yvcodesnap/src/utils/highlighter.ts

import { codeToHtml, codeToTokens, type BundledTheme, type BundledLanguage } from 'shiki';
import { CODE_THEMES, type CodeThemeId } from '../types';

let highlighterReady = false;

export async function highlightCode(
  code: string,
  language: string,
  theme: CodeThemeId
): Promise<string> {
  try {
    const html = await codeToHtml(code, {
      lang: language as BundledLanguage,
      theme: theme as BundledTheme,
    });
    highlighterReady = true;
    return html;
  } catch (error) {
    console.error('Highlighting error:', error);
    return `<pre><code>${escapeHtml(code)}</code></pre>`;
  }
}

export interface TokenInfo {
  content: string;
  color: string;
}

export interface LineTokens {
  tokens: TokenInfo[];
}

export async function tokenizeCode(
  code: string,
  language: string,
  theme: CodeThemeId
): Promise<LineTokens[]> {
  try {
    const result = await codeToTokens(code, {
      lang: language as BundledLanguage,
      theme: theme as BundledTheme,
    });
    highlighterReady = true;
    return result.tokens.map(line => ({
      tokens: line.map(token => ({
        content: token.content,
        color: token.color || '#ffffff',
      })),
    }));
  } catch (error) {
    console.error('Tokenization error:', error);
    // Fallback: return plain text tokens
    return code.split('\n').map(line => ({
      tokens: [{ content: line, color: '#ffffff' }],
    }));
  }
}

export function getThemeBackground(themeId: CodeThemeId): string {
  const theme = CODE_THEMES.find(t => t.id === themeId);
  return theme?.bg || '#1e1e2e';
}

export function isLightTheme(themeId: CodeThemeId): boolean {
  const lightThemes = ['github-light', 'vitesse-light', 'min-light', 'solarized-light', 'light-plus'];
  return lightThemes.includes(themeId);
}

function escapeHtml(text: string): string {
  return text
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#039;');
}

export function isHighlighterReady(): boolean {
  return highlighterReady;
}

// Language detection based on common patterns
export function detectLanguage(code: string): string {
  // Kotlin / Jetpack Compose patterns (check first - primary language)
  // Look for @Composable, fun, val, var, class, object, companion object, etc.
  if (/@Composable|@Preview|@OptIn|@Suppress/.test(code)) {
    return 'kotlin';
  }
  if (/^(fun|val|var|class|object|package|import|sealed|data\s+class|enum\s+class|interface)\s+/m.test(code)) {
    // Check for Kotlin-specific syntax
    if (/:\s*\w+(\s*[={()]|$|\s*,)/.test(code) || 
        /\b(Unit|String|Int|Long|Boolean|Float|Double|List|Map|Set|suspend|inline|crossinline|noinline|reified)\b/.test(code) ||
        /\bModifier\b|\bColumn\b|\bRow\b|\bBox\b|\bText\b|\bButton\b|\bScaffold\b/.test(code) ||
        /\.copy\(|\.let\s*\{|\.apply\s*\{|\.also\s*\{|\.run\s*\{/.test(code) ||
        /\blambda\b|->/.test(code)) {
      return 'kotlin';
    }
  }
  
  // TypeScript/JavaScript patterns
  if (/^import\s+.*from\s+['"]|^export\s+(default\s+)?|const\s+\w+:\s*\w+/m.test(code)) {
    if (/:\s*(string|number|boolean|any|void|Promise|Array)\b/.test(code)) {
      return 'typescript';
    }
    return 'javascript';
  }
  
  // Java patterns (after Kotlin to avoid false positives)
  if (/^(public|private|protected)\s+(static\s+)?(class|void|int|String)/m.test(code) &&
      !/@Composable/.test(code)) {
    return 'java';
  }
  
  // Swift patterns
  if (/^(func|var|let|class|struct|enum|protocol|import\s+\w+)\s+/m.test(code) &&
      /@State|@Binding|@Published|@ObservedObject|some\s+View/.test(code)) {
    return 'swift';
  }
  
  // Dart/Flutter patterns  
  if (/^(class|void|final|const|import\s+')/m.test(code) &&
      /Widget|StatelessWidget|StatefulWidget|BuildContext|setState/.test(code)) {
    return 'dart';
  }
  
  // Python patterns
  if (/^(def|class|import|from|if __name__|print\()/m.test(code) && !/[{};]/.test(code)) {
    return 'python';
  }
  
  // Rust patterns
  if (/^(fn|let|mut|impl|struct|enum|use|pub)\s+/m.test(code) && /->/.test(code)) {
    return 'rust';
  }
  
  // Go patterns
  if (/^(func|package|import|type|var|const)\s+/m.test(code) && /:=/.test(code)) {
    return 'go';
  }
  
  // Groovy/Gradle patterns
  if (/^(plugins|dependencies|android|buildscript)\s*\{/m.test(code) ||
      /implementation\s*\(|compile\s*\(/.test(code)) {
    return 'groovy';
  }
  
  // XML patterns (for Android layouts)
  if (/^<\?xml|^<resources|^<layout|^<LinearLayout|^<RelativeLayout|^<ConstraintLayout|^<androidx\./m.test(code)) {
    return 'xml';
  }
  
  // HTML patterns
  if (/^<!DOCTYPE|<html|<head|<body|<div/m.test(code)) {
    return 'html';
  }
  
  // CSS patterns
  if (/^[.#\w\-[\]]+\s*\{[^}]*\}/m.test(code)) {
    return 'css';
  }
  
  // JSON patterns
  if (/^\s*[{[]/.test(code) && /[}\]]\s*$/.test(code)) {
    try {
      JSON.parse(code);
      return 'json';
    } catch {
      // Not valid JSON, continue checking
    }
  }
  
  // YAML patterns
  if (/^[\w-]+:\s*(\n|$)|^\s+-\s+/m.test(code) && !/[{};]/.test(code)) {
    return 'yaml';
  }
  
  // SQL patterns
  if (/^(SELECT|INSERT|UPDATE|DELETE|CREATE|DROP|ALTER)\s+/im.test(code)) {
    return 'sql';
  }
  
  // Bash/Shell patterns
  if (/^#!\/bin\/(bash|sh)|^\$\s+|^echo\s+|^export\s+/m.test(code)) {
    return 'bash';
  }
  
  return 'kotlin'; // Default to Kotlin as primary language
}