OC Monitor

local interval = 1


local component = require("component")
local event = require("event")


local components = {
    gpu = {address = "87abc", type = "gpu"};
    screen = {address = "4ee56", type = "screen"};
    core = {address = "68e1d", type = "draconic_rf_storage"};
}

local resolution_x, resolution_y = 30, 15

local function set_resolution(gpu)
    if not gpu then
        gpu = components.gpu.proxy
        if not gpu then
            return
        end
    end

    gpu.setResolution(resolution_x, resolution_y)
end

for i,v in pairs(components) do
    local taddr = component.get(v.address, v.type)
    if not taddr then
        io.stderr:write("Could not find component " .. i)
    else
        v.proxy = component.proxy(taddr)
    end
end

if components.gpu.proxy and components.screen.proxy then
    components.gpu.proxy.bind(component.get(components.screen.address))

    set_resolution()
end


local lbase = math.log(10)
local si_prefixes = {
    [-4] = "p";
    [-3] = "n";
    [-2] = "u";
    [-1] = "m";
    [1] = "k";
    [2] = "M";
    [3] = "G";
    [4] = "T";
    [5] = "P";
    [6] = "E";
    [7] = "Z";
    [8] = "Y";
}
local si_low = -4
local si_high = 8

local function round(number, decimals)
    return math.floor((number * 10^decimals) + 0.5) / 10^decimals
end

local function format_si(number, unit)
    local mult = 1
    if number < 0 then
        mult = -1
        number = -number
    end

    local brack = math.floor((math.log(number) / lbase) / 3)
    brack = math.min(math.max(brack, si_low), si_high)
    if brack == 0 then
        return tostring(mult * round(number, 3)) .. " " .. unit
    end

    number = number / 10^(brack * 3)
    return tostring(round(mult * number, 3)) .. " " .. si_prefixes[brack] .. unit
end


local function print_center(gpu, text, y)
    local x = math.floor((resolution_x - #text) / 2)
    gpu.set(x, y, text)
end


local function check_core()
    local gpu = components.gpu.proxy
    local core = components.core.proxy
    if not gpu or not core then
        return
    end

    local stored_energy, max_energy, transfer = core.getEnergyStored(), core.getMaxEnergyStored(), core.getTransferPerTick()
    local stored_text, max_text, transfer_text = format_si(stored_energy, "RF"), format_si(max_energy, "RF"), format_si(transfer, "RF")

    print_center(gpu, "Stored: " .. stored_text .. " / " .. max_text, math.floor(resolution_y / 2))
end


local function on_component_added(event, address, component_type)
    for i,v in pairs(components) do
        if address:sub(1, #v.address) == v.address then
            io.stderr:write("component " .. i .. " added")
            v.proxy = component.proxy(address)

            if component_type == "gpu" or component_type == "screen" then
                if components.gpu.proxy and components.screen.proxy then
                    components.gpu.proxy.bind(component.get(components.screen.address))

                    set_resolution()
                end
            end
        end
    end
end

local function on_component_removed(event, address, component_type)
    for i,v in pairs(components) do
        if address:sub(1, #v.address) == v.address then
            io.stderr:write("component " .. i .. " removed")
            v.proxy = nil
        end
    end
end


function start()
    if timer then
        stop()
    end
    timer = event.timer(interval, check_core, math.huge)
end


function stop()
    if timer then
        event.cancel(timer)
        timer = nil

        event.ignore("component_added", on_component_added)
        event.ignore("component_removed", on_component_removed)
    end
end