// Loading Progress Component with Qt-style progress bar
export class LoadingProgress {
  constructor(container) {
    this.container = container;
    this.progressBar = null;
    this.progressFill = null;
    this.animationFrame = null;
    this.progress = 0;
    this.targetProgress = 0;
    this.isAnimating = false;
  }

  show(message = 'Loading...', showProgress = true) {
    if (!this.container) return;

    const loadingHTML = `
      <div class="loading-container">
        <div class="loading-spinner">
          <div class="spinner-ring"></div>
          <div class="spinner-ring"></div>
          <div class="spinner-ring"></div>
          <div class="spinner-ring"></div>
        </div>
        <div class="loading-text">${message}</div>
        ${showProgress ? `
          <div class="progress-container">
            <div class="progress-bar">
              <div class="progress-fill" id="progressFill"></div>
              <div class="progress-shine"></div>
            </div>
            <div class="progress-text" id="progressText">0%</div>
          </div>
        ` : ''}
      </div>
    `;

    this.container.innerHTML = loadingHTML;
    
    if (showProgress) {
      this.progressBar = this.container.querySelector('.progress-bar');
      this.progressFill = document.getElementById('progressFill');
      this.progressText = document.getElementById('progressText');
      this.startProgressAnimation();
    }
  }

  startProgressAnimation() {
    this.progress = 0;
    this.targetProgress = 0;
    this.isAnimating = true;
    
    // More stable progress simulation with smoother steps
    const steps = [
      { progress: 8, delay: 150 },
      { progress: 20, delay: 250 },
      { progress: 35, delay: 400 },
      { progress: 50, delay: 350 },
      { progress: 65, delay: 500 },
      { progress: 78, delay: 450 },
      { progress: 88, delay: 600 },
      { progress: 95, delay: 700 },
    ];

    let stepIndex = 0;
    let isCancelled = false;
    this.cancelProgress = () => { isCancelled = true; };
    
    const updateProgress = () => {
      if (isCancelled || !this.isAnimating) return;
      
      if (stepIndex < steps.length) {
        const step = steps[stepIndex];
        this.targetProgress = step.progress;
        stepIndex++;
        setTimeout(updateProgress, step.delay);
      } else {
        // Keep at 95% until actual loading completes
        this.targetProgress = 95;
      }
    };

    updateProgress();
    this.animateProgress();
  }

  animateProgress() {
    if (!this.isAnimating || !this.progressFill) return;

    // Smooth interpolation
    const diff = this.targetProgress - this.progress;
    if (Math.abs(diff) > 0.1) {
      this.progress += diff * 0.15; // Smooth easing
    } else {
      this.progress = this.targetProgress;
    }

    if (this.progressFill) {
      this.progressFill.style.width = `${this.progress}%`;
    }
    
    if (this.progressText) {
      this.progressText.textContent = `${Math.round(this.progress)}%`;
    }

    // Add class when progress starts
    if (this.progressBar) {
      if (this.progress > 0) {
        this.progressBar.classList.add('has-progress');
      } else {
        this.progressBar.classList.remove('has-progress');
      }
    }

    if (this.isAnimating) {
      this.animationFrame = requestAnimationFrame(() => this.animateProgress());
    }
  }

  setProgress(value) {
    this.targetProgress = Math.min(100, Math.max(0, value));
    if (!this.isAnimating && this.progressFill) {
      this.startProgressAnimation();
    }
  }

  complete() {
    this.targetProgress = 100;
    // Animate to 100% and then hide
    const checkComplete = () => {
      if (this.progress >= 99.9) {
        setTimeout(() => {
          this.hide();
        }, 200);
      } else {
        setTimeout(checkComplete, 50);
      }
    };
    checkComplete();
  }

  hide() {
    this.isAnimating = false;
    if (this.cancelProgress) {
      this.cancelProgress();
    }
    if (this.animationFrame) {
      cancelAnimationFrame(this.animationFrame);
    }
    // Clear progress elements
    this.progressBar = null;
    this.progressFill = null;
    this.progressText = null;
    if (this.container) {
      this.container.innerHTML = '';
    }
  }
}