--Start networking
rednet.open('right')

local currentSlot = 1

--Start location of turtle is its coordinates
local myX = 0
local myY = 0
local myZ = 0

--Start look direction - forward
local spinningVector = { {0, 1}, {1, 0}, {0, -1}, {-1, 0} }
local currentSpinningVector = 1

--ID server computer
local serverId = 0

--Current mission
local myMission = {x1 = 0, y1 = 0, z1 = 0, x2 = 0, y2 = 0, z2 = 0}

--Height to fly
local flyingHeight = 90

--Stop mission or not
local stopMission = false

--Get arguments from message
local function parseArgs(message)
	local args = {}
	for arg in string.gmatch(message, '<(%S+)>') do
		table.insert(args, arg)
	end
	return args
end

-- Helper functions
local function alwaysTrue()
	return true
end
local function alwaysFalse()
	return false
end

--Turn turtle (left or right)
local function rotate(direction)

	if (direction == 'right') then
		turtle.turnRight()
		currentSpinningVector = currentSpinningVector + 1
	else
		turtle.turnLeft()
		currentSpinningVector = currentSpinningVector - 1
	end

	if (currentSpinningVector < 1) then
		currentSpinningVector = 4
	end

	if (currentSpinningVector > 4) then
		currentSpinningVector = 1
	end

end


--Face turtle north in local coordinates
local function faceNorth()
	while (currentSpinningVector ~= 1) do
		rotate('left')
	end
end

local function changePosition(direction)
	if (direction == 'down') then
		myZ = myZ - 1
	end

	if (direction == 'up') then
		myZ = myZ + 1
	end

	if (direction == 'forward') then

		vec = spinningVector[currentSpinningVector]
		myX = myX + vec[1]
		myY = myY + vec[2]

	end

	if (direction == 'back') then

		vec = spinningVector[currentSpinningVector]
		myX = myX - vec[1]
		myY = myY - vec[2]

	end
end

--Move turtle one step in any direction
--If isSoft, will return false on facing something
local function stepUp(direction, isSoft)

	--Detect and move functions
	local moveF = turtle.forward
	local detectF = turtle.detect
	local digF = turtle.dig

	if (direction == 'down') then
		moveF = turtle.down
		detectF = turtle.detectDown
		digF = turtle.digDown
	end
	if (direction == 'up') then
		moveF = turtle.up
		detectF = turtle.detectUp
		digF = turtle.digUp
	end
	if (direction == 'back') then
		moveF = turtle.back
		detectF = alwaysFalse
		digF = alwaysTrue
	end



	while (detectF()) do
			if (isSoft) then
				return false
			end
			if (not digF()) then
					print('Cant dig!')
					error()
			end
	end

	if (not moveF()) then

			if (turtle.getFuelLevel() <= 0) then
					print('Refueling...')
					turtle.select(1)
					if (not turtle.refuel(1)) then
						print('Out of fuel.')
						return false
					end
					turtle.select(currentSlot)
			end

			if (not moveF()) then
					print('Cant move on! Trying to move later...')

					for i=0, 40 do
							os.sleep(3)

							if (moveF()) then
									break
							end

							if (i >= 39) then
									print('No more attempts. Im stuck.')
									return false
							end
					end

			end
	end

	--Change position
	changePosition(direction)

	return true
end

local function myPos()
	write('X = ')
	write(myX)
	write('; Y = ')
	write(myY)
	write('; Z = ')
	print(myZ)
end

local function gpsLocate()
	local location = {0,0,0}
	myX, myY, myZ = gps.locate(5, false)
	if (myX == nil or myY == nil or myZ == nil) then
		print('Cant reach GPS')
		return false
	end

	return true
end


--Try to purge inventory
local function unload()
	print('Trying to unload')

	local chestFound = false

	--Function to drop items
	local dropF = turtle.drop

	--Find chest

	--Try in front
	for i=1, 4 do
		if (turtle.detect()) then
			chestFound = true
			break
		end
		rotate('left')
	end

