Computercraft nbs player

--18107's Jukebox
--version 1.2.0
--last updated 13 November 2017
--requires 'project red' or 'computronics'
--Noteblock player at http://pastebin.com/aX8quTFy

local monitor = peripheral.find("monitor")
if monitor == nil then
  term.setTextColor(colors.red)
  print("Error: No monitor detected")
  return
end
local modem = peripheral.find("modem")
local noteblock = peripheral.find("iron_noteblock")

local musicList = {}
local monitorWidth, monitorHeight = monitor.getSize()
local currentlyPlaying = nil
local screen = "list"
local page = 1
local repeatMode = "off" -- off, single, all ordered, all random
local lastUpdate = 1
local paused = false
local timerRunning = false
local songFinished = false
local forceStop = false

local songLength, songName, songAuth, origSongAuth, songDesc
local tempo = 100
local currentTick = 1
local notes = {}

function newLine()
    local x, y = monitor.getCursorPos()
    monitor.setCursorPos(1, y + 1)
end --newline()

function refreshMusicList()
    local length = #musicList
    local thisSong
    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        thisSong = musicList[currentlyPlaying]
    end

    local list = fs.list("")
    local disks = {}
    musicList = {}
    local songCounter = 1
    local diskCounter = 1

    --get music from computer, get list of disks
    for i = 1, #list do
        if string.sub(list[i],-4) == ".nbs" then
            musicList[songCounter] = list[i]
            songCounter = songCounter + 1
        elseif string.sub(list[i],0,4) == "disk" and fs.isDir(list[i]) then
            disks[diskCounter] = list[i]
            diskCounter = diskCounter + 1
        end
    end --for #list

    --get music from disks
    for a = 1, #disks do
        list = fs.list(disks[a])
        for b = 1, #list do
            if string.sub(list[b],-4) == ".nbs" then
                musicList[songCounter] = disks[a].."/"..list[b]
                songCounter = songCounter + 1
            end --if
        end --for #list
    end --for #disks

    --if song does not exist, stop playing it
    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        if thisSong ~= musicList[currentlyPlaying] then
            currentlyPlaying = 0
        end --if thisSong
    end --if currentlyPlaying

    --check if musicList has shrunk, and decrease page number if needed
    if page > #musicList/(monitorHeight-3) and #musicList > 0 then
        page = math.ceil(#musicList/(monitorHeight-3))
    end --if page
end --refreshMusicList()

function displayMusicList()
    --draw top line
    monitor.clear()
    monitor.setCursorPos(monitorWidth-4-20, 1)
    monitor.setTextColor(colors.yellow)
    monitor.write("Repeat: "..repeatMode)
    monitor.setCursorPos(1, 1)
    monitor.setTextColor(colors.cyan)
    monitor.write("18107's Juke Box")
    monitor.setCursorPos(monitorWidth-3, 1)
    monitor.setTextColor(colors.red)
    monitor.write("Stop")
    monitor.setTextColor(colors.white)
    newLine()

    --draw songs
    if #musicList > 0 then
        for i = (monitorHeight-3)*(page-1)+1, (monitorHeight-3)*(page-1)+monitorHeight-3 do
            if currentlyPlaying == i then
                monitor.setTextColor(colors.blue)
            else
                monitor.setTextColor(colors.white)
            end --if currentlyPlaying
            if i < #musicList then
                if string.sub(musicList[i],0,4) == "disk" then
                    if string.sub(musicList[i],5,5) == "/" then
                        monitor.write("Disk : "..string.sub(musicList[i],6,-5))
                    else
                        monitor.write("Disk "..string.sub(musicList[i],5,5).." : "..string.sub(musicList[i],7,-5))
                    end --if "/"
                else
                    monitor.write(string.sub(musicList[i],0,-5))
                end --if disk
            end --if #musicList
            newLine()
        end --for
    end --if #musicList

    --draw second bottom line
    monitor.setCursorPos(1, monitorHeight-1)
    if currentlyPlaying == 0 or currentlyPlaying == nil then
        monitor.setTextColor(colors.lightGray)
    else
        monitor.setTextColor(colors.cyan)
    end --if currentlyPlaying
    monitor.write("Currently Playing")
    monitor.setCursorPos(monitorWidth-9, monitorHeight-1)
    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        monitor.setTextColor(colors.red)
    end --if currentlyPlaying
    if paused then
        monitor.write("Play  ")
    else
        monitor.write("Pause ")
    end --if paused
    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        monitor.setTextColor(colors.blue)
    end --if currentlyPlaying
    monitor.write("Skip")

