Computercraft Web Browser

local w, h = term.getSize()
local buffer = window.create(term.current(), 1, 1, w, h)
local oldTerm = term.redirect(buffer)
local succ, mess = pcall(function()
rednet.open("top")
local history = {}
local currentSite = 1
local siteElements = {}
local programElements = {}
local onSite = false
local moveToSite
serverId = 0
local getFileFromServer = function(site, serverIp)
  local serverIp = serverIp
  rednet.broadcast(site, "get")
  local siteData = {
    "Error 404",
    "",
    "Site does not exist"
  }
  local startTime = os.clock()
  local timer = os.startTimer(0.5)

  while true do
    local event, senderId, message, protocol = os.pullEventRaw()
    if event == "rednet_message" then
      if protocol == "send"..site and not serverIp or (senderId == serverIp) then
        local serverIp = serverId
        siteData = textutils.unserialize(message)
        break
      end
    elseif event == "timer" then
      break
    end
  end
  os.cancelTimer(timer)
  return siteData, serverIp
end
local loadSite
local newElement = function(elementTab)
  return function(argTab)
    return setmetatable(
      argTab,
        {
          __index = elementTab
        }
      )
  end
end
local lastPage = function()
  if history[currentSite-1] then
    currentSite = currentSite - 1
    siteElements, serverIp = loadSite(getFileFromServer(history[currentSite]))
  end
end
local nextPage = function()
  if history[currentSite+1] then
    currentSite = currentSite + 1
    siteElements, serverIp = loadSite(getFileFromServer(history[currentSite]))
  end
end
local uiElements = {
  button = newElement({
    mouse_click = function(self, button, x, y)
      if self.t then error("test") end
      if x>=self.x and y>=self.y then
        if x<self.x+self.w and y<self.y+self.h then
          if self.clickedFunc then self:clickedFunc() end
        end
      end
    end,
    draw = function(self)
      if self.text then
        self.text:draw()
      end
    end
  }),
  text = newElement({
    draw = function(self)
      term.setCursorPos(self.x, self.y)
      term.setTextColor(self.color)
      if self.backgroundColor then
        term.setBackgroundColor(self.backgroundColor)
      else
        term.setBackgroundColor(colors.white)
      end
      term.write(self.text)
    end
  }),
  image = newElement({
    draw = function(self)
      for lineNum = 1, #self.image do
        local line = self.image[lineNum]
        term.setCursorPos(self.x, lineNum+self.y-1)
        for x = 1, #line do
          local char = string.sub(line, x, x)
          if char == " " then
            local xpos, ypos = term.getCursorPos()
            term.setCursorPos(xpos+1, ypos)
          else
            term.blit(char, char, char)
          end
        end
      end
    end
  }),
  script = newElement({}),
  box = newElement({
    draw = function(self)
      paintutils.drawFilledBox(self.x, self.y, self.x+self.w, self.y+self.h, self.color)
    end
  }),
  line = newElement({
    draw = function(self)
      paintutils.drawLine(self.x, self.y, self.x2, self.y2, self.color)
    end
  })
}
local elements = {
  image = function(path)
    local image = getFileFromServer(path)
    local x, y = term.getCursorPos()
    term.setCursorPos(x, y+#image)

