export class LeftPanel {
  private container: HTMLDivElement;
  private panel: HTMLDivElement;
  private headerEl: HTMLDivElement;
  private contentArea: HTMLDivElement;
  private statsTab: HTMLDivElement;
  private eventsTab: HTMLDivElement;
  private inventionsTab: HTMLDivElement;
  private inventionsContent: HTMLDivElement;
  private notificationDot: HTMLDivElement;
  private expanded = false;
  private activeTab: 'stats' | 'events' | 'inventions' | null = null;
  private superlativesContent: HTMLDivElement;
  private eventsFeedContent: HTMLDivElement;

  constructor(superlativesContent: HTMLDivElement, eventsFeedContent: HTMLDivElement, inventionsContent: HTMLDivElement) {
    this.superlativesContent = superlativesContent;
    this.eventsFeedContent = eventsFeedContent;
    this.inventionsContent = inventionsContent;

    // Outer container for positioning
    this.container = document.createElement('div');
    this.container.style.cssText = `
      position: fixed;
      left: 0;
      top: 50%;
      transform: translateY(-50%);
      z-index: 1000;
      display: flex;
      flex-direction: row;
      font-family: 'Press Start 2P', monospace;
      transition: transform 0.35s ease;
    `;

    // Main panel
    this.panel = document.createElement('div');
    this.panel.style.cssText = `
      width: 340px;
      background: #1a1a2e;
      border: 3px solid #e0d0b0;
      border-left: none;
      padding: 0;
      box-sizing: border-box;
      max-height: 80vh;
      display: flex;
      flex-direction: column;
    `;

    // Inner frame (EarthBound double-border)
    const innerFrame = document.createElement('div');
    innerFrame.style.cssText = `
      border: 2px solid #8878a8;
      margin: 4px;
      padding: 8px;
      display: flex;
      flex-direction: column;
      overflow: hidden;
      flex: 1;
    `;

    // Header
    this.headerEl = document.createElement('div');
    this.headerEl.style.cssText = `
      text-align: center;
      color: #e0d0b0;
      font-size: 16px;
      padding: 4px 0 8px 0;
      border-bottom: 1px solid #8878a8;
      margin-bottom: 8px;
      flex-shrink: 0;
    `;
    this.headerEl.textContent = 'SUPERLATIVES';

    // Content area (swaps between superlatives and events)
    this.contentArea = document.createElement('div');
    this.contentArea.style.cssText = `
      flex: 1;
      overflow-y: auto;
      display: flex;
      flex-direction: column;
    `;

    innerFrame.appendChild(this.headerEl);
    innerFrame.appendChild(this.contentArea);
    this.panel.appendChild(innerFrame);

    // Tab buttons container (stacked vertically on right edge)
    const tabContainer = document.createElement('div');
    tabContainer.style.cssText = `
      display: flex;
      flex-direction: column;
      align-self: center;
      gap: 2px;
      flex-shrink: 0;
    `;

    // Stats tab ("S")
    this.statsTab = this.createTab('S');
    this.statsTab.addEventListener('click', () => {
      if (this.activeTab === 'stats' && this.expanded) {
        this.collapse();
      } else {
        this.expand('stats');
      }
    });

    // Events tab ("E")
    this.eventsTab = this.createTab('E');
    this.eventsTab.addEventListener('click', () => {
      if (this.activeTab === 'events' && this.expanded) {
        this.collapse();
      } else {
        this.expand('events');
      }
    });

    // Inventions tab ("I")
    this.inventionsTab = this.createTab('I');
    this.inventionsTab.style.position = 'relative';
    this.notificationDot = document.createElement('div');
    this.notificationDot.style.cssText = `
      position: absolute;
      top: 4px;
      right: 4px;
      width: 8px;
      height: 8px;
      background: #f0d060;
      border-radius: 50%;
      display: none;
    `;
    this.inventionsTab.appendChild(this.notificationDot);
    this.inventionsTab.addEventListener('click', () => {
      if (this.activeTab === 'inventions' && this.expanded) {
        this.collapse();
      } else {
        this.expand('inventions');
      }
    });

    tabContainer.appendChild(this.statsTab);
    tabContainer.appendChild(this.eventsTab);
    tabContainer.appendChild(this.inventionsTab);

    this.container.appendChild(this.panel);
    this.container.appendChild(tabContainer);

