vein miner

-- the function of this program is to get rid of
--  all of a block type attached to the block
--  underneath

-- crucial variables
blockName = nil
blockMeta = nil

currentBlocks = 0
killSwitch = 10000 -- How many blocks it will remove before it stops
-- this should help prevent any huge accidents

removedBlocks   = {}
startPoint = {}

-- functions

function checkForExisting(x,y,z)
    for k,v in pairs(startPoint) do
        if x == v.x and
        y == v.y and
        z == v.z then
            return true
        end
    end
    return false
end

function addStartPoint(x,y,z)
    for i = 1, 64 do
        if startPoint[i] == nil then
            if checkForExisting(x,y,z) == false then
                startPoint[i] = {x = x, y = y, z = z}
                break
            end
        end
    end
end

function condensePointList(t)
    -- credit for this function goes to CometWolf of the CCForums
    local compressed = {}
    for k,v in pairs(t) do
      compressed[#compressed+1] = {
            key = k,
            value = v
      }
    end
    table.sort(
      compressed,
      function(v1,v2)
            return v1.key < v2.key
      end
    )
    local ordered = {}
    for i=1,#compressed do
      ordered[i] = compressed[i].value
    end
    return compressed
end

function checkforBLock()
    for i = 1, #startPoint do
        local block = commands.getBlockInfo(startPoint[i].x,startPoint[i].y,startPoint[i].z)
        local name, meta
        for k,v in pairs(block) do
            if k == "name" then
                name = v
            elseif k == "metadata" then
                meta = v
            end
        end
        if name == "minecraft:air" then
            table.remove(startPoint, i)
        end
    end
end

function getBlockToRemove()
    local ccx, ccy, ccz = commands.getBlockPosition()
    -- get block type
    local block = commands.getBlockInfo(ccx, ccy-1, ccz)
    for k,v in pairs(block) do
        if k == "name" then
            blockName = v
        elseif k == "metadata" then
            blockMeta = v
        end
    end

    -- error if block below is air
    if blockName == "minecraft:air" then
        error("The block below is air!")
    end
    -- add start point
    addStartPoint(ccx, ccy-1, ccz)
end

function checkSides(x,y,z)

    for i = -1, 1, 2 do
        local block = commands.getBlockInfo(x+i,y,z)
        local name, meta
        for k,v in pairs(block) do
            if k == "name" then
                name = v
            elseif k == "metadata" then
                meta = v
            end
        end
        if name == blockName and meta == blockMeta then
            addStartPoint(x+i,y,z)
        end
    end
    for i = -1, 1, 2 do
        local block = commands.getBlockInfo(x,y+i,z)
        local name, meta
        for k,v in pairs(block) do
            if k == "name" then
                name = v
            elseif k == "metadata" then
                meta = v
            end
        end
        if name == blockName and meta == blockMeta then
            addStartPoint(x,y+i,z)
        end
    end
    for i = -1, 1, 2 do
        local block = commands.getBlockInfo(x,y,z+i)
        local name, meta
        for k,v in pairs(block) do
            if k == "name" then
                name = v
            elseif k == "metadata" then
                meta = v
            end
        end
        if name == blockName and meta == blockMeta then
            addStartPoint(x,y,z+i)
        end
    end
end

function removeBlock(spNumb)
    checkSides(startPoint[spNumb].x, startPoint[spNumb].y, startPoint[spNumb].z)
    commands.setBlock(startPoint[spNumb].x, startPoint[spNumb].y, startPoint[spNumb].z, "minecraft:air")
    -- animation?

    commands.say(#startPoint)
    table.remove(startPoint, spNumb)

    currentBlocks = currentBlocks + 1
    if currentBlocks >= killSwitch then
        commands.say("Kill Switch Reached!")
        error("Kill Switch limit reached!")
    end
end

function deleteBlocks()
    for i = 1, 64 do
        if startPoint[i] then
            removeBlock(i)
        end
    end
    condensePointList(startPoint)
end

function debug()
end

function removeBlockLoop()
    -- needs to know what direction it was detected from
    while #startPoint > 0 do
        deleteBlocks()
        -- sleep(.01)
        --break -- temporary
        -- checkforBLock()
    end
end

-- main

debug()
commands.gamerule("commandBlockOutput", false)
getBlockToRemove()
removeBlockLoop()
commands.gamerule("commandBlockOutput", true)
commands.say("I have removed the vein!")