MonitorProgram

local function Button(
                                width,
                                height,
                                label,
                                backgroundColorNormal,
                                backgroundColorPressed,
                                textColorNormal,
                                textColorPressed,
                                hasBorder,
                                borderColorNormal,
                                borderColorPressed,
                                startColumn,
                                startRow,
                                isPressed,
                                defaultBackgroundColor,
                                defaultTextColor
                            )
    local button = {}
    button.height=height or 1
    button.width=width or 1
    button.label=label or ""
    button.backgroundColorNormal=backgroundColorNormal or colors.black
    button.backgroundColorPressed=backgroundColorPressed or colors.white
    button.textColorNormal=textColorNormal or colors.white
    button.textColorPressed=textColorPressed or colors.black
    button.hasBorder = hasBorder or false
    button.borderColorNormal = borderColorNormal or backGroundColorNormal
    button.borderColorPressed = borderColorPressed or backGroundColorPressed
    button.defaultBackgroundColor = defaultBackgroundColor or colors.black
    button.defaultTextColor = defaultTextColor or colors.white
    button.startColumn = startColumn or 1
    button.startRow = startRow or 1
    button.isPressed=isPressed or false
    function button.press()
        button.isPressed = not button.isPressed
    end
    function button.clicked(column,row)
      return (column >= button.startColumn and column < button.startColumn + button.width and row >= button.startRow and row < button.startRow + button.height)
    end
    function button.draw(display,isPressed,startColumn,startRow)

        button.startColumn = startColumn or button.startColumn
        button.startRow = startRow or button.startRow
        display = display or term
        if isPressed == false or isPressed then
            button.isPressed = isPressed
        else isPressed = button.isPressed
        end
        local width = button.width
        local height = button.height
        startRow = button.startRow
        startColumn = button.startColumn

        local label = button.label
        local labelPad = 2

        -- set border params and draw border if hasBorder
        if button.hasBorder == true then
            -- button must be at least 3x3, if not, make it so
            if width < 3 then
                width = 3
            end
            if height < 3 then
                height = 3
            end

            -- set border colors
            if not isPressed then
                if not display.isColor() then
                    display.setBackgroundColor(colors.white)
                else
                    display.setBackgroundColor(button.borderColorNormal)
                end
            else
                if not display.isColor() then
                    display.setBackgroundColor(colors.white)
                else
                    display.setBackgroundColor(button.borderColorPressed)
                end
            end

            -- draw button border (inset)
            display.setCursorPos(startColumn,startRow)
            display.write(string.rep(" ",width))
            for row = 2,height-1 do
                display.setCursorPos(startColumn,button.startRow+row -1)
                display.write(" ")
                display.setCursorPos(startColumn+width -1 ,startRow + row-1)
                display.write(" ")
            end
            display.setCursorPos(startColumn,startRow+height-1)
            display.write(string.rep(" ",width))

            -- reset startColumn,startRow,width,column to inset button and label
            startColumn=startColumn+1
            startRow = startRow +1
            width = width - 2
            height = height - 2
        end

        --set button background and text colors
        if not isPressed then
            if not display.isColor() then
                display.setBackgroundColor(colors.black)
                display.setTextColor(colors.white)
            else
                display.setBackgroundColor(button.backgroundColorNormal)
                display.setTextColor(button.textColorNormal)
            end
        else
            if not display.isColor() then
                display.setBackgroundColor(colors.white)
                display.setTextColor(colors.black)
            else
                display.setBackgroundColor(button.backgroundColorPressed)
                display.setTextColor(button.textColorPressed)
            end
        end

        -- draw button background (will be inside border if there is one)
        for row = 1,height do
            --print(tostring(startColumn)..","..tostring(startRow-row))
            display.setCursorPos(startColumn,startRow + row -1)
            display.write(string.rep(" ",width))
        end

        -- prepare label, truncate label if necessary

        -- prepare label, truncate label if necessary
        if width < 3 then
            labelPad = 0
        end
        if #label > width - labelPad then
            label = label:sub(1,width - labelPad)
        end

