export interface Route {
  type: 'blog' | 'post' | 'browser-services' | 'browser-collections' | 'browser-record' | 'new'
  handle?: string
  collection?: string
  rkey?: string
  service?: string
}

export function parseRoute(pathname: string): Route {
  const parts = pathname.split('/').filter(Boolean)

  // / - Blog top
  if (parts.length === 0) {
    return { type: 'blog' }
  }

  // /new - New post form
  if (parts[0] === 'new') {
    return { type: 'new' }
  }

  // /app - SPA entry point (same as blog)
  if (parts[0] === 'app') {
    return { type: 'blog' }
  }

  // /post/${rkey} - Post detail
  if (parts[0] === 'post' && parts[1]) {
    return { type: 'post', rkey: parts[1] }
  }

  // /at/${handle} - Browser services
  // /at/${handle}/${service-or-collection} - Browser collections or records
  // /at/${handle}/${collection}/${rkey} - Browser record detail
  if (parts[0] === 'at' && parts[1]) {
    const handle = parts[1]

    if (!parts[2]) {
      // /at/${handle}
      return { type: 'browser-services', handle }
    }

    if (!parts[3]) {
      // /at/${handle}/${service-or-collection}
      // If it looks like a domain (2 parts), treat as service
      // Otherwise treat as collection NSID (3+ parts)
      const segment = parts[2]
      if (segment.split('.').length <= 2) {
        // Likely a service domain like "bsky.app"
        return { type: 'browser-collections', handle, service: segment }
      } else {
        // Likely a collection NSID like "app.bsky.feed.post"
        // Show record list for this collection
        return { type: 'browser-record', handle, collection: segment }
      }
    }

    // /at/${handle}/${collection}/${rkey}
    return { type: 'browser-record', handle, collection: parts[2], rkey: parts[3] }
  }

  // Fallback to blog
  return { type: 'blog' }
}

export function buildPath(route: Route): string {
  switch (route.type) {
    case 'blog':
      return '/'
    case 'new':
      return '/new'
    case 'post':
      return `/post/${route.rkey}`
    case 'browser-services':
      return `/at/${route.handle}`
    case 'browser-collections':
      return `/at/${route.handle}/${route.service}`
    case 'browser-record':
      if (route.rkey) {
        return `/at/${route.handle}/${route.collection}/${route.rkey}`
      }
      return `/at/${route.handle}/${route.collection}`
    default:
      return '/'
  }
}

export function navigate(path: string): void {
  window.history.pushState({}, '', path)
  window.dispatchEvent(new PopStateEvent('popstate'))
}