import { Marp } from '@marp-team/marp-core'

// Custom Marp engine with Mermaid support via HTML injection
export default {
  html: true,
  engine: (constructorOptions) => {
    const marp = new Marp(constructorOptions)

    // Transform mermaid code blocks to divs that mermaid.js can render
    const { code } = marp.markdown.renderer.rules
    marp.markdown.renderer.rules.code = (tokens, idx, options, env, self) => {
      const token = tokens[idx]
      if (token.info.trim() === 'mermaid') {
        return `<div class="mermaid">${token.content}</div>`
      }
      return code(tokens, idx, options, env, self)
    }

    return marp
  }
}