//
// ColorArrayBlend.ts
// Blends through colors in Array over duration set
// Written by @Fusedthreed – https://FusedThreeD.com
//

@customNode()
export class MultiColorBlendOverTime extends BasicScriptNode {

  @input()
  colors: APJS.Color[];

  @input()
  duration: number;

  @input()
  reset: boolean;

  @output()
  color: APJS.Color;

  private startTime: number = -1;
  private lastReset: boolean = false;
  private finished: boolean = false;

  execute() {
    const currentTime = Date.now() / 1000;

    const resetNow = this.reset === true && this.lastReset === false;
    this.lastReset = this.reset === true;

    const colorList = this.colors ?? [];

    if (resetNow || this.startTime < 0) {
      this.startTime = currentTime;
      this.finished = false;
    }

    if (this.finished || colorList.length < 2) return;

    const totalDuration = Math.max(this.duration ?? 1, 0.0001);
    const elapsed = currentTime - this.startTime;

    const segmentCount = colorList.length - 1;
    const segmentDuration = totalDuration / segmentCount;

    if (elapsed >= totalDuration) {
      this.color = colorList[colorList.length - 1];
      this.finished = true;
      return;
    }

    const totalT = elapsed / totalDuration;
    const segmentIndex = Math.floor(totalT * segmentCount);
    const segmentT = (elapsed - (segmentIndex * segmentDuration)) / segmentDuration;

    const colorA = colorList[segmentIndex];
    const colorB = colorList[segmentIndex + 1];

    const r = colorA.r + (colorB.r - colorA.r) * segmentT;
    const g = colorA.g + (colorB.g - colorA.g) * segmentT;
    const b = colorA.b + (colorB.b - colorA.b) * segmentT;
    const a = colorA.a + (colorB.a - colorA.a) * segmentT;

    this.color = new APJS.Color(r, g, b, a);
  }
}