .5
               local dist = ((p.x - s.x) ^ 2 + (p.y - s.y) ^ 2 + (p.z - s.z) ^ 2) ^ 0.5
               if dist > self.view_range or self.attack.player:get_hp() <= 0 then
                  self.state = "stand"
                  self.set_velocity(self, 0)
                  self:set_animation("stand")
                  return
               else
                  self.attack.dist = dist
               end

               local vec = {x = p.x - s.x, y = p.y - s.y, z = p.z - s.z}
               yaw = (math.atan(vec.z / vec.x) + math.pi / 2) - self.rotate
               if p.x > s.x then
                  yaw = yaw + math.pi
               end
               self.object:set_yaw(yaw)
               self.set_velocity(self, 0)

               if self.shoot_interval and self.timer > self.shoot_interval and math.random(1, 100) <= 60 then
                  self.timer = 0

                  self:set_animation("punch")

                  if self.sounds.attack then
                     minetest.sound_play(
                        self.sounds.attack,
                        {
                           object = self.object,
                           max_hear_distance = self.sounds.distance
                     })
                  end

                  local p = self.object:get_pos()
                  p.y = p.y + (self.collisionbox[2] + self.collisionbox[5]) / 2
                  local obj = minetest.add_entity(p, self.arrow)
                  local amount = (vec.x ^ 2 + vec.y ^ 2 + vec.z ^ 2) ^ 0.5
                  local v = obj:get_luaentity().velocity
                  vec.y = vec.y + self.shoot_offset -- this makes shoot aim accurate
                  vec.x = vec.x *v / amount
                  vec.y = vec.y *v / amount
                  vec.z = vec.z *v / amount
                  obj:set_velocity(vec)
               end
            end
         end,

         on_activate = function(self, staticdata, dtime_s)

            if self.type == "monster"
            and peaceful_only then
               self.object:remove()
            end

            -- load entity variables
            if staticdata then
               local tmp = minetest.deserialize(staticdata)
               if tmp then
                  for _,stat in pairs(tmp) do
                     self[_] = stat
                  end
               end
            end

            -- select random texture, set model and size
            if not self.base_texture then
               self.base_texture = def.textures[math.random(1, #def.textures)]
               self.base_mesh = def.mesh
               self.base_size = self.visual_size
               self.base_colbox = self.collisionbox
            end

            -- set texture, model and size
            local textures = self.base_texture
            local mesh = self.base_mesh
            local vis_size = self.base_size
            local colbox = self.base_colbox

            -- specific texture if gotten
            if self.gotten == true
            and def.gotten_texture then
               textures = def.gotten_texture
            end

            -- specific mesh if gotten
            if self.gotten == true
            and def.gotten_mesh then
               mesh = def.gotten_mesh
            end

            -- if object is child then set half size
            if self.child == true then
               vis_size = {
                  x = self.base_size.x / 2,
                  y = self.base_size.y / 2
               }
               if def.child_texture then
                  textures = def.child_texture[1]
               end
               colbox = {
                  self.base_colbox[1] / 2,
                  self.base_colbox[2] / 2,
                  self.base_colbox[3] / 2,
                  self.base_colbox[4] / 2,
                  self.base_colbox[5] / 2,
                  self.base_colbox[6] / 2
               }
            end

            if self.health == 0 then
               self.health = math.random (self.hp_min, self.hp_max)
            end

            self.object:set_hp( self.health )
            self.object:set_armor_groups({fleshy = self.armor})
            self.state = "stand"
            self.order = "stand"
            self.following = nil
            self.old_y = self.object:get_pos().y
            self.object:set_yaw(math.random(1, 360) / 180 * math.pi)
            self.sounds.distance = (self.sounds.distance or 10)
            self.textures = textures
            self.mesh = mesh
            self.collisionbox = colbox
            self.visual_size = vis_size
            -- set anything changed above
            self.object:set_properties(self)

            if self.on_spawn then
               self:on_spawn()
            end

         end,

         get_staticdata = function(self)

            -- remove mob when out of range unless tamed
            if mobs.remove == true and self.remove_ok and not self.tamed then
               minetest.log("action", "[mobs] Mob removed (out of range): " .. tostring(self.remove_ok) .." ".. self.name)
               self.object:remove()
            end
            self.remove_ok = true
            self.attack = nil

            local tmp = {}
            for _,stat in pairs(self) do
               local t = type(stat)
               if  t ~= 'function'
                  and t ~= 'nil'
               and t ~= 'userdata' then
                  tmp[_] = self[_]
               end
            end
            return minetest.serialize(tmp)
         end,

         on_punch = function(self, hitter, tflp, tool_capabilities, dir)
            -- weapon wear
            local weapon = hitter:get_wielded_item()
            if weapon:get_definition().tool_capabilities ~= nil then
               local wear = ( (weapon:get_definition().tool_capabilities.full_punch_interval or 1.4) / 75 ) * 9000
               if not minetest.settings:get_bool("creative_mode") then
                  weapon:add_wear(wear)
               end
               hitter:set_wielded_item(weapon)
            end

