CC Tweaked: Constellation mining

-- 0 -> North
-- 1 -> East
-- 2 -> South
-- 3 -> West

-- start of digging tranche
local tx = -6276;
local ty = -10;
local tz = 1380;
local odir = 3;

-- parking info (unload area)
local unloadX, unloadY, unloadZ = -6276, -7, 1379;

-- current info
local tdir = 3;
local lbtIndex = 1;
local slbtIndex = 0; -- to not start the row over and over again.

function saveData()
    local file = fs.open("save.txt", "w")
    file.writeLine(lbtIndex)
    file.writeLine(slbtIndex)
    file.close()
end

function checkData()
    if fs.exists("save.txt") then
        local file = fs.open("save.txt", "r")
        lbtIndex = tonumber(file.readLine())
        slbtIndex = tonumber(file.readLine())
        file.close()
    end
    validateCurrentDirection()
end

function checkInventoryFull()
    local filled = false
    for slot = 1, 16 do
        if turtle.getItemSpace(slot) == 0 then
            filled = true
        elseif turtle.getItemCount(slot) == 0 then
            return false
        end
    end
    return filled
end

function getCurrentLocation()
    local x, y, z = gps.locate()
    return x, y, z
end

function turnToDirection(newDir)
    while tdir ~= newDir do
        local rightDir = getRight(tdir)
        local leftDir = getLeft(tdir)

        if rightDir == newDir then
            turtle.turnRight()
            tdir = rightDir
        elseif leftDir == newDir then
            turtle.turnLeft()
            tdir = leftDir
        else
            turtle.turnRight()
            tdir = rightDir
        end
    end
end

local function moveUp()
    while not turtle.up() do
        safeMiningUp()
    end
end

local function moveDown()
    while not turtle.down() do
        safeMiningDown()
    end
end

local function moveForward()
    while not turtle.forward() do
        safeMiningForward()
    end
end


function validateCurrentDirection()
    local initialX, initialY, initialZ = gps.locate()
    moveForward()

    local newX, newY, newZ = gps.locate()
    if newX > initialX then
        tdir = 1 -- East
    elseif newX < initialX then
        tdir = 3 -- West
    elseif newZ > initialZ then
        tdir = 2 -- South
    elseif newZ < initialZ then
        tdir = 0 -- North
    end
    turtle.back()
end

function gotoLocation(targetX, targetY, targetZ)
    local currentX, currentY, currentZ = getCurrentLocation()

    while currentY < targetY do
        moveUp()
        currentY = currentY + 1
    end
    while currentY > targetY do
        moveDown()
        currentY = currentY - 1
    end

    if targetX > currentX then
        turnToDirection(1) -- East
        while currentX < targetX do
            moveForward()
            currentX = currentX + 1
        end
    elseif targetX < currentX then
        turnToDirection(3) -- West
        while currentX > targetX do
            moveForward()
            currentX = currentX - 1
        end
    end

    if targetZ > currentZ then
        turnToDirection(2) -- South
        while currentZ < targetZ do
            moveForward()
            currentZ = currentZ + 1
        end
    elseif targetZ < currentZ then
        turnToDirection(0) -- North
        while currentZ > targetZ do
            moveForward()
            currentZ = currentZ - 1
        end
    end
end

function safeMiningDown()
    while turtle.detectDown() do
        local success, data = turtle.inspectDown()
        if success and data.name == "computercraft:turtle_advanced" then
            os.sleep(1)
        else
            turtle.digDown()
            return
        end
    end
end

function safeMiningUp()
    while turtle.detectUp() do
        local success, data = turtle.inspectUp()
        if success and data.name == "computercraft:turtle_advanced" then
            os.sleep(1)
        else
            turtle.digUp()
            return
        end
    end
end

function safeMiningForward()
    while turtle.detect() do
        local success, data = turtle.inspect()
        if success and data.name == "computercraft:turtle_advanced" then
            os.sleep(1)
        else
            turtle.dig()
            return
        end
    end
end

function digAndBack()
    local initialX, initialY, initialZ = gps.locate()

