Tellraw system for OC

local event = require('event')
local term = require('term')
local gpu = term.gpu()
local debug = require('component').debug
local unicode = require('unicode')
local fs = require('filesystem')

local hex = '0123456789abcdef'
local colors = {
  0x000000, -- 0
  0x0000aa, -- 1
  0x00aa00, -- 2
  0x00aaaa, -- 3
  0xaa0000, -- 4
  0xaa00aa, -- 5
  0xffaa00, -- 6
  0xaaaaaa, -- 7
  0x555555, -- 8
  0x5555ff, -- 9
  0x55ff55, -- a
  0x55ffff, -- b
  0xff5555, -- c
  0xff55ff, -- d
  0xffff55, -- e
  0xffffff  -- f
}

local ofg = gpu.setForeground(colors[16])
local obg = gpu.setBackground(colors[1])
local ow, oh = gpu.getResolution()
gpu.setResolution(80, 25)

term.clear()

for i = 1, 16 do
  if i < 3 then
    gpu.setForeground(0xffffff)
  else
    gpu.setForeground(0x000000)
  end

  gpu.setBackground(colors[i])

  gpu.set((i - 1) * 5 + 1, 4, '  ' .. hex:sub(i, i) .. '  ')
end

gpu.set(76, 4, unicode.char(9656))
gpu.set(80, 4, unicode.char(9666))

gpu.fill(1, 5, 80, 1, ' ')
gpu.set(18, 5, 'Quit')
gpu.set(54, 5, 'Run /tellraw')

gpu.setForeground(colors[16])
gpu.setBackground(colors[1])

local text = ''
local colr = ''
local cursor = 1
local scroll = 0
local ccolor = 16

local function waitForEvent()
  local char, fg, bg = gpu.get(cursor - scroll, 1)
  local ofg = gpu.getForeground()
  local obg = gpu.getBackground()
  local isShown = true

  while true do
    if isShown then
      gpu.setForeground(bg)
      gpu.setBackground(fg)
    else
      gpu.setForeground(fg)
      gpu.setBackground(bg)
    end

    isShown = not isShown

    gpu.set(cursor - scroll, 1, char)

    local evt, arg1, arg2, arg3, arg4, arg5, arg6 = event.pull(0.5)

    if evt then
      gpu.setForeground(fg)
      gpu.setBackground(bg)
      gpu.set(cursor - scroll, 1, char)
      gpu.setForeground(ofg)
      gpu.setBackground(obg)

      return evt, arg1, arg2, arg3, arg4, arg5, arg6
    end
  end
end

local function getWidth()
  return ({gpu.getResolution()})[1]
end

local function setCursor(x)
  cursor = math.max(math.min(x, text:len() + 1), 1)

  if cursor - scroll < 6 then
    scroll = math.max(cursor - 6, 0)
  end

  local width = getWidth()

  if cursor - scroll > width - 7 then
    scroll = cursor - width + 7
  end
end

local function setCursorBy(delta)
  setCursor(cursor + delta)
end

local function drawLine()
  local width = getWidth()

  local toDraw = text:sub(scroll + 1, scroll + width - 3)
  local toColr = colr:sub(scroll + 1, scroll + width - 3)

  local obg = gpu.setBackground(0x000000)
  local ofg = gpu.setForeground(0xffffff)

  gpu.fill(1, 1, width - 3, 2, ' ')

  for i = 1, width do
    local color = hex:find(toColr:sub(i, i))
    gpu.setForeground(colors[color])

    if color == 1 then
      gpu.setBackground(0xffffff)
    else
      gpu.setBackground(obg)
    end

    gpu.set(i, 1, toDraw:sub(i, i))
  end

  gpu.setForeground(colors[9])
  gpu.setBackground(colors[1])
  gpu.set(1, 2, toColr)

  gpu.setForeground(colors[1])
  gpu.setBackground(colors[5])
  gpu.set(width - 2, 1, ' x ')

  gpu.setBackground(obg)
  gpu.setForeground(ofg)
end

local function escape(char)
  local hex = ('%x'):format(string.byte(char))

  return '\\u' .. string.rep('0', 4 - hex:len()) .. hex
end

local function runCommand()
  if text:len() > 0 then
    local json = '["'
    local last = nil

    for i = 1, colr:len() do
      local color = colr:sub(i, i)

      if color ~= last then
        json = json .. '\\u00a7' .. color
        last = color
      end

      local char = text:sub(i, i)
      json = json .. escape(char)

      if char == '\n' then
        last = 16
      end
    end

    json = json .. '"]'

    local status, result = debug.runCommand('/tellraw @a ' .. json)
  end
end

local function drawSaves()
  local obg = gpu.getBackground()
  local ofg = gpu.setForeground(colors[1])
  local w, h = gpu.getResolution()

  for i = 1, h - 5 do
    local num = tostring(i)

