02-svc-order

print("Loading CMD/Order Service")

-- Prototyping

local addOrder

-- Other local vars

local orders = {}
local orderFuncs = {}
local processingOrder = false

-- Peripheral Configs

local chatDir = "right"
local tesseractDir = "item_tesseract_0"
local rqpipeDir = "back"

-- Peripheral Init

local chat = peripheral.wrap(chatDir)
local tesseract = peripheral.wrap(tesseractDir)
local rqpipe = peripheral.wrap(rqpipeDir)

-- Helper functions

local function strsplit(str,sep)
  local sep,fields = sep or ":",{}
  local pattern = string.format("([^%s]+)",sep)
  str:gsub(pattern,function(c) fields[#fields+1]=c end)
  return fields
end

function strjoin(list,delimeter)
  local len = #list
  if len == 0 then
    return ""
  end
  local string = list[1]
  for i = 2, len do
    string = string .. delimiter .. list[i]
  end
  return string
end

function getItemInfo(itemName)
    local items = rqpipe.getAvailableItems()

    for i,v in pairs(items) do
        local uName = rqpipe.getUnlocalizedName(v[1]):lower()
        if uName == itemName then
            return v[1],v[2]
        end
    end
    return nil
end

function getItemAmount(iid)
    local items = rqpipe.getAvailableItems()

    for i,v in pairs(items) do
        if v[1] == iid then
            return v[2]
        end
    end
    return nil
end

-- Load state

local defState = {}
defState.registrations = {}

local state = state.new("/lib/svc-state/order",defState)

-- Service start

event.subscribe_once("service.start", function()
  print("CMD/Order Service Starting")
  if state.registrations == nil then state.registrations = {} end

  print("Service running")
end)

-- Handler Functions

function orderFuncs.help(name,cmd)
    cmd = cmd or ""
    cmd= cmd:lower()

    local cmdDescs = {}
    cmdDescs.help = " - Lists the available commands."
    cmdDescs.register = " <channel> - Register <channel> as tesseract channel to send orders on"
    cmdDescs.order = " <amount> <item> - Orders <amount> of <item> (sent through registered channel)"
    cmdDescs.info = " - Show your personal registration info"
    cmdDescs.unregister = " - Unregisters your channel"
    cmdDescs.check = " <item> - Shows the available amount of <item>"

    if cmd == "" then
        chat.tell(name,"Available commands: help, info, register, unregister, check, order")
    elseif cmdDescs[cmd] then
        chat.tell(name,cmd..cmdDescs[cmd])
    end
end

function orderFuncs.register(name,channel)
    if channel == nil then
        chat.tell(name,"Please specify a channel")
        return
    end

    channel = tonumber(channel)

    if channel == nil or channel < 0 or math.ceil(channel) ~= channel then
        chat.tell(name,"Please specify a valid channel.")
        return
    end

    if state.registrations[name] then
        chat.tell(name,"You already have a registered channel: "..state.registrations[name].channel)
        return
    end

    for k,v in pairs(state.registrations) do
        if v.channel == channel then
            chat.tell(name,k.." already has this channel registered.")
            return
        end
    end

    state.registrations[name]={["channel"]=channel}
    state:save_now()
    chat.tell(name,"Channel "..channel.. " successfully registered.")
end

function orderFuncs.unregister(name)
    if not state.registrations[name] then
        chat.tell(name,"You don't have a channel registered.")
        return
    end

    state.registrations[name] = nil
    state:save_now()
    chat.tell(name,"Successfully unregistered.")
end

function orderFuncs.info(name)
    if not state.registrations[name] then
        chat.tell(name,"You don't have a channel registered.")
        return
    end

    chat.tell(name,"Registered with channel "..state.registrations[name].channel)
end

function orderFuncs.order(name,amount,...)
    local args = {...}
    if args == nil or #args == 0 then
        orderFuncs.help(name,"order")
    end
    local item = strjoin(args," "):lower()
    local amount = tonumber(amount)

    if amount == nil or amount < 1 or math.ceil(amount) ~= amount then
        chat.tell(name,"Please specify a valid amount.")
        return
    end


    if type(state.registrations[name]) ~= "table" then
        chat.tell(name,"Please use the 'register' command to register a channel before ordering.")
        return
    end

    local iid = getItemInfo(item)

    if iid == nil then
        chat.tell(name,"Item "..item.." not found.")
        return
    else
        addOrder(name,iid,item,amount)
        chat.tell(name,"Order queued, will be processed momentarily.")
        if not processingOrders then
            os.queueEvent("newOrder")
        end
    end

end

-- Route chat

function onChat(ev,name,msg)
    if msg:sub(1,1) == "." then
        msg = msg:sub(2)

        local msgSplit = strsplit(msg," ")

        local cmd = table.remove(msgSplit,1)

        if type(orderFuncs[cmd]) == "function" then
            orderFuncs[cmd](name,unpack(msgSplit))
        end
    end
end

-- Order Processng

addOrder = function(name,iid,item,amount)
    local t = {}
    t.name = name
    t.iid = iid
    t.item = item
    t.amount = amount

    table.insert(orders,t)

end

function nextOrderCheck()
    if #orders > 0 then
        os.queueEvent("newOrder")
    else
        processingOrders = false
    end
end

function processOrder(ev)
    processingOrders = true

    local order = table.remove(orders,1)

    local amount = getItemAmount(order.iid)

    if amount < order.amount then
        chat.tell(order.name,"Only "..amount.. " of " ..order.item.. " available ("..order.amount.." requested).")
    else
        if state.registrations[order.name] ~= nil then
            tesseract.setFrequency(state.registrations[order.name].channel)
            rqpipe.makeRequest(order.iid,order.amount,false)
            chat.tell(order.name,"Sending "..order.amount.." "..order.item)
        else
            chat.tell(name,"Error: You are not registered. This shouldn't happen unless you unregister after ordering but before the order is processed.")
        end
    end

    timer.after(4,nextOrderCheck)

end

-- Event Subscriptions

local eGroup = event.new_group()

eGroup:subscribe("event.chat",onChat)
eGroup:subscribe("event.newOrder",processOrder)

event.subscribe_once("service.stop",function()
  print("Service Closing")
  eGroup:done()
end)