local gate = peripheral.wrap("top")
local meth = peripheral.getMethods("top")

-- Load config.json
local file = fs.open("config.json", "r")
local config = textutils.unserializeJSON(file.readAll())
file.close()

local PC_ID  = config["PC_ID"]
local WH_URL = config["WH_URL"]


while true do
  local low  = gate.getSignalLowFlow()
  local high = gate.getSignalHighFlow()
  
  if not fs.exists("data.json") then
    local data = textutils.unserializeJSON('{ "low": '.. low ..', "high": '.. high ..' }')
    local file = fs.open("data.json", "w")
    file.write(textutils.serialiseJSON(data))
    file.close()
  end

  local file = fs.open("data.json", "r")
  local json = textutils.unserializeJSON(file.readAll())
  file.close()

  if json.low ~= low then
    local success = false
    while not success do
      local res = http.post(
        WH_URL .. '?wait=true',
        '{"embeds": [ { "title": "Flow limit changed (low)", "author": { "name": "' .. PC_ID .. '" }, "description": "Flow rate (low): ' .. json.low .. ' RF/t -> ' .. low ..' RF/t", "color": 16747013 } ] }',
        { ['Content-Type'] = 'application/json' },
        false
      )
      if res ~= nil then
        success = true
      else
        print("POST request failed; retrying")
        sleep(1)
      end
    end
    json.low = low
  end

  if json.high ~= high then
    local success = false
    while not success do
      local res = http.post(
        WH_URL .. '?wait=true',
        '{"embeds": [ { "title": "Flow limit changed (high)", "author": { "name": "' .. PC_ID .. '" }, "description": "Flow rate (high): ' .. json.high .. ' RF/t -> ' .. high ..' RF/t", "color": 16747013 } ] }',
        { ['Content-Type'] = 'application/json' },
        false
      )
      if res ~= nil then
        success = true
      else
        print("POST request failed; retrying")
        sleep(1)
      end
    end
    json.high = high
  end

  local file = fs.open("data.json", "w")
  file.write(textutils.serialiseJSON(json))
  file.close()

  sleep(1)
end