local Pathing = require('pathfind')
local Point   = require('point')
local Util    = require('util')

local fs     = _G.fs
local read   = _G.read
local os     = _G.os
local turtle = _G.turtle

local args = { ... }
local options = {
	chunks      = { arg = 'c', type = 'number', value = -1,
								 desc = 'Number of chunks to mine' },
	depth       = { arg = 'd', type = 'number', value = 9000,
								 desc = 'Mining depth' },
--  enderChest = { arg = 'e', type = 'flag',   value = false,
--                 desc = 'Use ender chest' },
	resume      = { arg = 'r', type = 'flag',   value = false,
								 desc = 'Resume mining' },
	fortunePick = { arg = 'p', type = 'string', value = nil,
								 desc = 'Pick to use with CCTweaks toolhost' },
	setTrash    = { arg = 's', type = 'flag',   value = false,
								 desc = 'Set trash items' },
	help        = { arg = 'h', type = 'flag',   value = false,
								 desc = 'Displays the options' },
}

local fortuneBlocks = {
	[ 'minecraft:redstone_ore' ] = true,
	[ 'minecraft:lapis_ore'    ] = true,
	[ 'minecraft:coal_ore'     ] = true,
	[ 'minecraft:diamond_ore'  ] = true,
	[ 'minecraft:emerald_ore'  ] = true,
}

local MIN_FUEL = 7500
local LOW_FUEL = 1500
local MAX_FUEL = turtle.getFuelLimit()

local PROGRESS_FILE = 'usr/config/mining.progress'
local TRASH_FILE    = 'usr/config/mining.trash'

local mining = {
	diameter = 1,
	chunkIndex = 0,
	chunks = -1,
}

local trash, boreDirection, unload

local function getChunkCoordinates(diameter, index, x, z)
	local dirs = { -- circumference of grid
		{ xd =  0, zd =  1, heading = 1 }, -- south
		{ xd = -1, zd =  0, heading = 2 },
		{ xd =  0, zd = -1, heading = 3 },
		{ xd =  1, zd =  0, heading = 0 }  -- east
	}
	-- always move east when entering the next diameter
	if index == 0 then
		dirs[4].x = x + 16
		dirs[4].z = z
		return dirs[4]
	end
	local dir = dirs[math.floor(index / (diameter - 1)) + 1]
	dir.x = x + dir.xd * 16
	dir.z = z + dir.zd * 16
	return dir
end

local function getBoreLocations(x, z)

	local locations = {}

	while true do
		local a = math.abs(z)
		local b = math.abs(x)

		if x > 0 and z > 0 or
			 x < 0 and z < 0 then
			 -- rotate coords
			 a = math.abs(x)
			 b = math.abs(z)
		end
		if (a % 5 == 0 and b % 5 == 0) or
			 (a % 5 == 2 and b % 5 == 1) or
			 (a % 5 == 4 and b % 5 == 2) or
			 (a % 5 == 1 and b % 5 == 3) or
			 (a % 5 == 3 and b % 5 == 4) then
			 table.insert(locations, { x = x, z = z, y = 0 })
		end
		if z % 2 == 0 then -- forward dir
			if (x + 1) % 16 == 0 then
				z = z + 1
			else
				x = x + 1
			end
		else
			if (x - 1) % 16 == 15 then
				if (z + 1) % 16 == 0 then
					break
				end
				z = z + 1
			else
				x = x - 1
			end
		end
	end
	return locations
end

-- get the bore location closest to the miner
local function getClosestLocation(points)
	local key = 1
	local leastMoves = 9000
	for k,pt in pairs(points) do

		local moves = Point.calculateMoves(turtle.point, pt)

		if moves < leastMoves then
			key = k
			leastMoves = moves
			if leastMoves == 0 then
				break
			end
		end
	end
	return table.remove(points, key)
end

local function getCornerOf(c)
	return math.floor(c.x / 16) * 16, math.floor(c.z / 16) * 16
end

local function nextChunk()

	local x, z = getCornerOf({ x = mining.x, z = mining.z })
	local points = math.pow(mining.diameter, 2) - math.pow(mining.diameter-2, 2)
	mining.chunkIndex = mining.chunkIndex + 1

	if mining.chunkIndex >= points then
		mining.diameter = mining.diameter + 2
		mining.chunkIndex = 0
	end

	if mining.chunks ~= -1 then
		local chunks = math.pow(mining.diameter-2, 2) + mining.chunkIndex
		if chunks >= mining.chunks then
			return false
		end
	end

	local nc = getChunkCoordinates(mining.diameter, mining.chunkIndex, x, z)
	mining.locations = getBoreLocations(nc.x, nc.z)

