local PATH_FIND_ALGORITHM
PATH_FIND_ALGORITHM = "Dijkstra"

PyuTest.ENTITY_BLOOD_AMOUNT = 6
PyuTest.HUMAN_LIKE_CBOX = { -0.25, -1, -0.25, 0.25, 1, 0.25 }
PyuTest.SMALL_ANIMAL_CBOX = {-0.25, -0.5, -0.25, 0.25, 0.15, 0.25}

PyuTest.get_nearest_entity = function(entity, pos, range, only_player, dont_ignore_allies)
  local closet_distance = math.huge
  local nearest

  local function set_nearest_and_distance(n, d)
    nearest = n
    closet_distance = d
  end

  for obj in core.objects_inside_radius(pos, range) do
    local dist = vector.distance(pos, obj:get_pos())

    if dist < closet_distance and obj ~= entity then
      if only_player then
        if obj:is_player() then
          set_nearest_and_distance(obj, dist)
        end
      else
        local e = obj:get_luaentity()
        -- Ignore items
        if e then
          if e.name ~= "__builtin:item" then
            if not dont_ignore_allies then
              local self = entity:get_luaentity()

              if self then
                if self.name ~= e.name then
                  set_nearest_and_distance(obj, dist)
                end
              end
            end
          end
        else
          set_nearest_and_distance(obj, dist)
        end
      end
    end
  end

  return nearest
end

local class = {}

function class:do_physics()
  local obj = self.object
  local state = self.state
  local cfg = self.options
  local moveresult = self.moveresult
  local pos = obj:get_pos()


  if cfg.gravity then
    if not moveresult.touching_ground then

    end
  end
end

function class:path_find_entity(target)
  local obj = self.object
  local state = self.state
  local cfg = self.options
  local pos = obj:get_pos()

  if state.target.path == nil then
    state.target.object = target

    if state.target.object == nil then
      return
    end

    state.target.position = state.target.object:get_pos()
    state.target.path = core.find_path(pos, state.target.position, cfg.view_range, cfg.max_jump, cfg.max_drop,
      PATH_FIND_ALGORITHM)
    state.target.pathindex = 1
  else
    if state.target.pathindex == #state.target.path then
      state.target.path = nil
      state.target.object = nil
      state.target.position = nil
      state.target.pathindex = nil
    else
      local p = state.target.path[state.target.pathindex]
      -- obj:set_velocity(p * dtime)
      obj:move_to(p, true)
      state.target.pathindex = state.target.pathindex + 1
    end
  end
end

function class:path_find_nearest_entity(follow_only_player)
  local obj = self.object
  local state = self.state
  local cfg = self.options
  local pos = obj:get_pos()

  self:path_find_entity(PyuTest.get_nearest_entity(obj, pos, cfg.view_range, follow_only_player, false))
end

function class:on_punch()
  local pos = self.object:get_pos()
  core.sound_play({
      name = self.options.sounds.hurt,
      pos = pos
  })

  core.add_particlespawner({
      amount = 8,
      time = 0.4,
      minexptime = 0.4,
      maxexptime = 0.8,
      minsize = 1.5,
      maxsize = 1.62,
      vertical = false,
      glow = core.LIGHT_MAX,

      collisiondetection = false,
      texture = "pyutest-blood.png",

      minpos = pos,
      maxpos = pos,
      minvel = vector.new(-1, -1, 1),
      maxvel = vector.new(1, 1, 1),
  })
end

function class:on_death()
  local pos = self.object:get_pos()

  for _, v in pairs(self.options.drops) do
    PyuTest.drop_item(pos, v)
  end
end

function class:on_step(dtime, moveresult)
  self.dtime = dtime
  self.moveresult = moveresult

  local obj = self.object
  local cfg = self.options
  local p = obj:get_properties()


  local hp = obj:get_hp()
  if self.options.health_regen and not (hp >= p.hp_max) then
    obj:set_hp(hp + 0.5)
  end

  if obj:get_hp() > p.hp_max then
    obj:set_hp(p.hp_max)
  end

  p.infotext = string.format("Mob Health: %d/%d", obj:get_hp(), p.hp_max)
  obj:set_properties(p)

  self:do_physics()

  if not self.state.action_timer then
    core.after(1, function ()
        self.state.action_timer = true

        core.after(1, function ()
            self.action_timer = false
        end)
    end)
  end


  -- follow_player
  if self.options.follow_player then
    self:path_find_nearest_entity(false)
  end

  -- follow_items
  for o in core.objects_inside_radius(obj:get_pos(), cfg.view_range) do
    if o ~= obj then
      for _, v in pairs(self.options.follow_items) do
        local i = o:get_wielded_item()

        if i:get_name() == v then
          self:path_find_entity(o)
        end
      end
    end
  end

  -- attack_entities
  if self.state.action_timer then
    for o in core.objects_inside_radius(obj:get_pos(), cfg.hit_range) do
      if o ~= obj then
        for _, v in pairs(cfg.attack_entities) do
          local lua_entity = o:get_luaentity()

          if (v == "player" and o:is_player()) or (lua_entity and v == lua_entity.name) then
            PyuTest.deal_damage(o, cfg.hit_damage * dtime, {
                type = "punch",
                object = obj
            })
          end
        end
      end
    end
  end
end

PyuTest.make_mob = function(name, properties, options)
  local default_options = {
    max_jump = 1,
    max_drop = 8,
    speed = 3,
    hit_range = 3,
    hit_damage = 3,
    view_range = 10,
    gravity = true,
    gravity_multiplier = 1,
    health_regen = true,
    follow_player = false,
    follow_items = {},
    attack_entities = {},

    sounds = {
      hurt = "pyutest-entity-hurt"
    },
    drops = {}
  }
  local cfg = {}

  for k, v in pairs(options) do
    cfg[k] = v
  end

  for k, v in pairs(default_options) do
    if cfg[k] == nil then
      cfg[k] = v
    end
  end

  local collisionbox = properties.collisionbox or PyuTest.HUMAN_LIKE_CBOX

  core.register_entity(name, setmetatable({
        initial_properties = PyuTest.util.tableconcat(properties, {
            hp_max = properties.hp_max or 20,
            physical = true,
            collide_with_objects = false,
            stepheight = properties.stepheight or 1.1,
            collisionbox = collisionbox,
            selectionbox = properties.selectionbox or collisionbox,
            show_on_minimap = properties.show_on_minimap or true,
            infotext = "",
        }),
        options = cfg,
        state = {
          action_timer = false,
          target = {
            object = nil,
            position = nil,
            path = nil,
            pathindex = nil
          }
        },
  }, { __index = class }))
end