local MODEM_SIDE = "bottom"
local MONITOR_SIDE = "left"
local MASTER_PROTOCOL = "rtm_master_state"
local REQUEST_PROTOCOL = "rtm_master_query"
local CLIENT_NAME = "dispatcher_monitor"
local native = term.current()

local monitor = nil
local masterId = nil
local blink = false
local lastState = nil
local lastSeen = 0

local DEFAULT_MARKERS = {
  green = { 26, 4 },
  blue = { 42, 4 },
  red = { 26, 19 },
  purple = { 42, 19 },
}

local SEGMENTS = {
  top_left_outer   = { points = { {4,6}, {9,6}, {14,6}, {19,6} } },
  top_left_inner   = { points = { {21,6}, {25,6}, {29,6}, {33,6} } },
  top_right_inner  = { points = { {39,6}, {43,6}, {47,6}, {51,6} } },
  top_right_outer  = { points = { {53,6}, {58,6}, {63,6}, {68,6} } },
  bot_left_outer   = { points = { {4,17}, {9,17}, {14,17}, {19,17} } },
  bot_left_inner   = { points = { {21,17}, {25,17}, {29,17}, {33,17} } },
  bot_right_inner  = { points = { {39,17}, {43,17}, {47,17}, {51,17} } },
  bot_right_outer  = { points = { {53,17}, {58,17}, {63,17}, {68,17} } },
  green_diag       = { points = { {19,6}, {23,8}, {27,10}, {31,12}, {35,13} } },
  red_diag         = { points = { {21,16}, {25,14}, {29,12}, {33,10}, {36,9} } },
  blue_diag        = { points = { {39,10}, {43,9}, {47,7}, {51,6} } },
  purple_diag      = { points = { {39,12}, {43,14}, {47,16}, {51,18} } },
}

local function openNet()
  if peripheral.getType(MODEM_SIDE) ~= "modem" then error("Nincs modem a bottom oldalon") end
  if not rednet.isOpen(MODEM_SIDE) then rednet.open(MODEM_SIDE) end
end

local function initMonitor()
  if peripheral.getType(MONITOR_SIDE) ~= "monitor" then error("Nincs monitor a left oldalon") end
  monitor = peripheral.wrap(MONITOR_SIDE)
  monitor.setTextScale(0.5)
end

local function drawLineTerm(target, x1, y1, x2, y2, color)
  term.redirect(target)
  paintutils.drawLine(x1, y1, x2, y2, color)
end

local function drawPolyline(target, points, color)
  for i = 1, #points - 1 do
    drawLineTerm(target, points[i][1], points[i][2], points[i + 1][1], points[i + 1][2], color)
  end
end

local function routeByKey(key)
  if not lastState or not lastState.routes then return nil end
  for _, route in ipairs(lastState.routes) do
    if route.key == key then return route end
  end
  return nil
end

local function hasAlert(route)
  if not route then return true end
  return route.missing or route.offline
end

local function routeColor(route)
  if hasAlert(route) and blink then return colors.red end
  return route and route.color or colors.gray
end

local function drawSegment(name, color)
  local seg = SEGMENTS[name]
  if seg then drawPolyline(monitor, seg.points, color) end
end

local function drawMap()
  local green = routeByKey("green")
  local blue = routeByKey("blue")
  local red = routeByKey("red")
  local purple = routeByKey("purple")

  monitor.setBackgroundColor(colors.black)
  monitor.clear()

  drawSegment("top_left_outer", colors.gray)
  drawSegment("top_right_outer", colors.gray)
  drawSegment("bot_left_outer", colors.gray)
  drawSegment("bot_right_outer", colors.gray)

  drawSegment("top_left_inner", (green and not green.active) and routeColor(green) or colors.gray)
  drawSegment("top_right_inner", (blue and not blue.active) and routeColor(blue) or colors.gray)
  drawSegment("bot_left_inner", (red and not red.active) and routeColor(red) or colors.gray)
  drawSegment("bot_right_inner", (purple and not purple.active) and routeColor(purple) or colors.gray)

  drawSegment("green_diag", (green and green.active) and routeColor(green) or colors.gray)
  drawSegment("blue_diag", (blue and blue.active) and routeColor(blue) or colors.gray)
  drawSegment("red_diag", (red and red.active) and routeColor(red) or colors.gray)
  drawSegment("purple_diag", (purple and purple.active) and routeColor(purple) or colors.gray)
end

local function drawMarkers()
  if not lastState or not lastState.routes then return end
  for i, route in ipairs(lastState.routes) do
    local marker = route.marker or DEFAULT_MARKERS[route.key]
    if marker then
      monitor.setCursorPos(marker[1], marker[2])
      monitor.setBackgroundColor(colors.black)
      if hasAlert(route) and blink then
        monitor.setTextColor(colors.red)
      elseif lastState.selected == i then
        monitor.setTextColor(colors.white)
      else
        monitor.setTextColor(route.color)
      end
      monitor.write(route.active and "[*]" or "[ ]")
    end
  end
end

local function drawLegend()
  if not lastState or not lastState.routes then return end
  local _, h = monitor.getSize()
  local startY = math.max(1, h - #lastState.routes - 1)
  for i, route in ipairs(lastState.routes) do
    monitor.setCursorPos(2, startY + i - 1)
    monitor.setBackgroundColor(colors.black)
    if hasAlert(route) and blink then
      monitor.setTextColor(colors.red)
    elseif lastState.selected == i then
      monitor.setTextColor(colors.white)
    else
      monitor.setTextColor(route.color)
    end
    local stateText = route.active and "KERESZT" or "EGYENES"
    local line = (route.active and "[*] " or "[ ] ") .. route.name .. " ID:" .. tostring(route.slaveId or "-") .. " " .. stateText
    if route.missing then
      line = line .. " NINCS ID"
    elseif route.offline then
      line = line .. " OFFLINE"
    end
    monitor.write(line)
  end
end

local function drawStatus()
  monitor.setCursorPos(2, 22)
  monitor.setBackgroundColor(colors.black)
  monitor.setTextColor(colors.white)
  if masterId then
    monitor.write("MASTER ID: " .. masterId .. "  LAST: " .. math.floor(os.clock() - lastSeen) .. "s")
  else
    monitor.write("MASTER KERESES...")
  end
end

local function redraw()
  term.redirect(monitor)
  drawMap()
  drawMarkers()
  drawLegend()
  drawStatus()
  term.redirect(native)
end

local function findMaster()
  local found = rednet.lookup(MASTER_PROTOCOL, "rtm_master", 2)
  if found then masterId = found end
end

local function requestState()
  if not masterId then
    findMaster()
    return
  end
  rednet.send(masterId, { cmd = "get_panel_state", client = os.getComputerID() }, REQUEST_PROTOCOL)
  local senderId, msg, protocol = rednet.receive(REQUEST_PROTOCOL, 0.8)
  if senderId == masterId and protocol == REQUEST_PROTOCOL and type(msg) == "table" and msg.routes then
    lastState = msg
    lastSeen = os.clock()
  else
    masterId = nil
  end
end

openNet()
initMonitor()
redraw()

while true do
  requestState()
  blink = not blink
  redraw()
  sleep(1)
end