Lightbox & Image Gallery Rails Components

import { Controller } from "@hotwired/stimulus";
import PhotoSwipe from "photoswipe";

export default class extends Controller {
  static targets = ["trigger", "gallery"];
  static values = {
    options: Object,
    gallerySelector: String,
    showDownloadButton: { type: Boolean, default: true },
    showZoomIndicator: { type: Boolean, default: true },
    showDotsIndicator: { type: Boolean, default: true },
  };

  connect() {
    this.photoSwipeHostDialog = null;
    this.loadCSS();
    this.setupGallery();
  }

  loadCSS() {
    // Check if PhotoSwipe CSS is already loaded
    if (!document.querySelector('link[href*="photoswipe.css"]')) {
      const link = document.createElement("link");
      link.rel = "stylesheet";
      link.href = "https://cdn.jsdelivr.net/npm/photoswipe@5.4.3/dist/photoswipe.css";
      document.head.appendChild(link);
    }
  }

  setupGallery() {
    if (this.hasGalleryTarget) {
      this.galleryTarget.addEventListener("click", this.handleGalleryClick.bind(this));
    } else if (this.hasTriggerTarget) {
      this.triggerTargets.forEach((trigger) => {
        trigger.addEventListener("click", this.handleSingleClick.bind(this));
      });
    }
  }

  handleGalleryClick(e) {
    const clickedElement = e.target.closest("a[data-pswp-src]");
    if (!clickedElement) return;

    e.preventDefault();

    const galleryElements = this.galleryTarget.querySelectorAll("a[data-pswp-src]");
    const items = Array.from(galleryElements).map((el) => this.getItemData(el));
    const clickedIndex = Array.from(galleryElements).indexOf(clickedElement);

    this.openPhotoSwipe(items, clickedIndex);
  }

  handleSingleClick(e) {
    e.preventDefault();
    const clickedElement = e.currentTarget;
    const items = [this.getItemData(clickedElement)];
    this.openPhotoSwipe(items, 0);
  }

  getItemData(element) {
    const item = {
      src: element.dataset.pswpSrc || element.href,
      width: parseInt(element.dataset.pswpWidth) || 0,
      height: parseInt(element.dataset.pswpHeight) || 0,
      alt: element.dataset.pswpAlt || "",
    };

    // Add caption if exists
    const caption = element.dataset.pswpCaption;
    if (caption) {
      item.caption = caption;
    }

    // If dimensions not provided, we'll need to load them
    if (!item.width || !item.height) {
      // Try to get dimensions from the thumbnail if it's already loaded
      const thumbnail = element.querySelector("img");
      if (thumbnail && thumbnail.complete && thumbnail.naturalWidth) {
        // Calculate aspect ratio from thumbnail
        const aspectRatio = thumbnail.naturalWidth / thumbnail.naturalHeight;

        // Determine a reasonable full-size dimension based on aspect ratio
        // This provides better defaults for different image types
        if (aspectRatio > 1.2) {
          // Landscape image
          item.width = 2400;
          item.height = Math.round(2400 / aspectRatio);
        } else if (aspectRatio < 0.8) {
          // Portrait image
          item.height = 2400;
          item.width = Math.round(2400 * aspectRatio);
        } else {
          // Square or nearly square
          item.width = 2000;
          item.height = 2000;
        }
      } else {
        // Conservative fallback when we have no information
        // Use a moderate size that works for most cases
        item.width = 1920;
        item.height = 1080; // 16:9 as a safe default
      }
      item.needsUpdate = true;
    }

    return item;
  }

  openPhotoSwipe(items, index) {
    const { appendTarget, hostDialog } = this.getAppendTarget();

    const options = {
      index: index || 0,
      appendToEl: appendTarget,
      ...this.defaultOptions,
      ...this.optionsValue,
    };

    const pswp = new PhotoSwipe({
      dataSource: items,
      ...options,
    });

    let hostCancelHandler;
    const cleanupHostDialog = (() => {
      let cleanedUp = false;
      return () => {
        if (cleanedUp || !hostDialog) return;
        cleanedUp = true;

        if (hostCancelHandler) {
          hostDialog.removeEventListener("cancel", hostCancelHandler);
        }

        this.teardownPhotoSwipeHost(hostDialog);
      };
    })();

    if (hostDialog) {
      hostCancelHandler = (event) => {
        // Keep dialog state in sync when Escape is pressed on the host.
        event.preventDefault();
        pswp.close();
      };
      hostDialog.addEventListener("cancel", hostCancelHandler);
      pswp.on("destroy", cleanupHostDialog);
    }