	-- enter next chunk
	mining.x = nc.x
	mining.z = nc.z

	Util.writeTable(PROGRESS_FILE, mining)

	return true
end

local function addTrash()
	if not trash then
		trash = {
			[ 'minecraft:cobblestone:0' ] = true
		}
	end

	local slots = turtle.getFilledSlots()

	for _,slot in pairs(slots) do
		trash[slot.key] = true
	end

	trash['minecraft:bucket:0'] = nil
	Util.writeTable(TRASH_FILE, trash)
end

local function log(text)
	print(text)
end

local function status(newStatus)
	turtle.setStatus(newStatus)
	log(newStatus)
end

local function refuel()
	if turtle.getFuelLevel() < MIN_FUEL then
		local oldStatus = turtle.getStatus()
		status('refueling')

		if turtle.select('minecraft:coal:0') then
			local qty = turtle.getItemCount()
			print('refueling ' .. qty)
			turtle.refuel(qty)
		end
		if turtle.getFuelLevel() < MIN_FUEL then
			log('desperate fueling')

			turtle.eachFilledSlot(function(slot)
				if turtle.getFuelLevel() < MIN_FUEL then
					turtle.select(slot.index)
					turtle.refuel(64)
				end
			end)
		end
		log('Fuel: ' .. turtle.getFuelLevel())
		status(oldStatus)
	end

	turtle.select(1)
end

local function safeGoto(x, z, y, h)
	local oldStatus = turtle.getStatus()

	-- only pathfind above or around other turtles (never down)
	local box = Point.normalizeBox({ x = turtle.point.x, y = turtle.point.y, z = turtle.point.z,
								ex = x, ey = y, ez = z })
	box.x = box.x - 1
	box.z = box.z - 1
	box.ex = box.ex + 1
	box.ey = box.ey + 1
	box.ez = box.ez + 1

	Pathing.setBox(box)

	while not turtle.pathfind({ x = x, z = z, y = y or turtle.point.y, heading = h }) do
		--status('stuck')
		if turtle.isAborted() then
			return false
		end
		os.sleep(3)
	end
	turtle.setStatus(oldStatus)
	return true
end

local function safeGotoY(y)
	local oldStatus = turtle.getStatus()
	while not turtle.gotoY(y) do
		status('stuck')
		if turtle.isAborted() then
			return false
		end
		os.sleep(1)
	end
	turtle.setStatus(oldStatus)
	return true
end

local function makeWalkableTunnel(action, tpt, pt)
	if action ~= 'turn' and not Point.compare(tpt, { x = 0, z = 0 }) then -- not at source
		if not Point.compare(tpt, pt) then                                  -- not at dest
			local r, block = turtle.inspectUp()
			if r and not turtle.isTurtleAtSide('top') then
				if block.name ~= 'minecraft:cobblestone' and
					 block.name ~= 'minecraft:chest' then
					turtle.digUp()
				end
			end
		end
	end
end

--[[
local function enderChestUnload()
	log('unloading')
	turtle.select(1)
	if not Util.tryTimed(5, function()
			turtle.digDown()
			return turtle.placeDown()
		end) then
		log('placedown failed')
	else
		turtle.reconcileInventory(slots, turtle.dropDown)

		turtle.select(1)
		turtle.drop(64)
		turtle.digDown()
	end
end
]]

local function normalChestUnload()
	local oldStatus = turtle.getStatus()
	status('unloading')
	local pt = Util.shallowCopy(turtle.point)
	safeGotoY(0)

	turtle.setMoveCallback(function(action, tpt)
			makeWalkableTunnel(action, tpt, { x = pt.x, z = pt.z })
		end)

