/**
 * highlightCode — deterministic token markup for code blocks.
 *
 * The code editor's "colorful code" regression: a code block must render
 * Prism token spans (`<span class="token keyword">…`) for known languages so
 * globals.css can color them, and must return null (→ raw text, no spans)
 * for plaintext / unknown languages / empty input so a bad language value
 * never breaks rendering.
 */
import { describe, expect, it } from "vitest";
import { CODE_LANGUAGES, highlightCode } from "../code-highlight";

describe("highlightCode", () => {
  it("javascript: keywords, strings, functions and numbers become token spans", () => {
    const html = highlightCode('const x = "hello";\nfunction add(a, b) { return a + b; }\nlet n = 42;', "javascript");
    expect(html, "expected HTML output").toBeTruthy();
    expect(html).toContain('class="token keyword"');
    expect(html).toContain(">const<");
    expect(html).toContain('class="token string"');
    expect(html).toContain("hello");
    expect(html).toContain('class="token function"');
    expect(html).toContain("add");
    expect(html).toContain('class="token number"');
    expect(html).toContain(">42<");
    // Punctuation is tokenized too (the `;`, `{`, etc.).
    expect(html).toContain('class="token punctuation"');
  });

  it("typescript extends javascript (interface is a keyword)", () => {
    const html = highlightCode("interface Foo { x: number }", "typescript");
    expect(html).toContain('class="token keyword"');
    expect(html).toContain(">interface<");
  });

  it("python: keywords + strings + comments", () => {
    const html = highlightCode('# count\nx = "hi"\nif x:\n    print(x)', "python");
    expect(html).toContain('class="token comment"');
    expect(html).toContain("count");
    expect(html).toContain('class="token string"');
    expect(html).toContain('class="token keyword"');
  });

  it("sql: keywords are uppercased-matched and quoted", () => {
    const html = highlightCode("SELECT id, name FROM users WHERE id = 1;", "sql");
    expect(html).toContain('class="token keyword"');
    expect(html).toContain("SELECT");
    expect(html).toContain('class="token number"');
  });

  it("json: keys/strings/numbers tokenized", () => {
    const html = highlightCode('{ "a": 1, "b": true }', "json");
    expect(html).toContain('class="token property"');
    expect(html).toContain('class="token number"');
    expect(html).toContain('class="token boolean"');
  });

  it("bash: shebang/comment + strings", () => {
    const html = highlightCode("#!/usr/bin/env bash\n# done\necho \"hi\"", "bash");
    expect(html).toContain("token shebang");
    expect(html).toContain('class="token comment"');
    expect(html).toContain('class="token string"');
  });

  it("css: property, value and selector tokens", () => {
    const html = highlightCode("body { color: #ff0000; }", "css");
    expect(html).toContain("token");
  });

  it("html (markup): tags + attributes", () => {
    const html = highlightCode("<div class=\"a\">x</div>", "html");
    expect(html).toContain('class="token tag"');
    expect(html).toContain('class="token attr-name"');
  });

  it("plaintext: null (rendered raw, never wrapped in spans)", () => {
    expect(highlightCode("just some text", "plaintext")).toBeNull();
  });

  it("unknown language: null (fallback to raw, no broken markup)", () => {
    expect(highlightCode("def f(): pass", "cobol")).toBeNull();
    expect(highlightCode("x", "")).toBeNull();
  });

  it("empty input: null", () => {
    expect(highlightCode("", "javascript")).toBeNull();
  });

  it("escapes HTML special characters (no raw <b> markup inside token output)", () => {
    const html = highlightCode("const s = \"<b>&</b>\";", "javascript");
    // Prism entity-escapes `<` (and `&`) in token contents so the output
    // cannot open a real element inside the <code> DOM. A bare `>` can never
    // start a tag, so Prism leaves it as-is — the safety property is that no
    // raw `<tag>` survives the highlight.
    expect(html).toContain("&lt;b>");
    expect(html).toContain("&amp;");
    expect(html).not.toContain("<b>"); // raw markup must not appear
  });

  it("CODE_LANGUAGES matches the CodeBlock dropdown exactly (plaintext + 10 languages)", () => {
    expect([...CODE_LANGUAGES]).toEqual([
      "plaintext",
      "javascript",
      "typescript",
      "python",
      "bash",
      "json",
      "sql",
      "go",
      "rust",
      "css",
      "html",
    ]);
  });
});