    // Add dynamic cursor handling
    const updateCursor = () => {
      if (!pswp.currSlide || !pswp.currSlide.container) return;

      const currZoom = pswp.currSlide.currZoomLevel;
      const container = pswp.currSlide.container;
      const imageEl = container.querySelector(".pswp__img");

      // Set default cursor on container (the whole area)
      container.style.cursor = "default";

      // Only set zoom cursor on the actual image
      if (imageEl) {
        if (pswp.currSlide.isZoomable()) {
          if (currZoom < 0.95) {
            // Below 100%, will zoom to actual size
            imageEl.style.cursor = "zoom-in";
            imageEl.style.setProperty("cursor", "zoom-in", "important");
          } else if (currZoom < 1.5) {
            // At 100%, will zoom to 1.5x
            imageEl.style.cursor = "zoom-in";
            imageEl.style.setProperty("cursor", "zoom-in", "important");
          } else if (currZoom < 2) {
            // At 1.5x, will zoom to 2x
            imageEl.style.cursor = "zoom-in";
            imageEl.style.setProperty("cursor", "zoom-in", "important");
          } else {
            // At 2x or higher, will reset to fit
            imageEl.style.cursor = "zoom-out";
            imageEl.style.setProperty("cursor", "zoom-out", "important");
          }
        } else {
          // For non-zoomable images, use default cursor
          imageEl.style.cursor = "default";
          imageEl.style.setProperty("cursor", "default", "important");
        }
      }
    };

    // Override PhotoSwipe's default cursor behavior
    pswp.on("firstUpdate", () => {
      // Remove PhotoSwipe's default cursor handling
      const styleId = "pswp-custom-cursor-override";
      if (!document.getElementById(styleId)) {
        const style = document.createElement("style");
        style.id = styleId;
        style.textContent = `
          /* Override PhotoSwipe's default cursor styles */
          .pswp__img {
            /* Cursor will be set by JavaScript */
          }
          .pswp__img--placeholder {
            cursor: default !important;
          }
          .pswp__container {
            cursor: default !important;
          }
          .pswp__container.pswp__container--dragging {
            cursor: grabbing !important;
          }
          .pswp__container.pswp__container--dragging .pswp__img {
            cursor: grabbing !important;
          }
          /* Prevent PhotoSwipe from setting zoom-out cursor */
          .pswp--zoom-allowed .pswp__img {
            /* Cursor controlled by JavaScript */
          }
          .pswp__zoom-wrap {
            cursor: inherit !important;
          }
        `;
        document.head.appendChild(style);
      }
    });

    // Update cursor on various events
    pswp.on("zoomPanUpdate", () => {
      setTimeout(updateCursor, 0); // Defer to ensure DOM is updated
    });
    pswp.on("change", updateCursor);
    pswp.on("afterInit", updateCursor);

    // Update cursor after zoom animation completes
    pswp.on("slideDestroy", updateCursor);
    pswp.on("contentActivate", updateCursor);

    // Continuously enforce cursor to prevent PhotoSwipe from overriding
    let cursorInterval;
    pswp.on("openingAnimationStart", () => {
      // Start enforcing cursor when lightbox opens
      cursorInterval = setInterval(updateCursor, 50);
    });

    pswp.on("close", () => {
      // Stop enforcing cursor when lightbox closes
      if (cursorInterval) {
        clearInterval(cursorInterval);
      }
      cleanupHostDialog();
    });

