tracker

-- Consts
local PIPE_V = string.char(124)
local PIPE_H = string.char(173)
local PIPE_C = string.char(143)
local HIGHLIGHT = string.char(127)
local WIDTH, HEIGHT = term.getSize()

local KEY_TO_NOTE = {
    [keys.backspace] = -1,
    [keys.delete] = -1,
    [keys.z] = 0,
    [keys.s] = 1,
    [keys.x] = 2,
    [keys.d] = 3,
    [keys.c] = 4,
    [keys.v] = 5,
    [keys.g] = 6,
    [keys.b] = 7,
    [keys.h] = 8,
    [keys.n] = 9,
    [keys.j] = 10,
    [keys.m] = 11,
    [keys.q] = 12,
    [keys.two] = 13,
    [keys.w] = 14,
    [keys.three] = 15,
    [keys.e] = 16,
    [keys.r] = 17,
    [keys.five] = 18,
    [keys.t] = 19,
    [keys.six] = 20,
    [keys.y] = 21,
    [keys.seven] = 22,
    [keys.u] = 23,
    [keys.i] = 24
}

local NOTE_NAMES = {
    [0] = "C1",
    "C#1",
    "D1",
    "D#1",
    "E1",
    "F1",
    "F#1",
    "G1",
    "G#1",
    "A1",
    "A#1",
    "B1",
    "C2",
    "C#2",
    "D2",
    "D#2",
    "E2",
    "F2",
    "F#2",
    "G2",
    "G#2",
    "A2",
    "A#2",
    "B2",
    "C3"
}

-- Song info
local meta = {
    ["name"] = nil,
    ["speed"] = nil,
    ["patternLength"] = 16
}
local tracks = {
    {name = "basedrum", disp = "kick drum", notes = {}},
    {name = "snare", disp = "snare", notes = {}},
    {name = "hat", disp = "hat", notes = {}},
    {name = "bass", disp = "bass", notes = {}},
    {name = "guitar", disp = "guitar", notes = {}},
    {name = "flute", disp = "flute", notes = {}},
    {name = "chime", disp = "chime", notes = {}},
    {name = "bell", disp = "bells", notes = {}},
    {name = "xylophone", disp = "xylophone", notes = {}}
}

-- Working vars
local pos = 1 -- selected pattern
local subPos = 1 -- cursor position in pattern
local trackPos = 1 -- selected track
local relPos = 1 -- cursor position on screen
local scrollPos = 1 -- top row shown on screen

local trackPositions = {} -- x positions of tracks
local trackWidth -- width of a track
local windowWidth -- width of disp window
local windowHeight -- height of disp window
local linesHeight -- number of lines shown at once

local isPlaying = false -- is the song playing

local speaker -- speaker peripheral

local draw

-- Clear the terminal screen
local function clear()
    term.clear()
    term.setCursorPos(1,1)
end

-- Display a simple dialog box
local function dialog(x, y, message)
    term.setCursorPos(x, y)
    term.write(PIPE_C .. string.rep(PIPE_H, string.len(message)) .. PIPE_C)
    term.setCursorPos(x, y + 3)
    term.write(PIPE_C .. string.rep(PIPE_H, string.len(message)) .. PIPE_C)
    for i = 1, 2 do
        term.setCursorPos(x, y + i)
        term.write(PIPE_V .. string.rep(" ", string.len(message)) .. PIPE_V)
    end
    term.setCursorPos(x + 1, y + 1)
    term.write(message)
    term.setCursorPos(x + 1, y + 2)
    term.write("> OK")
    local event, param
    while param ~= keys.enter do
        event, param = os.pullEvent("key")
    end
end

-- Prompt the user for number input
local function numberPrompt(x, y, message, min, max)
    local ans
    repeat
        term.setCursorPos(x, y)
        term.write(PIPE_C .. string.rep(PIPE_H, string.len(message)) .. PIPE_C)
        term.setCursorPos(x, y + 3)
        term.write(PIPE_C .. string.rep(PIPE_H, string.len(message)) .. PIPE_C)
        for i = 1, 2 do
            term.setCursorPos(x, y + i)
            term.write(PIPE_V .. string.rep(" ", string.len(message)) .. PIPE_V)
        end
        term.setCursorPos(x + 1, y + 1)
        term.write(message)
        term.setCursorPos(x + 1, y + 2)
        ans = read()
        if not tonumber(ans) or tonumber(ans) < min or tonumber(ans) > max then
            dialog(x, y, "Invalid. Enter a number between " .. min .. " and " .. max .. ".")
            draw()
        end
    until tonumber(ans) and tonumber(ans) >= min and tonumber(ans) <= max
    return tonumber(ans)
end

-- Constructor for a menu option
local function menuOption(name, func)
    return {["name"] = name, ["func"] = func}
end