    while true do
        if turtle.detectDown() and not turtle.digDown() then
            break
        end
        moveDown()
    end

    local currentX, currentY, currentZ = gps.locate()
    while currentY < initialY do
        moveUp()
        currentY = currentY + 1
    end
end

function moveForwardRetry()
    while not turtle.forward() do
        if not turtle.detectUp() then
            turtle.up()
            os.sleep(2)
            while not turtle.down() do
                os.sleep(1)
            end
        else
            turtle.down()
            os.sleep(2)
            while not turtle.up() do
                os.sleep(1)
            end
        end

        os.sleep(1)
    end
end


function turnToSouth()
    while tdir ~= 2 do
        turtle.turnRight()
        tdir = (tdir + 1) % 4
    end
end

function parkAndEmpty()
    turnToSouth()
    moveForwardRetry()
    for slot = 1, 16 do
        turtle.select(slot)
        turtle.dropDown()
    end
    moveForwardRetry()
end

function trancheDigging(startX, startZ, forward, toDir)
    validateCurrentDirection()
    gotoLocation(startX, ty, startZ)
    turnToDirection(toDir)
    saveData()

    while slbtIndex > 0 do
        moveForward()
        slbtIndex = slbtIndex - 1
        forward = forward - 1
    end

    while forward > 1 do
        digAndBack()
        moveForward()
        forward = forward - 1

        slbtIndex = slbtIndex + 1
        saveData()

        if checkInventoryFull() then
            gotoLocation(unloadX, unloadY, unloadZ)
            parkAndEmpty()
            os.reboot()
            return
        end
    end
end

function getRight(currentDir)
    return (currentDir + 1) % 4
end

function getLeft(currentDir)
    return (currentDir + 3) % 4
end

function calculateLine(startX, startZ, initialDir, rightTurns)
    if initialDir == 0 then
        startX = startX - 1
    elseif initialDir == 2 then
        startX = startX + 1
    elseif initialDir == 1 then
        startZ = startZ - 1
    elseif initialDir == 3 then
        startZ = startZ + 1
    end

    local lx, lz = startX, startZ;
    local x, z = startX, startZ;
    local dir = initialDir;
    local distance = 2;

    for turn = 1, rightTurns do
        lx = x
        lz = z
        if dir == 0 then -- North
            z = z - distance
        elseif dir == 1 then -- East
            x = x + distance
        elseif dir == 2 then -- South
            z = z + distance
        elseif dir == 3 then -- West
            x = x - distance
        end

        dir = getRight(dir)

        distance = distance + 2
    end

    return lx, lz, x, z
end

function calculateDirection(x1, z1, x2, z2)
    if x2 > x1 then
        return 1 -- East
    elseif x2 < x1 then
        return 3 -- West
    elseif z2 > z1 then
        return 2 -- South
    elseif z2 < z1 then
        return 0 -- North
    else
        return nil
    end
end

function calculateDistance(x1, z1, x2, z2)
    local dx = x2 - x1
    local dz = z2 - z1
    return math.sqrt(dx * dx + dz * dz)
end

function main()
    checkData()
    term.clear()
    term.setCursorPos(1,1)
    term.write("turtle #" .. os.getComputerID())
    term.setCursorPos(1,2)
    term.write("fuel: " .. turtle.getFuelLevel())

    while true do
        if turtle.getFuelLevel() < 2000 then
            gotoLocation(unloadX, unloadY, unloadZ)
            turtle.up()
            turtle.up()
            turtle.up()
            os.shutdown()
        end
        if checkInventoryFull() then
            gotoLocation(unloadX, unloadY, unloadZ)
            parkAndEmpty()
        end
        local startX, startZ, endX, endZ = calculateLine(tx, tz, odir, lbtIndex)
        trancheDigging(startX, startZ, calculateDistance(startX, startZ, endX, endZ), calculateDirection(startX, startZ, endX, endZ))
        slbtIndex = 0
        lbtIndex = lbtIndex + 1;
        saveData()
    end
end

-- 0 -> North
-- 1 -> East
-- 2 -> South
-- 3 -> West
main()