    // Handle single clicks to zoom instead of close
    pswp.on("imageClickAction", (e) => {
      // Prevent default action (which might close the lightbox)
      e.preventDefault();

      const currZoom = pswp.currSlide.currZoomLevel;
      let newZoom;

      // Cycle through zoom levels
      if (currZoom < 0.95) {
        // If below 100%, first zoom to 100% (actual size)
        newZoom = 1;
      } else if (currZoom < 1.5) {
        // From 100%, zoom to 1.5x
        newZoom = 1.5;
      } else if (currZoom < 2) {
        // From 1.5x, zoom to 2x
        newZoom = 2;
      } else {
        // From 3x, reset to fit
        // Use the slide's minimum zoom level which is the "fit" level
        newZoom = pswp.currSlide.zoomLevels.fit || pswp.currSlide.zoomLevels.min || pswp.currSlide.min || 0.5;
      }

      // Get click position relative to the image
      const destZoomPoint = {
        x: e.originalEvent.clientX,
        y: e.originalEvent.clientY,
      };

      // Zoom to the new level
      pswp.currSlide.zoomTo(newZoom, destZoomPoint, 333, false);
    });

    // Register all UI elements
    pswp.on("uiRegister", () => {
      // Register caption UI element
      pswp.ui.registerElement({
        name: "caption",
        order: 9,
        isButton: false,
        appendTo: "root",
        html: "Caption text",
        onInit: (el, pswp) => {
          // Add caption styles
          el.style.cssText = `
            background: rgba(0, 0, 0, 0.75);
            color: white;
            font-size: 14px;
            line-height: 1.5;
            padding: 10px 15px;
            position: absolute;
            bottom: 0;
            left: 0;
            right: 0;
            max-height: 30%;
            overflow: auto;
            text-align: center;
          `;

          pswp.on("change", () => {
            const currSlideData = pswp.currSlide.data;
            el.innerHTML = currSlideData.caption || "";
            el.style.display = currSlideData.caption ? "block" : "none";
          });
        },
      });

      // Register download button
      if (this.showDownloadButtonValue) {
        pswp.ui.registerElement({
          name: "download-button",
          order: 8,
          isButton: true,
          tagName: "a",
          title: "Download image",
          ariaLabel: "Download image",
          html: {
            isCustomSVG: true,
            inner:
              '<path d="M20.5 14.3 17.1 18V10h-2.2v7.9l-3.4-3.6L10 16l6 6.1 6-6.1ZM23 23H9v2h14Z" id="pswp__icn-download"/>',
            outlineID: "pswp__icn-download",
          },
          onInit: (el, pswp) => {
            el.setAttribute("download", "");
            el.setAttribute("target", "_blank");
            el.setAttribute("rel", "noopener");

            pswp.on("change", () => {
              el.href = pswp.currSlide.data.src;
              // Update download filename based on image source
              const filename = pswp.currSlide.data.src.split("/").pop().split("?")[0];
              el.setAttribute("download", filename || "image.jpg");
            });
          },
        });
      }

      // Register zoom level indicator
      if (this.showZoomIndicatorValue) {
        pswp.ui.registerElement({
          name: "zoom-level-indicator",
          order: 9,
          onInit: (el, pswp) => {
            // Style the zoom indicator
            el.style.cssText = `
              background: rgba(0, 0, 0, 0.75);
              margin-top: auto;
              margin-bottom: auto;
              align-items: center;
              justify-content: center;
              color: white;
              height: fit-content;
              font-size: 14px;
              line-height: 1;
              padding: 8px 12px;
              border-radius: 8px;
              pointer-events: none;
              font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            `;

            let hideTimeout;
            let isInteracting = false;

            const updateZoomLevel = () => {
              if (pswp.currSlide) {
                const zoomLevel = Math.round(pswp.currSlide.currZoomLevel * 100);
                el.innerText = `${zoomLevel}%`;

                // Always show during zoom or interaction
                el.style.display = "block";
                el.style.opacity = "1";

                // Clear any existing timeout
                if (hideTimeout) {
                  clearTimeout(hideTimeout);
                }

