test

-- === Palette Setup ===
function set256Palette()
  local cubeSize = 6
  for i = 16, 231 do
    local index = i - 16
    local rIndex = math.floor(index / (cubeSize * cubeSize))
    local gIndex = math.floor((index % (cubeSize * cubeSize)) / cubeSize)
    local bIndex = index % cubeSize
    local r = math.floor(rIndex * 255 / (cubeSize - 1))
    local g = math.floor(gIndex * 255 / (cubeSize - 1))
    local b = math.floor(bIndex * 255 / (cubeSize - 1))
    term.setPaletteColor(i, r / 255, g / 255, b / 255)
  end
  for i = 232, 255 do
    local gray = math.floor((i - 232) * 255 / 23)
    term.setPaletteColor(i, gray / 255, gray / 255, gray / 255)
  end
end

-- === BMP Font and Color Helpers ===
local FONT_BMP_URL = "https://files.catbox.moe/zkdsi9.bmp"
local FONT_BMP_FILE = "font.bmp"
local TRANSPARENT_COLOR = { r = 34, g = 177, b = 76 }

local function download(url, file)
  if fs.exists(file) then return end
  local h = http.get(url, nil, true)
  assert(h, "Download failed: " .. url)
  local f = fs.open(file, "wb")
  f.write(h.readAll())
  f.close()
  h.close()
end

local function readBMP(filename)
  local file = fs.open(filename, "rb")
  if not file then return nil, "Failed to open file" end
  local header = file.read(54)
  local width = string.byte(header, 19) + string.byte(header, 20) * 256
  local height = string.byte(header, 23) + string.byte(header, 24) * 256
  local pixels = {}
  for y = height, 1, -1 do
    pixels[y] = {}
    for x = 1, width do
      local b = file.read(1)
      local g = file.read(1)
      local r = file.read(1)
      pixels[y][x] = {r = string.byte(r), g = string.byte(g), b = string.byte(b)}
    end
    if y % 10 == 0 then os.queueEvent("yield") os.pullEvent("yield") end
  end
  file.close()
  return {width = width, height = height, pixels = pixels}
end

local function mapColor256(r, g, b)
  local cubeSize = 6
  local rIndex = math.floor(r / (255 / (cubeSize - 1)))
  local gIndex = math.floor(g / (255 / (cubeSize - 1)))
  local bIndex = math.floor(b / (255 / (cubeSize - 1)))
  return 16 + rIndex * cubeSize * cubeSize + gIndex * cubeSize + bIndex
end

-- Accepts color as palette index
local function drawTextHalfRes(font, x, y, str, color)
  color = color or 231 -- Default to white for best visibility
  for i=1,#str do
    local c = string.byte(str,i)-32
    if c>=0 and c<120 then
      local sx = (c%15)*20
      local sy = math.floor(c/15)*20
      for dy=0,9 do
        for dx=0,9 do
          local p = font.pixels[sy+dy*2+1][sx+dx*2+1]
          if not (p.r==TRANSPARENT_COLOR.r and p.g==TRANSPARENT_COLOR.g and p.b==TRANSPARENT_COLOR.b) then
            term.setPixel(x+(i-1)*10+dx, y+dy, color)
          end
        end
      end
    end
  end
end

local function drawBMPScaled(bmp, x, y, maxw, maxh)
  local iw, ih = bmp.width, bmp.height
  local scale = math.min(maxw/iw, maxh/ih, 1)
  local w, h = math.floor(iw*scale), math.floor(ih*scale)
  for dy = 0, h-1 do
    local srcY = math.floor(dy * ih / h) + 1
    for dx = 0, w-1 do
      local srcX = math.floor(dx * iw / w) + 1
      local p = bmp.pixels[srcY][srcX]
      term.setPixel(x+dx, y+dy, mapColor256(p.r, p.g, p.b))
    end
  end
  return w, h
end

-- === Base64 decode for BMP data:images ===
local b='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
local function base64_decode(data)
  data = data:gsub("[^"..b.."=]", "")
  return (data:gsub('.', function(x)
    if (x == '=') then return '' end
    local r,f='',(b:find(x)-1)
    for i=6,1,-1 do r=r..(f%2^i - f%2^(i-1) > 0 and '1' or '0') end
    return r
  end):gsub('%d%d%d?%d?%d?%d?%d?%d?', function(x)
    if #x ~= 8 then return '' end
    local c=0
    for i=1,8 do c=c + (x:sub(i,i)=='1' and 2^(8-i) or 0) end
    return string.char(c)
  end))
end