    return uiElements.image({image = image, x = x, y = y})
  end,
  text = function(text)
    local x, y = term.getCursorPos()
    term.setCursorPos(x, y+1)
    return uiElements.text({
      text = text, color = term.getTextColor(), x = x, y = y
    })
  end,
  set = function(x, y)
    term.setCursorPos(tonumber(x), tonumber(y))
  end,
  move = function(mx, my)
    local x, y = term.getCursorPos()
    term.setCursorPos(x+mx, y+(my or 0))
  end,
  link = function(path, text)
    local x, y = term.getCursorPos()
    local text = text or path
    term.setCursorPos(x, y+1)
    return {
      uiElements.text({
        text = text, color = colors.blue, x = x, y = y
      }),
      uiElements.button({
        w = #text, h = 1,
        clickedFunc = function(self)
          moveToSite(path)
        end,
        x = x, y = y
      })
    }
  end,
  color = function(color)
    term.setTextColor(colors[color])
  end,
  script = function(path)
    local script = getFileFromServer(path)
    local scriptString = ""
    for lineNum = 1, #script do
      scriptString = scriptString .. script[lineNum].."\n"
    end
    local x, y = term.getCursorPos()
    local returnElement = uiElements.script({
      x = x, y = y,
      path = path,
      serverId = serverId
    })
    local succ
    local func, mess = load(scriptString, path, "t", setmetatable(returnElement,{__index = _G}))
    if func then
      succ, mess = pcall(func)
      if succ then
        return returnElement
      end
    end
    return uiElements.text({
      x = 1, y = h-1,
      text = mess, color = colors.red
    })
  end,
  box = function(w, h)
    local x, y = term.getCursorPos()
    return uiElements.box({
      x = x, y = y, w = w, h = h, color = term.getTextColor()
    })
  end,
  line = function(x2, y2)
    local x, y = term.getCursorPos()
    return uiElements.line({
      x = x, y = y, x2 = x+x2, y2 = y+y2, color = term.getTextColor()
    })
  end
}
local newElements = function(tab)
  return setmetatable(tab,
    {
      __index = {
        draw = function(self)
          for elementNum = 1, #self do
            local element = self[elementNum]
            if element[1] then
              self.draw(element)
            else
              if element.draw then
                element:draw()
              end
            end
          end
        end,
        scroll = function(self, move, hard)
          for i = 1, #self do
            if self[i][1] then
              self.scroll(self[i], move, self[i].movable or hard)
            else
              if self[i].y and (self[i].moveable or hard) then
                self[i].y = self[i].y - move
              end
            end
          end
        end,
        update = function(self, event, ...)
          if event == "mouse_scroll" then
            if self.scroll then
              self:scroll(({...})[1])
            end
          end
          for elementNum = 1, #self do
            local element = self[elementNum]
            if element[1] then
              self.update(element, event, ...)
            else
              if element.update then
                element:update(event, ...)
              end
              if element[event] then
                element[event](element, ...)
              end
            end
          end
        end
      }
    }
  )
end
local searchElements = newElements({movable=true})
loadSite = function(siteData)
  local siteElements = newElements({})
  term.setCursorPos(2, 2)
  for lineNum = 1, #siteData do
    local line = siteData[lineNum]
    local element = string.match(line, "^%S+")
    local arguments = {}
    if string.sub(line, 1, 1) == " " then
      element = "text"
      arguments = {string.sub(line, 2)}
    elseif not element then
      element = "text"
      arguments = {line}
    else
      for arg in string.gmatch(string.sub(line, #element+2), "[^,]+") do
        table.insert(arguments, arg)
      end
    end
    if elements[element] then
      table.insert(siteElements, elements[element](table.unpack(arguments)))
    end
  end
  siteElements:scroll(-1, true)
  return siteElements
end
moveToSite = function(site)
  for i = currentSite+1, #history do
    table.remove(history, i)
  end
  currentSite = currentSite + 1
  table.insert(history, site)
  siteElements, serverId = loadSite(getFileFromServer(site))
end
local search = function(str)
  if str ~= "" then
    searchElements = {}
    onSite = false
    rednet.broadcast(str, "find")
    local results = {}
    os.startTimer(0.1)
    while true do
      local event, var1, var2, var3 = os.pullEventRaw()
      if event == "rednet_message" and var3 == "findResult" then
        local siteResults = textutils.unserialize(var2)
        for i = 1, #siteResults do
          table.insert(results, siteResults[i])
        end
      elseif event == "timer" then
        break
      end
    end

