function _init()
		poke(0x5f34, 0x2) --activate inverted shapes
		room_x = 0
		room_y = 0
		
		room_width = 16
		room_height = 16
		
		final_room_x = 7
		final_room_y = 0
		
		ending = false
		ending_timer = 0
		failed = false
		
		spr_open = 2
		spr_closed = 4
		
		attention_band = 0
		
  px = 64
  py = 64
  attention = 0
  invert =0x1800
  eyes= {}
  sfx(1,-1)
end


function _update()

  -- early-out for ending/failure
  if ending or failed then
    ending_timer += 1
    if failed and ending_timer > 90 and btnp(5) then
      _init()
    end
    return
  end

  update_eyes()

  if btnp(0) then try_move(-8,0) end
  if btnp(1) then try_move( 8,0) end
  if btnp(2) then try_move( 0,-8) end
  if btnp(3) then try_move( 0, 8) end
  
  max_attention = 80
  if watched() then
    attention = min(attention + 1, max_attention)
  else
    attention = max(attention - 1, 0)
  end

  local new_band = 0
  if attention >= 20 and attention < 40 then
    new_band = 1
  elseif attention >= 40 and attention < 60 then
    new_band = 2
  elseif attention >= 60 then
    new_band = 3
  end

  if new_band != attention_band then
    attention_band = new_band
    spawn_eyes_for_band(attention_band)
  end

  if attention >= max_attention then
    if room_x == final_room_x and room_y == final_room_y then
      start_ending()
    else
      start_fail()
    end
  end
  
  local t = attention / max_attention
  
  poke(0x5f40, 32 + t * 16)
  
  poke(0x5f42, 2 +t * 4)
end

function room_sfx()
	target_vol = 2
	target_pitch = 32
	shake = 0
	
	--room 0-1
	if room_x <= 1 then
		target_vol = 1
		target_pitch = 28
		shake = 0
	end
	
	--room 2-3
	if room_x >= 2 and room_x <= 3 then
		target_vol = 2
		target_pitch = 32
		shake = 0
	end
	
	--room 4-5
	if room_x >= 4 and room_x <= 5 then
		target_vol = 3
		target_pitch = 36
		shake = attention_band >= 2 and 1 or 0
	end
	
	-- room 6
	if room_x == 6 then
		target_vol = 1
		target_pitch = 24
		shake = 0
	end
	
	-- room 7
	if room_x == 7 then
		target_vol = 0
		target_pitch = 20
		shake = 0
	end
	
	-- room 8
	if room_x == 8 then
		target_vol = 6
		target_pitch = 60
		shake = 2
	end
	
	poke(0x5f42, target_vol)
	poke(0x5f40, target_pitch)
	
	return shake
end

function start_ending()
	ending = true
	ending_timer = 0
end

function start_fail()
	failed = true
	ending_timer = 0
end

function solid_at(px, py)
  local tx = flr(px / 8)
  local ty = flr(py / 8)
  
  -- convert to map coordinates
  local map_x = tx + (room_x * room_width)
  local map_y = ty + (room_y * room_height)
  
  return fget(mget(map_x, map_y), 0)
end

function spawn_eyes_for_band(band)
	eyes = {}
	
	local count = 0
	if band == 1 then count = 2 end
	if band == 2 then count = 4 end
	if band == 3 then count = 6 end
	
	for i=1, count do
		add(eyes, {
		x = rnd(120),
		y = rnd(120),
		blink_timer = flr(rnd(60)) + 30,
		open = true,
		forced_timer = 0
		})
	end
end

function player_on_eye(e)
	return abs(px - e.x) < 8 and abs(py - e.y) < 8
end

function update_eyes()
  for e in all(eyes) do

    -- if player is standing on the eye
    if player_on_eye(e) then
      e.open = false
      e.forced_timer = 30 -- stays closed for half a second
    end

