startup

local rows = {}
for i = 1, 25 do
table.insert(rows,18)
end
local types = {}
for i = 1, 9 do
table.insert(types,14)
end
for i = 1, 2 do
table.insert(types,15)
end
for i = 1, 14 do
table.insert(types,16)
end
local travelDist = 10
local harvestTime = 2400
local skipFirstFarm = not(...)
local home = {x = -247, y = 64, z = 136}

farmerStatus = "Standby"
farmerNextHarvest = 0

local function main()
    while not gps.locate() do
        farmerStatus = "Error: No GPS signal"
        print("Error: No GPS signal")
        sleep(30)
    end
    local function goHomeByGPS(turned)
        farmerStatus = "Going home..."
        local function travel(dist, positive)
            if ((math.abs(dist) == dist) and positive) or ((math.abs(dist) ~= dist) and not positive) then
            else
                turtle.turnLeft()
                turtle.turnLeft()
                turtle.forward()
                turtle.forward()
            end
            for i = 1, math.abs(dist)-1 do
                if not turtle.forward() then
                    if turned then
                        if diffY ~= 0 then
                            print("Maybe if I go up/down...")
                            if math.abs(diffY) == diffY then
                                for i = 1, diffY do
                                    turtle.up()
                                end
                            else
                                for i = 1, math.abs(diffY) do
                                    turtle.down()
                                end
                            end
                            local ret = goHomeByGPS(true)
                            return ret
                        else
                            return false
                        end
                    end
                    turtle.turnLeft()
                    local ret = goHomeByGPS(true)
                    return ret
                end
            end
            turtle.turnLeft()
            return goHomeByGPS()
        end
        sleep(0.1)
        local initX, initY, initZ = gps.locate()
        print("I am currently at: "..initX..", "..initY..", "..initZ)
        local diffX = (initX - home.x)*-1
        local diffY = (initY - home.y)*-1
        local diffZ = (initZ - home.z)*-1
        print("I'm X:"..diffX.." and Z:"..diffZ.." away from home!")
        if (diffX == 0) and (diffZ == 0) then
            if math.abs(diffY) == diffY then
                for i = 1, diffY do
                    turtle.up()
                end
            else
                for i = 1, math.abs(diffY) do
                    turtle.down()
                end
            end
            local initX, initY, initZ = gps.locate()
            print("I am now at: "..initX..", "..initY..", "..initZ)
            if home.x == initX and home.y == initY and home.z == initZ then
                for i = 1, 4 do
                    turtle.forward()
                    local x = gps.locate()
                    turtle.back()
                    if x > home.x then
                        print("Alright, I'm home! Awesome!")
                        return true
                    end
                    turtle.turnLeft()
                end
                return false
            else
                print("Ah crap, I miscalculated :/")
                print("Well, I'm screwed")
                return false
            end
        elseif turtle.forward() then
            secondX, _, secondZ = gps.locate()
            if secondX > initX then
                if diffX == 0 then
                    turtle.back()
                    turtle.turnLeft()
                    local ret = goHomeByGPS()
                else
                    return travel(diffX, true)
                end
            elseif secondX < initX then
                if diffX == 0 then
                    turtle.back()
                    turtle.turnLeft()
                    local ret = goHomeByGPS()
                else
                    return travel(diffX, false)
                end
            elseif secondZ > initZ then
                if diffZ == 0 then
                    turtle.back()
                    turtle.turnLeft()
                    local ret = goHomeByGPS()
                else
                    return travel(diffZ, true)
                end
            elseif secondZ < initZ then
                if diffZ == 0 then
                    turtle.back()
                    turtle.turnLeft()
                    local ret = goHomeByGPS()
                else
                    return travel(diffZ, false)
                end
            end
        elseif turtle.back() then
            turtle.forward()
            turtle.turnLeft()
            turtle.turnLeft()
            local ret = goHomeByGPS()
            return ret
        elseif turned then
            print("Crap, I'm stuck!")
            print("D: Turtle is sad")
            if diffY ~= 0 then
                print("Maybe if I go up/down...")
                if math.abs(diffY) == diffY then
                    for i = 1, diffY do
                        turtle.up()
                    end
                else
                    for i = 1, math.abs(diffY) do
                        turtle.down()
                    end
                end
                local ret = goHomeByGPS(true)
                return ret
            else
                return false
            end
        elseif turtle.getFuelLevel() < 1 then
            print("Crap, out of fuel!")
            return false
        else
            turtle.turnLeft()
            local ret = goHomeByGPS(true)
            return ret
        end
    end