	safeGoto(0, 0, 0)
	if not turtle.detectUp() then
		error('Chest above starting point not found')
	end
	local slots = turtle.getFilledSlots()
	for _,slot in pairs(slots) do
		if not trash[slot.key] and
			slot.key ~= 'minecraft:bucket:0' and
			slot.name ~= 'minecraft:diamond_pickaxe' and
			slot.name ~= 'cctweaks:toolHost' then
			if slot.name ~= options.fortunePick.value then
				turtle.select(slot.index)
				turtle.dropUp(64)
			end
		end
	end
	turtle.condense()
	turtle.select(1)
	safeGoto(pt.x, pt.z, 0, pt.heading)

	turtle.clearMoveCallback()

	safeGotoY(pt.y)
	status(oldStatus)
end

local function ejectTrash()
	local cobbleSlotCount = 0

	turtle.eachFilledSlot(function(slot)
		if slot.key == 'minecraft:cobblestone:0' then
			if cobbleSlotCount == 0 and slot.count > 36 then
				turtle.select(slot.index)
				turtle.dropDown(slot.count - 36)
			end
			cobbleSlotCount = cobbleSlotCount + 1
		end

		if trash[slot.key] then
			-- retain 1 slot with cobble in order to indicate active mining
			if slot.key ~= 'minecraft:cobblestone:0' or cobbleSlotCount > 1 then
				turtle.select(slot.index)
				turtle.dropDown(64)
			end
		end
	end)
end

local function checkSpace()
	if turtle.getItemCount(16) > 0 then
		refuel()
		local oldStatus = turtle.getStatus()
		status('condensing')
		ejectTrash()
		turtle.condense()
		local lastSlot = 16
		if boreDirection == 'down' then
			lastSlot = 15
		end
		if turtle.getItemCount(lastSlot) > 0 then
			unload()
		end
		status(oldStatus)
		turtle.select(1)
	end
end

local function collectDrops(suckAction)
	for _ = 1, 50 do
		if not suckAction() then
			break
		end
		checkSpace()
	end
end

local function mineable(action)
	local r, block = action.inspect()
	if not r then
		return false
	end

	if block.name == 'minecraft:chest' then
		collectDrops(action.suck)
	end

	if turtle.getFuelLevel() < (MAX_FUEL - 1000) then
		if block.name == 'minecraft:lava' or block.name == 'minecraft:flowing_lava' then
			if turtle.select('minecraft:bucket:0') then
				if action.place() then
					log('Lava! ' .. turtle.getFuelLevel())
					turtle.refuel()
					log(turtle.getFuelLevel())
				end
				turtle.select(1)
			end
			return false
		end
	end

	if action.side == 'bottom' then
		return block.name
	end

	if trash[block.name .. ':0'] then
		return false
	end

	return block.name
end

local function fortuneDig(action, blockName)
	if options.fortunePick.value and fortuneBlocks[blockName] then
		turtle.select('cctweaks:toolHost')
		turtle.equipRight()
		turtle.select(options.fortunePick.value)
		repeat until not action.dig()
		turtle.select('minecraft:diamond_pickaxe')
		turtle.equipRight()
		turtle.select(1)
		return true
	end
end

local function mine(action)
	local blockName = mineable(action)
	if blockName then
		checkSpace()
		--collectDrops(action.suck)
		if not fortuneDig(action, blockName) then
			action.dig()
		end
	end
end

local function bore()

	local loc = turtle.point
	local level = loc.y

	turtle.select(1)
	status('boring down')
	boreDirection = 'down'

	while true do
		if turtle.isAborted() then
			status('aborting')
			return false
		end
		if loc.y <= -mining.depth then
			break
		end

		mine(turtle.getAction('down'))
		if not Util.tryTimed(3, turtle.down) then
			break
		end

		if loc.y < level - 1 then
			mine(turtle.getAction('forward'))
			turtle.turnRight()
			mine(turtle.getAction('forward'))
		end
	end

	boreDirection = 'up'
	status('boring up')

	turtle.turnRight()
	mine(turtle.getAction('forward'))

	turtle.turnRight()
	mine(turtle.getAction('forward'))

	turtle.turnLeft()

	while true do
		if turtle.isAborted() then
			status('aborting')
			return false
		end

