import { css, html, LitElement } from "lit";
import { customElement, property, state } from "lit/decorators.js";
import { unsafeHTML } from "lit/directives/unsafe-html.js";
import { AgentMessage } from "../types";
import { createRef, ref } from "lit/directives/ref.js";
import { marked, MarkedOptions, Renderer } from "marked";
import DOMPurify from "dompurify";

@customElement("mobile-chat")
export class MobileChat extends LitElement {
  @property({ type: Array })
  messages: AgentMessage[] = [];

  @property({ type: Boolean })
  isThinking = false;

  private scrollContainer = createRef<HTMLDivElement>();

  static styles = css`
    :host {
      display: block;
      height: 100%;
      overflow: hidden;
    }

    .chat-container {
      height: 100%;
      overflow-y: auto;
      padding: 16px;
      display: flex;
      flex-direction: column;
      gap: 16px;
      scroll-behavior: smooth;
      -webkit-overflow-scrolling: touch;
    }

    .message {
      display: flex;
      flex-direction: column;
      max-width: 85%;
      word-wrap: break-word;
    }

    .message.user {
      align-self: flex-end;
      align-items: flex-end;
    }

    .message.assistant {
      align-self: flex-start;
      align-items: flex-start;
    }

    .message-bubble {
      padding: 8px 12px;
      border-radius: 18px;
      font-size: 16px;
      line-height: 1.4;
    }

    .message.user .message-bubble {
      background-color: #007bff;
      color: white;
      border-bottom-right-radius: 6px;
    }

    .message.assistant .message-bubble {
      background-color: #f1f3f4;
      color: #333;
      border-bottom-left-radius: 6px;
    }


    .thinking-message {
      align-self: flex-start;
      align-items: flex-start;
      max-width: 85%;
    }

    .thinking-bubble {
      background-color: #f1f3f4;
      padding: 16px;
      border-radius: 18px;
      border-bottom-left-radius: 6px;
      display: flex;
      align-items: center;
      gap: 8px;
    }

    .thinking-text {
      color: #6c757d;
      font-style: italic;
    }

    .thinking-dots {
      display: flex;
      gap: 3px;
    }

    .thinking-dot {
      width: 6px;
      height: 6px;
      border-radius: 50%;
      background-color: #6c757d;
      animation: thinking 1.4s ease-in-out infinite both;
    }

    .thinking-dot:nth-child(1) { animation-delay: -0.32s; }
    .thinking-dot:nth-child(2) { animation-delay: -0.16s; }
    .thinking-dot:nth-child(3) { animation-delay: 0; }

    @keyframes thinking {
      0%, 80%, 100% {
        transform: scale(0.8);
        opacity: 0.5;
      }
      40% {
        transform: scale(1);
        opacity: 1;
      }
    }

    .empty-state {
      flex: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      color: #6c757d;
      font-style: italic;
      text-align: center;
      padding: 32px;
    }

    /* Markdown content styling for mobile */
    .markdown-content {
      line-height: 1.5;
      word-wrap: break-word;
      overflow-wrap: break-word;
    }

    .markdown-content p {
      margin: 0.3em 0;
    }

    .markdown-content p:first-child {
      margin-top: 0;
    }

    .markdown-content p:last-child {
      margin-bottom: 0;
    }

    .markdown-content h1,
    .markdown-content h2,
    .markdown-content h3,
    .markdown-content h4,
    .markdown-content h5,
    .markdown-content h6 {
      margin: 0.5em 0 0.3em 0;
      font-weight: bold;
    }

    .markdown-content h1 { font-size: 1.2em; }
    .markdown-content h2 { font-size: 1.15em; }
    .markdown-content h3 { font-size: 1.1em; }
    .markdown-content h4,
    .markdown-content h5,
    .markdown-content h6 { font-size: 1.05em; }

    .markdown-content code {
      background-color: rgba(0, 0, 0, 0.08);
      padding: 2px 4px;
      border-radius: 3px;
      font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
      font-size: 0.9em;
    }

    .markdown-content pre {
      background-color: rgba(0, 0, 0, 0.08);
      padding: 8px;
      border-radius: 6px;
      margin: 0.5em 0;
      overflow-x: auto;
      font-size: 0.9em;
    }