	if (not chestFound) then
		--Try up
		if (turtle.detectUp()) then
			chestFound = true
			dropF = turtle.dropUp
		end
	end
	if (not chestFound) then
		--Try down
		if (turtle.detectDown()) then
			chestFound = true
			dropF = turtle.dropDown
		end
	end
	if (not chestFound) then
		print('No chest around')
		return false
	end

	local totalUnloaded = 0
	for i=2, 16 do
		local thisCount = turtle.getItemCount(i);
		if (thisCount > 0) then
			totalUnloaded = totalUnloaded + thisCount
			turtle.select(i)
			dropF()
		end
	end

	--Done.
	print('Unloaded ' .. totalUnloaded .. ' items.')

	return true
end




--Refuel
local function refuelFromChest()
	print('Trying to refuel')

	local chestFound = false

	--Function to drop items
	local suckF = turtle.suck
	local dropF = turtle.drop

	--Find chest

	--Try in front
	for i=1, 4 do
		if (turtle.detect()) then
			chestFound = true
			break
		end
		rotate('left')
	end

	if (not chestFound) then
		--Try up
		if (turtle.detectUp()) then
			chestFound = true
			suckF = turtle.suckUp
			dropF = turtle.dropUp
		end
	end
	if (not chestFound) then
		--Try down
		if (turtle.detectDown()) then
			chestFound = true
			suckF = turtle.suchDown
			dropF = turtle.dropDown
		end
	end
	if (not chestFound) then
		print('No chest around')
		return false
	end

	turtle.select(1)
	dropF()
	while ( (turtle.getItemSpace(1) > 4) and (suckF())) do
		write('.')
	end

	--Drop unnecessary
	if (turtle.getItemSpace(2)) then
		turtle.select(2)
		if (turtle.compareTo(1)) then
			dropF()
		end
	end


	--Done.
	print('Refueled.')

	return true
end





--Calibrate turtle coordinates
--Find exit
local function findWayOut()
	for i=0, 5 do
		if (not turtle.detect()) then
			return;
		end
		turtle.turnLeft()
	end
end

local function calibrate()
	findWayOut()

	--Crawl out of cage
	if (not stepUp('forward', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end

	--Zero position
	if (not gpsLocate()) then
		error()
	end

	local zeroX = myX
	local zeroY = myY
	local zeroZ = myZ

	if (not stepUp('forward', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end

	--Y+1 position
	gpsLocate()
	local yX = myX
	local yY = myY
	local yZ = myZ

	if (not stepUp('back', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end

	rotate('right')
	if (not stepUp('forward', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end

	--X+1 position
	gpsLocate()
	local xX = myX
	local xY = myY
	local xZ = myZ

	rotate('left')
	rotate('left')
	if (not stepUp('forward', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end
	rotate('right')

	if (not stepUp('back', true)) then
		print('Error while calibrating. Cant be miner.')
		error()
	end

	--Calculate vectors now

	--Vector forward and back
	local fV = {0, 0}
	if (yX - zeroX > 0) then
		fV[1] = 1
	end
	if (yX - zeroX < 0) then
		fV[1] = -1
	end
	if (yY - zeroY > 0) then
		fV[2] = 1
	end
	if (yY - zeroY < 0) then
		fV[2] = -1
	end

	spinningVector[1][1] = fV[1]
	spinningVector[1][2] = fV[2]

	spinningVector[3][1] = 0-fV[1]
	spinningVector[3][2] = 0-fV[2]

	--Vector right and left
	local rV = {0, 0}
	if (xX - zeroX > 0) then
		rV[1] = 1
	end
	if (xX - zeroX < 0) then
		rV[1] = -1
	end
	if (xY - zeroY > 0) then
		rV[2] = 1
	end
	if (xY - zeroY < 0) then
		rV[2] = -1
	end

	spinningVector[2][1] = rV[1]
	spinningVector[2][2] = rV[2]

	spinningVector[4][1] = 0-rV[1]
	spinningVector[4][2] = 0-rV[2]


