Mystcraft Page Trader

peripherals = peripheral.getNames()

for i,j in pairs(peripherals) do
        if peripheral.getType(j) == "tradingpost" then trade = peripheral.wrap(j) end
        if peripheral.getType(j) == "container_chest" or peripheral.getType(j) == "iron" then chest = peripheral.wrap(j) end
end

emerald_buffer = {["direction"]="north",["slot"]=0}
pages = {}

function savePages()
        if fs.exists("pages.dat") then
                fs.delete("pages.dat")
        end
        file = fs.open("pages.dat", "w")
        file.write(textutils.serialize(pages))
        file.close()
end

function loadPages()
        if fs.exists("pages.dat") then
                file = fs.open("pages.dat", "r")
                pages = textutils.unserialize(file.readAll())
                file.close()
        else
                if not shell.run("pastebin get","pqqGZ2nW","pages.dat") then
                        error("Failed to initialise page list, please check http permissions")
                end
        end
end

function getTradeInfo(id)
        local sold = trade.getItemSold(id,0)
        if sold == nil then
                sold = {["name"]="nope",["qty"]=0,["rawName"]="nada"}
        end
        return sold.name, sold.qty, sold.rawName, id
end

function topUpEmeralds()
        chest.pullItem(emerald_buffer["direction"], emerald_buffer["slot"])
end

loadPages()
topUpEmeralds()
while true do
        ids = trade.getVillagerIds()
                chest.pullItem(emerald_buffer["direction"], emerald_buffer["slot"])
        for index, idnum in pairs(ids) do
                sold, soldQty, rawName, id = getTradeInfo(idnum)
                if rawName == "item.myst.page" and (sold == "Link Panel" or pages[sold] ~= true) then
                        if trade.performTrade(id, 0) then
                                print("New "..sold)
                                pages[sold] = true
                                savePages()
                                topUpEmeralds()
                        else
                                print("Failed to buy "..sold)
                        end
                end
        end
        sleep(3)
end