-- Display a menu with certain options
local function menu(x, y, curOpt, ...)
    local arg = {...}
    local longest = 0
    for i, opt in ipairs(arg) do
        if string.len(opt.name) + 2 > longest then
            longest = string.len(opt.name) + 2
        end
    end
    longest = longest
    term.setCursorPos(x, y)
    term.write(PIPE_C .. string.rep(PIPE_H, longest) .. PIPE_C)
    term.setCursorPos(x, y + #arg + 1)
    term.write(PIPE_C .. string.rep(PIPE_H, longest) .. PIPE_C)
    for i, opt in ipairs(arg) do
        term.setCursorPos(x, y + i)
        term.write(PIPE_V .. string.rep(" ", longest) .. PIPE_V)
    end
    local event, param
    while param ~= keys.enter do
        for i, opt in ipairs(arg) do
            term.setCursorPos(x + 1, y + i)
            if curOpt == i then
                term.write("> " .. opt.name)
            else
                term.write("  " .. opt.name)
            end
        end
        event, param = os.pullEvent("key")
        if param == keys.up then
            curOpt = curOpt - 1
            if curOpt < 1 then
                curOpt = #arg
            end
        elseif param == keys.down then
            curOpt = curOpt + 1
            if curOpt > #arg then
                curOpt = 1
            end
        end
    end
    arg[curOpt].func()
end

-- Add pattern
local function addPattern()
    for i = 1, #tracks do
        local pattern = {}
        for n = 1, meta.patternLength do
            pattern[n] = -1
        end
        tracks[i].notes[#tracks[i].notes + 1] = pattern
    end
end

-- New file menu
local function new()
    local accept = false
    local name
    while not accept do
        clear()
        print("Name your file.")
        name = read()
        print("The file will be saved at " .. name .. ".song. Is this OK?")
        menu(
            2, 5,
            1,
            menuOption("Yes", function() accept = true end),
            menuOption("No", function() return end))
    end
    meta.name = name .. ".song"
    meta.speed = 3
    meta.patternLength = 16
    addPattern()
end

-- Open file menu
local function open()
    local name
    repeat
        clear()
        print("What file do you want to open? Note that the program does not check filetypes, and as such opening a file of the incorrect format may cause a crash.")
        name = read()
        if not fs.exists(name) then
            print("That file does not exist.")
            os.sleep(1.5)
        end
    until fs.exists(name)
    local file = fs.open(name, "r")
    meta.name = name
    meta.speed = tonumber(file.readLine())
    meta.patternLength = tonumber(file.readLine())
    local patternCount = file.readLine()
    for n = 1, #tracks do
        tracks[n].notes = {}
    end
    for n = 1, patternCount do
        addPattern()
    end
    for n,track in ipairs(tracks) do
        for i = 1, patternCount do
            for note = 1, meta.patternLength do
                local s = file.readLine()
                noteV = tonumber(s)
                track.notes[i][note] = noteV
            end
        end
    end
    file.close()
end

-- Save file
local function save()
    local file = fs.open(meta.name, "w")
    file.writeLine(tostring(meta.speed))
    file.writeLine(tostring(meta.patternLength))
    file.writeLine(tostring(#tracks[1].notes))
    for i,track in ipairs(tracks) do
        for n,pattern in ipairs(track.notes) do
            for q,note in ipairs(pattern) do
                file.writeLine(tostring(note))
            end
        end
    end
    file.close()
    dialog(2, 2, "Saved successfully at " .. meta.name)
end

-- Determine values for ui dists
local function uiSetup()
    trackWidth = math.floor((WIDTH - 3.0) / #tracks)
    windowWidth = trackWidth * #tracks + 3
    windowHeight = math.min(HEIGHT - 3, meta.patternLength + 3)
    linesHeight = windowHeight - 3
    for i, track in ipairs(tracks) do
        trackPositions[#trackPositions + 1] = trackWidth * (i - 1) + 4
    end
end

-- Update scrollPos/relPos based on subPos
local function updateRelPos()
   if subPos < scrollPos then
       scrollPos = subPos
       relPos = 1
   elseif subPos > scrollPos + linesHeight - 1 then
       scrollPos = subPos - linesHeight + 1
       relPos = linesHeight
   else
       relPos = subPos - scrollPos + 1
   end
end

