import { Color } from "../filler/common";
import { LayerAB, Scene } from "./Scene";
import { createProgram, createShader } from "./utils";


export class BorderLayer extends LayerAB {


  private vertexShaderCode = /*glsl*/ `
    attribute vec2 a_position;
    uniform mat4 u_matrix;

    void main() {
      gl_Position = u_matrix * vec4(a_position, 0, 1);
    }

  `;

  private fragmentShaderCode = /*glsl*/ `
    precision mediump float;
    uniform vec4 u_color;

    void main() {
      gl_FragColor = u_color;
    }
  
  `

  program: WebGLProgram


  aPositionLoc: number
  uMatrixLoc: WebGLUniformLocation
  uColorLoc: WebGLUniformLocation

  vertexBuffer: WebGLBuffer

  vertexArray: Float32Array

  colorArray: Float32Array


  constructor(
    private scene: Scene,
    private x: number,
    private y: number,
    private width: number,
    private height: number,
    private color: number = 0xffff0000,
    private lineWidth: number = 1,
  ) {
    super()


    const gl = scene.gl;


    this.program = createProgram(gl,
      createShader(gl, gl.VERTEX_SHADER, this.vertexShaderCode)!,
      createShader(gl, gl.FRAGMENT_SHADER, this.fragmentShaderCode)!)!

    this.aPositionLoc = gl.getAttribLocation(this.program, "a_position")
    this.uMatrixLoc = gl.getUniformLocation(this.program, "u_matrix")!
    this.uColorLoc = gl.getUniformLocation(this.program, "u_color")!


    //fillRectangle(this.vertexArray, 0, x, y, width, height )

    this.vertexArray = new Float32Array([
      x, y,
      x, y + height,
      x + width, y + height,
      x + width, y
    ])


    this.vertexBuffer = gl.createBuffer()!;
    gl.bindBuffer(gl.ARRAY_BUFFER, this.vertexBuffer);
    gl.bufferData(gl.ARRAY_BUFFER, this.vertexArray, gl.STATIC_DRAW);

    this.colorArray = new Color(color).toFloatArray()


  }



  override draw() {
    const gl = this.scene.gl;
    gl.useProgram(this.program);

    gl.enableVertexAttribArray(this.aPositionLoc);
    gl.bindBuffer(gl.ARRAY_BUFFER, this.vertexBuffer);
    gl.vertexAttribPointer(this.aPositionLoc, 2, gl.FLOAT, false, 0, 0)


    gl.uniformMatrix4fv(this.uMatrixLoc, false, this.scene.drawMatrix)
    gl.uniform4fv(this.uColorLoc, this.colorArray)

    gl.lineWidth(this.lineWidth)
    gl.drawArrays(gl.LINE_LOOP, 0, 4);

  }


}