args = { ... }

torchSlot = 1
torchSpacing = 5
hitBedrock = false

-- define some relative coordinates
home = {0,0,0}  -- define home position
face = 1        -- define home direction
pos = {0,0,0}
backPos = {0,0,0}
if #args == 6 then  -- if specified, set quarry position
    quarryPos ={tonumber(args[4]), tonumber(args[5]), tonumber(args[6])}
end
movement = {{1,0,0},{0,0,1},{-1,0,0},{0,0,-1}}

-- movement functions

function quarryRight()
    turtle.turnRight()
    face = face + 1
    if face > 4 then
        face = 1
    end
end

function quarryLeft()
    turtle.turnLeft()
    face = face - 1
    if face < 1 then
        face = 4
    end
end

function digMove()
    if type(turtle.getFuelLevel()) == "number" then
        if turtle.getFuelLevel() < 10 then
            turtle.select(16)
            turtle.refuel(1)
        end
    end
    if digging then
        if turtle.getItemCount(16) > 0 then
            digging = false
            oldX = pos[1]
            oldY = pos[2]
            oldZ = pos[3]
            oldFace = face
            dropInv()
            goBack(oldX, oldY, oldZ, oldFace)
            print("we should be back now")
            digging = true
        end
    end
    moved = turtle.forward()
    while not moved do
        if not turtle.dig() then
            if not turtle.attack() then
                hitBedrock = true
                print("hit Bedrock, bailing out")
                dropInv()
            end
        end
        moved = turtle.forward()
    end
    if moved then
        pos[1] = pos[1] + movement[face][1]
        pos[2] = pos[2] + movement[face][2]
        pos[3] = pos[3] + movement[face][3]
    end
    print(pos[1].." "..pos[2].." "..pos[3].." "..face)
end

function digMoveDown()
    if type(turtle.getFuelLevel()) == "number" then
        if turtle.getFuelLevel() < 10 then
            turtle.select(16)
            turtle.refuel(1)
        end
    end
    moved = turtle.down()
    while not moved do
        if not turtle.digDown() then
            if not turtle.attackDown() then
                hitBedrock = true
                print("hit Bedrock, bailing out")
                dropInv()
            end
        end
        moved = turtle.down()
    end
    if moved then
        pos[2] = pos[2] - 1
    end
    print(pos[1].." "..pos[2].." "..pos[3].." "..face)
end

function digMoveUp()
    if type(turtle.getFuelLevel()) == "number" then
        if turtle.getFuelLevel() < 10 then
            turtle.select(16)
            turtle.refuel(1)
        end
    end
    moved = turtle.up()
    while not moved do
        if not turtle.digUp() then
            if not turtle.attackUp() then
                hitBedrock = true
            end
        end
        moved = turtle.up()
    end
    if moved then
        pos[2] = pos[2] + 1
    end
    print(pos[1].." "..pos[2].." "..pos[3].." "..face)
end

-- meta movement functions (gohome, goback)

function dropInv()
    print("iventory is getting full, gotta drop some stuff off")
    while pos[2] < 0 do
        digMoveUp()
    end
    if pos[1] ~= home[1] then
        if pos[1] > home[1] then
            while not (face == 3) do
                quarryLeft()
            end
        elseif pos[1] < home[1] then
            while not (face == 1) do
                quarryLeft()
            end
        end
    end
    while pos[1] ~= home[1] do
        digMove()
    end
    if pos[3] ~= home[3] then
        if pos[3] > home[3] then
            while not (face == 4) do
                quarryLeft()
            end
        elseif pos[3] < home[3] then
            while not (face == 2) do
                quarryLeft()
            end
        end
    end
    while pos[3] ~= home[3] do
        digMove()
    end
    while face ~= 3 do
        quarryLeft()
    end
    for i = 1,16 do
        turtle.select(i)
        turtle.drop()
    end
    turtle.select(1)
    if hitBedrock then
        os.reboot()
    end
end