            -- weapon sounds
            if weapon:get_definition().sounds ~= nil then
               local s = math.random(0, #weapon:get_definition().sounds)
               minetest.sound_play(weapon:get_definition().sounds[s], {
                                      object=hitter,
                                      max_hear_distance = 8
               })
            else
               minetest.sound_play("default_punch", {
                                      object = hitter,
                                      max_hear_distance = 5
               })
            end

            -- exit here if dead
            if check_for_death(self, hitter) then
               return
            end

            -- blood_particles
            if self.blood_amount > 0 then
               local pos = self.object:get_pos()
               pos.y = pos.y + (-self.collisionbox[2] + self.collisionbox[5]) / 3
               if enable_blood then
                  effect(pos, self.blood_amount, self.blood_texture)
               else
                  effect(pos, self.blood_amount, "default_grass_clump_tall.png")
               end
            end

            -- knock back effect
            if self.knock_back > 0 then
               local kb = self.knock_back
               local r = self.recovery_time
               local v = self.object:get_velocity()
               if tflp < tool_capabilities.full_punch_interval then
                  if kb > 0 then
                     kb = kb * ( tflp / tool_capabilities.full_punch_interval )
                  end
                  r = r * ( tflp / tool_capabilities.full_punch_interval )
               end
               self.object:set_velocity({x = dir.x * kb,y = 0,z = dir.z * kb})
               self.pause_timer = r
            end

            -- attack puncher and call other mobs for help
            if self.passive == false
            and not self.tamed then
               if self.state ~= "attack" then
                  self.do_attack(self, hitter, 1)
               end
               -- alert others to the attack
               local obj = nil
               for _, oir in pairs(minetest.get_objects_inside_radius(hitter:get_pos(), 5)) do
                  obj = oir:get_luaentity()
                  if obj then
                     if obj.group_attack == true
                     and obj.state ~= "attack" then
                        obj.do_attack(obj, hitter, 1)
                     end
                  end
               end
            end
         end,
   })
end

mobs.spawning_mobs = {}

function mobs:spawn_specific(name, nodes, neighbors, min_light, max_light, interval, chance, active_object_count, min_height, max_height)
   mobs.spawning_mobs[name] = true
   minetest.register_abm(
      {
         label = "Mob spawn (" .. name .. ")",
         nodenames = nodes,
         neighbors = neighbors,
         interval = interval,
         chance = chance,
         action = function(pos, node, _, active_object_count_wider)
            -- do not spawn if too many active entities in area
            if active_object_count_wider > active_object_count or not mobs.spawning_mobs[name] then
               --or not pos then
               return
            end

            -- spawn above node
            pos.y = pos.y + 1

            -- mobs cannot spawn inside protected areas if enabled
            if mobs.protected == 1
            and minetest.is_protected(pos, "") then
               return
            end

            -- check if light and height levels are ok to spawn
            local light = minetest.get_node_light(pos)
            if not light
               or light > max_light
               or light < min_light
               or pos.y > max_height
            or pos.y < min_height then
               return
            end

            -- are we spawning inside a solid node?
            local nod = minetest.get_node_or_nil(pos)
            if not nod
               or not nod.name
               or not minetest.registered_nodes[nod.name]
            or minetest.registered_nodes[nod.name].walkable == true then
               return
            end

            pos.y = pos.y + 1

            nod = minetest.get_node_or_nil(pos)
            if not nod
               or not nod.name
               or not minetest.registered_nodes[nod.name]
            or minetest.registered_nodes[nod.name].walkable == true then
               return
            end

            if minetest.settings:get_bool("display_mob_spawn") then
               minetest.chat_send_all("[mobs] "..S("Spawned @1 at @2", name, minetest.pos_to_string(pos)))
            end

            -- spawn mob half block higher
            pos.y = pos.y - 0.5
            minetest.add_entity(pos, name)
            minetest.log("action", "[mobs] Spawned "..name.." at "..minetest.pos_to_string(pos).." on "..node.name.." near "..neighbors[1])

         end
   })
end

-- compatibility with older mob registration
function mobs:register_spawn(name, nodes, max_light, min_light, chance, active_object_count, max_height)
   mobs:spawn_specific(name, nodes, {"air"}, min_light, max_light, 30, chance, active_object_count, -31000, max_height)
end