    // Start collapsed
    this.container.style.transform = 'translateY(-50%) translateX(-340px)';

    document.body.appendChild(this.container);
  }

  private createTab(label: string): HTMLDivElement {
    const tab = document.createElement('div');
    tab.style.cssText = `
      width: 32px;
      height: 56px;
      background: #1a1a2e;
      border: 3px solid #e0d0b0;
      border-left: none;
      border-radius: 0 6px 6px 0;
      display: flex;
      align-items: center;
      justify-content: center;
      cursor: pointer;
      flex-shrink: 0;
      transition: background 0.2s;
    `;

    const tabInner = document.createElement('div');
    tabInner.style.cssText = `
      color: #e0d0b0;
      font-size: 20px;
    `;
    tabInner.textContent = label;
    tab.appendChild(tabInner);

    tab.addEventListener('mouseenter', () => {
      if (tab.dataset.active !== 'true') {
        tab.style.background = '#2a2a4e';
      }
    });
    tab.addEventListener('mouseleave', () => {
      if (tab.dataset.active !== 'true') {
        tab.style.background = '#1a1a2e';
      }
    });

    return tab;
  }

  private updateTabs(): void {
    this.statsTab.style.background =
      this.activeTab === 'stats' && this.expanded ? '#2a2a4e' : '#1a1a2e';
    this.statsTab.dataset.active =
      this.activeTab === 'stats' && this.expanded ? 'true' : 'false';

    this.eventsTab.style.background =
      this.activeTab === 'events' && this.expanded ? '#2a2a4e' : '#1a1a2e';
    this.eventsTab.dataset.active =
      this.activeTab === 'events' && this.expanded ? 'true' : 'false';

    this.inventionsTab.style.background =
      this.activeTab === 'inventions' && this.expanded ? '#2a2a4e' : '#1a1a2e';
    this.inventionsTab.dataset.active =
      this.activeTab === 'inventions' && this.expanded ? 'true' : 'false';
  }

  private showContent(tab: 'stats' | 'events' | 'inventions'): void {
    // Remove current content
    while (this.contentArea.firstChild) {
      this.contentArea.removeChild(this.contentArea.firstChild);
    }

    if (tab === 'stats') {
      this.headerEl.textContent = 'SUPERLATIVES';
      this.contentArea.appendChild(this.superlativesContent);
    } else if (tab === 'events') {
      this.headerEl.textContent = 'EVENTS';
      this.contentArea.appendChild(this.eventsFeedContent);
    } else if (tab === 'inventions') {
      this.headerEl.textContent = 'INVENTIONS';
      this.contentArea.appendChild(this.inventionsContent);
    }
  }

  expand(tab: 'stats' | 'events' | 'inventions'): void {
    this.activeTab = tab;
    this.expanded = true;
    this.showContent(tab);
    this.updateTabs();
    this.container.style.transform = 'translateY(-50%) translateX(0)';
    if (tab === 'inventions') {
      this.hideNotificationDot();
    }
    document.dispatchEvent(
      new CustomEvent('left-panel-opened', { detail: { tab } }),
    );
  }

  collapse(): void {
    this.expanded = false;
    this.container.style.transform = 'translateY(-50%) translateX(-340px)';
    this.updateTabs();
    document.dispatchEvent(new CustomEvent('left-panel-closed'));
  }

  isExpanded(): boolean {
    return this.expanded;
  }

  getActiveTab(): 'stats' | 'events' | 'inventions' | null {
    return this.expanded ? this.activeTab : null;
  }

  showNotificationDot(): void {
    this.notificationDot.style.display = '';
  }

  hideNotificationDot(): void {
    this.notificationDot.style.display = 'none';
  }

  destroy(): void {
    this.container.remove();
  }
}