// ------------------------------------
// Markdown - GitHub-style Alerts
// ------------------------------------

module.exports = {
  init (md, conf) {
    // Plugin to parse GitHub-style alerts using renderer approach
    md.use(githubAlertsPlugin, conf)
  }
}

function githubAlertsPlugin(md, options = {}) {
  const alertTypes = {
    'note': { class: 'is-info' },
    'info': { class: 'is-info' },
    'tip': { class: 'is-success' },
    'warning': { class: 'is-warning' },
    'important': { class: 'is-info' },
    'caution': { class: 'is-danger' }
  }

  // Store original renderer
  const defaultRender = md.renderer.rules.blockquote_open || function(tokens, idx, options, env, slf) {
    return slf.renderToken(tokens, idx, options)
  }

  // Override blockquote_open renderer
  md.renderer.rules.blockquote_open = function(tokens, idx, opts, env, slf) {
    const nextToken = tokens[idx + 1]

    // Check if the next token is a paragraph containing inline content
    if (nextToken && nextToken.type === 'paragraph_open') {
      const inlineToken = tokens[idx + 2] // The inline token after paragraph_open

      if (inlineToken && inlineToken.type === 'inline' && inlineToken.children) {
        const firstChild = inlineToken.children[0]

        if (firstChild && firstChild.type === 'text') {
          const content = firstChild.content
          const alertMatch = content.match(/^\[!(NOTE|INFO|TIP|WARNING|IMPORTANT|CAUTION)\](?:\s+(.+?))?$/i)

          if (alertMatch) {
            const alertType = alertMatch[1].toLowerCase()
            const customTitle = alertMatch[2] ? alertMatch[2].trim() : null

            const alertConfig = alertTypes[alertType]
            if (alertConfig) {
              // Add CSS class to blockquote
              tokens[idx].attrJoin('class', alertConfig.class)

              // Handle custom title or remove alert tag
              if (customTitle && options.customTitle !== false) {
                // Replace with bold custom title
                firstChild.content = `**${customTitle}**`
              } else if (customTitle && options.customTitle === false) {
                // Custom titles disabled but title provided - remove the entire alert line
                firstChild.content = ''
              } else {
                // No custom title - remove the alert tag
                firstChild.content = ''
              }

              // If we emptied the first text node, remove it
              if (firstChild.content === '') {
                inlineToken.children.shift()
                // Also remove the following softbreak if it exists
                if (inlineToken.children[0] && inlineToken.children[0].type === 'softbreak') {
                  inlineToken.children.shift()
                }
              }
            }
          }
        }
      }
    }

    return defaultRender(tokens, idx, opts, env, slf)
  }
}