extends Camera2D

const MOVEMENT_SPEED = 500
const RUN_MULT = 2
const ZOOM_SPEED = 10
const ZOOM_WINDOW = [0.5, 2]
const SCREEN_BORDER_THRESHOLD = 40

var grabbing = false
var mouse_last_global_position = Vector2()

func _process(delta):
	var direction = Vector2()
	var zoom_change = 0
	var movement = Vector2()
	
	if Input.is_action_pressed("grab"):
		var grabbing_movement = mouse_last_global_position - get_global_mouse_position()
		print(grabbing_movement)
		movement += grabbing_movement
	
	var mouse_pos = get_viewport().get_mouse_position()
	var viewport_size = get_viewport().get_visible_rect().size
	
	if (
		Input.is_action_pressed("right") 
		or mouse_pos.x > viewport_size.x - SCREEN_BORDER_THRESHOLD and mouse_pos.x <= viewport_size.x
		)  :
		direction.x = 1
	if (
		Input.is_action_pressed("left")
		or mouse_pos.x < 0 + SCREEN_BORDER_THRESHOLD and mouse_pos.x >= 0
		):
		direction.x = -1
	if (
		Input.is_action_pressed("up")
		or mouse_pos.y < 0 + SCREEN_BORDER_THRESHOLD and mouse_pos.y >= 0
		):
		direction.y = -1
	if (
		Input.is_action_pressed("down")
		or mouse_pos.y > viewport_size.y - SCREEN_BORDER_THRESHOLD and mouse_pos.y <= viewport_size.y
		):
		direction.y = 1
	
	direction = direction.normalized()
	
	if Input.is_action_just_pressed("zoom"):
		zoom_change = 1
	if Input.is_action_just_pressed("dezoom"):
		zoom_change = -1

	var zoom_value = max(min(zoom.x + zoom_change*ZOOM_SPEED*delta, ZOOM_WINDOW[1]), ZOOM_WINDOW[0])
	zoom = Vector2(zoom_value, zoom_value)
	
	movement += direction*MOVEMENT_SPEED*delta
	
	if Input.is_action_pressed("run"):
		movement *= RUN_MULT
	
	move_camera_on_map(movement)
	mouse_last_global_position = get_global_mouse_position()

func move_camera_on_map(movement):
	var new_position = Vector2(
		max(
			min(position.x+movement.x, GameTerrain.TERRAIN_SIZE.x * GameTerrain.MAP_RATIO),
			0
		),
		max(
			min(position.y+movement.y, GameTerrain.TERRAIN_SIZE.y * GameTerrain.MAP_RATIO),
			0
		)
	)
	position = lerp(position, new_position, 0.7)