-- bar_ui.lua  (run on your UI-side computer)

-- ========================================================
-- Peripheral wrapping
-- ========================================================
rednet.open("left")
local monitorBar = assert(peripheral.wrap("back"), "Bar monitor not found")

-- ========================================================
-- Formatting
-- ========================================================
local function formatK(val)
  if not val then return "-" end
  if val >= 1000 then return string.format("%dk", math.floor(val/1000)) end
  return tostring(val)
end

-- ========================================================
-- Monitor Bar UI (with 3-color bar and min/max markers)
-- ========================================================
local function monitorBarUI(data)
  monitorBar.setBackgroundColor(colors.black)
  monitorBar.clear()
  monitorBar.setTextScale(0.5)

  local width, _    = monitorBar.getSize()
  local margin      = 2
  local barWidth    = width - margin * 2
  local curTotal    = data.totalEnergy
  local maxTotal    = data.totalCapacity
  local fillColumns = (data.accPct / 100) * barWidth

  -- compute marker positions
  local minPct       = maxTotal > 0 and (data.minEnergy / maxTotal) or 0
  local markerMinPos = math.floor(minPct * barWidth + 0.5)
  local maxPct       = maxTotal > 0 and (data.maxEnergy / maxTotal) or 0
  local markerMaxPos = math.floor(maxPct * barWidth + 0.5)

  -- decide bar color by current energy
  local barColor
  if curTotal < 36000000 then
    barColor = colors.red
  elseif curTotal < data.minEnergy then
    barColor = colors.orange
  else
    barColor = colors.lime
  end

  -- header: “XX.X%    123k/900k”
  local pctStr    = string.format("%.1f%%", data.accPct)
  local curMaxStr = formatK(curTotal) .. "/" .. formatK(maxTotal)
  local header    = pctStr .. string.rep(" ", width - #pctStr - #curMaxStr) .. curMaxStr

  local fillChar = string.char(149)
  local barLines = {}

  -- build each line of the bar
  for _ = 1, 5 do
    local line = ""
    for j = 1, barWidth do
      if j == markerMinPos or j == markerMaxPos then
        line = line .. "|"
      else
        local floor = math.floor(fillColumns)
        if j <= floor or (j == floor + 1 and fillColumns % 1 > 0) then
          line = line .. fillChar
        else
          line = line .. " "
        end
      end
    end
    table.insert(barLines, string.rep(" ", margin) .. line .. string.rep(" ", margin))
  end

  -- draw header
  monitorBar.setCursorPos(1, 2)
  monitorBar.setTextColor(colors.white)
  monitorBar.write(header)

  -- draw the bar
  for i, line in ipairs(barLines) do
    monitorBar.setCursorPos(1, 2 + i)
    for j = 1, #line do
      local c     = line:sub(j, j)
      local idx   = j - margin
      local floor = math.floor(fillColumns)
      if c == "|" then
        -- draw marker
        monitorBar.setTextColor(colors.black)
        monitorBar.setBackgroundColor(idx <= fillColumns and barColor or colors.gray)
        monitorBar.write("|")
      elseif idx >= 1 and idx <= floor then
        -- filled
        monitorBar.setTextColor(barColor)
        monitorBar.setBackgroundColor(barColor)
        monitorBar.write(fillChar)
      elseif idx == floor + 1 and fillColumns % 1 > 0 then
        -- partial fill
        monitorBar.setTextColor(barColor)
        monitorBar.setBackgroundColor(colors.gray)
        monitorBar.write(fillChar)
      elseif idx > 0 and idx <= barWidth then
        -- empty
        monitorBar.setTextColor(colors.gray)
        monitorBar.setBackgroundColor(colors.gray)
        monitorBar.write(" ")
      else
        -- margin
        monitorBar.setTextColor(colors.white)
        monitorBar.setBackgroundColor(colors.black)
        monitorBar.write(" ")
      end
    end
  end

  -- bottom labels: min and max as percentages
  local minLabel     = string.format("%.1f%%", (data.minEnergy / maxTotal) * 100)
  local maxLabel     = string.format("%.1f%%", (data.maxEnergy / maxTotal) * 100)
  local leftPadding  = margin + markerMinPos - math.floor(#minLabel / 2) - 1
  local bottomLine   = string.rep(" ", math.max(0, leftPadding)) .. minLabel
  local gap          = (margin + markerMaxPos - math.floor(#maxLabel / 2) - 1) - #bottomLine
  if gap > 0 then
    bottomLine = bottomLine .. string.rep(" ", gap)
  end
  bottomLine = bottomLine .. maxLabel

  monitorBar.setCursorPos(1, 2 + #barLines + 1)
  monitorBar.setTextColor(colors.white)
  monitorBar.setBackgroundColor(colors.black)
  monitorBar.write(bottomLine)
end

-- ========================================================
-- Receive & render loop
-- ========================================================
while true do
  local _, data = rednet.receive("generator_status")
  monitorBarUI(data)
end