    -- forced closed state
    if e.forced_timer > 0 then
      e.forced_timer -= 1
    else
      -- natural blinking
      e.blink_timer -= 1
      if e.blink_timer <= 0 then
        e.open = not e.open
        if e.open then
          e.blink_timer = flr(rnd(90)) + 60
        else
          e.blink_timer = 5
        end
      end
    end

  end
end

function try_move(dx, dy)
  local nx = px + dx
  local ny = py + dy

  if dx > 0 and (solid_at(nx+7, py) or solid_at(nx+7, py+7)) then return end
  if dx < 0 and (solid_at(nx,   py) or solid_at(nx,   py+7)) then return end
  if dy > 0 and (solid_at(px, ny+7) or solid_at(px+7, ny+7)) then return end
  if dy < 0 and (solid_at(px, ny)   or solid_at(px+7, ny))   then return end

  px = nx
  py = ny
  attention += 1
  sfx(0) -- footstep
  
  -- check for door after successful move
  check_door()
  
  return true
end

function watched()
	local tx = flr(px/8)
	local ty = flr(py/8)
	
	-- convert to map coordinates
	local map_x = tx + (room_x * room_width)
	local map_y = ty + (room_y * room_height)
	
	--check left
	for x = map_x-1, room_x * room_width, -1 do
		local t = mget(x, map_y)
		if fget(t, 0) then break end -- wall blocks
		if fget(t, 1) then return true end
	end
	
 -- check right
 for x = map_x+1, (room_x * room_width) + 15 do
   local t = mget(x, map_y)
   if fget(t, 0) then break end
   if fget(t, 1) then return true end
 end

 -- check up
 for y = map_y-1, room_y * room_height, -1 do
   local t = mget(map_x, y)
   if fget(t, 0) then break end
   if fget(t, 1) then return true end
 end

 -- check down
 for y = map_y+1, (room_y * room_height) + 15 do
   local t = mget(map_x, y)
   if fget(t, 0) then break end
   if fget(t, 1) then return true end
 end

 return false
end

function _draw()
  cls()
  
  local shake = room_sfx()
  if shake > 0 then
  	camera(rnd(shake*2)-shake, rnd(shake*2)-shake)
  else
    camera()
  end

  -- draw current room using offsets
  map(room_x * room_width, room_y * room_height, 0, 0, 16, 16)
  draw_eyes()
  local min_vision = 0
  local max_vision = 8
  
  
  local vision = max_vision - flr(attention / 10)
  vision = max(min_vision, vision)
  
  fillp(░)
  circfill(px,py,vision,invert)
  fillp(▒)
		circfill(px,py,vision+10,invert)
		fillp()
		circfill(px,py,vision+20,invert)
  spr(5,px, py)
  if ending then
  	draw_ending()
  elseif failed then
  	draw_fail()
  end

end

function draw_eyes()
	for e in all(eyes) do
		if e.open then
			spr(spr_open, e.x, e.y)
		else
			spr(spr_closed, e.x,e.y)
		end
	end
end

function check_door()
  local tx = flr(px / 8)
  local ty = flr(py / 8)
  
  local map_x = tx + (room_x * room_width)
  local map_y = ty + (room_y * room_height)
  
  local tile = mget(map_x, map_y)
  
  if fget(tile, 2) then
    go_to_next_room()
  end
end

function draw_ending()
	rectfill(0,0,127,127,0)
	
	local t = ending_timer
	
	if t > 30 then
		print("you were never alone",64, 60, 7)
	end
	
	if t > 120 then
		print("🅾️bversation does not end", 64, 70, 6)
	end
end	

function draw_fail()
	rectfill(0,0,127,127,0)
	
	local t = ending_timer
	
	if t > 30 then
		print("they found you.",44,60,2)
	end
	
	if t > 90 then
		print("press ❎ to restart.",34,70,7)
	end
end

function go_to_next_room()
  room_x += 1
  
  px = 16
  py = 64
  
  attention = max(0, attention - 10)
end