function goBack(oldX, oldY, oldZ, oldFace)
    print("alright, back to "..oldX.." "..oldY.." "..oldZ)
    if pos[1] ~= oldX then
        if pos[1] > oldX then
            while not (face == 3) do
                quarryLeft()
            end
        elseif pos[1] < oldX then
            while not (face == 1) do
                quarryLeft()
            end
        end
    end
    while pos[1] ~= oldX do
        digMove()
    end
    if pos[3] ~= oldZ then
        if pos[3] > oldZ then
            while not (face == 4) do
                quarryLeft()
            end
        elseif pos[3] < oldZ then
            while not (face == 2) do
                quarryLeft()
            end
        end
    end
    while pos[3] ~= oldZ do
        digMove()
    end
    while pos[2] > oldY do
        digMoveDown()
    end
    while face ~= oldFace do
        quarryLeft()
    end
end

function gotoQuarry(qPos)
    print("going to quarry position")
    if pos[1] ~= qPos[1] then
        if pos[1] > qPos[1] then
            while not (face == 3) do
                quarryLeft()
            end
        elseif pos[1] < qPos[1] then
            while not (face == 1) do
                quarryLeft()
            end
        end
    end
    while pos[1] ~= qPos[1] do
        digMove()
    end
    if pos[3] ~= qPos[3] then
        if pos[3] > qPos[3] then
            while not (face == 4) do
                quarryLeft()
            end
        elseif pos[3] < qPos[3] then
            while not (face == 2) do
                quarryLeft()
            end
        end
    end
    while pos[3] ~= qPos[3] do
        digMove()
    end
    print("going to quarry position")
    if pos[2] ~= qPos[2] then
        if pos[2] > qPos[2] then
            while not (pos[2] == qPos[2]) do
                digMoveDown()
            end
        elseif pos[2] < qPos[2] then
            while not (pos[2] == qPos[2]) do
                digMoveUp()
            end
        end
    end
    while not (face == 1) do
        quarryLeft()
    end
end

function digLine(length, lNumber)
    -- print("digging a "..length.." long line")
    for i = 2,length do
        turtle.digDown()
        turtle.digUp()
        if ((i - 1) % torchSpacing == 1) and (lNumber % torchSpacing == 1) then
            turtle.select(torchSlot)
            --turtle.placeDown()
        end
        digMove()
    end
    turtle.digDown()
    turtle.digUp()
end

function nextLine(oldLine, lDir)
    -- print("turning for next line")
    if oldLine % 2 == 1 then    -- odd linenumber -> turn in layer direction
        if lDir == "r" then     -- layer direction is right
            quarryRight()
            digMove()
            quarryRight()
        else                    -- layer direction is left
            quarryLeft()
            digMove()
            quarryLeft()
        end
    else                        -- even linenumber -> turn against layer direction
        if lDir == "l" then     -- layerdirection is left
            quarryRight()
            digMove()
            quarryRight()
        else                    -- layer direction is right
            quarryLeft()
            digMove()
            quarryLeft()
        end
    end
end

function digLayer(lWidth, lLength, lDir)
    -- print("digging a "..lLength.." long and "..lWidth.." wide layer")
    for n = 1,lWidth do
        digLine(lLength,n)
        if n < lWidth then
            nextLine(n, lDir)
        end
    end
end

function nextLayer(lWidth, lDir)
    -- print("going down for next layer")
    for n = 1,3 do
        digMoveDown()
    end
    turtle.digDown()
    if lWidth % 2 == 1 then     -- odd width -> turn aginst layerDirection
        -- print("old layer had an odd width, turning against it")
        if lDir == "l" then
            quarryRight()
        else
            quarryLeft()
        end
    else                        -- even width -> turn into layerDirection
        -- print("old layer had an even width, turning with it")
        if lDir == "r" then
            quarryRight()
        else
            quarryLeft()
        end
    end
end

function digQuarry(qWidth, qLength, qDir)
    digging = true
    depth = 50

    if #args == 6 then      -- goto quarry position
        gotoQuarry(quarryPos)
    end

    lWidth = qWidth
    lLength = qLength
    lDir = qDir
    for layer = 1,depth do
        digLayer(lWidth, lLength, lDir)
        if layer < depth then
            nextLayer(lWidth, lDir)
        end
        if lWidth % 2 == 1 then     -- odd layer width -> change direction
            -- print("last layer had an odd width, changing layer direction")
            if lDir == "l" then
                lDir = "r"
            else
                lDir = "l"
            end
        end
        lWidth, lLength = lLength, lWidth   --switch dimensions
    end
end

digQuarry(tonumber(args[1]),tonumber(args[2]),args[3])
--gotoQuarry({3,-2,-2})