/**
 * Deep Research Loader
 * Fullscreen 3-phase loading animation for Deep Research.
 * Phase 1: Rotating Earth with data arcs
 * Phase 2: Article with scanning magnifying glass
 * Phase 3: Skeleton report with charts
 */
import { Globe3D } from './globe3d.js';

export class DeepResearchLoader {
  constructor() {
    this.overlay = null;
    this.currentPhase = 0;
    this.statusTextEl = null;
    this.phaseLabelEl = null;
    this.dots = [];
  }

  /** Build and show the fullscreen overlay */
  show() {
    if (this.overlay) this.hide();

    this.overlay = document.createElement('div');
    this.overlay.className = 'dr-loader-overlay';
    this.overlay.innerHTML = this._buildHTML();
    document.body.appendChild(this.overlay);

    // Cache elements
    this.statusTextEl = this.overlay.querySelector('.dr-status-text');
    this.phaseLabelEl = this.overlay.querySelector('.dr-phase-label');
    this.dots = Array.from(this.overlay.querySelectorAll('.dr-phase-dot'));

    const earthSvg = this.overlay.querySelector('.dr-earth-svg');
    if (earthSvg) {
      this.globe3D = new Globe3D(earthSvg);
    }

    // Force reflow then fade in
    requestAnimationFrame(() => {
      requestAnimationFrame(() => {
        this.overlay.classList.add('visible');
        this.setPhase(1);
      });
    });
  }

  /** Switch to a phase (1, 2, or 3) with crossfade */
  setPhase(phase) {
    if (!this.overlay || phase === this.currentPhase) return;
    this.currentPhase = phase;

    // Update phase containers
    const phases = this.overlay.querySelectorAll('.dr-phase');
    phases.forEach(el => el.classList.remove('active'));
    const target = this.overlay.querySelector(`.dr-phase-${phase}`);
    if (target) target.classList.add('active');

    // Update dots
    this.dots.forEach((dot, i) => {
      dot.classList.remove('active', 'done');
      if (i + 1 < phase) dot.classList.add('done');
      else if (i + 1 === phase) dot.classList.add('active');
    });

    // Update phase label
    const labels = { 1: 'RECHERCHE', 2: 'QUELLEN LESEN', 3: 'BERICHT ERSTELLEN' };
    if (this.phaseLabelEl) this.phaseLabelEl.textContent = labels[phase] || '';
  }

  /** Update the status text */
  setStatus(text) {
    if (this.statusTextEl) this.statusTextEl.textContent = text;
  }

  /** Hide and destroy the overlay */
  hide() {
    if (!this.overlay) return;
    this.overlay.classList.remove('visible');
    
    if (this.globe3D) {
      this.globe3D.destroy();
      this.globe3D = null;
    }

    const el = this.overlay;
    setTimeout(() => el.remove(), 700);
    this.overlay = null;
    this.currentPhase = 0;
  }

  /** Build the full HTML for the overlay */
  _buildHTML() {
    return `
      <div class="dr-ambient-glow"></div>

      <!-- Top Status Text -->
      <div class="dr-status-text-container">
        <div class="dr-status-text">Starte Deep Research...</div>
      </div>

      <!-- PHASE 1: Earth -->
      <div class="dr-phase dr-phase-1">
        ${this._buildEarthSVG()}
      </div>

      <!-- PHASE 2: Article + Magnifier -->
      <div class="dr-phase dr-phase-2">
        ${this._buildArticleSVG()}
      </div>

      <!-- PHASE 3: Skeleton Report -->
      <div class="dr-phase dr-phase-3">
        ${this._buildReportSVG()}
      </div>

      <!-- Bottom Status Bar (Dots & Label) -->
      <div class="dr-status-bar">
        <div class="dr-phase-dots">
          <div class="dr-phase-dot"></div>
          <div class="dr-phase-dot"></div>
          <div class="dr-phase-dot"></div>
        </div>
        <div class="dr-phase-label">RECHERCHE</div>
      </div>
    `;
  }