	--Debug
	--print('zero: ' .. zeroX .. ', ' .. zeroY .. ', ' .. zeroZ)
	--print('y+  : ' .. yX .. ', ' .. yY .. ', ' .. yZ)
	--print('x+  : ' .. xX .. ', ' .. xY .. ', ' .. xZ)
	--print('z+  : ' .. zX .. ', ' .. zY .. ', ' .. zZ)
	--for i=1, 4 do
	--	write(spinningVector[i][1])
	--	print(', ' .. spinningVector[i][2])
	--	print('')
	--end
	--error()

	--Final position
	gpsLocate()
end

-- Send message via rednet
local function sendMessage(id, message)
	rednet.send(id, message)
end

--Rotate 180 degrees
local function rotate180()
	rotate('right')
	rotate('right')
end

-- Introduce turtle in network
local function introduce()
	local message = 'turtle <hello> <' .. myX .. '> <' .. myY .. '> <' .. myZ .. '>'

	write('Introducing myself: ')
	print(message)

	rednet.broadcast(message)
end

local function turnToVector(x, y)
	--Find right vector
	local targetId = 0
	for targetId,vector in pairs(spinningVector) do
		if (vector[1] == x and vector[2] == y) then
			break
		end
	end

	local dir = 'right'
	if ( (currentSpinningVector - targetId) % 4 == 1) then
		dir = 'left'
	end

	while (spinningVector[currentSpinningVector][1] ~= x or
			spinningVector[currentSpinningVector][2] ~= y) do
		rotate(dir)
	end
end

--Try to make step in any direction
local function vectorStep(x, y, z, isSoft)


	if (x == 0 and y == 0 and z == 0) then
		return true
	end

	local stepAmount = -1
	local vector = {0, 0}

	--Try to move along Y
	if (y ~= 0) then
		vector = {0, -1}
		if (y < 0) then
			vector = {0, 1}
			stepAmount = 1
		end
		turnToVector(vector[1], vector[2])

		if (stepUp('forward', isSoft)) then
			y = y + stepAmount
			return x,y,z
		end
	end

	--Try to move along X
	if (x ~= 0) then
		stepAmount = -1
		vector = {-1, 0}
		if (x < 0) then
			vector = {1, 0}
			stepAmount = 1
		end
		turnToVector(vector[1], vector[2])

		if (stepUp('forward', isSoft)) then
			x = x + stepAmount
			return x,y,z
		end
	end

	--Try to move along Z
	if (z ~= 0) then
		stepAmount = -1
		local zDir = 'down'
		if (z < 0) then
			zDir = 'up'
			stepAmount = 1
		end

		if (stepUp(zDir, isSoft)) then
			z = z + stepAmount
			return x,y,z
		end
	end

	--Too bad, nothig help.
	return x,y,z
end

--Try to reach point without destroying anything
local function moveTo(x, y, z)
	--Calculate distance
	local dX = myX - x
	local dY = myY - y
	local dZ = myZ - z

	local newX
	local newY
	local newZ

	while (dX ~= 0 or dY ~= 0 or dZ ~= 0) do
		newX,newY,newZ = vectorStep(dX, dY, dZ, true)

		if (newX == dX and newY == dY and newZ == dZ) then
			newX,newY,newZ = vectorStep(dX, dY, dZ, false)
		end
		if (newX == dX and newY == dY and newZ == dZ) then
			return false
		end

		dX = newX
		dY = newY
		dZ = newZ
	end

	--Arrived!