		while not Util.tryTimed(3, turtle.up) do
			status('stuck')
		end
		if turtle.getStatus() == 'stuck' then
			status('boring up')
		end

		if loc.y >= level - 1 then
			break
		end

		mine(turtle.getAction('forward'))
		turtle.turnLeft()
		mine(turtle.getAction('forward'))
	end

	if turtle.getFuelLevel() < LOW_FUEL then
		refuel()
		local veryMinFuel = Point.turtleDistance(turtle.point, { x = 0, y = 0, z = 0}) + 512
		if turtle.getFuelLevel() < veryMinFuel then
			log('Not enough fuel to continue')
			return false
		end
	end

	return true
end

function Point.compare(pta, ptb)
	if pta.x == ptb.x and pta.z == ptb.z then
		if pta.y and ptb.y then
			return pta.y == ptb.y
		end
		return true
	end
	return false
end

local function inspect(action, name)
	local r, block = action.inspect()
	if r and block.name == name then
		return true
	end
end

local function boreCommand()
	local pt = getClosestLocation(mining.locations)

	turtle.setMoveCallback(function(action, tpt)
			makeWalkableTunnel(action, tpt, pt)
		end)

	safeGotoY(0)
	safeGoto(pt.x, pt.z, 0)

	turtle.clearMoveCallback()

	-- location is either mined, currently being mined or is the
	-- dropoff point for a turtle
	if inspect(turtle.getAction('up'),   'minecraft:cobblestone') or
		 inspect(turtle.getAction('up'),   'minecraft:chest') or
		 inspect(turtle.getAction('down'), 'minecraft:cobblestone') then
		 return true
	end

	turtle.digUp()
	turtle.placeUp('minecraft:cobblestone:0')

	local success = bore()

	safeGotoY(0) -- may have aborted
	turtle.digUp()

	if success then
		turtle.placeDown('minecraft:cobblestone:0') -- cap with cobblestone to indicate this spot was mined out
	end

	return success
end

if not Util.getOptions(options, args) then
	return
end

-- TODO: this won't work - need to Util.merge file into mining
mining.depth = options.depth.value
mining.chunks = options.chunks.value

unload = normalChestUnload
--if options.enderChest.value then
--  unload = enderChestUnload
--end

mining.x = 0
mining.z = 0
mining.locations = getBoreLocations(0, 0)
trash = Util.readTable(TRASH_FILE)

if fs.exists(PROGRESS_FILE) then
	mining = Util.readTable(PROGRESS_FILE)
end

--[[
if options.resume.value then
	mining = Util.readTable(PROGRESS_FILE)
elseif fs.exists(PROGRESS_FILE) then
	print('Use -r to resume')
	print('Teminate or enter to continue')
	read()
end
]]

if not trash or options.setTrash.value then
	print('Place the blocks to ignore into the turtle')
	print('Example: stone, dirt, gravel')
	print('\nPress enter when ready')
	read()
	addTrash()
end

if not turtle.getSlot('minecraft:bucket:0') or
	 not turtle.getSlot('minecraft:cobblestone:0') then
	print('Add bucket and cobblestone, press enter when ready')
	read()
end

if options.fortunePick.value then
	local s = turtle.getSlot(options.fortunePick.value)
	if not s then
		error('fortunePick not found: ' .. options.fortunePick.value)
	end
	if not turtle.getSlot('cctweaks:toolHost:0') then
		error('CCTweaks tool host not found')
	end
	trash[s.key] = nil
	trash['minecraft:diamond_pickaxe:0'] = nil
	trash['cctweaks:toolHost:0'] = nil
end

local function main()
	repeat
		while #mining.locations > 0 do
			status('searching')
			if not boreCommand() then
				return
			end
			Util.writeTable(PROGRESS_FILE, mining)
		end
	until not nextChunk()
end

local s, m = turtle.run(function()
	turtle.reset()
	turtle.set({
		attackPolicy = 'attack',
		digPolicy = 'turtleSafe',
	})
	unload()
	status('mining')

	local s, m = pcall(main)
	if not s and m then
		_G.printError(m)
	end
	turtle.abort(false)
	safeGotoY(0)
	safeGoto(0, 0, 0, 0)
	unload()
	turtle.reset()
end)

if not s and m then
	error(m)
end