kandev/apps/web/lib/languages.ts

/**
 * Centralized language utilities for file extension mapping and syntax highlighting.
 */

import { javascript } from '@codemirror/lang-javascript';
import { python } from '@codemirror/lang-python';
import { go } from '@codemirror/lang-go';
import { rust } from '@codemirror/lang-rust';
import { java } from '@codemirror/lang-java';
import { cpp } from '@codemirror/lang-cpp';
import { css } from '@codemirror/lang-css';
import { html } from '@codemirror/lang-html';
import { json } from '@codemirror/lang-json';
import { markdown } from '@codemirror/lang-markdown';
import { yaml } from '@codemirror/lang-yaml';
import type { Extension } from '@codemirror/state';

/**
 * Map of file extensions to language identifiers.
 * Used for syntax highlighting and language detection.
 */
export const EXTENSION_TO_LANGUAGE: Record<string, string> = {
  // JavaScript/TypeScript
  js: 'javascript',
  mjs: 'javascript',
  cjs: 'javascript',
  jsx: 'jsx',
  ts: 'typescript',
  mts: 'typescript',
  cts: 'typescript',
  tsx: 'tsx',

  // Python
  py: 'python',
  pyw: 'python',
  pyi: 'python',

  // Go
  go: 'go',

  // Rust
  rs: 'rust',

  // Ruby
  rb: 'ruby',
  erb: 'ruby',

  // Java/JVM
  java: 'java',
  kt: 'kotlin',
  kts: 'kotlin',
  scala: 'scala',
  groovy: 'groovy',

  // Swift
  swift: 'swift',

  // C/C++
  c: 'c',
  h: 'c',
  cpp: 'cpp',
  cc: 'cpp',
  cxx: 'cpp',
  hpp: 'cpp',
  hxx: 'cpp',

  // C#
  cs: 'csharp',

  // PHP
  php: 'php',

  // Web
  html: 'html',
  htm: 'html',
  css: 'css',
  scss: 'scss',
  sass: 'sass',
  less: 'less',

  // Data formats
  json: 'json',
  jsonc: 'json',
  yaml: 'yaml',
  yml: 'yaml',
  xml: 'xml',
  toml: 'toml',
  ini: 'ini',
  env: 'properties',

  // Markup
  md: 'markdown',
  mdx: 'markdown',

  // Shell
  sh: 'bash',
  bash: 'bash',
  zsh: 'bash',
  fish: 'fish',

  // SQL
  sql: 'sql',

  // Docker
  dockerfile: 'dockerfile',

  // GraphQL
  graphql: 'graphql',
  gql: 'graphql',

  // Misc
  vue: 'vue',
  svelte: 'svelte',
};

/**
 * Get the language identifier from a file extension.
 * @param ext - File extension (without the dot)
 * @returns Language identifier or 'plaintext' if unknown
 */
export function getLanguageFromExtension(ext: string): string {
  return EXTENSION_TO_LANGUAGE[ext.toLowerCase()] || 'plaintext';
}

/**
 * Get the language identifier from a file path.
 * @param filePath - Full or relative file path
 * @returns Language identifier or 'plaintext' if unknown
 */
export function getLanguageFromPath(filePath: string): string {
  const ext = filePath.split('.').pop()?.toLowerCase() || '';
  return getLanguageFromExtension(ext);
}

/**
 * Get the CodeMirror language extension for a given language identifier.
 * @param language - Language identifier (e.g., 'typescript', 'python')
 * @returns CodeMirror Extension or undefined if no extension available
 */
export function getCodeMirrorExtension(language: string): Extension | undefined {
  const lang = language.toLowerCase();

  switch (lang) {
    case 'javascript':
    case 'js':
      return javascript();
    case 'jsx':
      return javascript({ jsx: true });
    case 'typescript':
    case 'ts':
      return javascript({ typescript: true });
    case 'tsx':
      return javascript({ jsx: true, typescript: true });
    case 'python':
    case 'py':
      return python();
    case 'go':
    case 'golang':
      return go();
    case 'rust':
    case 'rs':
      return rust();
    case 'java':
      return java();
    case 'cpp':
    case 'c++':
    case 'c':
    case 'cc':
    case 'cxx':
      return cpp();
    case 'css':
    case 'scss':
    case 'sass':
    case 'less':
      return css();
    case 'html':
    case 'htm':
      return html();
    case 'json':
    case 'jsonc':
      return json();
    case 'markdown':
    case 'md':
    case 'mdx':
      return markdown();
    case 'yaml':
    case 'yml':
      return yaml();
    default:
      return undefined;
  }
}

/**
 * Get the CodeMirror language extension directly from a file path.
 * @param filePath - Full or relative file path
 * @returns CodeMirror Extension or undefined if no extension available
 */
export function getCodeMirrorExtensionFromPath(filePath: string): Extension | undefined {
  const language = getLanguageFromPath(filePath);
  return getCodeMirrorExtension(language);
}