local IgnoreSlots = 2
local fuelIndex = 2

local TunnelLength = 120

-- Set this to false if you don't have a working GPS system
local UseGPS = false
--ALL THIS MUST BE FILLED IN IF YOU DON"T USE GPS
local StartX = 697
local StartY = 125
local StartZ = 1396
-- EX: "SOUTH", "NORTH", "EAST", "WEST"
local ForwardFacingDirection = "WEST"
--END NO GPS FILL INFORMATION



--DO NOT TOUCH ANYTHING BELOW THIS LINE
local mov = {}
local rot = {}
local dig = {}
local PositionInBranchMine = 0
local RotatePosition = "FORWARD"

local InsertedIntoLeftWall = false
local InsertedIntoRightWall = false
local InsertionAmount = 0

local XX = StartX
local YY = StartY
local ZZ = StartZ
local PrimaryAxis = ""
local SecondaryAxis = ""

local function Refuel()
        currentFuelRequired = (10 + (TunnelLength-PositionInBranchMine)*2)/40
        if turtle.getFuelLevel() < currentFuelRequired then
                turtle.select(fuelIndex)
                return turtle.refuel(currentFuelRequired)
        else
                return true
        end
end


local function readLines(sPath)
  local file = fs.open(sPath, "r") -- open the file
  if file then -- check if it's open
    local tLines = {} -- table to store the lines
    local sLine = file.readLine() -- read a line from the file
    while sLine do -- while there's a line in the file
          table.insert(tLines, sLine) -- add it to the table
          sLine = file.readLine() -- get the next line
    end
    file.close() -- close the file
    return tLines -- return the table with the lines
  end
  return nil -- there was an error opening the file, return nil to let the user know
end

local function writeLines(sPath, tLines)
  local file = fs.open(sPath, "w") -- open the file
  if file then -- check if the file is open
    for _, sLine in ipairs(tLines) do -- for each line in the table
          file.writeLine(sLine) -- write the line
    end
    file.close() -- close the file
  end
end

function filereadline(filename, line)
  local tLines = readLines(filename) -- read the lines from the file (using the previous functions)
  if not tLines then -- if there was an error
    return nil -- return nil/error
  end
  return tLines[line] -- return the line
end

function filewriteline(filename, line, text)
  local tLines = readLines(filename) -- read the lines from the file (using the previous functions)
  if tLines then -- if there was no error
    tLines[line] = text -- set the line
    writeLines(filename, tLines) -- write the lines back to the file (using the previous functions)
  end
end

local function incrementCoordinates(incX,incY,incZ)
XX = XX + incX
YY = YY + incY
ZZ = ZZ + incZ
filewriteline("BranchMineData", 7, XX)
filewriteline("BranchMineData", 8, YY)
filewriteline("BranchMineData", 9, ZZ)
end

--directionInteger 0 = forward, 1 = left, 2 = backward, 3 = right, 4 = up, 5 = down
local function updateCoordinates(directionInteger)
        --Displace the direction by the current Rotation
        if directionInteger <= 3 then
                if directionInteger == 0 then
                        if string.match(RotatePosition,"LEFT") then
                                directionInteger = 1
                        elseif string.match(RotatePosition,"BACKWARD") then
                                directionInteger = 2
                        elseif string.match(RotatePosition,"RIGHT") then
                                directionInteger = 3
                        end
                elseif directionInteger == 2 then
                        if string.match(RotatePosition,"LEFT") then
                                directionInteger = 3
                        elseif string.match(RotatePosition,"BACKWARD") then
                                directionInteger = 0
                        elseif string.match(RotatePosition,"RIGHT") then
                                directionInteger = 1
                        end
                end
        end

        local incrementPrimary = true
        local incrementBy = 0
        local incrementX = 0
        local incrementY = 0
        local incrementZ = 0
        --if we are moving forward
        if directionInteger == 0 then
                incrementPrimary = true
                incrementBy = 1
        --if we are moving left
        elseif directionInteger == 1 then
                incrementPrimary = false
                incrementBy = 1
        --if we are moving backward
        elseif directionInteger == 2 then
                incrementPrimary = true
                incrementBy = -1
        --if we are moving right
        elseif directionInteger == 3 then
                incrementPrimary =false
                incrementBy = -1
        elseif directionInteger == 4 then
                incrementY = 1
        elseif directionInteger == 5 then
                incrementY = -1
        end

        if incrementPrimary then
                if PrimaryAxis == "X" then
                        incrementX = incrementBy
                elseif PrimaryAxis == "-X" then
                        incrementX = -1 * incrementBy
                elseif PrimaryAxis == "Z" then
                        incrementZ = incrementBy
                elseif PrimaryAxis == "-Z" then
                        incrementZ = -1 * incrementBy
                end
        else
                if SecondaryAxis == "X" then
                        incrementX = incrementBy
                elseif SecondaryAxis == "-X" then
                        incrementX = -1 * incrementBy
                elseif SecondaryAxis == "Z" then
                        incrementZ = incrementBy
                elseif SecondaryAxis == "-Z" then
                        incrementZ = -1 * incrementBy
                end
        end
        incrementCoordinates(incrementX,incrementY,incrementZ)
end

mov.forward = function(times)
        local boolean v = false
        for i=1,times do
                if turtle.detect() == false then
                        while not turtle.forward() do
                                Refuel()
                                sleep(1)
                        end
                        updateCoordinates(0)
                        v = true
                else
                        v = false
                        return v
                end
        end
        return v
end

