import {
  DeesElement,
  css,
  cssManager,
  customElement,
  html,
  property,
  state,
  type TemplateResult,
} from '@design.estate/dees-element';

import { mobileComponentStyles } from '../../00componentstyles.js';
import '../dees-mobile-icon/dees-mobile-icon.js';
import { demoFunc } from './dees-mobile-gallery.demo.js';

export interface IGalleryItem {
  id: string;
  url: string;
  thumbnailUrl?: string;
  filename?: string;
  mimeType?: string;
  metadata?: Record<string, any>;
}

export interface IGalleryConfig {
  showFilename?: boolean;
  showActions?: boolean;
  allowDelete?: boolean;
  allowDownload?: boolean;
  allowShare?: boolean;
  startIndex?: number;
}

declare global {
  interface HTMLElementTagNameMap {
    'dees-mobile-gallery': DeesMobileGallery;
  }
}

@customElement('dees-mobile-gallery')
export class DeesMobileGallery extends DeesElement {
  public static demo = demoFunc;

  @property({ type: Array })
  accessor items: IGalleryItem[] = [];

  @property({ type: Object })
  accessor config: IGalleryConfig = {};

  @state()
  accessor currentIndex: number = 0;

  @state()
  accessor isLoading: boolean = true;

  @state()
  accessor showThumbnails: boolean = false;

  // Touch/swipe state
  private touchStartX: number = 0;
  private touchStartY: number = 0;
  private touchDeltaX: number = 0;
  private isSwiping: boolean = false;
  private swipeThreshold: number = 50;

  public static styles = [
    cssManager.defaultStyles,
    mobileComponentStyles,
    css`
      :host {
        position: fixed;
        inset: 0;
        z-index: var(--dees-z-modal, 500);
        display: flex;
        flex-direction: column;
        background: rgba(0, 0, 0, 0);
        animation: fadeInGallery 0.2s ease-out forwards;
      }

      @keyframes fadeInGallery {
        to {
          background: rgba(0, 0, 0, 0.95);
        }
      }

      .gallery-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: var(--dees-space-md);
        padding-top: calc(var(--dees-space-md) + env(safe-area-inset-top, 0px));
        background: linear-gradient(to bottom, rgba(0, 0, 0, 0.5), transparent);
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        z-index: 10;
      }

      .header-left {
        display: flex;
        align-items: center;
        gap: var(--dees-space-sm);
        flex: 1;
        min-width: 0;
      }

      .close-button {
        width: 40px;
        height: 40px;
        border: none;
        background: rgba(255, 255, 255, 0.1);
        border-radius: var(--dees-radius-full);
        color: white;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: background var(--dees-transition-fast);
        flex-shrink: 0;
      }

      .close-button:hover {
        background: rgba(255, 255, 255, 0.2);
      }

      .filename {
        color: white;
        font-size: 0.875rem;
        font-weight: 500;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
      }

      .counter {
        color: rgba(255, 255, 255, 0.7);
        font-size: 0.875rem;
        flex-shrink: 0;
      }

      .gallery-content {
        flex: 1;
        display: flex;
        align-items: center;
        justify-content: center;
        position: relative;
        overflow: hidden;
        touch-action: pan-y pinch-zoom;
      }

      .image-container {
        width: 100%;
        height: 100%;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: transform 0.3s ease-out;
      }

      .image-container.swiping {
        transition: none;
      }

      .gallery-image {
        max-width: 100%;
        max-height: 100%;
        object-fit: contain;
        opacity: 0;
        transition: opacity 0.2s ease-out;
      }

      .gallery-image.loaded {
        opacity: 1;
      }

      .loading-spinner {
        position: absolute;
        width: 40px;
        height: 40px;
        border: 3px solid rgba(255, 255, 255, 0.2);
        border-top-color: white;
        border-radius: 50%;
        animation: spin 0.8s linear infinite;
      }

      @keyframes spin {
        to {
          transform: rotate(360deg);
        }
      }