        -- draw label
        display.setCursorPos(startColumn + math.floor((width - #label)/2),startRow + math.floor((height-1)/2))
        display.write(label)
        display.setBackgroundColor(button.defaultBackgroundColor)
        display.setTextColor(button.defaultTextColor)
    end
    button.toggle = function ()
            button.isPressed = not button.isPressed
            return button.isPressed
        end
    return button
end

function tablelength(T)
  local count = 0
  for _ in pairs(T) do count = count + 1 end
  return count
end

function drawSongs()
songNameButtons = {}
	for i,song in ipairs(songNames) do
	  -- First check if its on our page
	  local lowestSong = currentPage * songsPerPage -- So 0 on page 0, we can use hard > which means the lowestSong+songsPerPage is included on this page and not the next one
	  if i > lowestSong and i <= lowestSong + songsPerPage then

		  if currentSong == i then
			songNameButtons[i] = Button(40,1,song,colors.white,colors.white,colors.black,colors.green,false,colors.white,colors.black,0,i%songsPerPage,false,nil,nil)
		  else
			songNameButtons[i] = Button(40,1,song,colors.black,colors.white,colors.orange,colors.green,false,colors.black,colors.black,0,i%songsPerPage,false,nil,nil)
		  end
		  songNameButtons[i].draw(monitor1)
	  end
	end
end

function drawScreen(monitor, screenIndex)
	monitor.clear()

	if screenIndex == 0 then
		drawSongs()
		left.draw(monitor)
		right.draw(monitor)
		bottom.draw(monitor)
		instrumentsButton.label = "Setup"
		instrumentsButton.draw(monitor)
		pageLabel.label = "Page " .. (currentPage+1) .. "/" .. maxPage
		pageLabel.draw(monitor)
	elseif screenIndex == 1 then
		left.draw(monitor)
		right.draw(monitor)
		bottom.draw(monitor)
		instrumentsButton.label = "Save"
		instrumentsButton.draw(monitor)
		-- Draw the current song title at the top
		monitor.setBackgroundColor(colors.white)
		monitor.setTextColor(colors.black)
		monitor.setCursorPos(1,1)
		monitor.write(songNames[currentSong])

		-- So we need to build a list of instruments
		-- And put the value beside each one
		-- And have < and > buttons beside each value to change it
		monitor.setBackgroundColor(colors.black)
		monitor.setTextColor(colors.white)
		for i,name in pairs(varNames) do
			monitor.setCursorPos(1,i+2)
			monitor.write(name)
		end
		instrumentLeftButtons = {}
		instrumentRightButtons = {}
		for i,name in pairs(varValues) do
			monitor.setCursorPos(30,i+2)
			monitor.write(name)
			instrumentLeftButtons[i] = Button(1,1,"<",colors.black,colors.white,colors.orange,colors.green,false,colors.black,colors.black,29,i+2,false,nil,nil)
			instrumentRightButtons[i] = Button(1,1,">",colors.black,colors.white,colors.orange,colors.green,false,colors.black,colors.black,38,i+2,false,nil,nil)
			instrumentLeftButtons[i].draw(monitor)
			instrumentRightButtons[i].draw(monitor)
			-- We should also set instrumentIndex; this represents what position in the instruments list the current variable is
			for j,k in pairs(instruments) do
				if string.lower(k) == string.lower(name) then
					instrumentIndex[i] = j
					break
				end
			end
			if instrumentIndex[i] == nil then
				write("Error: Could not find instrument " .. name)
			end
		end
	end
end

function saveData()
	-- Using songNames[currentSong], saves a file with that name
	-- Writes serialized varNames and varValues
	local writer = fs.open(songs[currentSong], "w")
	-- The data really should stay like this but too late now...
	-- I want to crunch it into one array
	-- ... But I can't do that because then I can't guarantee the order
	writer.writeLine(textutils.serialize(varNames))
	writer.close()
	writer = fs.open(songs[currentSong] .. "1", "w")
	writer.writeLine(textutils.serialize(varValues))
	writer.close()
end

function readData()
	-- Using songNames[currentSong], reads a file with that name
	-- Reads serialized varNames and varValues
	if(fs.exists(songs[currentSong]) and fs.exists(songs[currentSong] .. "1")) then
		varNames = {}
		varValues = {}
		local reader = fs.open(songs[currentSong], "r")
		varNames = textutils.unserialize(reader.readAll())
		reader.close()
		reader = fs.open(songs[currentSong] .. "1", "r")
		varValues = textutils.unserialize(reader.readAll())
		return true
	end
	return false
end

function changeToNewSong(toggleOnly)
	-- Using currentSong, sends a Stop request if playing, then Starts a new song
	if playing then
        playing = false
        rednet.send(targetid,"stop")
		if toggleOnly then
			return
		end
    end
	playing = true
	rednet.send(targetid,songs[currentSong])
	-- Directly wait for the responses, there should be two arrays sent back
	local id,msg = rednet.receive(1) -- Max out at 1 second tho, just in case
	local tempNames = textutils.unserialize(msg)
	local id,msg = rednet.receive(1)
	local tempValues = textutils.unserialize(msg)
	if readData() then -- Check if we have saved values
		if tempValues ~= varValues then
			for i,v in pairs(varValues) do
				if(v ~= tempValues[i]) then
					rednet.send(id,"changeinstrument:" .. tempNames[i] .. ":" .. v)
				end
			end
		end
	else
		-- We had no data, so store what they gave us
		varNames = tempNames
		varValues = tempValues
	end
end

