/** Represents an RGB color. All elements must be between 0 and 1. */
type Color = Array<number>[3];

/** Represents a direction vector. Will throw warnings if not normalized. */
type Direction = Array<number>[3];

/** Represents a location in the scene. */
type Position = Array<number>[3]; 

/** Defines the entire scene. This is the schema you should use for your scene JSON files. */
class Scene {
	/** The position the camera is looking towards. */
	camera_look_at?: Position = [0, 0, 0];

	/** The position the camera is looking from (the camera's position). */
	camera_look_from?: Position = [0, 0, 1];

	/** The "up" direction for the camera. */
	camera_look_up?: Direction = [0, 1, 0];

	/** The angle width of the camera's view. Must be between 0 and 359. */
	field_of_view?: float = 90;

	/** The direction to the directional light source. */
	light_direction?: Direction = [0, 1, 0];

	/** The color of the directional light. */
	light_color?: Color = [1, 1, 1];

	/** The color of the global ambient light. */
	ambient_light_color?: Color = [1, 1, 1];

	/** The color of the scene background. */
	background_color?: Color = [0, 0, 0];

	/** A list of all objects in the scene. */
	objects?: Array<Object>;
};

/** The universal values shared by all objects. */
class Object {
	/** The name of the object. Has no affect on the behavior of the object. */
	name?: string;

	/** The type of the object. Used to differentiate between different classes of objects.
	 * Must be one of the accepted values. See other object classes below. */
	type: string;

	/** The coefficient for ambient lighting. Must be between 0 and 1. */
	ambient_coefficient?: number = 0;

	/** The coefficient for diffuse lighting. Must be between 0 and 1. */
	diffuse_coefficient?: number = 1;

	/** The coefficient for specular lighting. Must be between 0 and 1. */
	specular_coefficient?: number = 0;

	/** The color for diffuse lighting. */
	diffuse_color?: Color = [1, 1, 1];

	/** The color for specular lighting. */
	specular_color?: Color = [1, 1, 1];

	/** The coefficient for specular glossiness. */
	gloss_coefficient?: number = 4;

	/** How reflective the object surface should be. Must be between 0 and 1. */
	reflectivity?: number = 0;
};

/** The specific values necessary for Planes. */
class Plane extends Object {
	/** Defines this object as a Plane. */
	type: string = "plane";

	/** Any position on the plane. */
	position: Position = [0, 0, 0];

	/** The direction the plane faces. */
	normal: Direction;
};

/** The specific values necessary for Circles. */
class Circle extends Object {
	/** Defines this object as a Circle. */
	type: string = "circle";

	/** The center of the Circle. */
	position: Position;

	/** The direction the circle faces. */
	normal: Direction = [0, 0, 1];

	/** The radius of the Circle. Must be greater than 0. */
	radius: number;
};

/** The specific values necessary for Polygons. */
class Polygon extends Object {
	/** Defines this object as a Polygon. */
	type: string = "polygon";

	/** A list of vertices in counterclockwise order. Must have at least 3. */
	vertices: Array<Position>;
};

/**
 * The specific values necessary for Triangles.
 * The algorithm for Triangle intersections is slightly faster than Polygons,
 * so 3-sided Polygons will be automatically converted to Triangles.
*/
class Triangle extends Polygon {
	/** Defines this object as a Triangle. */
	type: string = "triangle";

	/** The number of vertices must be ONLY 3. */
};

/** The specific values necessary for Spheres. */
class Sphere extends Object {
	/** Defines this object as a Sphere. */
	type: string = "sphere";

	/** The center of the Sphere. */
	position: Position;

	/** The radius of the Sphere. Must be greater than 0. */
	radius: number;
};

// More types of objects can be added later.
// In the meantime, most kinds of objects can be modeled with Polygons.