      .nav-button {
        position: absolute;
        top: 50%;
        transform: translateY(-50%);
        width: 48px;
        height: 48px;
        border: none;
        background: rgba(255, 255, 255, 0.1);
        border-radius: var(--dees-radius-full);
        color: white;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: background var(--dees-transition-fast), opacity var(--dees-transition-fast);
        z-index: 5;
        opacity: 0.7;
      }

      .nav-button:hover {
        background: rgba(255, 255, 255, 0.2);
        opacity: 1;
      }

      .nav-button.prev {
        left: var(--dees-space-md);
      }

      .nav-button.next {
        right: var(--dees-space-md);
      }

      .nav-button:disabled {
        opacity: 0.3;
        cursor: not-allowed;
      }

      /* Hide nav buttons on mobile - use swipe instead */
      @media (max-width: 640px) {
        .nav-button {
          display: none;
        }
      }

      .gallery-footer {
        padding: var(--dees-space-md);
        padding-bottom: calc(var(--dees-space-md) + env(safe-area-inset-bottom, 0px));
        background: linear-gradient(to top, rgba(0, 0, 0, 0.5), transparent);
        position: absolute;
        bottom: 0;
        left: 0;
        right: 0;
        z-index: 10;
      }

      .actions {
        display: flex;
        justify-content: center;
        gap: var(--dees-space-lg);
      }

      .action-button {
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: var(--dees-space-xs);
        border: none;
        background: none;
        color: white;
        cursor: pointer;
        padding: var(--dees-space-sm);
        border-radius: var(--dees-radius-md);
        transition: background var(--dees-transition-fast);
        min-width: 64px;
      }

      .action-button:hover {
        background: rgba(255, 255, 255, 0.1);
      }

      .action-button .icon {
        width: 40px;
        height: 40px;
        display: flex;
        align-items: center;
        justify-content: center;
        background: rgba(255, 255, 255, 0.15);
        border-radius: var(--dees-radius-full);
      }

      .action-button .label {
        font-size: 0.75rem;
        opacity: 0.9;
      }

      .action-button.danger .icon {
        background: rgba(220, 38, 38, 0.3);
      }

      .action-button.danger {
        color: #fca5a5;
      }

      .thumbnails {
        display: flex;
        gap: var(--dees-space-xs);
        justify-content: center;
        margin-bottom: var(--dees-space-md);
        overflow-x: auto;
        padding: 0 var(--dees-space-md);
        -webkit-overflow-scrolling: touch;
      }

      .thumbnail {
        width: 48px;
        height: 48px;
        border-radius: var(--dees-radius-sm);
        object-fit: cover;
        cursor: pointer;
        opacity: 0.5;
        transition: opacity var(--dees-transition-fast), transform var(--dees-transition-fast);
        flex-shrink: 0;
        border: 2px solid transparent;
      }

      .thumbnail:hover {
        opacity: 0.8;
      }

      .thumbnail.active {
        opacity: 1;
        border-color: white;
      }

      .pdf-preview {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: var(--dees-space-md);
        color: white;
      }

      .pdf-icon {
        width: 80px;
        height: 80px;
        background: rgba(255, 255, 255, 0.1);
        border-radius: var(--dees-radius-lg);
        display: flex;
        align-items: center;
        justify-content: center;
      }

      .pdf-text {
        font-size: 0.875rem;
        opacity: 0.7;
      }
    `,
  ];

  async connectedCallback() {
    await super.connectedCallback();
    this.currentIndex = this.config.startIndex ?? 0;
    document.addEventListener('keydown', this.handleKeydown);
  }

  async disconnectedCallback() {
    await super.disconnectedCallback();
    document.removeEventListener('keydown', this.handleKeydown);
  }

  private handleKeydown = (e: KeyboardEvent) => {
    switch (e.key) {
      case 'Escape':
        this.handleClose();
        break;
      case 'ArrowLeft':
        this.goToPrevious();
        break;
      case 'ArrowRight':
        this.goToNext();
        break;
    }
  };

  private handleClose() {
    this.dispatchEvent(new CustomEvent('close', {
      bubbles: true,
      composed: true,
    }));
  }

  private handleTouchStart = (e: TouchEvent) => {
    this.touchStartX = e.touches[0].clientX;
    this.touchStartY = e.touches[0].clientY;
    this.touchDeltaX = 0;
    this.isSwiping = false;
  };

  private handleTouchMove = (e: TouchEvent) => {
    const deltaX = e.touches[0].clientX - this.touchStartX;
    const deltaY = e.touches[0].clientY - this.touchStartY;

