net1

-- User Options
side = "left"
username = "gecko"

-- Initialize terminal
term.setBackgroundColor(colours.black)
term.clear()
width, height = term.getSize()
term.setCursorPos(1,height)
term.setCursorBlink(true)

-- Initialize rednet
rednet.open(side)

-- Helpers

function table.append(t1, t2)
  for i=1,#t2 do
    t1[#t1+i]=t2[i]
  end
end

function string.insert(s,a,i)
  return string.sub(s,1,i)..a..string.sub(s,i+1,-1)
end

function term.clearLines(n)
  local cx,cy = term.getCursorPos()
  for i=cy,cy+n-1 do
    term.setCursorPos(1,i)
    term.clearLine()
  end
  term.setCursorPos(cx,cy)
end

function getTextHeight(text,endLineDrop)
  -- Calculates number of lines text would take to
  -- print. endLineDrop controls wether text that
  -- ends on the end of a line will count as
  -- another row or not.
  local nLines = (#text)/width
  if endLineDrop then
    return 1+math.floor(nLines)
  else
    return math.ceil(nLines)
  end
end

function getTextLines(text)
  local tLines = {}
  local nLines = getTextHeight(text, false)
  for i=1,nLines do
    local line = string.sub(text,(i-1)*width+1,math.min(i*width,#text))
    table.insert(tLines, line)
  end
  return tLines
end

-- Supporting Functions

function timestamp()
  return "[D"..os.day().." "..textutils.formatTime(os.time(), true).."]"
end

function getMessageText(msg)
  if msg.type == "text" then
    return "["..msg.sender.."] "..msg.text
  end
end

function typerowRefresh()
  typerowHeight = getTextHeight(typerow, true)
  local cursorRow = height-(typerowHeight-1)+math.floor(typerowCursor/width)
  local cursorCol = 1+(typerowCursor%width)

  term.setCursorPos(1,height-typerowHeight)
  term.clearLines(typerowHeight+1)

  term.write(string.rep("-",width))
  for i=1,typerowHeight do
    term.setCursorPos(1,height-typerowHeight+i)
    term.write(string.sub(typerow,(i-1)*width+1,math.min(i*width,#typerow)))
  end
  term.setCursorPos(cursorCol, cursorRow)
  -- term.setCursorBlink(true)
end

function getQueueSize()
  local size = 0
  for i=1,#queue do
    local text = getMessageText(queue[i])
    local msgHeight = getTextHeight(text, false)
    size = size + msgHeight
  end
  return size
end

function getQueueText()
  local qText = {}
  for i=1,#queue do
    local text = getMessageText(queue[i])
    local tLines = getTextLines(text)
    table.append(qText, tLines)
  end
  return qText
end

function queueRefresh()
  local qHeight = height-typerowHeight-1
  local qText = getQueueText()
  local qToprow = math.max(0, #qText - qHeight)

  term.setCursorPos(1,1)
  --term.clearLines(math.min(qHeight, #qText))
  for i=1,#qText do
    term.write(qText[i])
  end
end

function sendMessage(message)
  local msg = {}
  msg.type = "text"
  msg.sender = username
  msg.text = message
  table.insert(queue, msg)
  queueRefresh()
end

-- queue state
queue = {}

-- typerow state
typerow = ""
typerowHeight = 1
typerowCursor = 0

-- init display
typerowRefresh()

-- Main event loop
while true do
  -- Get next event
  local event, p1, p2, p3 = os.pullEventRaw()
  -- Event switch case
  if event == "terminate" then
    -- Termination signal sent (Ctrl+T)
    -- Logoff and exit program
    return
  elseif event == "key" then
    -- Key pressed
    -- Handle special keys, printable keys handled in char
    if p1 == keys.right then
      if typerowCursor < #typerow then
        typerowCursor = typerowCursor+1
        typerowRefresh()
      end
    elseif p1 == keys.left then
      if typerowCursor > 0 then
        typerowCursor = typerowCursor-1
        typerowRefresh()
      end
    elseif p1 == keys.home then
      typerowCursor = 0
      typerowRefresh()
    elseif p1 == keys["end"] then
      typerowCursor = #typerow
      typerowRefresh()
    elseif p1 == keys.backspace then
      if typerowCursor > 0 then
        typerow = string.sub(typerow,1,typerowCursor-1)..string.sub(typerow,typerowCursor+1,-1)
        typerowCursor = typerowCursor-1
        typerowRefresh()
      end
    elseif p1 == keys.enter then
      if typerow == "q" then return end
      sendMessage(typerow)
      typerow = ""
      typerowCursor = 0
      typerowRefresh()
    end
  elseif event == "char" then
    -- Printable key pressed
    -- Append char to typerow
    typerow = string.insert(typerow,p1,typerowCursor)
    typerowCursor = typerowCursor+1
    typerowRefresh()
  end
end