	--Face north
	--faceNorth()

	print('Moved to finish. My position: ')
	myPos()

	return true
end

-- Dir through to point
local function digTo(x, y, z)

	--Calculate distance
	local dX = x - myX
	local dY = y - myY
	local dZ = z - myZ


	local vector = {0, 0}

	--Move along Y
	if (dY ~= 0) then
		vector = {0, 1}
		if (dY < 0) then
			vector = {0, -1}
			dY = math.abs(dY)
		end
		turnToVector(vector[1], vector[2])

		for i=1, dY do
			if (not stepUp('forward', false)) then
				return false
			end
		end
	end

	--Move along X
	if (dX ~= 0) then
		vector = {1, 0}
		if (dX < 0) then
			dX = math.abs(dX)
			vector = {-1, 0}
		end
		turnToVector(vector[1], vector[2])

		for i=1, dX do
			if (not stepUp('forward', false)) then
				return false
			end
		end
	end

	--Move along Z
	if (dZ ~= 0) then
		local zDir = 'up'
		if (dZ < 0) then
			dZ = math.abs(dZ)
			zDir = 'down'
		end


		for i=1, dZ do
			if (not stepUp(zDir, false)) then
				return false
			end
		end
	end

	--Arrived!

	--Face north
	--faceNorth()

	--print('Digged to finish. My position: ')
	--myPos()

	return true
end


--Get turtles global fuel level
function fuelLevel()
	return turtle.getItemCount(1)
end


--Get on flying height to move long distances
local function toFlyingHeight()
	print('Getting on flying height ' .. flyingHeight)
	if (not moveTo(myX, myY, flyingHeight)) then
		print('Cant get on flying height!')
		error()
	end
end

local function outputMission()
	print('From: ' .. myMission.x1 .. ', ' .. myMission.y1 .. ', ' .. myMission.z1)
	print('To: ' .. myMission.x2 .. ', ' .. myMission.y2 .. ', ' .. myMission.z2)
	print('Home: ' .. myMission.homeX .. ', ' .. myMission.homeY .. ', ' .. myMission.homeZ)
	print('Start fuel: ' .. myMission.totalFuel)
end

--Return home
local function goHome()
	stopMission = false

	print('Going home: ' .. myMission.homeX .. ', ' .. myMission.homeY .. ', ' .. myMission.homeZ)

	--Get no flying height
	toFlyingHeight()

	--Move to landing point
	if (not moveTo(myMission.homeX, myMission.homeY, flyingHeight)) then
		print('Cant reach home landing point!')
		error()
	end

	print('Landing...')
	--Land
	if (not moveTo(myMission.homeX, myMission.homeY, myMission.homeZ)) then
		print('Cant land!')
		error()
	end

	print('Asking home')
	--We are home, ask get in
	sendMessage(serverId, 'turtle <wanthome>')

	return true
end


--Do our mission.
local function doMission()

	print('Doing mission!')
	outputMission()

	--Get on flying height
	toFlyingHeight()


	--Calculate start and end point
	local sX = myMission.x1
	local sY = myMission.y1
	local sZ = myMission.z1

	local eX = myMission.x2
	local eY = myMission.y2
	local eZ = myMission.z2

	if (sZ < eZ) then
		local t
		t = eZ
		eZ = sZ
		sZ = t
	end
	if (sX > eX) then
		local t
		t = eX
		eX = sX
		sX = t
	end
	if (sY > eY) then
		local t
		t = eY
		eY = sY
		sY = t
	end

	--Go to start point
	print('Going to start point of mining: ' .. sX .. ', ' .. sY .. ', ' .. sZ)
	if (not moveTo(sX, sY, sZ)) then
		print('Cant reach start point!')
		error()
	end

	--We are on start position.