    .markdown-content pre code {
      background: none;
      padding: 0;
    }

    .markdown-content ul,
    .markdown-content ol {
      margin: 0.5em 0;
      padding-left: 1.2em;
    }

    .markdown-content li {
      margin: 0.2em 0;
    }

    .markdown-content blockquote {
      border-left: 3px solid rgba(0, 0, 0, 0.2);
      margin: 0.5em 0;
      padding-left: 0.8em;
      font-style: italic;
    }

    .markdown-content a {
      color: inherit;
      text-decoration: underline;
    }

    .markdown-content strong,
    .markdown-content b {
      font-weight: bold;
    }

    .markdown-content em,
    .markdown-content i {
      font-style: italic;
    }
  `;

  updated(changedProperties: Map<string, any>) {
    super.updated(changedProperties);
    if (changedProperties.has('messages') || changedProperties.has('isThinking')) {
      this.scrollToBottom();
    }
  }

  private scrollToBottom() {
    // Use requestAnimationFrame to ensure DOM is updated
    requestAnimationFrame(() => {
      if (this.scrollContainer.value) {
        this.scrollContainer.value.scrollTop = this.scrollContainer.value.scrollHeight;
      }
    });
  }

  private formatTime(timestamp: string): string {
    const date = new Date(timestamp);
    return date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
  }

  private getMessageRole(message: AgentMessage): string {
    if (message.type === 'user') {
      return 'user';
    }
    return 'assistant';
  }

  private getMessageText(message: AgentMessage): string {
    return message.content || '';
  }

  private shouldShowMessage(message: AgentMessage): boolean {
    // Show user, agent, and error messages with content
    return (message.type === 'user' || message.type === 'agent' || message.type === 'error') && 
           message.content && message.content.trim().length > 0;
  }

  private renderMarkdown(markdownContent: string): string {
    try {
      // Create a custom renderer for mobile-optimized rendering
      const renderer = new Renderer();
      
      // Override code renderer to simplify for mobile
      renderer.code = function ({ text, lang }: { text: string; lang?: string }): string {
        const langClass = lang ? ` class="language-${lang}"` : "";
        return `<pre><code${langClass}>${text}</code></pre>`;
      };

      // Set markdown options for mobile
      const markedOptions: MarkedOptions = {
        gfm: true, // GitHub Flavored Markdown
        breaks: true, // Convert newlines to <br>
        async: false,
        renderer: renderer,
      };

      // Parse markdown and sanitize the output HTML
      const htmlOutput = marked.parse(markdownContent, markedOptions) as string;
      return DOMPurify.sanitize(htmlOutput, {
        ALLOWED_TAGS: [
          "p", "br", "strong", "em", "b", "i", "u", "s", "code", "pre",
          "h1", "h2", "h3", "h4", "h5", "h6", "ul", "ol", "li", "blockquote", "a"
        ],
        ALLOWED_ATTR: ["href", "title", "target", "rel", "class"],
        KEEP_CONTENT: true,
      });
    } catch (error) {
      console.error("Error rendering markdown:", error);
      // Fallback to sanitized plain text if markdown parsing fails
      return DOMPurify.sanitize(markdownContent);
    }
  }

  render() {
    const displayMessages = this.messages.filter(msg => this.shouldShowMessage(msg));
    
    return html`
      <div class="chat-container" ${ref(this.scrollContainer)}>
        ${displayMessages.length === 0 ? html`
          <div class="empty-state">
            Start a conversation with Sketch...
          </div>
        ` : displayMessages.map(message => {
          const role = this.getMessageRole(message);
          const text = this.getMessageText(message);
          const timestamp = message.timestamp;
          
          return html`
            <div class="message ${role}">
              <div class="message-bubble">
                ${role === 'assistant' 
                  ? html`<div class="markdown-content">${unsafeHTML(this.renderMarkdown(text))}</div>`
                  : text
                }
              </div>
            </div>
          `;
        })}
        
        ${this.isThinking ? html`
          <div class="thinking-message">
            <div class="thinking-bubble">
              <span class="thinking-text">Sketch is thinking</span>
              <div class="thinking-dots">
                <div class="thinking-dot"></div>
                <div class="thinking-dot"></div>
                <div class="thinking-dot"></div>
              </div>
            </div>
          </div>
        ` : ''}
      </div>
    `;
  }
}