    --draw bottom line
    monitor.setTextColor(colors.green)
    monitor.setCursorPos(1, monitorHeight)
    monitor.write("Previous")
    monitor.setCursorPos(monitorWidth-3, monitorHeight)
    monitor.write("Next")
    monitor.setTextColor(colors.yellow)
    monitor.setCursorPos(monitorWidth/2+1, monitorHeight)
    monitor.write(tostring(page))
end --displayMusicList()

function displayCurrentlyPlaying()
    --draw top line
    monitor.clear()
    monitor.setCursorPos(monitorWidth-4-20, 1)
    monitor.setTextColor(colors.yellow)
    monitor.write("Repeat: "..repeatMode)
    monitor.setCursorPos(1, 1)
    monitor.setTextColor(colors.cyan)
    monitor.write("18107's Juke Box")
    monitor.setCursorPos(monitorWidth-3, 1)
    monitor.setTextColor(colors.red)
    monitor.write("Stop")
    monitor.setTextColor(colors.white)
    newLine()
    newLine()

    --song info
    if string.sub(musicList[currentlyPlaying],0,4) == "disk" then
        if string.sub(musicList[currentlyPlaying],5,5) == "/" then
            monitor.write("Disk :"..string.sub(musicList[currentlyPlaying],6,-5))
        else
            monitor.write("Disk "..string.sub(musicList[currentlyPlaying],5,5).." : "..string.sub(musicList[currentlyPlaying],7,-5))
        end --if "/"
    else
        monitor.write(string.sub(musicList[currentlyPlaying],0,-5))
    end --if disk
    newLine()
    newLine()
    if type(songAuth) == "string" then
        monitor.write("Author: "..songAuth)
    end --if songAuth
    newLine()
    newLine()
    if type(origSongAuth) == "string" then
        monitor.write("Original author: "..origSongAuth)
    end --if origSongAuth
    newLine()
    newLine()
    if type(songDesc) == "string" then
        for desc = 0, #songDesc/monitorWidth+1 do
            monitor.write(string.sub(songDesc, desc*monitorWidth+1, (desc+1)*monitorWidth))
            newLine()
        end --for desc
    end --songDesc

    --second bottom line
    monitor.setCursorPos(1, monitorHeight-1)
    monitor.setTextColor(colors.cyan)
    monitor.write("Song list")
    monitor.setCursorPos(monitorWidth-9, monitorHeight-1)
    monitor.setTextColor(colors.red)
    if paused then
        monitor.write("Play  ")
    else
        monitor.write("Pause ")
    end --if paused
    monitor.setTextColor(colors.blue)
    monitor.write("Skip")

    --bottom line
    monitor.setTextColor(colors.lightGray)
    local minutes = math.floor(songLength*100/tempo/60) --right side
    local seconds = math.floor(songLength*100/tempo) % 60
    monitor.setCursorPos(monitorWidth-4, monitorHeight)
    if minutes < 10 then
        monitor.write(" ")
    end --if minutes
    monitor.write(minutes..":")
    if seconds < 10 then
        monitor.write("0")
    end --if seconds
    monitor.write(seconds.."")

    minutes = math.floor(currentTick*100/tempo/60)--left side
    seconds = math.floor(currentTick*100/tempo) % 60
    monitor.setCursorPos(1, monitorHeight)
    if minutes < 10 then
        monitor.write(" ")
    end --if minutes
    monitor.write(minutes..":")
    if seconds < 10 then
        monitor.write("0")
    end --if seconds
    monitor.write(seconds.."")

    monitor.write(" <") --center
    for i = 8, monitorWidth-7 do
        monitor.write("=")
    end --for monitorWidth
    monitor.write(">")
    monitor.setCursorPos((currentTick/songLength)*(monitorWidth-14)+8, monitorHeight)
    monitor.write("|")
end --displayCurrentlyPlaying

function refreshDisplay()
    if screen == "list" then
        displayMusicList()
    elseif screen == "playing" then
        displayCurrentlyPlaying()
    end --if screen
end --refreshDisplay()

function readNumber(file, size)
    local number = 0
    for siz = 1, size do
        number = number + bit.blshift(file.read(), 8*(siz-1))
    end --for size
    return number
end --readNumber()

function readString(file, length)
    if length ~= 0 then
        local text = string.char(file.read())
        for char = 2, length do
            text = text..string.char(file.read())
        end --for char
        return text
    end --if length
end --readString()

function loadSong()
    local song = fs.open(musicList[currentlyPlaying], "rb")
    if song == nil then
        print("File not found")
        currentlyPlaying = 0
        return
    end --if nil

