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

local _aux = maidroid.modules._aux

local state = {
	walk = 0,
	punch = 1,
	plant = 2,
	walk_to_plant = 3,
	walk_to_soil = 4,
	walk_avoid = 5,
}
local max_punch_time = 20
local max_plant_time = 15
local max_avoid_time = 15
local search_lenvec = {x = 3, y = 0, z = 3}


-- find max size of each plants
local target_plants_list = {}
minetest.after(0, function()
	local max = {}
	for name, node in pairs(minetest.registered_nodes) do
		if minetest.get_item_group(name, "plant") > 0 then
			local s, i = string.match(name, "(.+)_(%d+)")
			if (s and i) and (max[s] == nil or max[s] < i) then max[s] = i end
		end
	end
	for s, i in pairs(max) do
		table.insert(target_plants_list, s.."_"..i)
	end
end)


-- check the maidroid has seed items
local function has_seed_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 minetest.get_item_group(item_name, "seed") > 0 then
			return true
		end
	end
	return false
end


-- check can plant plants.
local function can_plant(self, pos)
	local node = minetest.get_node(pos)
	local upos = _aux.get_under_pos(pos)
	local unode = minetest.get_node(upos)
	return node.name == "air"
	and minetest.get_item_group(unode.name, "wet") > 0
	and has_seed_item(self)
end


-- check can punch plant
local function can_punch(self, pos)
	local node = minetest.get_node(pos)
	return maidroid.util.table_find_value(target_plants_list, node.name)
end


-- change state to walk
local function to_walk(self)
	self.state = state.walk
	self.destination = nil
	self.object:set_animation(maidroid.animations.walk, 15, 0)
	self.time_count = 0
	_aux.change_dir(self)
end


local function to_walk_avoid(self)
	to_walk(self)
	self.state = state.walk_avoid
end


maidroid.register_module("maidroid:farming_module", {
	description = "Maidroid Module : Farming",
	inventory_image = "maidroid_farming_module.png",

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

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

	on_step = function(self, dtime)
		local pos = self.object:getpos()
		local rpos = vector.round(pos)
		local upos = _aux.get_under_pos(pos)
		local yaw = self.object:getyaw()

		_aux.pickup_item(self, 1.5, function(itemstring) -- pickup droped seed items
			return minetest.get_item_group(itemstring, "seed") > 0
		end)
		if self.state == state.walk then -- searching plants or spaces
			local b1, dest1 = _aux.search_surrounding(self, search_lenvec, can_plant)
			local b2, dest2 = _aux.search_surrounding(self, search_lenvec, can_punch)
			-- search soil node near
			if b1 then -- to soil
				self.state = state.walk_to_soil
				self.destination = dest1
				_aux.change_dir_to(self, dest1)
			elseif b2 then
				self.state = state.walk_to_plant
				self.destination = dest2
				_aux.change_dir_to(self, dest2)
			elseif pos.x == self.preposition.x or pos.z == self.preposition.z then
				_aux.change_dir(self)
			end

		elseif self.state == state.punch then
			if self.time_count >= max_punch_time then
				if can_punch(self, self.destination) then
					local destnode = minetest.get_node(self.destination)
					minetest.remove_node(self.destination)
					local inv = minetest.get_inventory{type = "detached", name = self.invname}
					local stacks = minetest.get_node_drops(destnode.name)
					for _, stack in ipairs(stacks) do
						local leftover = inv:add_item("main", stack)
						minetest.add_item(self.destination, leftover)
					end
				end
				to_walk(self)
			else
				self.time_count = self.time_count + 1
			end

		elseif self.state == state.plant then
			if self.time_count >= max_plant_time then
				if can_plant(self, self.destination) then
					local inv = minetest.get_inventory{type = "detached", name = self.invname}
					local stacks = inv:get_list("main")
					for idx, stack in ipairs(stacks) do
						local item_name = stack:get_name()
						if minetest.get_item_group(item_name, "seed") > 0 then
							minetest.add_node(self.destination, {name = item_name, param2 = 1})
							stack:take_item(1)
							inv:set_stack("main", idx, stack)
							break
						end
					end
				end
				to_walk(self)
			else
				self.time_count = self.time_count + 1
			end

		elseif self.state == state.walk_to_soil then
			if vector.distance(pos, self.destination) < 1.5 then -- to plant state
				local destnode = minetest.get_node(self.destination)
				if (can_plant(self, self.destination)) then
					self.state = state.plant
					self.object:set_animation(maidroid.animations.mine, 15, 0)
					self.object:setvelocity{x = 0, y = 0, z = 0}
				else to_walk(self) end
			else
				if pos.x == self.preposition.x or pos.z == self.preposition.z then
					to_walk_avoid(self)
				end
			end

		elseif self.state == state.walk_to_plant then
			if vector.distance(pos, self.destination) < 1.5 then
				local destnode = minetest.get_node(self.destination)
				if maidroid.util.table_find_value(target_plants_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 to_walk(self) end
			else
				if pos.x == self.preposition.x or pos.z == self.preposition.z then
					to_walk_avoid(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
		return
	end
})