import type { Root, Paragraph, Image } from "mdast";
import { visit } from "unist-util-visit";

/**
 * Remark plugin to detect consecutive images in paragraphs and apply grid classes
 * This replaces the client-side JavaScript detection with build-time processing
 * Skips paragraphs containing Obsidian-sized images (manually sized)
 */
export function remarkImageGrids() {
  return (tree: Root) => {
    visit(
      tree,
      "paragraph",
      (node: Paragraph, index: number | undefined, parent: any) => {
        if (!node.children || node.children.length === 0) {
          return;
        }

        // Find all image nodes in this paragraph
        const images: Image[] = [];
        const otherNodes: any[] = [];

        node.children.forEach((child) => {
          if (child.type === "image") {
            images.push(child as Image);
          } else if (
            child.type === "link" &&
            child.children &&
            child.children.some((linkChild: any) => linkChild.type === "image")
          ) {
            // Skip linked images - they should not be processed as gallery images
            otherNodes.push(child);
          } else if (
            child.type !== "text" ||
            (child as any).value.trim() !== ""
          ) {
            // Count non-empty text nodes and other elements as meaningful content
            otherNodes.push(child);
          }
        });

        // Skip grid processing if any image has manual sizing (Obsidian syntax)
        const hasObsidianSizedImage = images.some((img) => {
          return img.data?.hProperties?.class?.includes('obsidian-sized');
        });

        // Only process paragraphs with 2+ images and no other meaningful content
        // Skip if any image has manual Obsidian sizing
        if (images.length >= 2 && otherNodes.length === 0 && !hasObsidianSizedImage) {
          // Add image-grid classes to the paragraph
          if (!node.data) {
            node.data = {};
          }
          if (!node.data.hProperties) {
            node.data.hProperties = {};
          }

          const hProperties = node.data.hProperties as Record<string, any>;

          // Remove any existing image-grid classes
          const existingClasses = (hProperties.class || "")
            .split(" ")
            .filter(Boolean);
          const filteredClasses = existingClasses.filter(
            (cls: string) => !cls.startsWith("image-grid")
          );

          // Add the appropriate grid classes
          const gridClass = `image-grid-${Math.min(images.length, 6)}`;
          const newClasses = [...filteredClasses, "image-grid", gridClass];

          hProperties.class = newClasses.join(" ");
        }
      }
    );
  };
}

export default remarkImageGrids;