MCNet devices/forwarder

--[[

    Minecraft Intranet
    Forwarder device

--]]

mcnet = mcnet or {}
local device = mcnet.device or {}
mcnet.device = device

local Forwarder = common.newClass(device.Device)
device.Forwarder = Forwarder

-- Constructor
function Forwarder:init()
    device.Device.init(self)

    self:addMessageHandler("", self.handleForwarder)
end

-- Check if the given message can be forwarded
function Forwarder:canForward(senderId, msg)
    -- Ignore device messages
    if (common.startsWith(msg.type, "device")) then
        return false
    end

    return true
end

-- Get the receivers for the given forwarded message
function Forwarder:getReceivers(senderId, msg)
    return self:neighboursExcept(senderId)
end

function Forwarder:handleForwarder(senderId, msg)
    if (self:canForward(senderId, msg)) then
        -- Forward message
        local success = false
        if msg.to == nil then
            success = true
            for i,deviceId in ipairs(self:neighboursExcept(senderId)) do
                self:send(deviceId, msg)
            end
        else
            for i,deviceId in ipairs(self:getReceivers(senderId, msg)) do
                self:send(deviceId, msg)
                success = true
            end
        end

        self:trigger("forwardMessage", success, senderId, msg)
        if not success then
            -- Reply with error message
            local errorMsg = mcnet.message.new{
                type = "errorNotFound",
                to = msg.from,
                data = msg.to:format()
            }
            self:send(senderId, errorMsg)
        end
    end

    return false
end