-- Draw everything
draw = function()
    -- Draw borders and track names
    term.setCursorPos(3, 1)
    term.write(PIPE_V)
    term.setCursorPos(1, 2)
    term.write(PIPE_H .. PIPE_H .. PIPE_C)
    term.setCursorPos(1, windowHeight)
    term.write(PIPE_H .. PIPE_H .. PIPE_C)
    for i = 3, windowHeight - 1 do
        term.setCursorPos(3, i)
        term.write(PIPE_V)
    end
    term.setCursorPos(3, windowHeight)
    term.write(PIPE_C)
    for i,track in ipairs(tracks) do
        term.setCursorPos(trackPositions[i], 1)
        term.write(string.sub(track.disp, 1, math.min(trackWidth - 1, string.len(track.name))))
        term.setCursorPos(trackPositions[i], 2)
        term.write(string.rep(PIPE_H, trackWidth - 1))
        term.setCursorPos(trackPositions[i], windowHeight)
        term.write(string.rep(PIPE_H, trackWidth - 1))
        local sepX = trackWidth * i + 3
        for i = 1, windowHeight do
            term.setCursorPos(sepX, i)
            if i == 2 or i == windowHeight then
                term.write(PIPE_C)
            else
                term.write(PIPE_V)
            end
        end
    end

    -- Draw spaces after last column to clear any unwanted chars
    for i = 1, windowHeight do
        term.setCursorPos(windowWidth + 1, i)
        term.write(" ")
    end

    -- Draw line numbers
    for i = 1, linesHeight do
        term.setCursorPos(1, 2 + i)
        local s = tostring(scrollPos + i - 1)
        if string.len(s) == 1 then
            s = "0" .. s
        end
        term.write(s)
    end

    -- Draw notes
    for i, track in ipairs(tracks) do
        local pattern = track.notes[pos]
        for n = scrollPos, math.min(#pattern, scrollPos + linesHeight - 1) do
            term.setCursorPos(trackPositions[i], 3 + n - scrollPos)
            local noteName = NOTE_NAMES[pattern[n]]
            if not noteName then noteName = "" end
            term.write(noteName .. string.rep(" ",trackWidth - 1 - string.len(noteName)))
        end
    end

    -- Draw meta info below window
    term.setCursorPos(1, HEIGHT - 2)
    term.write("Current track: " .. tracks[trackPos].disp .. "          ")
    term.setCursorPos(1, HEIGHT - 1)
    term.write("Speed: " .. meta.speed ..
        " -- MeasLength: " .. meta.patternLength ..
        " -- Measure: " .. pos .. "/" .. #tracks[1].notes .. "          ")
    term.setCursorPos(1, HEIGHT)
    term.write("[Press left ctrl for menu]                 ")

    -- Draw selected position
    if isPlaying then
        term.setCursorPos(1, HEIGHT)
        term.write("[PLAYING... Press Enter to stop]")
        local selY = 2 + relPos
        term.setCursorPos(1, selY)
        term.write(string.rep(HIGHLIGHT, windowWidth))
    else
        local selY = 2 + relPos
        term.setCursorPos(1, selY)
        term.write("=")
        for i, track in ipairs(tracks) do
            term.setCursorPos(trackPositions[i] - 1, selY)
            term.write("=")
        end
        term.setCursorPos(trackPositions[#tracks] + trackWidth - 1, selY)
        term.write("=")
        term.setCursorPos(trackPositions[trackPos] - 2, selY)
        term.write(">>")
        if trackPos == #tracks then
            term.setCursorPos(trackPositions[trackPos] + trackWidth - 1, selY)
        else
            term.setCursorPos(trackPositions[trackPos + 1] - 1, selY)
        end
        term.write("<<")
    end
end

-- Play the song
local function play()
    isPlaying = true
    subPos = 1
    while pos <= #tracks[1].notes do
        updateRelPos()
        draw()
        for i,track in ipairs(tracks) do
            local note = track.notes[pos][subPos]
            if note ~= -1 then
                speaker.playNote(track.name, 3, note)
            end
        end
        os.startTimer(.05 * meta.speed)
        local event, param
        repeat
            event, param = os.pullEvent()
        until event == "timer" or (event == "key" and param == keys.enter)
        if event == "key" then
            updateRelPos()
            isPlaying = false
            draw()
            return
        end
        subPos = subPos + 1
        if subPos > meta.patternLength then
            subPos = 1
            pos = pos + 1
        end
    end
    pos = pos - 1
    subPos = meta.patternLength
    updateRelPos()
    isPlaying = false
    draw()
end

-- Get speaker peripheral
clear()
for i, v in ipairs(peripheral.getNames()) do
    if peripheral.getType(v) == "speaker" then
        speaker = peripheral.wrap(v)
    end
end

if not speaker then
    print("No speaker present...")
    return
end
print("Connected to speaker. Initializing...")
os.sleep(1.5)

local exitRequested, toMenuRequested
local function main()
    -- Open main menu
    clear()
    exitRequested = false
    toMenuRequested = false
    menu(
        2, 2,
        1,
        menuOption("New", new),
        menuOption("Open", open),
        menuOption("Exit", function() exitRequested = true end)
    )
    if exitRequested then
        clear()
        return
    end