-- register arrow for shoot attack
function mobs:register_arrow(name, def)
   if not name or not def then return end -- errorcheck
   minetest.register_entity(
      name,
      {
         physical = false,
         visual = def.visual,
         visual_size = def.visual_size,
         textures = def.textures,
         velocity = def.velocity,
         hit_player = def.hit_player,
         hit_node = def.hit_node,
         hit_mob = def.hit_mob,
         drop = def.drop or false,
         collisionbox = {0, 0, 0, 0, 0, 0}, -- remove box around arrows

         on_step = function(self, dtime)
            self.timer = (self.timer or 0) + 1
            if self.timer > 150 then self.object:remove() return end

            local engage = 10 - (self.velocity / 2) -- clear entity before arrow becomes active
            local pos = self.object:get_pos()
            local node = minetest.get_node_or_nil(self.object:get_pos())
            if node then node = node.name else node = "air" end

            if self.hit_node
               and minetest.registered_nodes[node]
            and minetest.registered_nodes[node].walkable then
               self.hit_node(self, pos, node)
               if self.drop == true then
                  pos.y = pos.y + 1
                  self.lastpos = (self.lastpos or pos)
                  minetest.add_item(self.lastpos, self.object:get_luaentity().name)
               end
               self.object:remove()
               return
            end

            if (self.hit_player or self.hit_mob)
            and self.timer > engage then
               for _,player in pairs(minetest.get_objects_inside_radius(pos, 1.0)) do
                  if self.hit_player
                  and player:is_player() then
                     self.hit_player(self, player)
                     self.object:remove()
                     return
                  end
                  if self.hit_mob
                     and player:get_luaentity().name ~= self.object:get_luaentity().name
                  and player:get_luaentity().name ~= "__builtin:item" then
                     self.hit_mob(self, player)
                     self.object:remove()
                     return
                  end
               end
            end
            self.lastpos = pos
         end
   })
end

-- Spawn Egg
function mobs:register_egg(mob, desc, background)
   local invimg = background
   minetest.register_craftitem(
      mob,
      {
         description = desc,
         inventory_image = invimg,
         groups = { spawn_egg = 1 },
         on_place = function(itemstack, placer, pointed_thing)
            local pos = pointed_thing.above
            if pointed_thing.above
            and not minetest.is_protected(pos, placer:get_player_name()) then
               pos.y = pos.y + 0.5
               local mob = minetest.add_entity(pos, mob)
               local ent = mob:get_luaentity()
               if ent.type ~= "monster" then
                  -- set owner
                  ent.owner = placer:get_player_name()
                  ent.tamed = true
               end
               if not minetest.settings:get_bool("creative_mode") then
                   itemstack:take_item()
               end
            end
            return itemstack
         end,
   })
end

-- Capture critter (thanks to blert2112 for idea)

function mobs:capture_mob(self, clicker, chance_hand, chance_net, chance_lasso,
                          force_take, replacewith)
   if clicker:is_player() and clicker:get_inventory() and not self.child then
      local mobname = self.name

      -- If not nil change what will be added to inventory

      if replacewith then
         mobname = replacewith
      end

      local name = clicker:get_player_name()

      -- Is mob tamed?

      if self.tamed == false and force_take == false then
         minetest.chat_send_player(name, minetest.colorize("#FFFF00", S("Not tamed!")))

         return
      end

      -- Cannot pick up if not owner

      if self.owner ~= name and force_take == false then
         minetest.chat_send_player(name, minetest.colorize("#FFFF00", S("@1 is owner!", self.owner)))

         return
      end

      if clicker:get_inventory():room_for_item("main", mobname) then
         -- Was mob clicked with hand, net, or lasso?

         local tool = clicker:get_wielded_item()
         local chance = 0

         if tool:is_empty() then
	    chance = chance_hand
         elseif tool:get_name() == "mobs:net" then
	    chance = chance_net
            if not minetest.settings:get_bool("creative_mode") then
	        tool:add_wear(4000) -- 17 uses
            end
	    clicker:set_wielded_item(tool)
         elseif tool:get_name() == "mobs:lasso" then
	    chance = chance_lasso
            if not minetest.settings:get_bool("creative_mode") then
	        tool:add_wear(1500) -- 43 uses
            end
	    clicker:set_wielded_item(tool)
         end

         -- Return if no chance

         if chance == 0 then return end

         -- Calculate chance.. was capture successful?

         if math.random(100) <= chance then
	    -- Cuccessful capture.. add to inventory
	    clicker:get_inventory():add_item("main", mobname)

	    self.object:remove()

            achievements.trigger_achievement(clicker, "ranger")
         else
	    minetest.chat_send_player(name, minetest.colorize("#FFFF00", S("Missed!")))
         end
      end
   end
end

-- Feeding, taming and breeding (thanks blert2112)

function mobs:feed_tame(self, clicker, feed_count, breed)
   -- Feed a mob(mostly a wrapper to handle self.check_fed)

   local item = nil
   local itemstring = clicker
   local name = nil

   if type(clicker) ~= "string" then
      item = clicker:get_wielded_item()

      itemstring = item:get_name()

      name = clicker:get_player_name()
   end

   if itemstring == self.follow then
      if name ~= nil then
         -- Take item

         if not minetest.settings:get_bool("creative_mode") then
	    item:take_item()

	    clicker:set_wielded_item(item)
         end
      end

      self:check_fed(name, feed_count, breed)

      return true
   else
      return false
   end
end