mov.back = function(times)
        local boolean v = false
        for i=1,times do
                while not turtle.back() do
                        Refuel()
                        sleep(1)
                end
                updateCoordinates(2)
                v = true
        end
        return v
end

mov.up = function(times)
        local boolean v = false
        for i=1,times do
                if turtle.detectUp() == false then
                        while not turtle.up() do
                                Refuel()
                                sleep(1)
                        end
                        YY = YY + 1
                        v = true
                else
                        v = false
                        return v
                end
        end
        return v
end

mov.down = function(times)
        local boolean v = false
        for i=1,times do
                if turtle.detectDown() == false then
                        while not turtle.down() do
                                Refuel()
                                sleep(1)
                        end
                        YY = YY - 1
                        v = true
                else
                        v = false
                        return v
                end
        end
        return v
end

mov.place = function()
    while not turtle.place() do
          sleep(1)
    end
    return true
end

rot.right = function()
    while not turtle.turnRight() do
            sleep(1)
    end

        if RotatePosition == "FORWARD" then
                RotatePosition = "RIGHT"
        elseif RotatePosition == "RIGHT" then
                RotatePosition = "BACKWARD"
        elseif RotatePosition == "BACKWARD" then
                RotatePosition = "LEFT"
        elseif RotatePosition == "LEFT" then
                RotatePosition = "FORWARD"
        end
        filewriteline("BranchMineData", 5, RotatePosition)
    return true
end

rot.left = function()
    while not turtle.turnLeft() do
            sleep(1)
    end

        if RotatePosition == "FORWARD" then
                RotatePosition = "LEFT"
        elseif RotatePosition == "LEFT" then
                RotatePosition = "BACKWARD"
        elseif RotatePosition == "BACKWARD" then
                RotatePosition = "RIGHT"
        elseif RotatePosition == "RIGHT" then
                RotatePosition = "FORWARD"
        end
        filewriteline("BranchMineData", 5, RotatePosition)
    return true
end


-- RotateTo is a number where 0 = Forward, 1 = Left, 2 = Backward, and 3 = Right
local function look(RotateTo)
        --This rids one odd occurance
        if RotatePosition == "RIGHT" and RotateTo == 0 then
                rot.left()
                return
        end
        --

        rotateNumber = 0
        if RotatePosition == "LEFT" then
                rotateNumber = 1
        elseif RotatePosition == "BACKWARD" then
                rotateNumber = 2
        elseif RotatePosition == "RIGHT" then
                rotateNumber = 3
        end

        rotateRight = rotateNumber - RotateTo
        if rotateRight >= 0 then
                        for i = 1,rotateRight do
                                rot.right()
                        end
        else
                        for i = 1,math.abs(rotateRight) do
                                rot.left()
                        end
        end

end

dig.forward = function()
        if turtle.detect() then
                while not turtle.dig() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine forward")
                return false
        end
end

dig.up = function()
        if turtle.detectUp() then
                while not turtle.digUp() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine up")
                return false
        end
end

dig.down = function()
        if turtle.detectDown() then
                while not turtle.digDown() do
                                sleep(1)
                end
                return true
        else
                print("No Block to mine down")
                return false
        end
end

local function DigMoveForward()
        if mov.forward(1) == false then
                dig.forward()
                sleep(0.5)
                DigMoveForward()
        end
end

local function DigMoveUp()
        if mov.up(1) == false then
                dig.up()
                sleep(0.5)
                DigMoveUp()
        end
end

local function DigMoveDown()
        if mov.down(1) == false then
                dig.down()
                sleep(0.5)
                DigMoveDown()
        end
end

local function DepositChest()
    turtle.select(1)
    if not turtle.compareUp() then
        print("ERROR: Should be below chest.")
        return
    end

    print("Depositing the Load...")
    for i = IgnoreSlots + 1,16 do
            turtle.select(i)
            turtle.dropUp()
    end
end

local function ReturnBack()
    print("ReturnBack")
    turtle.select(1)
    while not turtle.compareUp() do
        DigMoveUp()
    end
end

local function Finish()
    print("Finishing!")
    ReturnBack()
    DepositChest()
    DigMoveForward()
    DigMoveForward()
    DigMoveForward()
    DigMoveForward()
    print("Finished!")
end

local function InventoryFull()
    SlotsFull = 0
    for i=1,16 do
            if turtle.getItemCount(i) > 0 then
                    SlotsFull = SlotsFull + 1
            end
    end

    if SlotsFull == 16 then
            return true;
    else
            return false;
    end
end

function StartMining()

    BlocksTillEnd = TunnelLength - PositionInBranchMine

    while BlocksTillEnd > 0 do
        if Refuel() == false then
                print("***Out of fuel***")
                ReturnBack()
                while Refuel() do

                end
                for i=1,PositionInBranchMine do
                    DigMoveDown()
                end
        end

        if InventoryFull() then
                print("***Inventory Full***")
                ReturnBack()
                DepositChest()
                for i=1,PositionInBranchMine do
                    DigMoveDown()
                end
        end

        dig.forward()

        for i=1,4 do
            DigMoveDown()
            PositionInBranchMine = PositionInBranchMine + 1
            BlocksTillEnd = TunnelLength - PositionInBranchMine
        end

        print("Depth: ")
        print(PositionInBranchMine)
    end
    Finish()
end

local FuelCount = turtle.getItemCount(fuelIndex)

if FuelCount == 0 then
        print("please put fuel in the last slot of the Turtle.")
        return
else
        if FuelCount < 10 then
                print("Please put at least 10 of the fuel you are using in the Turtle.")
                return
        end
end

Refuel()
turtle.select(1)
turtle.placeUp()
StartMining()