MIN_CAP = 10;
ALLOW_CAP = 80;
TEST_INTERVAL = 3;
MSG_INTERVAL = 10 * 60;
CMD_NAME = "wsp";
CHAT_NAME = "§6WS Power";

local accus = {peripheral.find("modular_accumulator")};
local chatBox = peripheral.find("chatBox");

local doNotice = false;

local rsOutput = false;
local forceOutput = false;
local forcedOutput = false;
redstone.setOutput("top", rsOutput)

local maxCap = 0;
for _, accu in ipairs(accus) do
  maxCap = maxCap + accu.getCapacity();
end

string.startswith = function(self, str)
  return self:find('^' .. str) ~= nil
end

local function getEnergyPercent()
  local total = 0;
  for _, accu in ipairs(accus) do
    total = total + accu.getEnergy();
  end
  return math.floor(total / maxCap * 100);
end

local function getAlert(amt, error)
  local msg = amt .. "% base power remaining.";
  if forceOutput then
    msg = msg .. " Forcing output: " .. (forcedOutput and "OFF" or "ON");
  end
  return msg;
end

local function chatAlert(amt, error)
  error = error or false;
  local msg = getAlert(amt, error);
  print(msg);

  local color = error and "§c" or "§b";
  chatBox.sendMessage(msg, CHAT_NAME, "<>", color)
end

local function chatAlertPlayer(msg, username, error)
  error = error or false;

  local color = error and "§c" or "§b";
  chatBox.sendMessageToPlayer(msg, username, CHAT_NAME, "<>");
end

local function modPower()
  local remain = getEnergyPercent();

  if remain < MIN_CAP then
    if not rsOutput then chatAlert(remain, true); end
    rsOutput = true
  elseif rsOutput and remain > ALLOW_CAP then
    if rsOutput then chatAlert(remain); end
    rsOutput = false
  end

  local activePower = false;
  if forceOutput then activePower = forcedOutput
  else activePower = rsOutput
  end

  redstone.setOutput("top", activePower);
end

modPower();

local updateTimer = os.startTimer(MSG_INTERVAL);
local checkTimer = os.startTimer(TEST_INTERVAL);

while true do
  local event, id, message, _, isHidden = os.pullEvent();

  if event == "timer" then
    if id == updateTimer then
      if not rsOutput and doNotice then
        chatAlert(getEnergyPercent());
      end
      updateTimer = os.startTimer(MSG_INTERVAL);
    end
    if id == checkTimer then
      modPower();
      checkTimer = os.startTimer(TEST_INTERVAL);
    end
  elseif event == "chat" and isHidden and string.startswith(message, CMD_NAME) then
    if message == CMD_NAME .. " on" then
      forceOutput = true;
      forcedOutput = false;
      chatAlertPlayer("Forcing output ON.", id);
    elseif message == CMD_NAME .. " off" then
      forceOutput = true;
      forcedOutput = true;
      chatAlertPlayer("Forcing output OFF.", id);
    elseif message == CMD_NAME .. " reset" then
      forceOutput = false;
      chatAlertPlayer("Reset.", id);
    elseif message == CMD_NAME .. " status" then
      local msg = getAlert(getEnergyPercent());
      chatAlertPlayer(msg, id);
    elseif message == CMD_NAME .. " notify" then
      doNotice = not doNotice;
      chatAlertPlayer("Updates: " .. (doNotice and "ON" or "OFF"), id);
    end
  end
end