--This is the classroom monitor setup routine
--written by Matt Kelliher
--
-- Useage: <program_name> [-d] [-A|-R|-G|-B|-P] <text>
-- If you would like to see debugging comments on the terminal then pass in the -d
-- option when you run this program before your text
local tArgs = { ... }
assert( #tArgs >= 1, "Useage: <program_name> [-d] <text>" )

--Parse the flags:
local param1 = tArgs[1]
local param2 --optional
local param3 --optional
if #tArgs >= 2 then param2 = tArgs[2] end
if #tArgs >= 3 then param3 = tArgs[3] end

--Now figure out if the debug flag was set
local debug = false
local GLOBALtext = ""
if param1 == "-d" then 
  debug = true
  assert( #tArgs >= 2, "Useage: <program_name> [-d] <text>" )
  GLOBALtext = param2
else
  GLOBALtext = param1
end


--First: we assume there are 4 equal-sized
--monitors in the room connected to the network
--we'll find them on the network,
--give them names based on color, and
--wrap them with a variable
local Rmon, Gmon, Bmon, Pmon = peripheral.find("monitor", function(name, object) return object.isColor() end)

--We'll also get the dimensions of the monitors
--and store them (we'll assume all monitors are 
--the same number of columns and rows)
local monRows, monColumns

--A useful function for centering text
--on a monitor from the ComputerCraft forums
function centerPrint(text, y, mon)
  local w, h = mon.getSize() or term.getSize()
  if mon then
    mon.setCursorPos( math.ceil( w/2 - #text/2 + 1), y )
    mon.write( text)
  else
    mon.setCursorPos( math.ceil( w/2 - #text/2 ), y )
    term.write( text )
  end
end

--A function that wraps text on monitor
--and calls the center function
function printCenterWrap( mon, text, size )
  --size is an optional parameter,
  --we default to 0.5
  if size == nil then size = 0.5 end
  
  if size > 0 then mon.setTextScale(size) end
  
  local MaxCols, MaxRows = mon.getSize()
  local stBuffer = text
  local rowCount = 1

  if debug then print("MaxCols: "..MaxCols.." MaxRows: "..MaxRows) end
  while string.len(stBuffer) > 0 and rowCount <= MaxRows do
    if debug then 
      print("LoopStartBuffer: "..stBuffer.." ("..string.len(stBuffer)..")")
      t=read() --pause to debug
    end

    --find if there's a space character
    local space = string.find(stBuffer, " ")

    if space == nil or space >= MaxCols then
      if debug then print("found no space before EOL") end
      --This is the easiest case: we didn't
      --find a space before the End-of-Line MaxCols
      --so just print a substring up to EOL
      --For Left Justify: mon.setCursorPos(1,rowCount)
      if debug then print("SetCursorPos(1,"..rowCount..")") end
      local wl = string.sub(stBuffer,1,MaxCols)
      --mon.write(wl) --center this later
      centerPrint(wl,rowCount,mon)
      if debug then print("Wrote:"..wl) end
      if (MaxCols + 1) > (string.len(stBuffer)) then
        --we're don't processing
        stBuffer = ""
        if debug then print("Set Buffer to EOL") end
      else
        stBuffer = string.sub(stBuffer, MaxCols + 1)
        if debug then print("Set Buffer to:"..stBuffer.." ("..string.len(stBuffer)..")") end
      end
    else
      if debug then print("found space at: "..space) end
      local sentence = ""
      local nextspace
      --loop to find the next space in the buffer
      local word = string.sub(stBuffer,1,space)
      if debug then print("Word: "..word) end
      repeat        
        sentence = sentence..word
        if debug then 
          print("Sentence: "..sentence.." ("..string.len(sentence)..")")
          s=read() --pause to debug
        end
        --test that we don't go past the end
        if (string.len(word)+1) > string.len(stBuffer) then
          stBuffer = ""
        else
          stBuffer = string.sub(stBuffer,string.len(word)+1)
          if debug then print("Set Buffer to:"..stBuffer.." ("..string.len(stBuffer)..")") end
        end
        
        nextspace = string.find(stBuffer, " ")
        if nextspace == nil then
          if debug then print("nextspace: nil") end
        else
          if debug then print("nextspace: "..nextspace) end
        end
        
        word = string.sub(stBuffer,1,nextspace) --this should be checking for nil!
        if debug then print("nextword: "..word.." ("..string.len(word)..")") end
        
      until nextspace == nil or (string.len(sentence)+nextspace) > MaxCols
      
      --LEFT JUSTIFY: mon.setCursorPos(1, rowCount)
      if debug then print("SetCursorPos(1, "..rowCount..")") end
      if nextspace == nil then
        --mon.write(sentence..word)
        centerPrint(sentence..word,rowCount,mon)
        if debug then print("Wrote sen+word:"..sentence..word.." ("..#sentence+#word..")") end
        --check that we don't go past the end
        if (string.len(word)+1) > string.len(stBuffer) then
            stBuffer = ""
            if debug then print("Cleared the buffer") end
        else
          stBuffer = string.sub(stBuffer,string.len(word)+1)
          if debug then print("Set Buffer to:"..stBuffer.." ("..string.len(stBuffer)..")") end
        end
      else
        --mon.write(sentence)
        centerPrint(sentence,rowCount,mon)
        if debug then print("Wrote sen:"..sentence.." ("..#sentence..")") end
      end      
      
    end --of finding a space
    
    --increment row counter
    rowCount = rowCount + 1
  end --while for each row
  
end


--Have a Function to clear monitors where you
--Input/Parameter the monitor object/variable
--and the colors.color you want it to be
function clearMonitor(mon, xcolor)
  mon.clear()
  mon.setTextScale(0.5)
  mon.setCursorPos(1,1)
  mon.setBackgroundColor(xcolor)
  mon.clear()
  mon.setCursorPos(1,1)
  --printCenterWrap(mon, "Welcome to Beyond Minecraft 101 Class!", 3)
end

--This function will display text on all monitiors at once
function displayOnAll(text, size)
  if size == nil then size = 0.5 end
  if Rmon then
    clearMonitor(Rmon, colors.red)
    printCenterWrap(Rmon, text, size)
  end
  if Gmon then
    clearMonitor(Gmon, colors.green)
    printCenterWrap(Gmon, text, size)
  end
  if Bmon then
    clearMonitor(Bmon, colors.blue)
    printCenterWrap(Bmon, text, size)
  end
  if Pmon then
    clearMonitor(Pmon, colors.purple)
    printCenterWrap(Pmon, text, size)
  end
end

--This function sets up the initial settings
--for the monitors with their colors
--and a blank screen displayed
function initMonitors()
  --Determine which of the 4 monitors we have
  --on our network and set them up accordingly
  if Rmon then
    clearMonitor(Rmon, colors.red)
    print("Connected Red Monitor")
  end 
  if Gmon then
    clearMonitor(Gmon, colors.green)
    print("Connected Green Monitor")
  end
  if Bmon then
    clearMonitor(Bmon, colors.blue)
    print("Connected Blue Monitor")
  end 
  if Pmon then
    clearMonitor(Pmon, colors.purple)
    print("Connected Purple Monitor")
  end
end


--This is our main control function
--to run the program
function main()
  initMonitors()
  if GLOBALtext ~= "test" then
    displayOnAll(GLOBALtext, 3)
  else
    displayOnAll("Welcome to the Beyond Minecraft 101 Class!", 3)
  end

end

--Now kick-off our main program:
main()