sys2_boot_unit

--sys2_boot_unit
os.loadAPI("sys/syslib")

--syslib end

rednet.open("back")

function searchForUnits()
    local units = {}
    if peripheral.isPresent("left") and peripheral.getType("left") == "computer" then
        units[peripheral.call("left", "getID")] = "left"
    end
    if peripheral.isPresent("right") and peripheral.getType("right") == "computer" then
        units[peripheral.call("right", "getID")] = "right"
    end
    if peripheral.isPresent("top") and peripheral.getType("top") == "computer" then
        units[peripheral.call("top", "getID")] = "top"
    end
    if peripheral.isPresent("bottom") and peripheral.getType("bottom") == "computer" then
        units[peripheral.call("bottom", "getID")] = "bottom"
    end
    return units
end

local connectedUnits = searchForUnits()

function identify()
    local label = os.getComputerLabel()
    if label == nil then
        label = "<unnamed>"
    end
    local txtUnits = ""
    for id, side in pairs(connectedUnits) do
        if txtUnits ~= "" then
            txtUnits = txtUnits .. "|"
        end
        txtUnits = txtUnits .. id
    end
    rednet.broadcast("@root:identifyBootUnit," .. label .. "," .. txtUnits)
end

print("<bootUnit>")

identify()
local rootId

function main()
    local id, msg = syslib.receiveRednet()
    local tag, pts = syslib.getMsgData(msg)
    if tag == "@bootUnit" then
        if pts[1] == "initialise" then
            rootId = id
            identify()
            local connectedUnits = searchForUnits()
            for id, side in pairs(connectedUnits) do
                syslib.sendRednet(id, "@serviceUnit:identifyToRoot," .. rootId)
            end
        elseif pts[1] == "reboot" then
            if pts[2] == nil then
                local connectedUnits = searchForUnits()
                for id, side in pairs(connectedUnits) do
                    peripheral.call(side, "reboot")
                end
                os.reboot()
            else
                for id, side in pairs(connectedUnits) do
                    if id == tonumber(pts[2]) then
                        syslib.log("root", "rebooting unit " .. id .. " (label '" .. pts[3] .. "')")
                        peripheral.call(side, "reboot")
                    end
                end
            end
        elseif pts[1] == "action" then
            if pts[2] == "setStartup" then
                shell.run("delete", "startup")
                local f = fs.open("startup", "w")
                f.write("shell.run(\"delete\",\"unitHandler\")\n")
                f.write("shell.run(\"pastebin\",\"get\",\"" .. pts[3] .. "\",\"unitHandler\")\n")
                f.write("shell.run(\"unitHandler\")\n")
                f.close()
            else print("unknown message>action: ", msg)
            end
        else print("unknown message: ", msg)
        end
    end
end

local cErr = 0
while true do
    local status, err = pcall(main)
    if err == "Terminated" then
        break
    elseif not status then
        print("error thrown: " .. err)
        sleep(3)
        cErr = cErr + 1
        if cErr == 3 then
            os.reboot()
        end
        rednet.broadcast("@err:" .. os.getComputerID() .. "," .. os.getComputerLabel() .. ",bootUnit")
    end
end