-- === CSS helpers ===
local css_colors = { red=196, green=46, blue=21, black=16, white=231, yellow=226, gray=244 }
local function cssColorToPalette(c)
  if css_colors[c] then return css_colors[c]
  elseif c:sub(1,1) == "#" and #c == 7 then
    local r = tonumber(c:sub(2,3),16)
    local g = tonumber(c:sub(4,5),16)
    local b = tonumber(c:sub(6,7),16)
    return mapColor256(r,g,b)
  else return 231 end
end

local function parseFontSize(sz)
  if not sz then return 12 end
  local n = tonumber(sz:match("^(%d+)"))
  if not n then return 12 end
  return math.max(8, math.min(36, n))
end

-- Check if a palette index is light or dark for contrast
local function isLightPalette(idx)
  local r, g, b = term.getPaletteColor(idx)
  local brightness = 0.299*r + 0.587*g + 0.114*b
  return brightness > 0.5
end

-- === HTML/CSS Parsing ===

-- Minimal HTML to DOM tree
local function parseHTMLtoDOM(html)
  local dom = { tag="body", children={}, style={}, attrs={} }
  local stack = { dom }
  local pos = 1
  while pos <= #html do
    local tagStart, tagEnd, tagText = html:find("<([/%w][^>]*)>", pos)
    if tagStart then
      -- Text before tag
      if tagStart > pos then
        local text = html:sub(pos, tagStart-1):gsub("\n", "")
        if #text > 0 then
          table.insert(stack[#stack].children, { tag="text", text=text, style={}, attrs={} })
        end
      end
      -- Tag
      local isClose = tagText:sub(1,1) == "/"
      local tagName = tagText:match("^/?([%w]+)")
      if isClose then
        table.remove(stack) -- pop
      else
        local attrs = {}
        for k,v in tagText:gmatch("([%w-]+)%s*=%s*['\"](.-)['\"]") do
          attrs[k] = v
        end
        local node = { tag=tagName, children={}, style={}, attrs=attrs }
        table.insert(stack[#stack].children, node)
        if not tagText:find("/$") then -- not self-closing
          table.insert(stack, node)
        end
      end
      pos = tagEnd+1
    else
      -- Remaining text
      local text = html:sub(pos):gsub("\n", "")
      if #text > 0 then
        table.insert(stack[#stack].children, { tag="text", text=text, style={}, attrs={} })
      end
      break
    end
  end
  return dom
end

-- Simple CSS parser (only color, background, font-size)
local function parseCSS(css)
  local rules = {}
  for selector, body in css:gmatch("([%w%.#%s]+)%s*{%s*([^}]+)}") do
    local props = {}
    for k,v in body:gmatch("([%w-]+)%s*:%s*([^;]+)") do
      props[k] = v
    end
    table.insert(rules, { selector=selector:match("^%s*(.-)%s*$"), props=props })
  end
  return rules
end

-- Apply CSS rules to DOM nodes (very basic: tag, .class, #id)
local function applyCSS(dom, rules)
  local function matches(node, selector)
    if selector:sub(1,1) == "." then
      return node.attrs.class == selector:sub(2)
    elseif selector:sub(1,1) == "#" then
      return node.attrs.id == selector:sub(2)
    else
      return node.tag == selector
    end
  end
  local function apply(node)
    for _,rule in ipairs(rules) do
      if matches(node, rule.selector) then
        for k,v in pairs(rule.props) do
          node.style[k] = v
        end
      end
    end
    -- Inline style
    if node.attrs.style then
      for k,v in node.attrs.style:gmatch("([%w-]+)%s*:%s*([^;]+)") do
        node.style[k] = v
      end
    end
    for _,child in ipairs(node.children or {}) do apply(child) end
  end
  apply(dom)
end

-- === DOM Renderer ===
local function renderDOM(node, font, x, y, maxw)
  if node.tag == "text" then
    local bg = node.style["background"] and cssColorToPalette(node.style["background"]) or 16 -- black default
    local color = node.style.color and cssColorToPalette(node.style.color) or (isLightPalette(bg) and 16 or 231)
    local fontSize = parseFontSize(node.style["font-size"])
    term.drawPixels(x, y, bg, maxw, fontSize)
    drawTextHalfRes(font, x, y, node.text, color)
    return y + fontSize
  elseif node.tag == "img" and node.attrs.src and node.attrs.src:find("^data:image/bmp;base64,") then
    local b64 = node.attrs.src:match("^data:image/bmp;base64,(.+)")
    if b64 then
      local bmpData = base64_decode(b64)
      local tmpFile = ".browser_img_"..os.epoch("utc")..".bmp"
      local f = fs.open(tmpFile, "wb")
      f.write(bmpData)
      f.close()
      local bmp = readBMP(tmpFile)
      if bmp then
        local w, h = drawBMPScaled(bmp, x, y, 200, 60)
        return y + h + 2
      end
    end
    return y + 12
  else
    local newY = y
    for _,child in ipairs(node.children or {}) do
      newY = renderDOM(child, font, x, newY, maxw)
    end
    return newY
  end
end