    gpu.setBackground(colors[4])
    gpu.set(1, i + 5, ' ' .. string.rep('0', 3 - num:len()) .. num .. ' ')
    gpu.setBackground(colors[5])
    gpu.set(w - 2, i + 5, ' x ')
    gpu.setBackground(colors[8])
    gpu.fill(6, i + 5, (w / 2) - 4, 1, ' ')
    gpu.set(2 + w / 4, i + 5, 'Save')

    if fs.exists('/home/tellraw.save.' .. num) then
      gpu.setBackground(colors[8])
    else
      gpu.setBackground(colors[9])
    end

    gpu.fill(w / 2 + 2, i + 5, (w / 2) - 4, 1, ' ')
    gpu.set(w / 2 + (w / 4) - 2, i + 5, 'Load')
  end

  gpu.setForeground(ofg)
  gpu.setBackground(obg)
end

drawSaves()
drawLine()

local function deleteSave(num)
  fs.remove('/home/tellraw.save.' .. tostring(num))
end

local function loadSave(num)
  local path = '/home/tellraw.save.' .. tostring(num)
  local handle = fs.open(path, 'r')

  if handle then
    local size = fs.size(path)
    local data = handle:read(size)
    handle:close()

    local match = data:find('(%x+)$')
    local dcolr = data:sub(match)
    local dtext = data:sub(1, match - 2)

    if dcolr:len() == dtext:len() then
      text = dtext
      colr = dcolr
      scroll = 0
      setCursor(text:len() + 1)
      drawLine()
    end
  end
end

local function saveTo(num)
  local path = '/home/tellraw.save.' .. tostring(num)
  local handle = fs.open(path, 'w')

  if handle then
    handle:write(text .. '\n' .. colr)
    handle:close()
  end
end

while true do
  local oscroll = scroll
  local otext = text
  local evt, _, arg1, arg2 = waitForEvent()

  if evt == 'key_down' then
    if arg1 > 0 and arg1 < 127 then
      local char = unicode.char(arg1)

      if arg1 == 13 then
        char = '\n'
      end

      local cpos = hex:sub(ccolor, ccolor)

      text = text:sub(1, cursor - 1) .. char .. text:sub(cursor)
      colr = colr:sub(1, cursor - 1) .. cpos .. colr:sub(cursor)
      setCursorBy(1)
    elseif arg1 == 127 and cursor > 1 then
      text = text:sub(1, cursor - 2) .. text:sub(cursor)
      colr = colr:sub(1, cursor - 2) .. colr:sub(cursor)
      setCursorBy(-1)
    elseif arg1 == 63234 then -- left arrow
      setCursorBy(-1)
    elseif arg1 == 63235 then -- right arrow
      setCursorBy(1)
    elseif arg1 == 63273 then -- Home
      setCursor(1)
    elseif arg1 == 63275 then -- End
      setCursor(#text + 1)
    end
  elseif evt == 'clipboard' then
    local cpos = hex:sub(ccolor, ccolor)

    text = text:sub(1, cursor - 1) .. arg1 .. text:sub(cursor)
    colr = colr:sub(1, cursor - 1) .. string.rep(cpos, arg1:len()) .. colr:sub(cursor)
    setCursorBy(arg1:len())
    drawLine()
  elseif evt == 'touch' or evt == 'drag' then
    local w = getWidth()

    if arg2 == 1 then
      if arg1 > w - 3 then
        text = ''
        colr = ''
        setCursor(1)
        drawLine()
      else
        setCursor(arg1 + scroll)
      end
    elseif arg2 == 2 then
      if arg1 + scroll <= #colr then
        colr = colr:sub(1, arg1 + scroll - 1) .. hex:sub(ccolor, ccolor) .. colr:sub(arg1 + scroll + 1)
        drawLine()
      end
    elseif arg2 == 4 then
      local ofg = gpu.setForeground(ccolor < 3 and 0xffffff or 0x000000)
      local obg = gpu.setBackground(colors[ccolor])
      gpu.set((ccolor - 1) * 5 + 1, 4, ' ')
      gpu.set((ccolor - 1) * 5 + 5, 4, ' ')
      ccolor = math.floor((arg1 - 1) / 5) + 1

      gpu.setForeground(ccolor < 3 and 0xffffff or 0x000000)
      gpu.setBackground(colors[ccolor])
      gpu.set((ccolor - 1) * 5 + 1, 4, unicode.char(9656))
      gpu.set((ccolor - 1) * 5 + 5, 4, unicode.char(9666))

      gpu.setForeground(ofg)
      gpu.setBackground(obg)
    elseif arg2 == 5 then
      if arg1 < 40 then
        break
      elseif arg1 <= 80 then
        runCommand()
      end
    elseif arg2 > 5 then
      local num = math.floor(arg2 - 5)

      if arg1 > 5 then
        if arg1 > w - 3 then
          deleteSave(num)
        elseif arg1 > w / 2 + 1 then
          loadSave(num)
        elseif arg1 > 5 then
          saveTo(num)
        end
      end

      drawSaves()
    end
  end

  if oscroll ~= scroll or otext ~= text then
    drawLine()
  end
end

gpu.setForeground(ofg)
gpu.setBackground(obg)
gpu.setResolution(ow, oh)
term.clear()