love.graphics.setDefaultFilter('nearest', 'nearest')
enemy = {}
enemies_controller = {}
enemies_controller.enemies = {}
enemies_controller.image = love.graphics.newImage('enemy.png')
enemies_controller.waveTime = 0
enemies_controller.wonWaves = 0

function checkCollisions(enemies, bullets)
  for i,e in ipairs(enemies) do
    for _,b in pairs(bullets) do
      if b.y <= e.y + e.height and
         b.x > e.x and
         b.x < e.x + e.width then
           table.remove(enemies, i)
           table.remove(bullets, i)
      end
    end
  end
end

function love.load()
  background_music = love.audio.newSource('music2.mp3')
  love.audio.play(background_music)
  background_music:setVolume(0.2)
  victory_music = love.audio.newSource('victory.wav')
  victory_music:setVolume(0.3)
  victory_music:setLooping(false)
  defeat_music = love.audio.newSource('defeat.wav')
  defeat_music:setVolume(0.3)
  defeat_music:setLooping(false)
  game_over = false
  background_image = love.graphics.newImage('background2.png')
  player = {}
  player.x = 0
  player.y = 108
  player.bullets = {}
  player.cooldown = 18
  player.speed = 2
  player.image = love.graphics.newImage('spaceship.png')
  player.fire_sound = love.audio.newSource('laser.wav')
  player.fire = function()
    if player.cooldown <= 0 then
      love.audio.play(player.fire_sound)
      player.cooldown = 18
      bullet = {}
      bullet.x = player.x + 4
      bullet.y = player.y - 1
      table.insert(player.bullets, bullet)
    end
  end
end

function enemies_controller:spawnEnemy(x, y)
  enemy = {}
  enemy.x = x
  enemy.y = y
  enemy.width = 10
  enemy.height = 10
  enemy.bullets = {}
  enemy.cooldown = 2
  enemy.speed = .1
  table.insert(self.enemies, enemy)
end

function enemies_controller:spawnWave()
  for i=0, 10 do
    enemies_controller:spawnEnemy(i * 15, 0)
  end
end

function enemy:fire()
  if self.cooldown <= 0 then
    self.cooldown = 20
    bullet = {}
    bullet.x = self.x + 35
    bullet.y = self.y
    table.insert(self.bullets, bullet)
  end
end

function love.update(dt)
  player.cooldown = player.cooldown - 1

  if love.keyboard.isDown("right") or love.keyboard.isDown("d") then
    player.x = player.x + player.speed
  elseif love.keyboard.isDown("left") or love.keyboard.isDown("a") then
    player.x = player.x - player.speed
  end

  if love.keyboard.isDown("space") then
    player.fire()
  end

  if enemies_controller.wonWaves == 100 then
    -- we win!
    game_win = true
  end

  for _,e in pairs(enemies_controller.enemies) do
    if e.y >= love.graphics.getHeight()/5 then
      game_over = true
    end
    e.y = e.y + 1 * e.speed
  end

  if enemies_controller.waveTime <= 0 then
      enemies_controller:spawnWave()
      enemies_controller.waveTime = 5
      enemies_controller.wonWaves = enemies_controller.wonWaves + 1
    else
      enemies_controller.waveTime = enemies_controller.waveTime - dt
    end

  for i,b in ipairs(player.bullets) do
    if b.y < -10 then
      table.remove(player.bullets, i)
    end
    b.y = b.y - 3
  checkCollisions(enemies_controller.enemies, player.bullets)
  end
 end

function love.draw()
  love.graphics.setColor(255,255,255)
  love.graphics.draw(background_image, 0,0,0,1.25)
  love.graphics.scale(5)

  if game_over then
    love.graphics.print("Game Over!", 45, 45)
    background_music:stop()
    defeat_music:play()
    return
  elseif game_win then
    love.graphics.print("Victory!", 55, 45)
    background_music:stop()
    victory_music:play()
  end

  -- draw the players image specified in player.image
  love.graphics.setColor(255, 255, 255)
  love.graphics.draw(player.image, player.x, player.y, 0)

  -- draw enemies image specified in enemies_controller.image
  for _,e in pairs(enemies_controller.enemies) do
    love.graphics.draw(enemies_controller.image, e.x, e.y, 0)
  end

  -- draw bullets
  love.graphics.setColor(255, 0, 0)
  for _,b in pairs(player.bullets) do
    love.graphics.rectangle("fill", b.x, b.y, 2, 2)
  end
end