-- === Browser Logic ===
term.setGraphicsMode(2)
set256Palette()
local pxw, pxh = term.getSize(2)
download(FONT_BMP_URL, FONT_BMP_FILE)
local font = readBMP(FONT_BMP_FILE)

local function getURLInput(current)
  term.setGraphicsMode(0)
  term.setCursorPos(1, 1)
  term.clearLine()
  write("URL: ")
  local url = read()
  if url == "" then url = current end
  term.setGraphicsMode(2)
  return url
end

local url = "https://example.com"
local dom, cssRules = nil, {}
local scroll = 0
local contentHeight = 0

while true do
  term.setFrozen(true)
  term.drawPixels(0, 0, 240, pxw, 20)
  term.drawPixels(0, 20, 255, pxw, pxh-20)
  drawTextHalfRes(font, 10, 5, url)
  if dom then
    -- Measure content height for scroll bounds
    local function measureDOM(node, font, x, y, maxw)
      if node.tag == "text" then
        local fontSize = parseFontSize(node.style["font-size"])
        return y + fontSize
      elseif node.tag == "img" and node.attrs.src and node.attrs.src:find("^data:image/bmp;base64,") then
        local b64 = node.attrs.src:match("^data:image/bmp;base64,(.+)")
        if b64 then
          local bmpData = base64_decode(b64)
          local tmpFile = ".browser_img_"..os.epoch("utc")..".bmp"
          local f = fs.open(tmpFile, "wb")
          f.write(bmpData)
          f.close()
          local bmp = readBMP(tmpFile)
          if bmp then
            local w, h = drawBMPScaled(bmp, -1000, -1000, 200, 60) -- offscreen
            return y + h + 2
          end
        end
        return y + 12
      else
        local newY = y
        for _,child in ipairs(node.children or {}) do
          newY = measureDOM(child, font, x, newY, maxw)
        end
        return newY
      end
    end
    contentHeight = measureDOM(dom, font, 10, 25, pxw-20) - 25
    renderDOM(dom, font, 10, 25 - scroll, pxw-20)
  end
  term.setFrozen(false)
  local event, p1, p2, p3 = os.pullEvent()
  if event == "mouse_click" then
    local btn, x, y = p1, p2, p3
    if y <= 20 then
      url = getURLInput(url)
      term.setFrozen(true)
      drawTextHalfRes(font, 10, 25, "Loading...")
      term.setFrozen(false)
      local ok, resp = pcall(function() return http.get(url) end)
      if ok and resp then
        local html = resp.readAll()
        resp.close()
        dom = parseHTMLtoDOM(html)
        -- Extract <style>...</style> and parse CSS
        local css = ""
        for style in html:gmatch("<style[^>]*>(.-)</style>") do css = css .. style end
        cssRules = parseCSS(css)
        applyCSS(dom, cssRules)
      else
        dom = { tag="body", children={ {tag="text", text="Failed to load: "..tostring(url), style={}, attrs={}} }, style={}, attrs={} }
      end
      scroll = 0
    end
  elseif event == "mouse_scroll" then
    local dir = p1
    local maxScroll = math.max(0, contentHeight - (pxh-30))
    scroll = math.max(0, math.min(scroll + dir*12, maxScroll))
  elseif event == "key" then
    if p1 == keys.up then
      scroll = math.max(scroll-12, 0)
    elseif p1 == keys.down then
      local maxScroll = math.max(0, contentHeight - (pxh-30))
      scroll = math.min(scroll+12, maxScroll)
    elseif p1 == keys.pageup then
      scroll = math.max(scroll-(pxh-30), 0)
    elseif p1 == keys.pagedown then
      local maxScroll = math.max(0, contentHeight - (pxh-30))
      scroll = math.min(scroll+(pxh-30), maxScroll)
    elseif p1 == keys.q or p1 == keys.escape then
      break
    end
  elseif event == "terminate" then
    break
  end
end

term.setGraphicsMode(0)
term.clear()
print("Browser exited.")