/**
 * The Markdown language for the pager. Coloring and structure live in {@link
 * ./markdown.ts}; this module adapts them to the {@link Language} contract.
 *
 * Markdown has no semantic layer (no `createSemantics`/`createDiffSemantics`),
 * and its diff-hunk navigation is heading-based rather than the generic node
 * remap, so {@link hunkStructure} routes to {@link markdownHeadingNodes}.
 */

import type { StructureNode } from "../../model.ts";
import type { HunkStructureContext, Language } from "../language.ts";
import { utf8Decoder } from "../decoder.ts";
import {
  createMarkdownHighlighter,
  highlightMarkdownLines,
  markdownDocument,
  markdownHeadingNodes,
  renderMarkdownLines,
} from "./markdown.ts";

export const markdownLanguage: Language = {
  id: "markdown",

  input: { kind: "text", decoder: utf8Decoder },

  metadata: {
    extensions: [".md", ".markdown", ".mdown", ".mkd", ".mdx"],
    filenames: [],
    filenamePatterns: [],
    aliases: ["md"],
    interpreters: [],
    signatures: [],
    sharedExtensions: [],
  },

  parseDocument: (text) => markdownDocument(text),

  highlightLines: (text) => highlightMarkdownLines(text),

  renderLines: (text) => renderMarkdownLines(text),

  renderNeedsCompleteFile: true,

  highlightFullFileOnDiffEdit: true,

  createHighlighter: (text) => createMarkdownHighlighter(text),

  hunkStructure(ctx: HunkStructureContext): StructureNode[] {
    return markdownHeadingNodes(
      ctx.doc.flatStructure,
      ctx.lineToDiff,
      ctx.hunkEnd,
      ctx.diffLineStarts,
      ctx.rawLines,
    );
  },
};