    -- Main loop
    clear()
    uiSetup()
    local event, param
    while not exitRequested and not toMenuRequested do
        draw()
        event, param = os.pullEvent("key")
        if param == keys.up then
            subPos = subPos - 1
            if subPos < 1 then
                subPos = meta.patternLength
            end
        elseif param == keys.down then
            subPos = subPos + 1
            if subPos > meta.patternLength then
                subPos = 1
            end
        elseif param == keys.left then
            trackPos = trackPos - 1
            if trackPos < 1 then
                trackPos = #tracks
            end
        elseif param == keys.right then
            trackPos = trackPos + 1
            if trackPos > #tracks then
                trackPos = 1
            end
        elseif param == keys.comma then
            pos = pos - 1
            if pos < 1 then
                pos = #tracks[1].notes
            end
        elseif param == keys.period then
            pos = pos + 1
            if pos > #tracks[1].notes then
                pos = 1
            end
        elseif param == keys.enter then
            -- Play the song
            play()
        elseif param == keys.leftCtrl then
            -- Menu
            menu(
                2,2,
                1,
                menuOption("Save", save),
                menuOption("Copy",
                    function()
                        local valid = false
                        while not valid do
                            local start = numberPrompt(2,2,"Start measure:",1,#tracks[1].notes)
                            local stop = numberPrompt(2,2,"End measure:",1,#tracks[1].notes)
                            local dest = numberPrompt(2,2,"Paste at measure:",1,#tracks[1].notes)
                            if stop < start then
                                dialog(2,2,"End measure must be >= start measure.")
                            else
                                valid = true
                                for i = 1, stop - start + 1 do
                                    for t, track in ipairs(tracks) do
                                        for n = 1, meta.patternLength do
                                            track.notes[dest + i - 1][n] = track.notes[start + i - 1][n]
                                        end
                                    end
                                end
                            end
                        end
                    end),
                menuOption("Copy (Current Track)",
                    function()
                        local valid = false
                        while not valid do
                            local start = numberPrompt(2,2,"Start measure:",1,#tracks[1].notes)
                            local stop = numberPrompt(2,2,"End measure:",1,#tracks[1].notes)
                            local dest = numberPrompt(2,2,"Paste at measure:",1,#tracks[1].notes)
                            if stop < start then
                                dialog(2,2,"End measure must be >= start measure.")
                            else
                                valid = true
                                local track = tracks[trackPos]
                                for i = 1, stop - start + 1 do
                                    for n = 1, meta.patternLength do
                                        track.notes[dest + i - 1][n] = track.notes[start + i - 1][n]
                                    end
                                end
                            end
                        end
                    end),
                menuOption("Add Measures",
                    function()
                        local n = numberPrompt(2,2,"How many to add?",0,64)
                        for i = 1, n do
                            addPattern()
                        end
                    end),
                menuOption("Remove Measures",
                    function()
                        if #tracks[1].notes == 1 then
                            dialog("Can't remove with only 1 measure.")
                            return
                        end
                        local valid = false
                        while not valid do
                            local start = numberPrompt(2,2,"Start measure:",1,#tracks[1].notes)
                            local stop = numberPrompt(2,2,"End measure:",1,#tracks[1].notes)
                            if stop < start then
                                dialog("End measure must be >= start measure.")
                            else
                                valid = true
                                for i = start, stop do
                                    for t = 1, #tracks do
                                        for n = start, #tracks[t].notes do
                                            tracks[t].notes[n] = tracks[t].notes[n + 1]
                                        end
                                    end
                                end
                            end
                        end
                        if pos > #tracks[1].notes then
                            pos = #tracks[1].notes
                        end
                    end),
                menuOption("Set Measure Length",
                    function()
                        local n = numberPrompt(2,2,"Set the new measure length:",4,32)
                        meta.patternLength = n
                        for t, track in ipairs(tracks) do
                            for p, pattern in ipairs(track.notes) do
                                if #pattern > n then
                                    pattern[n + 1] = nil
                                elseif #pattern < n then
                                    for i = #pattern + 1, n do
                                        pattern[i] = -1
                                    end
                                end
                            end
                        end
                        uiSetup()
                        clear()
                    end),
                menuOption("Set Speed",
                    function()
                        local n = numberPrompt(2,2,"Set the new speed:",1,16)
                        meta.speed = n
                    end),
                menuOption("Back to Editing", function() end),
                menuOption("Exit", function() toMenuRequested = true end)
            )
        elseif KEY_TO_NOTE[param] then
            -- Note input
            tracks[trackPos].notes[pos][subPos] = KEY_TO_NOTE[param]
            if tracks[trackPos].notes[pos][subPos] > -1 then
                speaker.playNote(tracks[trackPos].name, 3, tracks[trackPos].notes[pos][subPos])
            end
        end

        updateRelPos()
    end
    clear()
    return
end

while not exitRequested do
    main()
end