    --header
    local strLen = 0
    songLength = readNumber(song, 2) --song length (in ticks)
    readNumber(song, 2) --song height
    strLen = readNumber(song, 4)
    songName = readString(song, strLen) --song name
    strLen = readNumber(song, 4)
    songAuth = readString(song, strLen) --song author
    strLen = readNumber(song, 4)
    origSongAuth = readString(song, strLen) --original song author
    strLen = readNumber(song, 4)
    songDesc = readString(song, strLen) --song description
    tempo = readNumber(song, 2) --tempo (ticks per second x100)
    readNumber(song, 1) --auto saving
    readNumber(song, 1) --auto saving duration
    readNumber(song, 1) --time signature
    readNumber(song, 4) --minutes spent
    readNumber(song, 4) --left clicks
    readNumber(song, 4) --right clicks
    readNumber(song, 4) --blocks added
    readNumber(song, 4) --blocks removed
    strLen = readNumber(song, 4)
    readString(song, strLen) --MIDI/schematic file name

    local tick = 1
    local nextTick = 1
    local hasNext = true

    local instrument = 0
    local key = 0
    local chord = 1

    currentTick = 1
    notes = {}

    --read song
    while hasNext do
        nextTick = readNumber(song, 2)

        while nextTick > 1 do
            notes[tick] = {}
            tick = tick + 1
            nextTick = nextTick - 1
        end --while nextTick

        if nextTick ~= 0 then
            notes[tick] = {}
            chord = 1
            while readNumber(song, 2) ~= 0 do --play chord
                instrument = readNumber(song, 1)
                key = readNumber(song, 1)
                notes[tick][chord] = {instrument, key}
                chord = chord + 1
            end --while readNumber
            tick = tick + 1
        else
            hasNext = false
        end --if nextTick
    end --while hasNext

    song.close()
    if timerRunning == false then
        timerRunning = true
        os.startTimer(100/tempo)
    end --if timerRunning
end --loadSong()

function nextSong()
    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        if repeatMode == "all random" then
            currentlyPlaying = math.random(#musicList)
        elseif repeatMode == "all ordered" then
            currentlyPlaying = currentlyPlaying + 1
            if currentlyPlaying >= #musicList then
                currentlyPlaying = 1
            end --if #musicList
        elseif repeatMode == "off" then
            currentlyPlaying = 0
            songFinished = true
            screen = "list"
        end --if repeatMode
    end --if currentlyPlaying

    if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
        page = math.floor((currentlyPlaying-1)/(monitorHeight-3)) + 1
        loadSong()
    end --if currentlyPlaying
end --nextSong()

function playNote(instrument, key)
    if noteblock ~= nil then
        if instrument == 0 then
            noteblock.playNote(0, key-33)
        elseif instrument == 1 then
            noteblock.playNote(4, key-33)
        else
            noteblock.playNote(instrument-1, key-33)
        end --if instrument
    end --if noteblock

    if modem ~= nil then
        modem.transmit(instrument, 0, bit.blshift(1, key-33))
    end --if modem
end --playNote()

function transmitNotes(notes)
    if modem ~= nil then
        for instrument = 1, 5 do
            modem.transmit(instrument, 0, notes[instrument])
        end --for i
    end --if modem
end --transmitNotes

function playSong()
    local modemData = {0, 0, 0, 0, 0}
    if not paused then
        if notes[currentTick] ~= nil then
            if (#notes[currentTick] ~= 0) then
                for _,note in pairs(notes[currentTick]) do
                    playNote(note[1], note[2])
                    if note[2] >= 33 then
                        modemData[note[1]+1] = bit.bor(modemData[note[1]+1], bit.blshift(1, note[2]-33))
                    end
                end --for notes
                transmitNotes(modemData)
            end --if #notes
            currentTick = currentTick + 1
        else
            songFinished = true
        end --if notes
    end --if not paused
end --playSong()

