class Funfriend::BuddyContext < Funfriend::WindowContext
  CHATTER_TIMER = 3.0

  getter buddy : Buddy

  getter renderer : BuddyRenderer
  property chatter_timer : Float64 = 1.0
  property chatter_index : Int32 = 0
  property chatter_array : Array(String)?

  property held : Bool = false
  property held_at : Vec2 = Vec2.zero
  property started_holding_at : Vec2 = Vec2.zero
  STAY_STILL_AFTER_HELD = 1.0
  property held_timer : Float64 = 0.0
  property waiting_for_stable_pos : Bool = false

  property static_pos : Vec2

  property easing_from : Vec2 = Vec2.zero
  property easing_to : Vec2 = Vec2.zero
  property easing_dur : Float64 = 0.0
  property easing_t : Float64 = 0.0

  WANDER_TIMER = 4.0
  property wander_timer : Float64 = WANDER_TIMER

  def initialize(@buddy : Buddy)
    super(
      title: "??_#{buddy.name}_??",
      width: window_size.x_i, height: window_size.y_i,
      transparent: true
    )

    # just for initialization, let OpenGL know this is the current context
    window.make_context_current
    @renderer = BuddyRenderer.new(buddy)

    window.on_mouse_button do |event|
      if event.mouse_button.one?
        if event.action.press?
          buddy.talk_sound
          @easing_dur = 0.0
          @held = true
          @held_at = Vec2.new({
            x: window.cursor.position[:x].to_i,
            y: window.cursor.position[:y].to_i,
          })
          if @held_timer <= 0
            @started_holding_at = Vec2.new(window.position)
            LOG.info { "starting holding at #{started_holding_at}" }
          end
          @held_timer = STAY_STILL_AFTER_HELD
          window.cursor Window::Cursor::Shape::Hand
        elsif event.action.release?
          @held = false
          window.cursor Window::Cursor::Shape::Arrow
        end
      end
    end

    window.on_key do |event|
      if event.action.press? && event.key.escape?
        event.window.should_close
      end
    end

    # pick a random pos
    monitor = Monitor.primary
    random_pos = {
      x: monitor.position[:x] + (monitor.video_mode.size[:width] * rand((0.0..1.0))).to_i,
      y: monitor.position[:y] + (monitor.video_mode.size[:height] * rand((0.0..1.0))).to_i
    }
    window.position = random_pos
    @static_pos = Vec2.new(random_pos)

    @chatter_array = buddy.dialog(DialogType::Chatter).sample
  end

  def window_size
    funfriend_size = ConfigMan.config["window"]["funfriend_size"].as(Int32)
    Vec2.new((funfriend_size * 1.3).floor)
  end

  def render(dt : Float64)
    # let OpenGL draw to it
    window.make_context_current

    # draw funfriend
    renderer.render(dt, window_size.x_i, window_size.y_i)
  end

  def goto(pos : Vec2, dur : Float64, set_as_static : Bool = true)
    @easing_t = 0.0
    @easing_dur = dur
    @easing_from = Vec2.new(window.position)
    @easing_to = pos

    if set_as_static
      @static_pos = @easing_to
    end

    LOG.info { "going from #{easing_from} to #{easing_to}" }
  end

  enum Behavior
    Wander
    Follow
    Stay
  end

  FOLLOW_DIST = 120

  def behavior : Behavior
    speaking ? Behavior::Follow : Behavior::Wander
  end

  def moving
    @easing_dur != 0.0 && @easing_t <= @easing_dur
  end

  def update_wander(dt : Float64)
    if moving
      @easing_t = @easing_t + dt
      a = Ease.inOutSine(@easing_t / @easing_dur)

      window.position = (@easing_from * (1.0 - a) + @easing_to * a).xy_i

      @wander_timer = WANDER_TIMER
    else
      case behavior
      when .wander?
        @wander_timer = @wander_timer - dt
        if @wander_timer <= 0
          goto(@static_pos + Vec2.rand((0 .. 40)), 4.0, set_as_static: false)
        end
      when .follow?
        if !moving
          x_dist = window.cursor.position[:x]
          y_dist = window.cursor.position[:y]

          x_target = window.position[:x].to_f
          y_target = window.position[:y].to_f

          if x_dist.abs > FOLLOW_DIST
            x_target = window.position[:x] + x_dist - FOLLOW_DIST * x_dist.sign
          end
          if y_dist.abs > FOLLOW_DIST
            y_target = window.position[:y] + y_dist - FOLLOW_DIST * y_dist.sign
          end

          goto(Vec2.new(x_target, y_target), 1.0)
        end
      end
    end
  end

  def update_pos(dt : Float64)
    if held
      @static_pos = Vec2.new(window.position) - held_at + Vec2.new(window.cursor.position)
      window.position = @static_pos.xy_i
    else
      @held_timer = @held_timer - dt
      if @held_timer <= 0
        update_wander(dt)

        if @waiting_for_stable_pos
          @waiting_for_stable_pos = false

          stable_pos_dist = @static_pos.dist(@started_holding_at)
          LOG.info { "travelled #{stable_pos_dist}" }

          if !speaking
            if stable_pos_dist > 50
              # moved quite a bit from initial point
              say buddy.dialog(DialogType::Moved)
            else
              # just touched
              say buddy.dialog(DialogType::Touched)
            end
          end
        end
      else
        @waiting_for_stable_pos = true
      end
    end
  end

  def say(text : String)
    Funfriend.contexts.each do |context|
      if context.is_a?(ChatterContext) && context.parent == self
        context.bump
      end
    end

    Funfriend.add_context(ChatterContext.new(text, Vec2.new(
      window.position[:x] + window_size.x / 2,
      window.position[:y] - 20
    ), parent: self))

    buddy.talk_sound
  end

  def say(text : Array(String))
    @chatter_array = text
    @chatter_timer = 0.0
    @chatter_index = 0
  end

  def say(text : Array(Array(String)))
    if text.size > 0
      say text.sample
    end
  end

  def speaking
    @chatter_array && @chatter_index < @chatter_array.not_nil!.size
  end

  def update(dt : Float64)
    @chatter_timer = @chatter_timer - dt
    if @chatter_timer <= 0.0
      @chatter_timer = @chatter_timer + CHATTER_TIMER

      if @chatter_array.try &.[(@chatter_index)]?
        say(@chatter_array.not_nil![@chatter_index])
      end

      @chatter_index = @chatter_index + 1
    end

    update_pos(dt)

    render(dt)

    window.swap_buffers
  end

  def clean_up
    renderer.clean_up
  end
end