--  Start of test Program

instrumentIndex = {} -- Contains the index of the instruments list that is currently selected

instrumentLeftButtons = {}
instrumentRightButtons = {} -- Indexed by the variable it would adjust

varNames = {}
varValues = {}

monitor1 = peripheral.wrap("back")
screenNum = 0 -- Indicates what to display on screen

left= Button(4,3,"<<",colors.green,colors.red,colors.black,colors.yellow,true,colors.gray,colors.pink,1,30,false,nil,nil)
right = Button(4,3,">>",colors.green,colors.red,colors.black,colors.yellow,true,colors.gray,colors.pink,36,30,false,nil,nil)
bottom = Button(29,3,"Play",colors.lime,colors.red,colors.black,colors.yellow,true,colors.gray,colors.pink,6,30,false,nil,nil)

pageLabel = Button(40,1,"Page 1/1",colors.black,colors.black,colors.orange,colors.orange,false,colors.orange,colors.orange,1,29,false,nil,nil)

instrumentsButton = Button(40,1,"Setup",colors.orange,colors.red,colors.black,colors.lime,false,colors.orange,colors.pink,1,33,false,nil,nil)

songs = {"Megalovania"}
songNames = {"Undertale - Megalovania"}

instruments = {"Harp","Bass","Pling","Bell","Chime","Flute","Guitar","Xylophone","BaseDrum","Hat","Snare"}

songNameButtons = {}

currentSong = 1
currentPage = 0
songsPerPage = 27

maxPage = math.ceil(tablelength(songNames)/songsPerPage)

-- Display buttons on monitor1

-- And text I guess

drawScreen(monitor1,screenNum)


rednet.open("left")
targetid = 0

playing = false

-- this is our event loop
while true do
  event ={os.pullEvent()}
  -- Check for signal to go to next song
  if playing and event[1] =="rednet_message" then
	 if event[3] == "done" and playing then
		  currentSong = currentSong + 1
		  if currentSong > tablelength(songNames) then
			currentSong = 1
		  end
		  changeToNewSong()
		  drawScreen(monitor1,screenNum)
	  end
  end
  if event[1] =="monitor_touch" then
    if left.clicked(event[3],event[4]) then
      currentPage = currentPage - 1
      if currentPage < 0 then
        currentPage = maxPage-1
      end
    elseif right.clicked(event[3],event[4]) then
      currentPage = currentPage + 1
      if currentPage >= maxPage then
       currentPage = 0
      end
    elseif bottom.clicked(event[3],event[4]) then
		changeToNewSong(true) -- Plays or stops as appropriate
	elseif instrumentsButton.clicked(event[3],event[4]) then
		-- Swap screens...
		if screenNum == 0 then
			screenNum = 1
		elseif screenNum == 1 then
		    screenNum = 0
			-- Save our song data
			saveData()
		end
	   -- drawScreen(monitor1,screenNum)
    elseif screenNum == 1 then
		for i,v in pairs(instrumentLeftButtons) do
			if(v.clicked(event[3],event[4])) then
				-- Cycle 1 instrument left for this index and send rednet command to change it
				instrumentIndex[i] = instrumentIndex[i]-1
				if instrumentIndex[i] <= 0 then
					instrumentIndex[i] = tablelength(instruments)
				end
				varValues[i] = instruments[instrumentIndex[i]]
				rednet.send(targetid,"changeinstrument:" .. varNames[i] .. ":" .. varValues[i])
				break
			end
		end
		for i,v in pairs(instrumentRightButtons) do
			if(v.clicked(event[3],event[4])) then
				-- Cycle 1 instrument right for this index and send rednet command to change it
				instrumentIndex[i] = instrumentIndex[i]+1
				if instrumentIndex[i] > tablelength(instruments) then
					instrumentIndex[i] = 1
				end
				varValues[i] = instruments[instrumentIndex[i]]
				rednet.send(targetid,"changeinstrument:" .. varNames[i] .. ":" .. varValues[i])
				break
			end
		end
	else
		for i,v in pairs(songNameButtons) do
			if(v.clicked(event[3],event[4])) then
				-- Set the selected index to this index and do play things
				currentSong = i
				if playing then changeToNewSong() end
				break
			end
		end

	end
    -- Redraw songs
    drawScreen(monitor1,screenNum)

  end
end