beavergram/frontend/src/lib/components/EntityText.svelte

<script lang="ts">
  import { SvelteSet } from "svelte/reactivity";
  import type { EntityView } from "$lib/api/types";
  import {
    buildEntityTree,
    type EntityNode,
    type EntityTreeNode,
    jumboEmojiCount,
    linkHref,
  } from "$lib/format/entities";

  interface Props {
    entities: EntityView[];
    own?: boolean;
    text: string;
  }

  let { text, entities, own = false }: Props = $props();

  const nodes = $derived(buildEntityTree(text, entities));
  const jumbo = $derived(entities.length === 0 ? jumboEmojiCount(text) : 0);

  const revealed = new SvelteSet<string>();

  function spoilerKey(entity: EntityView): string {
    return `${entity.offset}:${entity.length}`;
  }
</script>

{#snippet tree(items: EntityTreeNode[])}
  {#each items as node, i (i)}
    {#if node.kind === "text"}
      {node.text}
    {:else}
      {@render entity(node)}
    {/if}
  {/each}
{/snippet}

{#snippet entity(node: EntityNode)}
  {@const type = node.entity.type}
  {#if type === "bold"}
    <strong>{@render tree(node.children)}</strong>
  {:else if type === "italic"}
    <em>{@render tree(node.children)}</em>
  {:else if type === "underline"}
    <ins>{@render tree(node.children)}</ins>
  {:else if type === "strikethrough"}
    <del>{@render tree(node.children)}</del>
  {:else if type === "spoiler"}
    {@const key = spoilerKey(node.entity)}
    <button
      class="spoiler"
      onclick={() => revealed.add(key)}
      type="button"
      class:revealed={revealed.has(key)}
    >
      {@render tree(node.children)}
    </button>
  {:else if type === "code"}
    <code class="code" class:own>{@render tree(node.children)}</code>
  {:else if type === "pre"}
    <pre
      class="pre"
      class:own
    >{#if node.entity.language}<span class="pre-lang">{node.entity.language}</span>{/if}<code>{@render tree(node.children)}</code></pre>
  {:else if type === "blockquote"}
    <blockquote class="blockquote">{@render tree(node.children)}</blockquote>
  {:else if type === "url" || type === "text_link" || type === "email" || type === "phone_number"}
    <a
      class="link"
      href={linkHref(node)}
      rel="noopener noreferrer"
      target="_blank"
      class:own
      >{@render tree(node.children)}</a
    >
  {:else if type === "mention" || type === "text_mention" || type === "hashtag" || type === "cashtag" || type === "bot_command"}
    <span class="link" class:own>{@render tree(node.children)}</span>
  {:else}
    {@render tree(node.children)}
  {/if}
{/snippet}

<span class="EntityText" class:jumbo={jumbo > 0} class:jumbo-1={jumbo === 1}>
  {@render tree(nodes)}
</span>

<style lang="scss">
  .EntityText {
    overflow-wrap: anywhere;
    white-space: pre-wrap;

    &.jumbo {
      font-size: 1.75rem;
      line-height: 1.25;
    }

    &.jumbo-1 {
      font-size: 2.5rem;
    }
  }

  .link {
    color: var(--color-links);
    text-decoration: none;
    word-break: break-all;

    &:hover {
      text-decoration: underline;
    }

    &.own {
      color: var(--color-own-links);
    }
  }

  a.link.own {
    text-decoration: underline;
    text-decoration-color: color-mix(
      in srgb,
      var(--color-own-links) 45%,
      transparent
    );
    text-underline-offset: 0.15em;

    &:hover {
      text-decoration-color: currentcolor;
    }
  }

  .code,
  .pre {
    font-family: var(--font-family-monospace, monospace);
    font-size: 0.9375rem;
    color: var(--color-code);
    background-color: var(--color-code-bg);

    &.own {
      color: var(--color-code-own);
      background-color: var(--color-code-own-bg);
    }
  }

  .code {
    padding: 0.0625rem 0.25rem;
    border-radius: 0.25rem;
  }

  .pre {
    overflow-x: auto;

    display: block;
    margin: 0.125rem 0;
    padding: 0.375rem 0.5rem;
    border-radius: 0.375rem;

    white-space: pre;
  }

  .pre-lang {
    display: block;
    margin-bottom: 0.25rem;

    font-size: 0.75rem;
    opacity: 0.7;
  }

  .blockquote {
    margin: 0.125rem 0;
    padding: 0.125rem 0.5rem;
    border-left: 0.1875rem solid var(--color-links);
    border-radius: 0.25rem;

    background-color: var(--color-primary-tint);
  }

  .spoiler {
    cursor: pointer;

    padding: 0;
    border: none;

    font: inherit;
    color: transparent;
    text-shadow: none;

    background-color: var(--color-text);
    border-radius: 0.25rem;

    transition: color 0.15s, background-color 0.15s;

    &.revealed {
      color: inherit;
      background-color: transparent;
    }
  }
</style>