exc

os.unloadAPI("gxm")
os.loadAPI  ("gxm")

local tArgs = { ... }
local data = { start = {}, from = {} }

if not gxm.load() then gxm.save() end
gxm.positionTrack(true)

loadPosition = function()
    if not fs.exists("excavateConfig") then
        data.start = gxm.getData().position
        data.start.f = gxm.correctDir(data.start.f + 2)
        file = fs.open("excavateConfig", "w")
        if file then
            file.write(textutils.serialize(data))
            file.close()
        end
    else
        file = fs.open("excavateConfig", "r")
        if file then
            data = textutils.unserialize(file.readAll())
            file.close()
        end
    end
end

if tArgs[1] == "-b" then
    loadPosition()
    gxm.goto(data.start.x, data.start.y, data.start.z, data.start.f - 2)
    return
elseif tArgs[1] == "-r" then
    gxm.regExecPattern("")
    return
end

zSize = tonumber(tArgs[1])
xSize = tonumber(tArgs[2]) or zSize
ySize = tonumber(tArgs[3]) or gxm.getData().position.y or 64


savePosition = function()
    if fs.exists("excavateConfig") then
        file = fs.open("excavateConfig", "w")
        if file then
            data.from = gxm.getData().position
            file.write(textutils.serialize(data))
            file.close()
        end
    end
end

excavatePattern = function()
    local excString = ""
    local alter     = true
    local excMove   = "UDfr"
    local lastMove  = "UD3d"

    local sideX      = xSize % 2 == 0
    local sideZ      = zSize % 2 == 0
    local side       = not sideX and not sideZ

    for i = 1, math.ceil(ySize/3) do
        if i == math.ceil(ySize/3) then
            excMove   = gxm.correctY(ySize) == 2 and "U0fr"  or (gxm.correctY(ySize) == 1 and "00fr" or excMove)
        end
        if i == math.ceil(ySize/3) - 1 then lastMove = gxm.correctY(ySize) == 1 and "UD2d" or lastMove end

        for j = 1, xSize do
            local cmds      = ""

            cmds = excMove:sub(1, -2):rep(zSize - 2) .. excMove:rep(2)

            alter = not alter
            if j ~= xSize then
                cmds = alter and cmds:gsub("r", "l") or cmds
            else
                if not sideX and not sideZ then
                    side = not side
                elseif sideX and not sideZ then
                    if i == 1 then
                        side = true
                    elseif i % 2 == 0 then
                        side = not side
                    end
                elseif sideZ and not sideX then
                    if i == 1 then
                        side = false
                    elseif (i+1) % 2 == 0 then
                        side = not side
                    end
                else
                    side = true
                end

                cmds = side and cmds:sub(1, -6) .. "r" .. lastMove or cmds:sub(1, -6) .. "l" .. lastMove
            end

            excString = excString .. cmds
        end
        xSize, zSize = zSize, xSize
    end
    return excString:sub(1, -4):gsub("0", "")
end

checkInventory = function()
    for i = 1, 16 do
        if turtle.getItemCount(i) == 0 then
            return true
        end
    end
    return false
end

unload = function()
    if not turtle.detect() then
        print("Nothing in front of me! Need a chest to drop my stuff! Waiting for a chest or any block as a matter of fact :).")
        while not turtle.detect() do
            sleep(2)
        end
    end

    for i = 1, 16 do
        if turtle.getItemCount(i) > 0 then
            turtle.select(i)
            while turtle.getItemCount(i) ~= 0 do
                if not turtle.drop() then
                    print("Chest is probably full! Waiting for more space!")
                    while not turtle.drop() do
                        sleep(2)
                    end
                end
            end
        end
    end
    print("Unloading complete!")
end

checkFuel = function( limit )
    return gxm.getFuelAbove(limit)
end

parseAction = function()
    loadPosition()
    if gxm.getAction() == "gotoHome" then
        gxm.goto(data.start.x, data.start.y, data.start.z, data.start.f)
        loadPosition()
        unload()
        gxm.goto(data.from.x, data.from.y, data.from.z, data.from.f)
    elseif gxm.getAction() == "unloading" then
        unload()
        gxm.goto(data.from.x, data.from.y, data.from.z, data.from.f)
    elseif gxm.getAction() == "gotoBack" then
        gxm.goto(data.from.x, data.from.y, data.from.z, data.from.f)
    end
end

function main()
    if gxm.getData().pattern == "" or not gxm.getData().pattern then gxm.regExecPattern(excavatePattern()) end
    loadPosition()
    parseAction()
    parallel.waitForAny(
        function()
            local r = coroutine.create(gxm.exec)
            local filter
            local eventData = {}
            while true do
                if filter == nil or filter == eventData[1] or eventData[1] == "terminate" then
                    _, filter = coroutine.resume(r, unpack(eventData))
                    if coroutine.status(r) == "dead" then return end
                end
                if eventData[1] == "moved" then
                    checkFuel(1000)
                    if not checkInventory() then
                        savePosition()
                        gxm.setAction("gotoHome")
                        gxm.goto(data.start.x, data.start.y, data.start.z, data.start.f)
                        gxm.setAction("unloading")
                        unload()
                        gxm.setAction("goBack")
                        loadPosition()
                        gxm.goto(data.from.x, data.from.y, data.from.z, data.from.f)
                        gxm.setAction("")
                        r = coroutine.create(gxm.exec)
                        _, filter = coroutine.resume(r)
                    end
                end
                eventData = { os.pullEventRaw() }
            end
            gxm.goto(data.start.x, data.start.y, data.start.z, data.start.f-2)
            return
        end)
end
if tArgs[2] == "-t" or tArgs[3] == "-t" or tArgs[4] == "-t" then
    gxm.regExecPattern(excavatePattern())
    print(gxm.getData().pattern)
else
    main()
end