local mineVein = require("minevein")

local symmetricBranches
if arg[1] == nil then
    symmetricBranches = 20
else
    symmetricBranches = tonumber(arg[1])
end

branchDistance = 2
branchDepth = 16

function keepFueled()
    if turtle.getFuelLevel() < 200 then
        for n = 1,16 do
            turtle.select(n)
            if turtle.refuel(64) == true then
                break
            end
        end

        turtle.select(1)
    end
end

keepFueled()

function blockInfront()
    local hasBlock, data = turtle.inspect()
    return hasBlock
end

function tunnel()
    print("fuel level: "..tostring(turtle.getFuelLevel()))

    repeat
        turtle.dig()
    until turtle.forward(0) == true
    turtle.digDown()

    mineTunnelSidesIfOre()
end

function turn(direction)
    if direction == "left" then
        turtle.turnLeft()
    elseif direction == "right" then
        turtle.turnRight()
    end
end

function endsWith(string, suffix)
    return string:sub(-#suffix) == suffix
end

function isOre(blockData)
    if blockData ~= nil then
        print(blockData.name)
        return endsWith(blockData.name, "ore")
    else
        return false
    end
end

function mineIfOre(direction)
    local inspect, dig
    if direction == "up" then
        inspect = function() return turtle.inspectUp() end
        dig = function() return turtle.digUp() end
    elseif direction == "forward" then
        inspect = function() return turtle.inspect() end
        dig = function() return turtle.dig() end
    elseif direction == "down" then
        inspect = function() return turtle.inspectDown() end
        dig = function() return turtle.digDown() end
    end

    if inspectPotentialBlockData(inspect, isOre) then
        --dig()
        mineVein(isOre)
    end
end

function inspectPotentialBlockData(inspect, doSomethingWithBlockData)
    local hasBlock, data = inspect()
    if hasBlock then
        print(data.name)
        return doSomethingWithBlockData(data)
    end
end

function doSomethingOnTunnelSides(doSomethingInDirection)
    doSomethingInDirection("up")
    turtle.turnLeft()
    doSomethingInDirection("forward")
    turtle.down()
    doSomethingInDirection("forward")
    turtle.turnRight()
    doSomethingInDirection("down")
    turtle.turnRight()
    doSomethingInDirection("forward")
    turtle.up()
    doSomethingInDirection("forward")
    turtle.turnLeft()
end

function mineTunnelSidesIfOre()
    doSomethingOnTunnelSides(mineIfOre)
end

function branch(direction)
    turn(direction)

    for i = 1,branchDepth do
        tunnel()
    end
    --turtle.dig()
    
    turtle.turnLeft()
    turtle.turnLeft()
    
    for i = 1,branchDepth do
        turtle.forward()
    end

    turn(direction)
end

function symmetricBranchPair()
    keepFueled()

    for n = 0,branchDistance do
        tunnel()
    end
    branch("left")
    branch("right")
end

-- Go to chest, put mined blocks in one and pick up fuel from the other
function exchangeItems()
    turtle.forward()
    turtle.down()
    --chestLeft = peripheral.find("minecraft:chest")
    turtle.turnLeft()
    --chestRight = peripheral.find("minecraft:chest")
    for n = 1,16 do
        turtle.select(n)

        slotItem = turtle.getItemDetail(n)
        if slotItem ~= nil then
            if endsWith(slotItem.name, "coal") then
                turtle.turnRight()
                turtle.turnRight()
                turtle.drop()
                turtle.turnLeft()
                turtle.turnLeft()
            else
                turtle.drop()
            end
        end
    end
    
    turtle.select(1)
    
    turtle.turnRight()
    turtle.turnRight()
    turtle.suck()
    
    turtle.turnRight()
    turtle.up()
    turtle.forward()
end

function moveAlongBranches(branches)
    for n = 1,(branches * (branchDistance + 1)) do
        turtle.forward()
    end
end

for n = 1,symmetricBranches do
    symmetricBranchPair()
    if turtle.getItemCount(15) ~= 0 then
        turtle.turnLeft()
        turtle.turnLeft()
        moveAlongBranches(n)
        exchangeItems()
        moveAlongBranches(n)
    end
end

-- return turtle to starting point
turtle.turnLeft()
turtle.turnLeft()
moveAlongBranches(symmetricBranches)

print("stripmining operation complete")