import { ContextMenuDirectory, ContextMenuReadOnlyEntry } from '../context-menu/context-menu.js';

declare const markdownit: ( options?: Record<string, unknown> ) => { render: ( md: string ) => string };

function extractRawText( node: Node ): string
{
  if ( node.nodeType === Node.TEXT_NODE ) return node.nodeValue ?? '';
  if ( node.nodeName === 'BR' ) return '\n';
  if ( node.nodeType !== Node.ELEMENT_NODE ) return '';
  let text = '';
  node.childNodes.forEach( child => text += extractRawText( child ) );
  return text;
}

class RojoChatPanel extends HTMLElement
{
  _initialized = false;
  _conversationId: string = '';
  _sending = false;
  _md: { render: ( s: string ) => string } | null = null;

  connectedCallback(): void
  {
    if ( this._initialized ) return;
    this._initialized = true;

    this._conversationId = crypto.randomUUID();
    this._md = markdownit( { html: false, linkify: true, breaks: true } );

    this.className = 'rojo-chat-panel';
    this.innerHTML = `
      <div class="rcp-toolbar">
        <div class="rcp-toolbar-icon">🤖</div>
        <span class="rcp-toolbar-name">Rojo</span>
        <button class="rcp-toolbar-btn" title="Actions">★</button>
        <button class="rcp-toolbar-btn" title="Settings">☰</button>
      </div>
      <div class="rcp-history"></div>
      <div class="rcp-input-area">
        <div class="rcp-input-text" contenteditable="true"></div>
        <div class="rcp-input-buttons">
          <button class="rcp-input-btn rcp-plus-btn" title="Attach">+</button>
          <button class="rcp-input-btn rcp-send-btn" title="Send">▲</button>
        </div>
      </div>
    `;

    const sendBtn   = this.querySelector( '.rcp-send-btn' ) as HTMLButtonElement;
    const inputText = this.querySelector( '.rcp-input-text' ) as HTMLElement;

    sendBtn.addEventListener( 'click', () => this._send() );

    inputText.addEventListener( 'keydown', ( e: KeyboardEvent ) =>
    {
      if ( e.key === 'Enter' && !e.shiftKey )
      {
        e.preventDefault();
        this._send();
      }
    } );
  }

  async _send(): Promise<void>
  {
    if ( this._sending ) return;

    const inputText     = this.querySelector( '.rcp-input-text' ) as HTMLElement;
    const sendBtn       = this.querySelector( '.rcp-send-btn' ) as HTMLButtonElement;
    const history       = this.querySelector( '.rcp-history' ) as HTMLElement;

    const text = extractRawText( inputText ).replaceAll( ' ', ' ' ).trim();
    if ( !text ) return;

    inputText.innerHTML = '';
    this._sending       = true;
    sendBtn.disabled    = true;

    const userBubble       = document.createElement( 'div' );
    userBubble.className   = 'rcp-user-bubble';
    userBubble.textContent = text;
    history.appendChild( userBubble );
    history.scrollTop = history.scrollHeight;

    const assistantBubble     = document.createElement( 'div' );
    assistantBubble.className = 'rcp-assistant-bubble';
    assistantBubble.textContent = '…';
    history.appendChild( assistantBubble );
    history.scrollTop = history.scrollHeight;

    try
    {
      const response = await fetch( '/api/rojos/chat',
        {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify( { id: this._conversationId, message: text } ),
        }
      );

      if ( !response.body ) throw new Error( 'No response body' );

      const reader  = response.body.getReader();
      const decoder = new TextDecoder();
      let markdown  = '';

      while ( true )
      {
        const { done, value } = await reader.read();
        if ( done ) break;

        const raw = decoder.decode( value, { stream: true } );

        console.log( "Received raw:", raw );

        for ( const line of raw.split( '\n' ) )
        {
          const trimmed = line.trim();
          if ( !trimmed ) continue;

          try
          {
            const msg = JSON.parse( trimmed ) as { type: string; text?: string };

            if ( msg.type === 'CHAT' && msg.text )
            {
              markdown += msg.text;
              assistantBubble.innerHTML = this._md!.render( markdown );
              history.scrollTop = history.scrollHeight;
            }
          }
          catch
          {
            // partial or non-JSON chunk — skip
          }
        }
      }

      const remaining = decoder.decode();
      if ( remaining.trim() )
      {
        try
        {
          const msg = JSON.parse( remaining.trim() ) as { type: string; text?: string };
          if ( msg.type === 'CHAT' && msg.text )
          {
            markdown += msg.text;
            assistantBubble.innerHTML = this._md!.render( markdown );
          }
        }
        catch {}
      }

      if ( !markdown )
      {
        assistantBubble.textContent = '(no response)';
      }
    }
    catch ( err )
    {
      assistantBubble.textContent = '(error: could not reach Rojo)';
      console.error( err );
    }

    this._sending    = false;
    sendBtn.disabled = false;
    history.scrollTop = history.scrollHeight;
  }

  addContextMenuEntries( dir: ContextMenuDirectory ): void
  {
    dir.add( new ContextMenuReadOnlyEntry( dir, `Rojo Chat — ${this._conversationId.slice( 0, 8 )}` ) );
  }
}

customElements.define( 'rojo-chat-panel', RojoChatPanel );