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

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

local state = {
  walk = 0,
  plant = 1,
  punch = 2,
  walk_to_tree = 3,
  walk_avoid = 4,
}
local find_lenvec = {x = 3, y = 0, z = 3}
local plant_lenvec = {x = 2, y = 0, z = 2}
local max_punch_time = 20
local max_plant_time = 20
local max_avoid_time = 15
local target_tree_list = { "default:tree" }
local target_sapling_list = { "default:sapling" }

-- check the maidroid need to start to punch
local function check_punch_flag(forward_pos)
  local forward_upper_pos = util.table_shallow_copy(forward_pos)
  while true do
    local forward_upper_node = minetest.get_node(forward_upper_pos)
    if util.table_find_value(target_tree_list, forward_upper_node.name) then
      return true, forward_upper_pos, forward_upper_node
    elseif forward_upper_node.name ~= "air" then break end
    forward_upper_pos.y = forward_upper_pos.y + 1
  end
  return false, nil, nil
end

-- check the maidroid has sapling items
local function has_sapling_item(self)
  local inv = maidroid._aux.get_maidroid_inventory(self)
  local stacks = inv:get_list("main")
  for _, stack in ipairs(stacks) do
    local item_name = stack:get_name()
    if util.table_find_value(target_sapling_list, item_name) then
      return true
    end
  end
  return false
end

maidroid.register_module("maidroid:lumberjack_module", {
  description = "Maidroid Module : Lumberjack",
  inventory_image = "maidroid_lumberjack_module.png",

  initialize = function(self)
    self.state = state.walk
    self.time_count = 0
    self.object:setacceleration{x = 0, y = -10, z = 0}
    self.object:set_animation(maidroid.animations.walk, 15, 0)
    self.preposition = self.object:getpos()
    self.destination = nil
    _aux.change_dir(self)
  end,

  finalize = function(self)
    self.state = nil
    self.time_count = nil
    self.preposition = nil
    self.object:setvelocity{x = 0, y = 0, z = 0}
    self.destination = nil
  end,

  on_step = function(self, dtime)
    local pos = self.object:getpos()
    local rpos = vector.round(pos)
    local yaw = self.object:getyaw()
    local forward = _aux.get_forward(yaw)
    local rforward = _aux.get_round_forward(forward)
    local forward_pos = vector.add(rpos, rforward)
    local forward_node = minetest.get_node(forward_pos)
    local forward_under_pos = _aux.get_under_pos(forward_pos)
    local forward_under_node = minetest.get_node(forward_under_pos)

    if self.state == state.walk then
      local b, dest = _aux.search_surrounding(self, find_lenvec, function(self, pos, node)
        return util.table_find_value(target_tree_list, node.name)
      end)
      if b then -- walk to tree
        self.state = state.walk_to_tree
        self.destination = dest
        _aux.change_dir_to(self, dest)
      -- to plant sapling
      elseif forward_node.name == "air"
      and minetest.get_item_group(forward_under_node.name, "soil") > 0
      and not _aux.search_surrounding(self, plant_lenvec, function(self, pos, node) -- no tree around
        return util.table_find_value(target_tree_list, node.name)
          or util.table_find_value(target_sapling_list, node.name)
      end)
      and has_sapling_item(self) then
        self.state = state.plant
        self.object:set_animation(maidroid.animations.mine, 15, 0)
        self.object:setvelocity{x = 0, y = 0, z = 0}
      -- else continue to walk
      else
        if pos.x == self.preposition.x or pos.z == self.preposition.z then
          _aux.change_dir(self)
        end
      end
      -- pickup sapling items
      _aux.pickup_item(self, 1.5, function(itemstring)
        return util.table_find_value(target_sapling_list, itemstring)
      end)

    elseif self.state == state.punch then
      if self.time_count >= max_punch_time then
        local punch_flag, forward_upper_pos, forward_upper_node = check_punch_flag(self.destination)
        if punch_flag then
          minetest.remove_node(forward_upper_pos)
          local inv = minetest.get_inventory{type = "detached", name = self.invname}
          local stacks = minetest.get_node_drops(forward_upper_node.name)
          for _, stack in ipairs(stacks) do
            local leftover = inv:add_item("main", stack)
            minetest.add_item(forward_pos, leftover)
          end
        end
        if (not forward_upper_pos) or (forward_upper_pos and
        not check_punch_flag(_aux.get_upper_pos(forward_upper_pos))) then
          self.state = state.walk
          self.object:set_animation(maidroid.animations.walk, 15, 0)
          _aux.change_dir(self)
        end
        self.time_count = 0
      else
        self.time_count = self.time_count + 1
      end

    elseif self.state == state.plant then
      if self.time_count > max_plant_time then
        if forward_node.name == "air"
        and minetest.get_item_group(forward_under_node.name, "soil") > 0 then
          local inv = minetest.get_inventory{type = "detached", name = self.invname}
          local stacks = inv:get_list("main")
          for i, stack in ipairs(stacks) do
            local itemname = stack:get_name()
            if util.table_find_value(target_sapling_list, itemname) then
              minetest.add_node(forward_pos, {name = itemname, param2 = 1})
              stack:take_item(1)
              inv:set_stack("main", i, stack)
              break
            end
          end
        end
        self.state = state.walk
        self.object:set_animation(maidroid.animations.walk, 15, 0)
        self.time_count = 0
        _aux.change_dir(self)
      else
        self.time_count = self.time_count + 1
      end

    elseif self.state == state.walk_to_tree then
      if vector.distance(pos, self.destination) < 1.5 then -- to punch state
        local destnode = minetest.get_node(self.destination)
        if (util.table_find_value(target_tree_list, destnode.name)) then
          self.state = state.punch
          self.object:set_animation(maidroid.animations.mine, 15, 0)
          self.object:setvelocity{x = 0, y = 0, z = 0}
        else
          self.state = state.walk
          self.object:set_animation(maidroid.animations.walk, 15, 0)
          self.time_count = 0
          _aux.change_dir(self)
        end
      else
        if pos.x == self.preposition.x or pos.z == self.preposition.z then
          self.state = state.walk_avoid
          self.object:set_animation(maidroid.animations.walk, 15, 0)
          self.time_count = 0
          _aux.change_dir(self)
        end
      end

    elseif self.state == state.walk_avoid then
      if self.time_count > max_avoid_time then
        self.state = state.walk
        self.time_count = 0
      else
        self.time_count = self.time_count + 1
      end
    end
    self.preposition = pos
  end
})