invSRV

-- program startup and networking
rednet.open("left")

local function sendMessage(id, sendMsg, rcvMsg)
    local protocol = "inventory"
    print("SENDING "..sendMsg)
    rednet.send(id, sendMsg, protocol)
    local senderID, senderMessage, senderProtocol = rednet.receive("inventory",5)
    if senderMessage == rcvMsg then
        print(sendMsg.." ACKNOWLEDGED, STATE "..rcvMsg)
        return true
    else
        return false
    end
end

local function stateCheck(id, sendMsg, rcvMsg)
    local state = sendMessage(id, sendMsg, rcvMsg)
    if state == true then
        sleep(0)
    else
        error(sendMsg.." timed out. Turtle "..id.." is not responding.")
    end
end

local function receive(rcvID, rcvMsg, sendID, sendMsg)
    local senderID, senderMessage, senderProtocol = rednet.receive("inventory")
    if senderID == rcvID and senderMessage == rcvMsg then
        print("Received "..rcvMsg.." from Server "..rcvID.." Sending "..sendMsg)
        rednet.send(sendID, sendMsg, "inventory")
    else
        error("Critical Failure, stopping...")
    end
end

local id = 399
stateCheck(id, "STATUS", "READY")
stateCheck(id, "SCAN", "SCANNING")
-- if scan is true, wait for it to finish scanning
receive(id, "SCANDONE", id, "SCANDONEACK")
-- once the scan is acknowledged, I have to receive the data
local senderID, senderMessage, senderProtocol = rednet.receive("inventory")
if senderID == id then
    -- handle the data here
    local items2 = textutils.unserialize(senderMessage)
    -- if data file exists, load variables from file
    if fs.exists("items") then
        -- var loader
        local file = assert(fs.open("items", "r"), "Couldn't load items")
        local input = file.readAll()
        file.close()

        local items = textutils.unserialize(input)
        -- how to access primary array
        --print(destination["minecraft:rotten_flesh 0"]["display"])
        --print(destination["minecraft:rotten_flesh 0"]["count"])
        -- loop to update primary database with new data.
        for k, v in pairs(items2) do
            items[k]["count"] = items[k]["count"] + v
        end
        -- write the new data to primary database
        local output = textutils.serialize(items)
        local file = assert(fs.open("items", "w"), "Couldn't save items")
        file.write(output)
        file.close()
    elseif fs.exists("items") == false then
        -- if data file doesn't exist, create one
        shell.run("createdatabase")
        local file = assert(fs.open("items", "r"), "Couldn't load items")
        local input = file.readAll()
        file.close()

        local items = textutils.unserialize(input)
        for k, v in pairs(items2) do
            items[k]["count"] = items[k]["count"] + v
        end
        local output = textutils.serialize(items)
        local file = assert(fs.open("items", "w"), "Couldn't save items")
        file.write(output)
        file.close()
      end
else
    error("Critical Failure, stopping...")
end