function monitorTouch(x, y)
    if screen == "list" then
        --top line
        if y == 1 then
            if x > monitorWidth-4 then --stop
                forceStop = true
                paused = false
            elseif x > 16 and x <= monitorWidth-6 then --repeatMode
                if repeatMode == "off" then
                    repeatMode = "single"
                elseif repeatMode == "single" then
                    repeatMode = "all ordered"
                elseif repeatMode == "all ordered" then
                    repeatMode = "all random"
                else--if repeatMode == "all random" then
                    repeatMode = "off"
                end --if repeatMode
            end --x
        --bottom line
        elseif y == monitorHeight then
            if x < 9 then --previous
                if page > 1 then
                    page = page - 1
                end --if page
            elseif x > monitorWidth-4 then --next
                if page*(monitorHeight-3) < #musicList then
                    page = page + 1
                end --if page
            end --if x
        --second bottom line
        elseif y == monitorHeight-1 then
            if x <= 17 then --currentlyPlaying
                if currentlyPlaying ~= 0 and currentlyPlaying ~= nil then
                    screen = "playing"
                end --if currentlyPlaying
            elseif x >= monitorWidth-9 and x < monitorWidth-4 then --pause
                paused = not paused
            elseif x >= monitorWidth-3 then --skip
                nextSong()
            end --if x
        --song list
        else
            currentlyPlaying = (y-1) + (page-1)*(monitorHeight-3)
            loadSong()
            if forceStop then
                forceStop = false
            end --if forceStop
        end --if y

    elseif screen == "playing" then
        --top line
        if y == 1 then
            if x > monitorWidth-4 then --stop
                forceStop = true
                paused = false
            elseif x > 16 and x <= monitorWidth-6 then --repeatMode
                if repeatMode == "off" then
                    repeatMode = "single"
                elseif repeatMode == "single" then
                    repeatMode = "all ordered"
                elseif repeatMode == "all ordered" then
                    repeatMode = "all random"
                else--if repeatMode == "all random" then
                    repeatMode = "off"
                end --if repeatMode
            end --if x
        --second bottom line
        elseif y == monitorHeight-1 then
            if x <= 9 then --song list
                screen = "list"
            elseif x >= monitorWidth-9 and x < monitorWidth-4 then --pause
                paused = not paused
            elseif x >= monitorWidth-3 then --skip
                nextSong()
            end --if x
        --bottom line
        elseif y == monitorHeight then
            if x == 8 then
                currentTick = 1
            elseif x >= 8 and x <= monitorWidth-7 then
                currentTick = math.floor((x-8)/(monitorWidth-14)*songLength+0.5)
            end --if x
        end --if y
    end --if screen

    refreshDisplay()
end --monitorTouch

function start()
    math.randomseed(os.time())
    math.random()
    refreshMusicList()
    displayMusicList()
end --start()

function run()
    local running = true
    local event, side, x, y
    while running do
        event, side, x, y = os.pullEventRaw()

        if event == "terminate" then
            running = false

        elseif event == "monitor_touch" then
            monitorTouch(x, y)

        elseif event == "timer" then
            if forceStop == true then
                forceStop = false
                timerRunning = false
                currentlyPlaying = 0
                screen = "list"
                refreshDisplay()
            else
                if songFinished then
                    nextSong()
                    songFinished = false
                    timerRunning = false
                    refreshDisplay()
                else
                    os.startTimer(100/tempo)
                    playSong()
                    if math.floor(currentTick*100/tempo) ~= math.floor(lastUpdate*100/tempo) then
                        lastUpdate = currentTick
                        refreshDisplay()
                    end --if lastUpdate
                end --if not songFinished
            end --if forceStop

        elseif event == "peripheral" or event == "peripheral_detach" or event == "monitor_resize" then
            --reload everything
            modem = peripheral.find("modem")
            noteblock = peripheral.find("iron_noteblock")
            monitor = peripheral.find("monitor")
            if monitor == nil then
                term.setTextColor(colors.red)
                print("Error: monitor detached")
                return
            end --if monitor
            monitorWidth, monitorHeight = monitor.getSize()
            refreshDisplay()
        end --if event

    end --while running
end --run()

function stop()
    monitor.clear()
end --stop()

start()
run()
stop()