vncd

local args = {...}

local connections = {}

local nshAPI = {
    connList = connections
}

nshAPI.getRemoteID = function()
    return false
end

nshAPI.send = function(msg)
    return false
end

nshAPI.receive = function(timeout)
    return false
end

nshAPI.getClientCapabilities = function()
    return false
end

nshAPI.getRemoteConnections = function()
    local remotes = {}
    for cNum, cInfo in pairs(nshAPI.connList) do
        table.insert(remotes, cNum)
        if cInfo.outbound then
            table.insert(remotes, cInfo.outbound)
        end
    end
    return remotes
end

nshAPI.packFile = function(path)
    return false
end

nshAPI.unpackAndSaveFile = function(path, data)
    return false
end

local packetConversion = {
    query = "SQ",
    response = "SR",
    data = "SP",
    close = "SC",
    textTable = "TT",
    event = "EV",
    SQ = "query",
    SR = "response",
    SP = "data",
    SC = "close",
    TT = "textTable",
    EV = "event",
}

local function openModem()
    local modemFound = false
    for _, side in ipairs(rs.getSides()) do
        if peripheral.getType(side) == "modem" then
            if not rednet.isOpen(side) then rednet.open(side) end
            modemFound = true
            break
        end
    end
    return modemFound
end

local function send(id, pType, message)
    if pType and message then
        if term.current then
            return rednet.send(id, packetConversion[pType]..":;"..message, "tror")
        else
            return rednet.send(id, packetConversion[pType]..":;"..message)
        end
    end
end

local function resumeThread(co, event)
    if not co.filter or event[1] == co.filter then
        co.filter = nil
        local _old = term.redirect(co.target)
        local passback = {coroutine.resume(co.thread, unpack(event))}
        if _old then term.redirect(_old) else term.restore() end
        if passback[1] and passback[2] then
            co.filter = passback[2]
        end
        if coroutine.status(co.thread) == "dead" then
            for cNum, cInfo in pairs(connections) do
                send(cNum, "close", "disconnect")
            end
            connections = {}
        end
        if connections[conn] and conn ~= "localShell" and framebuffer then
            for cNum, cInfo in pairs(connections) do
                send(cNum, "textTable", textutils.serialize(co.target.buffer))
            end
        end
        framebuffer.draw(co.target.buffer)
    end
end

if not openModem() then error("No modem present!") end

if not framebuffer then if not shell.resolveProgram("framebuffer") or not os.loadAPI(shell.resolveProgram("framebuffer")) then error("Could not load framebuffer API") end end

term.clear()
term.setCursorPos(1,1)
local x, y = term.getSize()

local redirect = framebuffer.new(x, y, term.isColor())

local shellRoutine = coroutine.create(function() shell.run("/rom/programs/shell", unpack(args)) end)
local co = {thread = shellRoutine, target = redirect}

resumeThread(co, {})

_G.nsh = nshAPI

while true do
    event = {os.pullEventRaw()}
    if event[1] == "rednet_message" then
        if packetConversion[string.sub(event[3], 1, 2)] then
            --this is a packet meant for us.
            conn = event[2]
            packetType = packetConversion[string.sub(event[3], 1, 2)]
            message = string.match(event[3], ";(.*)")
            if connections[conn] and connections[conn].status == "open" then
                if packetType == "event" then
                    local eventTable = textutils.unserialize(message)
                    resumeThread(co, eventTable)
                elseif packetType == "query" then
                    connections[conn] = {status = "open"}
                    send(conn, "response", "OK")
                    send(conn, "textTable", textutils.serialize(co.target.buffer))
                elseif packetType == "close" then
                    connections[conn] = nil
                    send(conn, "close", "disconnect")
                    --close connection
                end
            elseif packetType ~= "query" then
                --usually, we would send a disconnect here, but this prevents one from hosting nsh and connecting to other computers.  Pass these to all shells as well.
                resumeThread(co, event)
            else
                --open new connection
                connections[conn] = {status = "open"}
                send(conn, "response", "OK")
                send(conn, "textTable", textutils.serialize(co.target.buffer))
            end
        else
            --rednet message, but not in the correct format, so pass to all shells.
            resumeThread(co, event)
        end
    else
        --dispatch all other events to all shells
        resumeThread(co, event)
    end
end