extends Control

const Brand := preload("res://scripts/ui/medmind_style.gd")

var points: Array = []
var mode := "rating"
var dark := true
var hover_index := -1


func _ready() -> void:
	mouse_filter = Control.MOUSE_FILTER_STOP


func set_series(next_points: Array, next_mode: String, dark_mode: bool) -> void:
	points = next_points.duplicate(true)
	mode = next_mode
	dark = dark_mode
	hover_index = -1
	queue_redraw()


func _notification(what: int) -> void:
	if what == NOTIFICATION_RESIZED:
		queue_redraw()


func _gui_input(event: InputEvent) -> void:
	if event is InputEventMouseMotion:
		var next_hover := _index_near_x(event.position.x)
		if next_hover != hover_index:
			hover_index = next_hover
			queue_redraw()
	elif event is InputEventMouseButton and not event.pressed:
		hover_index = _index_near_x(event.position.x)
		queue_redraw()


func _draw() -> void:
	var left := 52.0
	var top := 12.0
	var right := maxf(left + 1.0, size.x - 12.0)
	var bottom := maxf(top + 1.0, size.y - 34.0)
	var grid := Color("24314b") if dark else Color("dbe3ef")
	var muted := Brand.muted_color(dark)
	var bounds := axis_bounds(points, mode)
	var minimum := float(bounds.x)
	var maximum := float(bounds.y)
	for tick_index in range(5):
		var ratio := float(tick_index) / 4.0
		var y := bottom - (bottom - top) * ratio
		var tick_value := lerpf(minimum, maximum, ratio)
		draw_line(Vector2(left, y), Vector2(right, y), grid, 1.0)
		draw_string(Brand.font, Vector2(2, y + 4), str(int(round(tick_value))), HORIZONTAL_ALIGNMENT_RIGHT, 43, 11, muted)
	if mode == "accuracy":
		var target_y := _value_y(70.0, minimum, maximum, top, bottom)
		draw_dashed_line(Vector2(left, target_y), Vector2(right, target_y), Brand.ROYAL_BLUE, 5.0, 2.0)
	if points.is_empty():
		return

	var previous: Variant = null
	for index in range(points.size()):
		var value: Variant = point_value(points[index], mode)
		if value == null:
			previous = null
			continue
		var point := Vector2(_point_x(index, left, right), _value_y(float(value), minimum, maximum, top, bottom))
		if previous != null:
			draw_line(previous, point, Brand.ROYAL_BLUE, 2.5, true)
		draw_circle(point, 3.5, Brand.PURPLE)
		draw_circle(point, 2.0, Color.WHITE)
		previous = point

	for label_index in [0, int(floor(float(points.size() - 1) / 2.0)), points.size() - 1]:
		var x := _point_x(label_index, left, right)
		var label := _short_date(str((points[label_index] as Dictionary).get("dateUtc", "")))
		draw_string(Brand.font, Vector2(x - 24, bottom + 19), label, HORIZONTAL_ALIGNMENT_CENTER, 48, 10, muted)

	if hover_index >= 0 and hover_index < points.size():
		var hover_value: Variant = point_value(points[hover_index], mode)
		if hover_value != null:
			var hover_x := _point_x(hover_index, left, right)
			var hover_y := _value_y(float(hover_value), minimum, maximum, top, bottom)
			draw_line(Vector2(hover_x, top), Vector2(hover_x, bottom), muted, 1.0)
			draw_circle(Vector2(hover_x, hover_y), 5.0, Brand.ROYAL_BLUE)
			var suffix := "%" if mode == "accuracy" else ""
			var tooltip := "%s  %d%s" % [
				_short_date(str((points[hover_index] as Dictionary).get("dateUtc", ""))),
				int(hover_value),
				suffix
			]
			var tooltip_size := Brand.font.get_string_size(tooltip, HORIZONTAL_ALIGNMENT_LEFT, -1, 11) + Vector2(16, 10)
			var tooltip_x := clampf(hover_x - tooltip_size.x / 2.0, left, right - tooltip_size.x)
			var tooltip_y := maxf(top, hover_y - tooltip_size.y - 10.0)
			var tooltip_rect := Rect2(Vector2(tooltip_x, tooltip_y), tooltip_size)
			draw_style_box(_tooltip_box(), tooltip_rect)
			draw_string(Brand.font, Vector2(tooltip_x + 8, tooltip_y + tooltip_size.y - 7), tooltip, HORIZONTAL_ALIGNMENT_LEFT, -1, 11, Brand.text_color(dark))


static func point_value(point: Dictionary, series_mode: String) -> Variant:
	if series_mode == "accuracy":
		return float(point.get("accuracy", 0)) if int(point.get("total", 0)) > 0 else null
	var value: Variant = point.get("questionBankRating", null)
	return null if value == null else float(value)


static func axis_bounds(series_points: Array, series_mode: String) -> Vector2:
	if series_mode == "accuracy":
		return Vector2(0, 100)
	var values: Array[float] = []
	for point in series_points:
		var value: Variant = point_value(point, series_mode)
		if value != null:
			values.append(float(value))
	if values.is_empty():
		return Vector2(900, 1100)
	var minimum: float = values.min()
	var maximum: float = values.max()
	if maximum - minimum < 100.0:
		var center: float = (minimum + maximum) / 2.0
		minimum = center - 50.0
		maximum = center + 50.0
	var padding := maxf(25.0, (maximum - minimum) * 0.15)
	minimum = floor((minimum - padding) / 25.0) * 25.0
	maximum = ceil((maximum + padding) / 25.0) * 25.0
	return Vector2(minimum, maximum)


func _index_near_x(mouse_x: float) -> int:
	if points.is_empty() or size.x <= 64.0:
		return -1
	var ratio := clampf((mouse_x - 52.0) / maxf(1.0, size.x - 64.0), 0.0, 1.0)
	return int(round(ratio * float(points.size() - 1)))


func _point_x(index: int, left: float, right: float) -> float:
	return left if points.size() <= 1 else lerpf(left, right, float(index) / float(points.size() - 1))


func _value_y(value: float, minimum: float, maximum: float, top: float, bottom: float) -> float:
	return bottom - (bottom - top) * inverse_lerp(minimum, maximum, clampf(value, minimum, maximum))


func _short_date(iso_value: String) -> String:
	var date := iso_value.left(10)
	if date.length() < 10:
		return ""
	return "%s/%s" % [date.substr(5, 2), date.substr(8, 2)]


func _tooltip_box() -> StyleBoxFlat:
	var box := StyleBoxFlat.new()
	box.bg_color = Color("111d31") if dark else Color.WHITE
	box.border_color = Color("34435e") if dark else Brand.LIGHT_BORDER
	box.set_border_width_all(1)
	box.set_corner_radius_all(5)
	return box