local Equipper    = require('turtle.equipper')
local Point       = require('opus.point')
local Util        = require('opus.util')

local fs          = _G.fs
local os          = _G.os
local peripheral  = _G.peripheral
local turtle      = _G.turtle

local CONFIG_FILE  = 'usr/config/farmer'
local STARTUP_FILE = 'usr/autorun/farmer.lua'
local MIN_FUEL     = 2500

local FUEL = Util.transpose {
	'minecraft:coal:0',
	'minecraft:coal:1',
	'minecraft:blaze_rod:0',
}

local scanner = Equipper.equipRight('plethora:scanner')

local crops = Util.readTable(CONFIG_FILE) or {
	['minecraft:wheat'] =
		{ seed = 'minecraft:wheat_seeds', mature = 7, action = 'plant' },
	['minecraft:carrots'] =
		{ seed = 'minecraft:carrot', mature = 7, action = 'plant' },
	['minecraft:potatoes'] =
		{ seed = 'minecraft:potato', mature = 7, action = 'plant' },
	['minecraft:beetroots'] =
		{ seed = 'minecraft:beetroot_seeds', mature = 3, action = 'plant' },
	['minecraft:nether_wart'] =
		{ seed = 'minecraft:nether_wart', mature = 3, action = 'plant' },
	['minecraft:cocoa'] =
		{ seed = 'minecraft:dye:3', mature = 8, action = 'pick' },
	['minecraft:reeds'] = { action = 'bash' },
	['minecraft:chorus_flower'] = { action = 'bash' },
	['minecraft:chorus_plant'] =
		{ seed = 'minecraft:chorus_flower', mature = 0, action = 'bash-smash', },
	['minecraft:melon_block'] = { action = 'smash' },
	['minecraft:pumpkin'] = { action = 'smash' },
	['minecraft:chest'] = { action = 'drop' },
	['minecraft:cactus'] = { action = 'smash' },
}

if not fs.exists(CONFIG_FILE) then
	Util.writeTable(CONFIG_FILE, crops)
end

if not fs.exists(STARTUP_FILE) then
	Util.writeFile(STARTUP_FILE,
		[[os.sleep(1)
shell.openForegroundTab('farmer.lua')]])
	print('Autorun program created: ' .. STARTUP_FILE)
end

local retain = Util.transpose {
	"minecraft:diamond_pickaxe",
	"plethora:module:2",
	"plethora:module:3",
}

for _, v in pairs(crops) do
	if v.seed then
		retain[v.seed] = true
	end
end

local function scan()
	local blocks = scanner.scan()
	local summed = turtle.getSummedInventory()
	local doDropOff

	for _,v in pairs(summed) do
		if v.count > 32 then
			doDropOff = true
			break
		end
	end

	Util.filterInplace(blocks, function(b)
		b.action = crops[b.name] and crops[b.name].action

		if b.action == 'bash' then
			return b.y == 0
		end
		if b.action == 'drop' then
			return doDropOff and (b.y == -1 or b.y == 1)
		end
		if b.action == 'bash-smash' then
			if b.y == -1 then
				b.action = 'smash'
			end
			if b.y == 0 then
				b.action = 'bash'
			end
			return b.action ~= 'bash-smash'
		end

		if b.action == 'smash' then
			return b.y == -1
		end
		if b.action == 'pick' then
			return b.y == 0 and b.state.age == 2
		end
		if b.action == 'bump' then
			return b.y == 0
		end
		if b.action == 'plant' and b.y == -1 then
			if not b.metadata then -- minecraft 1.10
				b = scanner.getBlockMeta(b.x, b.y, b.z)
			end
			return b.metadata == crops[b.name].mature
		end
	end)

	local harvestCount = 0
	for _,b in pairs(blocks) do
		b.x = b.x + turtle.point.x
		b.y = b.y + turtle.point.y
		b.z = b.z + turtle.point.z
		if b.action ~= 'drop' then
			harvestCount = harvestCount + 1
		end
	end

	return blocks, harvestCount
end

local function harvest(blocks)
	Equipper.equipRight('minecraft:diamond_pickaxe')

	local dropped

	Point.eachClosest(turtle.point, blocks, function(b)
		turtle.select(1)

		if b.action == 'bash' then
			turtle.digForwardAt(b)

		elseif b.action == 'drop' and not dropped then
			if turtle.go(b.y == 1 and Point.below(b) or Point.above(b)) then
				local dropFn = b.y == 1 and turtle.dropUp or turtle.dropDown
				local dropDir = b.y == 1 and 'down' or 'up'

				turtle.eachFilledSlot(function(slot)
					if not retain[slot.name] and not retain[slot.key] then
						turtle.select(slot.index)
						dropFn()
					end
				end)
				local summed = turtle.getSummedInventory()
				for k,v in pairs(summed) do
					if v.count > 16 then
						dropFn(k, v.count - 16)
					end
				end

				dropped = true
				turtle.condense()

				if turtle.getFuelLevel() < MIN_FUEL then
					local inv = peripheral.wrap('bottom')
					if inv and inv.list then
						for k, v in pairs(inv.list()) do
							if FUEL[table.concat({ v.name, v.damage }, ':')] then
								local count = inv.pushItems(dropDir, k, v.count)
								if count > 0 then
									turtle.refuel(v.name, v.count)
									print('Fuel: ' .. turtle.getFuelLevel())
									break
								end
							end
						end
					end
				end
			end

		elseif b.action == 'smash' then
			if turtle.digDownAt(b) then
				if crops[b.name].seed then
					turtle.placeDown(crops[b.name].seed)
				end
			end

		elseif b.action == 'plant' then
			if turtle.digDownAt(b) then
				turtle.placeDown(crops[b.name].seed)
			end

		elseif b.action == 'bump' then
			if turtle.faceAgainst(b) then
				Equipper.equipRight('plethora:sensor')
				os.sleep(.5)
				-- search the ground for the dropped cactus
				local sensed = peripheral.call('right', 'sense')
				Equipper.equipRight('minecraft:diamond_pickaxe')
				Util.filterInplace(sensed, function(s)
					if s.displayName == 'item.tile.cactus' then
						s.x = Util.round(s.x) + turtle.point.x
						s.z = Util.round(s.z) + turtle.point.z
						s.y = -1
						if  Point.distance(b, s) < 6 then
							return true
						end
					end
				end)
				Point.eachClosest(turtle.point, sensed, function(s)
					turtle.suckDownAt(s)
				end)
			end

		elseif b.action == 'pick' then
			local h = Point.facings[b.state.facing].heading
			local hi = Point.headings[(h + 2) % 4] -- opposite heading

			-- without pathfinding, will be unable to circle log
			if turtle.go({ x = b.x + hi.xd, z = b.z + hi.zd, heading = h }) then
				if turtle.dig() then
					turtle.place(crops[b.name].seed)
				end
			end
		end
	end)
	Equipper.equipRight('plethora:scanner')
end

local s, m = turtle.run(function()
	local facing = scanner.getBlockMeta(0, 0, 0).state.facing
	turtle.point.heading = Point.facings[facing].heading

	turtle.setStatus('farming')
	print('Fuel: ' .. turtle.getFuelLevel())

	turtle.setMovementStrategy('goto')
	repeat
		local blocks, harvestCount = scan()
		if harvestCount > 0 then
			turtle.setStatus('Harvesting')
			harvest(blocks)
			turtle.setStatus('Sleeping')
		end
		os.sleep(10)
		if turtle.getFuelLevel() < 10 then
			turtle.setStatus('Out of fuel')
			error('Out of fuel')
		end
	until turtle.isAborted()
end)

if not s and m then
	error(m)
end