	local totalLevels = math.abs(eZ - sZ)-1
	outputMission()
	print('Total levels: ' .. totalLevels)

	for iZ=0, totalLevels do
		if (stopMission) then
			break
		end

		z = sZ - iZ
		print('Z-level: ' .. iZ .. ' / ' .. totalLevels )

		if (not digTo(myX, myY, z)) then
			print('Cant reach start point of Z-level!')
			error()
		end


		local reverse = false
		if (myX == eX) then
			reverse = true
		end

		for x = sX, eX do
			if (stopMission) then
				break
			end

			if (reverse) then
				x = eX - (x-sX)
			end


			--Dig along Y
			if (not digTo(x, myY, myZ)) then
				print('Cant reach start point of row!')
				error()
			end
			--On start pos

			local toY = eY
			if (myY == eY) then
				toY = sY
			end

			--Dig
			if (not digTo(myX, toY, myZ)) then
				print('Cant dig row!')
				error()
			end

		end
	end





	--Mission is over, go home
	goHome()
end

print('Calibrating...')
calibrate()
write('I am on position: ')
myPos()
introduce()

term.clear()
print('Awaiting orders. Press Q to terminate client.')

while true do

	--Recieve event
	local event, id, message = os.pullEvent()

	--Rednet signal
	if (event == "rednet_message") then

		--print(message)

		--Command from server
		local pos = string.find(message, "command")

		if ((pos ~= nil) and (pos == 1)) then
			local args = parseArgs(message)

			command = args[1]

			--Asked for states
			if (command == 'states') then

				--The one who asked for states is server
				serverId = id

				--Fuel
				local fuel = fuelLevel()

				--Loaded slots
				local loadedSlots = 0
				for i=2, 16 do
					if (turtle.getItemCount(i) > 0) then
						loadedSlots = loadedSlots + 1
					end
				end

				--Send back message
				local states = "turtle <states> <" .. tostring(fuel) .. '> <' .. tostring(loadedSlots) .. '>'

				print('Sending ' .. states .. ' to ' .. tostring(id))

				sendMessage(id, states)
			end

			--Move to
			if (command == 'move') then
				local toX = tonumber(args[2])
				local toY = tonumber(args[3])
				local toZ = tonumber(args[4])
				local response = args[5]

				myPos()
				print('Moving to ' .. toX .. ', ' .. toY .. ', ' .. toZ)

				moveTo(toX, toY, toZ)

				--Send back report
				if (response ~= nil) then
					sendMessage(id, 'turtle <' .. response .. '> <' .. myX .. '> <' .. myY .. '> <' .. myZ .. '>')
				end
			end

			--Reintroduce
			if (command == 'reintroduce') then
				introduce()
				serverId = id
				print('Reintroduced.')
			end

			--Get mission
			if (command == 'mission') then
				myMission.x1 = tonumber(args[2])
				myMission.y1 = tonumber(args[3])
				myMission.z1 = tonumber(args[4])
				myMission.x2 = tonumber(args[5])
				myMission.y2 = tonumber(args[6])
				myMission.z2 = tonumber(args[7])
				local response = args[8]

				write('Got new mission: ')
				write(myMission.x1)
				write(', ')
				write(myMission.y1)
				write(', ')
				write(myMission.z1)
				write(' - ')
				write(myMission.x2)
				write(', ')
				write(myMission.y2)
				write(', ')
				write(myMission.z2)
				--error()

				--Send back report
				if (response ~= nil) then
					sendMessage(id, 'turtle <' .. response .. '>')
				end
			end

			--We are telled to do out mission by ourselves.
			if (command == 'domission') then

				--Init mission

				--Current position is our home.
				myMission.homeX = args[2]
				myMission.homeY = args[3]
				myMission.homeZ = args[4]

				--Start fuel level
				myMission.totalFuel = fuelLevel()


				--Do mission.
				doMission()
			end

			--Unload
			if (command == 'unload') then
				unload()
				local response = args[2]
				--Send back report
				if (response ~= nil) then
					sendMessage(id, 'turtle <' .. response .. '>')
				end
			end

			--Refuel
			if (command == 'refuel') then
				refuelFromChest()
				local response = args[2]
				--Send back report
				if (response ~= nil) then
					sendMessage(id, 'turtle <' .. response .. '>')
				end
			end
		end
	end


	--Exit
	if (event == "char" and id == "q") then
		break
	end


end

sendMessage(serverId, 'turtle <quit>')
print('Miner stopped.')