                // Only hide after 2 seconds if at 100% and not interacting
                if (zoomLevel === 100 && !isInteracting) {
                  hideTimeout = setTimeout(() => {
                    if (!isInteracting) {
                      el.style.opacity = "0";
                      setTimeout(() => {
                        el.style.display = "none";
                      }, 200);
                    }
                  }, 2000);
                }
              }
            };

            // Track mouse interaction
            pswp.template.addEventListener("mouseenter", () => {
              isInteracting = true;
              if (hideTimeout) {
                clearTimeout(hideTimeout);
              }
              // Show indicator when hovering
              if (pswp.currSlide) {
                el.style.display = "block";
                el.style.opacity = "1";
              }
            });

            pswp.template.addEventListener("mouseleave", () => {
              isInteracting = false;
              updateZoomLevel(); // This will set the hide timeout if at 100%
            });

            // Add transition for smooth fade
            el.style.transition = "opacity 0.2s ease";

            pswp.on("zoomPanUpdate", updateZoomLevel);
            pswp.on("change", updateZoomLevel);
            updateZoomLevel();
          },
        });
      }

      // Register dots/bullets navigation indicator
      // Only show dots if enabled and there's more than one item
      if (this.showDotsIndicatorValue && pswp.getNumItems() > 1) {
        pswp.ui.registerElement({
          name: "bulletsIndicator",
          className: "pswp__bullets-indicator",
          appendTo: "wrapper",
          onInit: (el, pswp) => {
            const bullets = [];
            let bullet;
            let prevIndex = -1;

            // Style the bullets container
            el.style.cssText = `
              display: flex;
              flex-direction: row;
              align-items: center;
              justify-content: center;
              position: absolute;
              bottom: 50px;
              left: 50%;
              transform: translateX(-50%);
              z-index: 10;
              pointer-events: auto;
            `;

            // Create bullets for each slide
            for (let i = 0; i < pswp.getNumItems(); i++) {
              bullet = document.createElement("button");
              bullet.className = "pswp__bullet";
              bullet.setAttribute("aria-label", `Go to slide ${i + 1}`);
              bullet.style.cssText = `
                width: 8px;
                height: 8px;
                border-radius: 50%;
                background: rgba(255, 255, 255, 0.5);
                margin: 0 4px;
                padding: 0;
                border: none;
                cursor: pointer;
                transition: all 0.2s ease;
                box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2), 0 0 0 1px rgba(0, 0, 0, 0.1);
              `;
              bullet.onmouseover = (e) => {
                if (!e.target.classList.contains("pswp__bullet--active")) {
                  e.target.style.background = "rgba(255, 255, 255, 0.7)";
                }
              };
              bullet.onmouseout = (e) => {
                if (!e.target.classList.contains("pswp__bullet--active")) {
                  e.target.style.background = "rgba(255, 255, 255, 0.5)";
                }
              };
              bullet.onclick = ((index) => {
                return (e) => {
                  pswp.goTo(index);
                };
              })(i);
              el.appendChild(bullet);
              bullets.push(bullet);
            }

            // Update bullets on slide change
            pswp.on("change", () => {
              if (prevIndex >= 0) {
                bullets[prevIndex].classList.remove("pswp__bullet--active");
                bullets[prevIndex].style.background = "rgba(255, 255, 255, 0.5)";
                bullets[prevIndex].style.transform = "scale(1)";
                bullets[prevIndex].style.boxShadow = "0 1px 3px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(0, 0, 0, 0.1)";
              }
              bullets[pswp.currIndex].classList.add("pswp__bullet--active");
              bullets[pswp.currIndex].style.background = "rgba(255, 255, 255, 1)";
              bullets[pswp.currIndex].style.transform = "scale(1.2)";
              bullets[pswp.currIndex].style.boxShadow = "0 2px 6px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(0, 0, 0, 0.2)";
              prevIndex = pswp.currIndex;
            });
          },
        });
      }
    });