  /** Phase 1: 3D rotating globe via Globe3D JS class */
  _buildEarthSVG() {
    return `
      <div class="dr-earth-container">
        <svg class="dr-earth-svg" viewBox="0 0 400 400" xmlns="http://www.w3.org/2000/svg">
          <defs>
            <clipPath id="earth-clip">
              <circle cx="200" cy="200" r="175" />
            </clipPath>
            <!-- 3D sphere shading: darken edges, highlight top-left -->
            <radialGradient id="earth-3d-shade" cx="35%" cy="32%" r="65%">
              <stop offset="0%" stop-color="rgba(140,200,255,0.12)" />
              <stop offset="60%" stop-color="rgba(0,0,0,0)" />
              <stop offset="100%" stop-color="rgba(0,0,0,0.55)" />
            </radialGradient>
            <!-- Atmosphere rim glow -->
            <radialGradient id="earth-atmosphere" cx="50%" cy="50%" r="50%">
              <stop offset="85%" stop-color="rgba(0,0,0,0)" />
              <stop offset="95%" stop-color="rgba(66,133,244,0.15)" />
              <stop offset="100%" stop-color="rgba(66,133,244,0.3)" />
            </radialGradient>
          </defs>

          <!-- Ocean background (stays fixed) -->
          <circle class="dr-earth-ocean" cx="200" cy="200" r="175" />

          <!-- Globe3D class will inject the <g> with continents and arcs here -->

          <!-- 3D shading overlay (fixed, gives sphere depth) -->
          <circle cx="200" cy="200" r="175" fill="url(#earth-3d-shade)" />

          <!-- Atmosphere rim -->
          <circle cx="200" cy="200" r="175" fill="url(#earth-atmosphere)" />

          <!-- Edge ring -->
          <circle cx="200" cy="200" r="175" fill="none" stroke="rgba(122,186,255,0.25)" stroke-width="1.5" />
        </svg>
      </div>
    `;
  }

  /** Phase 2: Scrolling article/website with scanning magnifying glass */
  _buildArticleSVG() {
    // Build a tall content strip that scrolls vertically, duplicated for seamless loop
    const buildContentBlock = () => `
      <div class="dr-article-line title"></div>
      <div class="dr-article-line subtitle"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line medium"></div>
      <div class="dr-article-line short"></div>
      <div class="dr-article-img-placeholder"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line medium"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line short"></div>
      <div class="dr-article-line title"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line medium"></div>
      <div class="dr-article-img-placeholder"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line medium"></div>
      <div class="dr-article-line short"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line long"></div>
      <div class="dr-article-line medium"></div>
    `;

    return `
      <div class="dr-article-container">
        <!-- Browser chrome -->
        <div class="dr-article-chrome">
          <div class="dr-chrome-dot"></div>
          <div class="dr-chrome-dot"></div>
          <div class="dr-chrome-dot"></div>
          <div class="dr-chrome-urlbar"></div>
        </div>

        <!-- Scrolling content (duplicated for seamless loop) -->
        <div class="dr-article-scroll-content">
          ${buildContentBlock()}
          ${buildContentBlock()}
        </div>

        <!-- Magnifying glass overlay -->
        <div class="dr-magnifier-overlay">
          <svg viewBox="0 0 420 480" xmlns="http://www.w3.org/2000/svg">
            <g class="dr-magnifier-group">
              <circle class="dr-magnifier-lens" cx="0" cy="0" r="36" />
              <path class="dr-magnifier-highlight" d="M-20,-26 A36,36 0 0,1 20,-26" />
              <line class="dr-magnifier-handle" x1="25" y1="25" x2="50" y2="50" />
            </g>
          </svg>
        </div>
      </div>
    `;
  }

  /** Phase 3: Skeleton report with image placeholders, pie & bar charts (continuously loops) */
  _buildReportSVG() {
    // Build a tall content strip that scrolls upward, duplicated for seamless loop
    const buildReportBlock = () => `
      <div class="dr-report-skel-line title"></div>
      <div class="dr-report-skel-line subtitle"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line medium"></div>
      <div class="dr-report-skel-line short"></div>
      <div class="dr-report-skel-image"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line medium"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line short"></div>
      <div class="dr-report-skel-pie"></div>
      <div class="dr-report-skel-line medium"></div>
      <div class="dr-report-skel-line short"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-bars">
        <div class="dr-report-skel-bar"></div>
        <div class="dr-report-skel-bar"></div>
        <div class="dr-report-skel-bar"></div>
        <div class="dr-report-skel-bar"></div>
        <div class="dr-report-skel-bar"></div>
      </div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line medium"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-image"></div>
      <div class="dr-report-skel-line long"></div>
      <div class="dr-report-skel-line short"></div>
      <div class="dr-report-skel-line medium"></div>
    `;

    return `
      <div class="dr-report-container">
        <div class="dr-report-scroll">
          <div class="dr-report-block">${buildReportBlock()}</div>
          <div class="dr-report-block">${buildReportBlock()}</div>
        </div>
      </div>
    `;
  }
}

export const deepResearchLoader = new DeepResearchLoader();