import { Component, ElementRef, ViewChild } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { CommonModule } from '@angular/common';
import { HttpClientModule } from '@angular/common/http';
import { FormsModule } from '@angular/forms';
import { ChatBotService } from './chatbot.service';
import { MarkdownModule } from 'ngx-markdown';

type ChatPair = { user: string; bot: string | null };

@Component({
  selector: 'app-chatbot',
  standalone: true,
  imports: [CommonModule, HttpClientModule, FormsModule, MarkdownModule],
  templateUrl: './chatbot.html',
  styleUrls: ['./chatbot.scss'],
})
export class Chatbot {
  @ViewChild('chatBox') chatBoxRef!: ElementRef<HTMLDivElement>;

  question: string = '';
  loading: boolean = false;
  messages: ChatPair[] = [];

  constructor(private chatService: ChatBotService) { }

  askQuestion(): void {
    const q = this.question.trim();
    if (!q) return;

    // push one pair: user + empty bot (will show typing dots)
    this.messages.push({ user: q, bot: '' });
    this.question = '';
    this.loading = true;
    this.scrollToBottomSoon();

    this.chatService.generateResponse(q).subscribe({
      next: (response) => {
        const answer = response?.answer ?? 'No response received.';
        this.messages[this.messages.length - 1].bot = answer;
        this.loading = false;
        this.scrollToBottomSoon();
      },
      error: () => {
        this.messages[this.messages.length - 1].bot =
          'Error: Could not get a response from the server.';
        this.loading = false;
        this.scrollToBottomSoon();
      },
    });
  }

  isLast(msg: ChatPair): boolean {
    return this.messages.length > 0 && this.messages[this.messages.length - 1] === msg;
  }

  trackByIndex(index: number): number {
    return index;
  }

  private scrollToBottomSoon() {
    // Wait for DOM update
    setTimeout(() => {
      try {
        const el = this.chatBoxRef?.nativeElement;
        if (el) el.scrollTop = el.scrollHeight;
      } catch { }
    }, 0);
  }
}