    // Update dimensions for items that need it
    pswp.on("imageSrcChange", (e) => {
      const { content, isLazy } = e;

      if (content.data.needsUpdate && !isLazy) {
        // Listen for the image load event
        const updateDimensions = () => {
          const img = content.pictureElement.querySelector("img");
          if (img && img.naturalWidth && img.naturalHeight) {
            content.width = img.naturalWidth;
            content.height = img.naturalHeight;
            content.updateContentSize(true);
          }
        };

        if (content.pictureElement) {
          content.pictureElement.addEventListener("load", updateDimensions, { once: true });
        }
      }
    });

    pswp.init();
  }

  get defaultOptions() {
    return {
      showHideAnimationType: "zoom",
      pswpModule: () => import("photoswipe"),
      preload: [1, 2],
      wheelToZoom: true,
      padding: { top: 20, bottom: 40, left: 20, right: 20 },
      // Zoom settings to prevent closing on click
      maxZoomLevel: 4,
      getDoubleTapZoom: (isMouseClick, item) => {
        // Smart zoom behavior that includes 100% as a stop
        if (isMouseClick) {
          // For mouse clicks, cycle through zoom levels
          const currentZoom = item.instance.currSlide.currZoomLevel;
          if (currentZoom < 0.95) {
            return 1; // First zoom to 100% (actual size)
          } else if (currentZoom < 1.5) {
            return 2; // Then zoom to 2x
          } else if (currentZoom < 2.5) {
            return 3; // Then zoom to 3x
          } else {
            // Reset to fit - return the fit zoom level
            const slide = item.instance.currSlide;
            return slide.zoomLevels.fit || slide.zoomLevels.min || slide.min || 1;
          }
        }
        // For touch devices, zoom to 100% first if below, otherwise 2x
        const touchZoom = item.instance.currSlide.currZoomLevel;
        return touchZoom < 0.95 ? 1 : 2;
      },
      // Prevent closing on vertical drag
      closeOnVerticalDrag: false,
      // Disable tap to close
      tapAction: false,
      // Allow click on background to close (but not on image)
      clickToCloseNonZoomable: false,
      // Ensure pinch to close is disabled
      pinchToClose: false,
    };
  }

  getAppendTarget() {
    const parentDialog = this.element.closest("dialog[open]");

    if (!parentDialog) {
      return { appendTarget: document.body, hostDialog: null };
    }

    this.ensurePhotoSwipeHostStyles();
    this.teardownPhotoSwipeHost();

    const hostDialog = document.createElement("dialog");
    hostDialog.className = "pswp-host-dialog";
    hostDialog.setAttribute("data-lightbox-pswp-host", "true");
    hostDialog.setAttribute("aria-label", "Image viewer");
    document.body.appendChild(hostDialog);
    hostDialog.showModal();

    this.photoSwipeHostDialog = hostDialog;

    return { appendTarget: hostDialog, hostDialog };
  }

  ensurePhotoSwipeHostStyles() {
    const styleId = "pswp-host-dialog-styles";
    if (document.getElementById(styleId)) return;

    const style = document.createElement("style");
    style.id = styleId;
    style.textContent = `
      dialog.pswp-host-dialog {
        margin: 0;
        padding: 0;
        border: none;
        width: 100vw;
        max-width: none;
        height: 100vh;
        max-height: none;
        background: transparent;
        overflow: visible;
      }

      dialog.pswp-host-dialog::backdrop {
        background: transparent;
      }
    `;
    document.head.appendChild(style);
  }

  teardownPhotoSwipeHost(hostDialog = this.photoSwipeHostDialog) {
    if (!hostDialog) return;

    if (hostDialog.open) {
      hostDialog.close();
    }

    hostDialog.remove();

    if (this.photoSwipeHostDialog === hostDialog) {
      this.photoSwipeHostDialog = null;
    }
  }

  disconnect() {
    this.teardownPhotoSwipeHost();

    if (this.hasGalleryTarget) {
      this.galleryTarget.removeEventListener("click", this.handleGalleryClick.bind(this));
    }
  }
}