-- showimg <nfp_url> [scale]
-- Downloads a .nfp (paintutils image) and displays it centered on the first connected monitor.

local args = { ... }
if not args[1] then
  print("Usage: showimg <nfp_url> [scale]")
  return
end

local url   = args[1]
local scale = tonumber(args[2]) or 0.5

local mon = peripheral.find("monitor")
if not mon then
  print("No monitor found. Place the computer next to a monitor.")
  return
end

if scale < 0.5 then scale = 0.5 end
if scale > 5 then scale = 5 end
mon.setTextScale(scale)

if not http then
  print("HTTP API unavailable. Enable http in CC config/server config.")
  return
end

local function fetch(u)
  local r = http.get(u, { ["Cache-Control"] = "no-cache" })
  if not r then return nil, "HTTP request failed" end
  local body = r.readAll()
  r.close()
  return body
end

local body, err = fetch(url)
if not body then
  print("Download error: " .. (err or "unknown"))
  return
end

local tmp = "/.showimg.nfp"
local fh = fs.open(tmp, "w")
fh.write(body)
fh.close()

local img = paintutils.loadImage(tmp)
if not img then
  print("Invalid .nfp content. Make sure the URL is the RAW .nfp file.")
  return
end

-- determine image width/height in characters
local ih = #img
local iw = 0
for y = 1, ih do
  iw = math.max(iw, #img[y])
end

local ow, oh = mon.getSize()
local ox = math.max(1, math.floor((ow - iw) / 2) + 1)
local oy = math.max(1, math.floor((oh - ih) / 2) + 1)

local old = term.redirect(mon)
paintutils.drawFilledBox(1, 1, ow, oh, colors.black)
paintutils.drawImage(img, ox, oy)
term.redirect(old)

print(("Done: %dx%d image at scale %.1f"):format(iw, ih, scale))