import { createHighlighter, HighlighterGeneric, BundledLanguage, BundledTheme } from 'shiki'
import type { Element } from 'hast'

let highlighter: HighlighterGeneric<BundledLanguage, BundledTheme> | null = null

export async function getHighlighterInstance() {
  if (!highlighter) {
    highlighter = await createHighlighter({
      themes: ['catppuccin-latte', 'catppuccin-mocha'],
      langs: [
        'javascript', 'typescript', 'python', 'java', 'rust', 
        'go', 'c', 'cpp', 'csharp', 'php', 'ruby', 'cobol',
        'plaintext', 'txt', 'bash', 'nix'
      ]
    })
  }
  return highlighter
}

export async function highlightCode(code: string, lang: string) {
  const highlighter = await getHighlighterInstance()
  
  try {
    return highlighter.codeToHtml(code, {
      lang: lang,
      themes: {
        light: 'catppuccin-latte',
        dark: 'catppuccin-mocha'
      },
      transformers: [
        {
          line(node: Element, line: number) {
            node.properties['code-line'] = line
          }
        }
      ]
    })
  } catch (error) {
    console.warn(`Language "${lang}" not supported by Shiki, falling back to plaintext`)
    return highlighter.codeToHtml(code, {
      lang: 'txt',
      themes: {
        light: 'catppuccin-latte',
        dark: 'catppuccin-mocha'
      }
    })
  }
}