local Peripheral = require('peripheral')
local Point      = require('point')
local Util       = require('util')

local device     = _G.device
local os         = _G.os
local turtle     = _G.turtle

local mobTypes = Util.transpose({ ... })

local function equip(side, item, rawName)
	local equipped = Peripheral.lookup('side/' .. side)

	if equipped and equipped.type == item then
		return true
	end

	if not turtle.equip(side, rawName or item) then
		if not turtle.selectSlotWithQuantity(0) then
			error('No slots available')
		end
		turtle.equip(side)
		if not turtle.equip(side, item) then
			error('Unable to equip ' .. item)
		end
	end

	turtle.select(1)
end

equip('left', 'minecraft:diamond_sword')

equip('right', 'plethora:scanner', 'plethora:module:2')
local scanner = device['plethora:scanner']

turtle.reset()
local facing = scanner.getBlockMeta(0, 0, 0).state.facing
turtle.point.heading = Point.facings[facing].heading

local data = scanner.scan()
local spawners = Util.findAll(data, 'name', 'minecraft:mob_spawner')
local spawner = Point.closest(turtle.point, spawners) or error('spawner not in range')

turtle._goto(Point.below(spawner))

Util.filterInplace(data, function(b)
	return b.name == 'minecraft:chest' or
		 b.name == 'minecraft:dispenser' or
		 b.name == 'minecraft:hopper'
end)
local chest = Point.closest(spawner, data) or error('missing drop off chest')
turtle._goto(Point.above(chest))

equip('right', 'plethora:sensor', 'plethora:module:3')
local sensor = device['plethora:sensor']

turtle.setMovementStrategy('goto')
turtle.setPolicy(turtle.policies.attack)

local function dropOff()
	local inv = turtle.getSummedInventory()
	for _, slot in pairs(inv) do
		if slot.count >= 16 then
			if turtle.getFuelLevel() < 5000 then
				turtle.refuel(slot.name, 16)
			end
		end
	end

	inv = turtle.getSummedInventory()
	for _, slot in pairs(inv) do
		if slot.count >= 16 or turtle.getSlot(8).count > 0 then
			turtle.eachFilledSlot(function(s)
				if s.name ~= 'plethora:module' then
					turtle.dropDownAt(chest, s.name, s.count)
				end
			end)
			break
		end
	end
	turtle.select(1)
end

local function normalize(b)
	b.x = Util.round(b.x) + turtle.point.x
	b.y = Util.round(b.y) + turtle.point.y
	b.z = Util.round(b.z) + turtle.point.z

	return b.x >= spawner.x - 4 and b.x <= spawner.x + 4 and
			   b.y >= spawner.y - 4 and b.y <= spawner.y + 4 and
	       b.z >= spawner.z - 4 and b.z <= spawner.z + 4
end

local function aboveAttack(b)
	if turtle.attackDownAt(b) then
		repeat until not turtle.attackDown()
	end
end

local function moveAgainst(b)
	if turtle.faceAgainst(b) then
		return turtle.attack()
	end
end

local function getAttackStrategy(name)
	local Strategies = {
		Pig = {
			attack = aboveAttack,
		},
		Default = {
			attack = moveAgainst,
		}
	}

	return Strategies[name] or Strategies.Default
end

while true do
	local blocks = sensor.sense()
	local mobs = Util.filterInplace(blocks, function(b)
		if mobTypes[b.name] then
			return normalize(b)
		end
	end)

	if turtle.getFuelLevel() == 0 then
		error('Out of fuel')
	end

print(#mobs)
	if #mobs == 0 then
print('sleeping')
		os.sleep(3)
	else
		Point.eachClosest(turtle.point, mobs, function(b)
print('attack: ' .. b.id)
			local strategy = getAttackStrategy(b.name)
			if strategy.attack(b) then
				while true do
					local mob = sensor.getMetaByID(b.id)
					if not mob or Util.empty(mob) then
						break
					end
					normalize(mob)
					if not strategy.attack(mob) then
						break
					end
				end
			end
		end)
	end

	dropOff()
end