--[[OpenMatrix v0.7.1 by Karasuro]]--

-- Requirements
local computer = require "computer";
local component = require "component";
local term = require "term";
local event = require "event";
local gpu = component.gpu;
local source = component.note_block;
local note = require "note";
local keyboard = require "keyboard";
local color = require "colors";

-- Variables and Tables
term.clear();
local maxX, maxY = gpu.getResolution();

if (maxX ~= 80) then
  if (maxY ~= 25) then
    gpu.setResolution(80, 25);
  end
end

local w, h = gpu.getResolution();
local UI = {bg=0x000000, fg=0xFFFFFF, txt=0x000000, width=w, height=h};
local UI_btn = {on=0xFFFFFF, off=0xFFAA00, play=0xFFFF55};
local UI_menu = {default=0xFFAA00, hit=0xFFFF55};
local buttons = {};

for Y = 2,16 do
  local row = {};
  table.insert(buttons, row);
  for X = 2,47,3 do
    if (Y == 2) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=25});
    elseif (Y == 3) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=24});
    elseif (Y == 4) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=22});
    elseif (Y == 5) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=20});
    elseif (Y == 6) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=18});
    elseif (Y == 7) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=17});
    elseif (Y == 8) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=15});
    elseif (Y == 9) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=13});
    elseif (Y == 10) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=12});
    elseif (Y == 11) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=10});
    elseif (Y == 12) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=8});
    elseif (Y == 13) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=6});
    elseif (Y == 14) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=5});
    elseif (Y == 15) then
      table.insert(row, {state=3, posX=X, posY=Y, pitch=3});
    else
      table.insert(row, {state=3, posX=X, posY=Y, pitch=1})
    end
  end
end

local printDebug = false;
local mX = 0;
local mY = 0;
local pitch = 1;
local playing = false;
local tick = 0;
local beat = 16;
local tempo = 40;
local cycle = 0;
local dt = 0;



local menu = {
  {id="play", posX=2, posY=(h - 1), state=1, label="Play", width=6, height=1}
};
local header = {posX=47,posY=18,width=2,height=1,col=0x00AA00};

local myEventHandlers = setmetatable({}, {__index = function() return unknownEvent end});

-- Functions
function unknownEvent()
  -- Do Nothing!
end

function myEventHandlers.key_up(adress, char, code, playerName)
  -- Space Bar
  if (code == 0x39) then
    playing = not playing;
  end

  -- Backspace
  if (code == 0x0E) then
    gpu.setResolution(maxX, maxY);
    term.clear();
    os.exit();
  end

  -- Grave or ~
  if (code == 0x29) then
    printDebug = not printDebug;
  end
end

function myEventHandlers.touch(screenAdress, x, y, button, playerName)
  mX = x;
  mY = y;
  if (button == 0) then
    -- Buttons Table Handling
    for r in pairs(buttons) do
      for c in pairs(buttons[r]) do
        if (mX >= buttons[r][c].posX) and (mX <= (buttons[r][c].posX + 2)) and (mY == buttons[r][c].posY) then
          if (buttons[r][c].state == 3) then
            buttons[r][c].state = 1;
          else
            buttons[r][c].state = 3;
          end
        end
      end
    end

    -- Menu Table Handling
    for i in pairs(menu) do
      if (mX >= menu[i].posX) and (mX <= (menu[i].posX + menu[i].width)) and (mY == menu[i].posY) then
        --play/stop button
        if menu[i].id == "play" then
          playing = not playing;
          menu[i].label = "Stop";
        end
      end
    end
  end
 end

function handleEvent(eventID, ...)
  if (eventID) then
    myEventHandlers[eventID](...);
  end
end

function playTone(pitch)
  if (source ~= nil) then
    source.trigger(pitch);
  else
    computer.beep(pitch);
  end
end

  --Draw Instructions ONCE
  gpu.setBackground(UI.bg); --Black
  gpu.setForeground(UI.fg); --White
  gpu.set(2,20,"~ = debug info | space = play/stop | backspace = exit");
  gpu.set(2,21,"Multiple notes on each column = more processing time.")