--[[
    local storage = {}
    local storageData = {}
    storage.save = function()
            for i = 1, 16 do
                    storageData[i] = turtle.getItemCount(i)
            end
    end

    storage.getSlotDiff = function()
            local diff = {}
            for i = 1, 16 do
                    if storageData[i] ~= turtle.getItemCount(i) then
                            table.insert(diff,i)
                    end
            end
            return diff
    end
]]--

    local enoughFuel = function()
            local total = travelDist
            for _, row in pairs(rows) do
                    total = total+row
            end
            total = total*1.2
            return turtle.getFuelLevel() > total
    end

    local function farm()
        local direction = "down"

        for rowNumber, rowLength in pairs(rows) do
            for block = 1, rowLength do
                turtle.select(1)
                turtle.digDown()
                for slot = 1, 4 do
                    turtle.select(slot)
                    if turtle.compareTo(types[rowNumber]) then
                        turtle.placeDown()
                    end
                end
                if block ~= rowLength then
                    if not turtle.forward() then
                        print("There is an obstruction in the way!")
                        print("Bailing: Returning to base")
                        local ret = goHomeByGPS()
                        return false, ret
                    end
                end
            end
            if rowNumber == #rows then
                local ret = goHomeByGPS()
                return true, ret
            elseif direction == "down" then
                turtle.turnRight()
                turtle.turnRight()
                if rowNumber == #rows then
                        break
                end
                for i = 1, rows[rowNumber]-rows[rowNumber+1] do
                        turtle.forward()
                end
                turtle.turnLeft()
                turtle.forward()
                turtle.turnRight()
                direction = "up"
            elseif direction == "up" then
                turtle.turnLeft()
                turtle.forward()
                turtle.turnLeft()
                direction = "down"
            end
        end
    end

    local function farmingMonitor()
        while true do
            if not farmerStatus:find("Lost") then
                if enoughFuel() then
                    print("Time to farm!")
                    if not skipFirstFarm then
                        farmerStatus = "Farming..."
                        local ret, stat = farm()
                    else
                        print("Skipping initial farm")
                        skipFirstFarm = true
                    end
                    if stat == false then
                        print("I'm lost! D: Help me!")
                        farmerStatus = "Lost! \\[Save me pwease :(\\]"
                    else
                        farmerStatus = "Waiting for next harvest..."
                        for i = 1, harvestTime/5 do
                            sleep(5)
                            farmerNextHarvest = harvestTime-(i*5)
                            print("Waiting for next harvest: "..farmerNextHarvest)
                        end
                    end
                else
                    farmerStatus = "Outta fuel D:!"
                    print("I'm out of fuel! Please place fuel")
                    print("In slot 13 (Bottom left corner)")
                    print("and press any key to continue")
                    os.pullEvent("key")
                    turtle.select(13)
                    if not turtle.refuel() then
                        print("D: That's not fuel! Try again.")
                    else
                        print("Thanks! Now farming...")
                        farmerStatus = "Farming..."
                        farm()
                    end
                end

            end
            sleep(2)
        end
    end

    if not goHomeByGPS() then
        if turtle.getFuelLevel() > 0 then
                farmerStatus = "Lost! \\[Save me pwease :(\\]"
        else
            farmerStatus = "Outta fuel D:!"
            while true do
                print("I'm out of fuel! Please place fuel")
                print("In slot 13 (Bottom left corner)")
                print("and press a key to continue")
                os.pullEvent("key")
                turtle.select(13)
                if not turtle.refuel() then
                    print("That's not fuel! D: Try again")
                else
                    print("Thanks, heading home!")
                    goHomeByGPS()
                    break
                end
            end
        end
    end

    farmingMonitor()
end

while true do
        parallel.waitForAny(function() shell.run("/lost") end, main)
        print("Terminate now.")
        sleep(3)
end