    // Only swipe horizontally if horizontal movement is greater than vertical
    if (Math.abs(deltaX) > Math.abs(deltaY) && Math.abs(deltaX) > 10) {
      this.isSwiping = true;
      this.touchDeltaX = deltaX;
      this.requestUpdate();
    }
  };

  private handleTouchEnd = () => {
    if (this.isSwiping) {
      if (this.touchDeltaX > this.swipeThreshold) {
        this.goToPrevious();
      } else if (this.touchDeltaX < -this.swipeThreshold) {
        this.goToNext();
      }
    }
    this.isSwiping = false;
    this.touchDeltaX = 0;
    this.requestUpdate();
  };

  private goToPrevious() {
    if (this.currentIndex > 0) {
      this.currentIndex--;
      this.isLoading = true;
      this.dispatchChangeEvent();
    }
  }

  private goToNext() {
    if (this.currentIndex < this.items.length - 1) {
      this.currentIndex++;
      this.isLoading = true;
      this.dispatchChangeEvent();
    }
  }

  private goToIndex(index: number) {
    if (index >= 0 && index < this.items.length && index !== this.currentIndex) {
      this.currentIndex = index;
      this.isLoading = true;
      this.dispatchChangeEvent();
    }
  }

  private dispatchChangeEvent() {
    this.dispatchEvent(new CustomEvent('change', {
      detail: {
        index: this.currentIndex,
        item: this.items[this.currentIndex],
      },
      bubbles: true,
      composed: true,
    }));
  }

  private handleImageLoad() {
    this.isLoading = false;
  }

  private handleDownload() {
    const item = this.items[this.currentIndex];
    this.dispatchEvent(new CustomEvent('download', {
      detail: item,
      bubbles: true,
      composed: true,
    }));
  }

  private handleDelete() {
    const item = this.items[this.currentIndex];
    this.dispatchEvent(new CustomEvent('delete', {
      detail: item,
      bubbles: true,
      composed: true,
    }));
  }

  private handleShare() {
    const item = this.items[this.currentIndex];
    this.dispatchEvent(new CustomEvent('share', {
      detail: item,
      bubbles: true,
      composed: true,
    }));
  }

  private isPdf(item: IGalleryItem): boolean {
    return item.mimeType?.toLowerCase() === 'application/pdf' ||
           item.filename?.toLowerCase().endsWith('.pdf') ||
           item.url.toLowerCase().endsWith('.pdf');
  }

  public render(): TemplateResult {
    const currentItem = this.items[this.currentIndex];
    const showFilename = this.config.showFilename ?? true;
    const showActions = this.config.showActions ?? true;
    const allowDelete = this.config.allowDelete ?? false;
    const allowDownload = this.config.allowDownload ?? true;
    const allowShare = this.config.allowShare ?? false;
    const showThumbnails = this.items.length > 1;

    const swipeTransform = this.isSwiping ? `translateX(${this.touchDeltaX}px)` : '';

    return html`
      <div class="gallery-header">
        <div class="header-left">
          <button class="close-button" @click=${this.handleClose}>
            <dees-mobile-icon icon="x" size="24"></dees-mobile-icon>
          </button>
          ${showFilename && currentItem?.filename ? html`
            <span class="filename">${currentItem.filename}</span>
          ` : ''}
        </div>
        ${this.items.length > 1 ? html`
          <span class="counter">${this.currentIndex + 1} / ${this.items.length}</span>
        ` : ''}
      </div>