-- Main Loop
while true do

  --[[UPDATE DATA]]--
  if playing then
    -- Update UI
    menu[1].label = "Stop";

    -- Start ticking
    tick = tick + (tempo * 0.1);
    if tick > 1 then
      header.posX = header.posX + 3;
      if header.posX > 47 then
        header.posX = 2;
      end
      tick = 0;
      beat = beat + 1;
    end

    if (beat > 16) then
      beat = 1;
    end

    -- Get Active Notes
    for r in pairs(buttons) do
      for c in pairs(buttons[r]) do
        if (buttons[r][c].posX == header.posX) then
          if (buttons[r][c].state == 1) then
            buttons[r][c].state = 2;
            pitch = buttons[r][c].pitch;
            playTone(pitch);
          end
        else
          if (buttons[r][c].state == 2) then
            buttons[r][c].state = 1;
          end
        end
      end
    end
  else
    -- Reset UI
    header.posX = 47;
    tick = 0;
    beat = 16;
    menu[1].label = "Play";
    for r in pairs(buttons) do
      for c in pairs(buttons[r]) do
        if (buttons[r][c].state == 2) or (buttons[r][c].state == 1) then
          buttons[r][c].state = 1;
        else
          buttons[r][c].state = 3;
        end
      end
    end
  end

  --[[DRAW STUFF]]--
  -- Draw Buttons and their states
  for r in pairs(buttons) do
    for c in pairs(buttons[r]) do
      if (buttons[r][c].state == 3) then
        --Draw Button OFF
        gpu.setBackground(UI_btn.off); --Orange
        gpu.fill(buttons[r][c].posX,buttons[r][c].posY,2,1," ");
        gpu.setBackground(UI.bg); --Black
      end

      if (buttons[r][c].state == 2) then
        -- Draw Buttons ON
        gpu.setBackground(UI_btn.on); --White
        gpu.fill(buttons[r][c].posX,buttons[r][c].posY,2,1," ");
        gpu.setBackground(UI.bg); --Black
      end

      if (buttons[r][c].state == 1) then
        -- Draw Buttons PLAY
        gpu.setBackground(UI_btn.play); --Yellow
        gpu.fill(buttons[r][c].posX,buttons[r][c].posY,2,1," ");
        gpu.setBackground(UI.bg); --Black
      end
    end
  end

  -- Draw Play Head
  gpu.setBackground(header.col); --Green
  gpu.fill(header.posX,header.posY,2,1," ");
  gpu.setBackground(UI.bg); --Black
  if (header.posX ~= 2) then
    gpu.fill((header.posX - 3),header.posY,2,1," ");
  end
  if (header.posX == 2) then
    gpu.fill(47,18,2,1," ");
  end
  if (header.posX == 47) then
    gpu.fill(2,header.posY,45,1," ");
  end

  --Draw Menu
  for i in pairs(menu) do
    if (menu[i].state == 1) then
      gpu.setBackground(UI_menu.default) --Orange
      gpu.fill(menu[i].posX,menu[i].posY,menu[i].width,menu[i].height," ");
      gpu.setForeground(UI.txt); --Black
      gpu.set(menu[i].posX,menu[i].posY,menu[i].label);
      gpu.setBackground(UI.bg); --Black
      gpu.setForeground(UI.fg); --White
    end

    if (menu[i].state == 2) then
      gpu.setBackground(UI_menu.hit); --Yellow
      gpu.fill(menu[i].posX,menu[i].posY,menu[i].width,menu[i].height," ");
      gpu.setForeground(UI.txt); --Black
      gpu.set(menu[i].posX,menu[i].posY,menu[i].label);
      gpu.setBackground(UI.bg); --Black
      gpu.setForeground(UI.fg); --White
    end
  end

  -- print debug information
  if (printDebug) then
    gpu.fill(50,2,80,5," ");
    gpu.setBackground(UI.bg) --Black
    gpu.setForeground(UI.fg) --White
    gpu.set(50,2,tostring(mX)..", "..tostring(mY));
    gpu.set(50,3,"playing: "..tostring(playing));
    gpu.set(50,4,"beat: "..tostring(beat));
    gpu.set(50,5,"pitch: "..tostring(pitch));
  else
    gpu.fill(50,2,80,5," ");
  end

  handleEvent(event.pull(0.001));
end