import { Shader, ShaderAttrs } from "./shader";
import { Attr } from "./attr";
import { Uniform, UniformType } from "./uniform";
import { Texture, TextureOptions } from "./texture";
import { Buffer, TexturePointer, BufferAttachment } from "./buffer";
import { Wggl } from "./wggl";

// Convenience function for creating attrs
export function attr(
  size: number = 1,
  stride: number = 0,
  offset: number = 0,
  normalize: boolean = false
): Attr {
  return new Attr(size, stride, offset, normalize);
}

// Convenience function for creating uniforms
export function uniform(
  length: number = 1,
  type: UniformType = UniformType.float
): Uniform {
  return new Uniform(length, type);
}

// Creates a partially applied Texture factory
export function texture(
  width: number,
  height: number,
  pixels: WebGLTexture | ArrayBufferView,
  props: TextureOptions
): (canvas: HTMLCanvasElement) => Texture {
  return canvas => new Texture(canvas, width, height, pixels, props);
}

// Creates a partially applied Buffer factory
export function buffer(
  canvas: HTMLCanvasElement,
  attachment: BufferAttachment = BufferAttachment.COLOR_ATTACHMENT0,
  level: number = 0
): (
  texture: Texture,
  target: TexturePointer,
  attachment?: BufferAttachment,
  level?: number
) => Buffer | void {
  const gl = canvas.getContext("webgl");

  if (!gl) {
    console.warn("No WebGL support");
    return () => {};
  }

  const buffer = gl.createFramebuffer();

  return (
    texture: Texture,
    target: TexturePointer = TexturePointer.TEXTURE_2D,
    customAttachment?: BufferAttachment,
    customLevel?: number
  ) =>
    new Buffer(
      gl,
      texture,
      target,
      buffer as WebGLBuffer,
      customAttachment || attachment,
      customLevel || level
    );
}

// Convenience function for constructing a Wggl instance
export default (
  canvas: HTMLCanvasElement,
  vertShader: Shader,
  fragShader: Shader
) => {
  return new Wggl(canvas, vertShader, fragShader);
};

export const QUAD2 = [-1, -1, 1, -1, -1, 1, 1, 1];

export { vs, fs } from "./shader";