      <div
        class="gallery-content"
        @touchstart=${this.handleTouchStart}
        @touchmove=${this.handleTouchMove}
        @touchend=${this.handleTouchEnd}
      >
        ${this.isLoading ? html`<div class="loading-spinner"></div>` : ''}

        <div
          class="image-container ${this.isSwiping ? 'swiping' : ''}"
          style=${swipeTransform ? `transform: ${swipeTransform}` : ''}
        >
          ${currentItem ? (
            this.isPdf(currentItem) ? html`
              <div class="pdf-preview">
                <div class="pdf-icon">
                  <dees-mobile-icon icon="file-text" size="48" color="white"></dees-mobile-icon>
                </div>
                <span class="pdf-text">${currentItem.filename || 'PDF Document'}</span>
              </div>
            ` : html`
              <img
                class="gallery-image ${!this.isLoading ? 'loaded' : ''}"
                src=${currentItem.url}
                alt=${currentItem.filename || ''}
                @load=${this.handleImageLoad}
              />
            `
          ) : ''}
        </div>

        ${this.items.length > 1 ? html`
          <button
            class="nav-button prev"
            @click=${this.goToPrevious}
            ?disabled=${this.currentIndex === 0}
          >
            <dees-mobile-icon icon="chevron-left" size="28"></dees-mobile-icon>
          </button>
          <button
            class="nav-button next"
            @click=${this.goToNext}
            ?disabled=${this.currentIndex === this.items.length - 1}
          >
            <dees-mobile-icon icon="chevron-right" size="28"></dees-mobile-icon>
          </button>
        ` : ''}
      </div>

      <div class="gallery-footer">
        ${showThumbnails ? html`
          <div class="thumbnails">
            ${this.items.map((item, index) => html`
              <img
                class="thumbnail ${index === this.currentIndex ? 'active' : ''}"
                src=${item.thumbnailUrl || item.url}
                alt=""
                @click=${() => this.goToIndex(index)}
              />
            `)}
          </div>
        ` : ''}

        ${showActions ? html`
          <div class="actions">
            ${allowDownload ? html`
              <button class="action-button" @click=${this.handleDownload}>
                <div class="icon">
                  <dees-mobile-icon icon="download" size="22"></dees-mobile-icon>
                </div>
                <span class="label">Download</span>
              </button>
            ` : ''}

            ${allowShare ? html`
              <button class="action-button" @click=${this.handleShare}>
                <div class="icon">
                  <dees-mobile-icon icon="share" size="22"></dees-mobile-icon>
                </div>
                <span class="label">Share</span>
              </button>
            ` : ''}

            ${allowDelete ? html`
              <button class="action-button danger" @click=${this.handleDelete}>
                <div class="icon">
                  <dees-mobile-icon icon="trash-2" size="22"></dees-mobile-icon>
                </div>
                <span class="label">Delete</span>
              </button>
            ` : ''}
          </div>
        ` : ''}
      </div>
    `;
  }

  /**
   * Static factory method to show the gallery
   */
  public static async show(
    items: IGalleryItem[],
    config: IGalleryConfig = {}
  ): Promise<{ action: 'close' | 'delete' | 'download' | 'share'; item?: IGalleryItem }> {
    return new Promise((resolve) => {
      const gallery = document.createElement('dees-mobile-gallery') as DeesMobileGallery;
      gallery.items = items;
      gallery.config = config;

      const cleanup = () => {
        gallery.remove();
      };

      gallery.addEventListener('close', () => {
        cleanup();
        resolve({ action: 'close' });
      });

      gallery.addEventListener('delete', (e: CustomEvent) => {
        cleanup();
        resolve({ action: 'delete', item: e.detail });
      });

      gallery.addEventListener('download', (e: CustomEvent) => {
        // Don't close on download - user might want to download multiple
        resolve({ action: 'download', item: e.detail });
      });

      gallery.addEventListener('share', (e: CustomEvent) => {
        resolve({ action: 'share', item: e.detail });
      });

      document.body.appendChild(gallery);
    });
  }
}