    local sortedResults = table.sort(
      results,
      function(list1, list2)
        return list1.num>list2.num
      end
    )
    local y = 4
    for i = 1, #results do
      if results[i].num > 0 then
        local name = string.match(results[i].page, "[^/]*$")
        if name == "website" then
          name = string.match(results[i].page, "[^'mc.'']%a*.sol")
        end
        name = string.upper(string.sub(name, 1, 1))..string.sub(name, 2)
        local siteText = getFileFromServer(results[i].page)
        local tipText = ""
        local altTipText = ""
        for i = 1, #siteText do
          if string.sub(siteText[i], 1, 1) == " " then
            local line = string.sub(siteText[i], 2)
            tipText = string.match(line, ".*"..str..".*") or tipText
            altTipText = string.match(string.lower(line), ".*"..string.lower(str)..".*") or altTipText
          end
        end
        if tipText == "" then tipText = altTipText end
        table.insert(
          searchElements,
          {
            movable = true,
            uiElements.box({
              x = 3, y = y, w = 40, h = 2, color = colors.lightGray
            }),
            uiElements.button({
              x = 3, y = y, w = 40, h = 3, clickedFunc = function()
                searchElements = newElements({})
                onSite = true
                moveToSite(results[i].page)
              end
            }),
            uiElements.text({
              x = 3, y = y,
              text = name,
              color = colors.black,
              backgroundColor = colors.lightGray
            }),
            uiElements.text({
              x = 3, y = y+1,
              text = results[i].page,
              color = colors.gray,
              backgroundColor = colors.lightGray
            }),
            uiElements.text({
              x = 3, y = y+2,
              text = string.sub(tipText, 1, 41),
              color = colors.gray,
              backgroundColor = colors.lightGray
            })
          }
        )
        y = y + 4
      end
    end
    table.insert(searchElements,
    uiElements.text({
      x=1, y = 2, color = colors.gray,
      text = "Search had "..#searchElements.." results",
    }))
    searchElements = newElements(searchElements)
  end
end
programElements = newElements({
  uiElements.line({
    x = 1, y = 1, x2 = w, y2 = 1, color = colors.gray
  }),
  uiElements.button({
    x = 2, y = 1, w = 3, h = 1,
    text = uiElements.text({
      x = 2, y = 1, text = " < ", color = colors.gray, backgroundColor = colors.lightGray
    }),
    clickedFunc = function()
      lastPage()
    end
  }),
  uiElements.button({
    x = 6, y = 1, w = 3, h = 1,
    text = uiElements.text({
      x = 6, y = 1, text = " > ", color = colors.gray, backgroundColor = colors.lightGray
    }),
    clickedFunc = function()
      nextPage()
    end
  }),
  uiElements.button({
    x = 11, y = 1, w = 20, h = 1,
    text = uiElements.text({
      x = 11, y = 1, text = "search...       ", color = colors.gray, backgroundColor = colors.lightGray
    }),
    clickedFunc = function(self)
      term.setCursorPos(self.x, self.y)
      term.setBackgroundColor(colors.lightGray)
      term.setTextColor(colors.black)
      search(io.read())
    end
  }),
  uiElements.button({
    x = w, y = 1, h = 1, w = 1,
    clickedFunc = function(self)
      term.setBackgroundColor(colors.black)
      term.clear()
      term.setCursorPos(1, 1)
      error("", 0)
    end,
    text = uiElements.text({
      x = w, y = 1, text = "X", color = colors.orange, backgroundColor = colors.red
    }),
  })
})

while true do
  buffer.setVisible(false)
  term.setBackgroundColor(colors.white)
  term.clear()
  if onSite then
    siteElements:draw()
  else
    searchElements:draw()
  end
  programElements:draw()
  buffer.setVisible(true)
  local event, var1, var2, var3 = os.pullEventRaw()
  if event == "mouse_scroll" then
    if onSite then
      siteElements:scroll(var1, true)
    else
      programElements:scroll(var1)
    end
  end
  if event == "key" then
    local key = keys.getName(var1)
    if key == "left" then
      lastPage()
    elseif key == "right" then
      nextPage()
    end
    if onSite and key == "r" then
      --moveToSite(history[currentSite])
    end
  end
  programElements:update(event, var1, var2, var3)
  if onSite then
    siteElements:update(event, var1, var2, var3)
  else
    searchElements:update(event, var1, var2, var3)
  end
end
end)
term.redirect(oldTerm)
buffer.setVisible(false)
term.setBackgroundColor(colors.black)
term.setTextColor(colors.red)
term.clear()
term.setCursorPos(1, 1)
print(mess)