MyBlog-Next/src/layouts/PostDetails.astro

---
import { render, type CollectionEntry } from "astro:content";
import Layout from "@/layouts/Layout.astro";
import Header from "@/components/Header.astro";
import Footer from "@/components/Footer.astro";
import Tag from "@/components/Tag.astro";
import Datetime from "@/components/Datetime.astro";
import EditPost from "@/components/EditPost.astro";
import ShareLinks from "@/components/ShareLinks.astro";
import BackButton from "@/components/BackButton.astro";
import { getPath } from "@/utils/getPath";
import { slugifyStr } from "@/utils/slugify";
import IconChevronLeft from "@/assets/icons/IconChevronLeft.svg";
import IconChevronRight from "@/assets/icons/IconChevronRight.svg";
import { SITE } from "@/config";

export interface Props {
  post: CollectionEntry<"blog">;
  posts: CollectionEntry<"blog">[];
}

const { post, posts } = Astro.props;

const {
  title,
  author,
  description,
  ogImage: initOgImage,
  canonicalURL,
  pubDatetime,
  modDatetime,
  tags,
  hideEditPost,
} = post.data;

const { Content } = await render(post);

let ogImageUrl: string | undefined;

// Determine OG image source
if (typeof initOgImage === "string") {
  ogImageUrl = initOgImage; // Remote OG image (absolute URL)
} else if (initOgImage?.src) {
  ogImageUrl = initOgImage.src; // Local asset
}

// Use dynamic OG image if enabled and no remote|local ogImage
if (!ogImageUrl && SITE.dynamicOgImage) {
  ogImageUrl = `${getPath(post.id, post.filePath)}/index.png`;
}

// Resolve OG image URL (or fallback to SITE.ogImage / default `og.png`)
const ogImage = ogImageUrl
  ? new URL(ogImageUrl, Astro.url.origin).href
  : undefined;

const layoutProps = {
  title: `${title} | ${SITE.title}`,
  author,
  description,
  pubDatetime,
  modDatetime,
  canonicalURL,
  ogImage,
  scrollSmooth: true,
};

/* ========== Prev/Next Posts ========== */

const allPosts = posts.map(({ data: { title }, id }) => ({
  slug: id,
  title,
}));

const currentPostIndex = allPosts.findIndex(a => a.slug === post.id);

const prevPost = currentPostIndex !== 0 ? allPosts[currentPostIndex - 1] : null;
const nextPost =
  currentPostIndex !== allPosts.length ? allPosts[currentPostIndex + 1] : null;
---

<Layout {...layoutProps}>
  <Header />
  <BackButton />
  <main
    id="main-content"
    class:list={[
      "mx-auto w-full max-w-3xl px-4 pb-12",
      { "mt-8": !SITE.showBackButton },
    ]}
    data-pagefind-body
  >
    <h1
      transition:name={slugifyStr(title)}
      class="inline-block text-2xl font-bold text-accent sm:text-3xl"
    >
      {title}
    </h1>
    <div class="flex items-center gap-4">
      <Datetime
        pubDatetime={pubDatetime}
        modDatetime={modDatetime}
        size="lg"
        class="my-2"
      />
      <EditPost class="max-sm:hidden" {hideEditPost} {post} />
    </div>
    <article id="article" class="mx-auto prose mt-8 max-w-3xl">
      <Content />
    </article>

    <hr class="my-8 border-dashed" />

    <EditPost class="sm:hidden" {hideEditPost} {post} />

    <ul class="mt-4 mb-8 sm:my-8">
      {tags.map(tag => <Tag tag={slugifyStr(tag)} tagName={tag} />)}
    </ul>

    <div
      class="flex flex-col items-center justify-between gap-6 sm:flex-row sm:items-end sm:gap-4"
    >
      <ShareLinks />

      <button
        id="back-to-top"
        class="focus-outline py-1 whitespace-nowrap hover:opacity-75"
      >
        <IconChevronLeft class="inline-block rotate-90" />
        <span>Back to Top</span>
      </button>
    </div>

