export enum ShaderType {
  VERTEX,
  FRAGMENT,
}

export const createShader = (
  gl: WebGLRenderingContext,
  type: ShaderType,
  source: string
): WebGLShader | null => {
  const SHADER_TYPE_TO_GL_TYPE = {
    [ShaderType.VERTEX]: gl.VERTEX_SHADER,
    [ShaderType.FRAGMENT]: gl.FRAGMENT_SHADER,
  };
  const shader = gl.createShader(SHADER_TYPE_TO_GL_TYPE[type]);

  gl.shaderSource(shader, source);
  gl.compileShader(shader);

  const success = gl.getShaderParameter(shader, gl.COMPILE_STATUS);
  if (!success) {
    console.error(gl.getShaderInfoLog(shader));
    gl.deleteShader(shader);
    return null;
  }

  return shader;
};

export const createProgram = (
  gl: WebGLRenderingContext,
  vertexShader: WebGLShader,
  fragmentShader: WebGLShader
): WebGLProgram | null => {
  const program = gl.createProgram();

  gl.attachShader(program, vertexShader);
  gl.attachShader(program, fragmentShader);
  gl.linkProgram(program);

  const success = gl.getProgramParameter(program, gl.LINK_STATUS);
  if (!success) {
    console.error(gl.getProgramInfoLog(program));
    gl.deleteProgram(program);
    return null;
  }

  return program;
};