------------------------------------------------------------
-- Copyright (c) 2016 tacigar
-- https://github.com/tacigar/maidroid
------------------------------------------------------------

local util = maidroid.util
local _aux = maidroid.modules._aux

local state = { idle = 0, chase = 1}
local view_of_range = 7 
local stop_of_range = 2 

maidroid.register_module("maidroid:chasing_player_module", {
  description = "Maidroid Module : Chasing Player",
  inventory_image = "maidroid_chasing_player_module.png",
  
  initialize = function(self)
    self.state = state.idle
    self.object:setacceleration{x = 0, y = -10, z = 0}
    self.object:setvelocity{x = 0, y = 0, z = 0}
  end,
  
  finalize = function(self)
    self.state = nil
    self.object:setvelocity{x = 0, y = 0, z = 0}
  end,
  
  on_step = function(self, dtime)
    local pos = self.object:getpos()
    local all_objects = minetest.get_objects_inside_radius(pos, view_of_range)
    local player = nil
    for _, obj in pairs(all_objects) do
      if obj:is_player() then player = obj; break end
    end
    if not player then
      self.object:set_animation(maidroid.animations.stand, 15, 0)
      self.state = state.idle
      return
    end
    local ppos = player:getpos()
    local dir = vector.subtract(ppos, pos)
    local vel = self.object:getvelocity()
    if (vector.length(dir) < stop_of_range) then
      if self.state == state.chase then
	self.object:set_animation(maidroid.animations.stand, 15, 0)
	self.state = state.idle
	self.object:setvelocity({x = 0, y = vel.y, z = 0})
      end
    else
      if self.state == state.idle then
	self.object:set_animation(maidroid.animations.walk, 15, 0)
	self.state = state.chase
      end
      self.object:setvelocity({x = dir.x, y = vel.y, z = dir.z})
    end
    local yaw = math.atan2(dir.z, dir.x) + math.pi/2
    self.object:setyaw(yaw)
    
    -- jump process
    if vel.y == 0 and self.state == state.chase then
      local rdir = vector.round(dir)
      local front_vec = { x = 0, y = 0, z = 0 }
      if math.abs((rdir.x / (math.abs(rdir.x) + math.abs(rdir.z)))) > 0.5 then
	if rdir.x > 0 then front_vec.x = 1 else front_vec.x = -1 end
      end
      if math.abs((rdir.z / (math.abs(rdir.x) + math.abs(rdir.z)))) > 0.5 then
	if rdir.z > 0 then front_vec.z = 1 else front_vec.z = -1 end
      end
      local front_pos = vector.add(vector.round(pos), front_vec)
      if minetest.get_node(front_pos).name ~= "air" then
	self.object:setvelocity({x = dir.x, y = 5, z = dir.z})
      end
    end
  end,
})