    <hr class="my-6 border-dashed" />

    <!-- Previous/Next Post Buttons -->
    <div data-pagefind-ignore class="grid grid-cols-1 gap-6 sm:grid-cols-2">
      {
        prevPost && (
          <a
            href={`/posts/${prevPost.slug}`}
            class="flex w-full gap-1 hover:opacity-75"
          >
            <IconChevronLeft class="inline-block flex-none" />
            <div>
              <span>Previous Post</span>
              <div class="text-sm text-accent/85">{prevPost.title}</div>
            </div>
          </a>
        )
      }
      {
        nextPost && (
          <a
            href={`/posts/${nextPost.slug}`}
            class="flex w-full justify-end gap-1 text-right hover:opacity-75 sm:col-start-2"
          >
            <div>
              <span>Next Post</span>
              <div class="text-sm text-accent/85">{nextPost.title}</div>
            </div>
            <IconChevronRight class="inline-block flex-none" />
          </a>
        )
      }
    </div>
  </main>
  <Footer />
</Layout>

<script is:inline data-astro-rerun>
  /** Create a progress indicator
   *  at the top */
  function createProgressBar() {
    // Create the main container div
    const progressContainer = document.createElement("div");
    progressContainer.className =
      "progress-container fixed top-0 z-10 h-1 w-full bg-background";

    // Create the progress bar div
    const progressBar = document.createElement("div");
    progressBar.className = "progress-bar h-1 w-0 bg-accent";
    progressBar.id = "myBar";

    // Append the progress bar to the progress container
    progressContainer.appendChild(progressBar);

    // Append the progress container to the document body or any other desired parent element
    document.body.appendChild(progressContainer);
  }
  createProgressBar();

  /** Update the progress bar
   *  when user scrolls */
  function updateScrollProgress() {
    document.addEventListener("scroll", () => {
      const winScroll =
        document.body.scrollTop || document.documentElement.scrollTop;
      const height =
        document.documentElement.scrollHeight -
        document.documentElement.clientHeight;
      const scrolled = (winScroll / height) * 100;
      if (document) {
        const myBar = document.getElementById("myBar");
        if (myBar) {
          myBar.style.width = scrolled + "%";
        }
      }
    });
  }
  updateScrollProgress();

  /** Attaches links to headings in the document,
   *  allowing sharing of sections easily */
  function addHeadingLinks() {
    const headings = Array.from(
      document.querySelectorAll("h2, h3, h4, h5, h6")
    );
    for (const heading of headings) {
      heading.classList.add("group");
      const link = document.createElement("a");
      link.className =
        "heading-link ml-2 opacity-0 group-hover:opacity-100 focus:opacity-100";
      link.href = "#" + heading.id;

      const span = document.createElement("span");
      span.ariaHidden = "true";
      span.innerText = "#";
      link.appendChild(span);
      heading.appendChild(link);
    }
  }
  addHeadingLinks();

  /** Attaches copy buttons to code blocks in the document,
   * allowing users to copy code easily. */
  function attachCopyButtons() {
    const copyButtonLabel = "Copy";
    const codeBlocks = Array.from(document.querySelectorAll("pre"));

    for (const codeBlock of codeBlocks) {
      const wrapper = document.createElement("div");
      wrapper.style.position = "relative";

      const copyButton = document.createElement("button");
      copyButton.className =
        "copy-code absolute right-3 -top-3 rounded bg-muted px-2 py-1 text-xs leading-4 text-foreground font-medium";
      copyButton.innerHTML = copyButtonLabel;
      codeBlock.setAttribute("tabindex", "0");
      codeBlock.appendChild(copyButton);

      // wrap codebock with relative parent element
      codeBlock?.parentNode?.insertBefore(wrapper, codeBlock);
      wrapper.appendChild(codeBlock);

      copyButton.addEventListener("click", async () => {
        await copyCode(codeBlock, copyButton);
      });
    }

    async function copyCode(block, button) {
      const code = block.querySelector("code");
      const text = code?.innerText;

      await navigator.clipboard.writeText(text ?? "");

      // visual feedback that task is completed
      button.innerText = "Copied";

      setTimeout(() => {
        button.innerText = copyButtonLabel;
      }, 700);
    }
  }
  attachCopyButtons();

  /** Scrolls the document to the top when
   * the "Back to Top" button is clicked. */
  function backToTop() {
    document.querySelector("#back-to-top")?.addEventListener("click", () => {
      document.body.scrollTop = 0; // For Safari
      document.documentElement.scrollTop = 0; // For Chrome, Firefox, IE and Opera
    });
  }
  backToTop();

  /* Go to page start after page swap */
  document.addEventListener("astro:after-swap", () =>
    window.scrollTo({ left: 0, top: 0, behavior: "instant" })
  );
</script>