import {
  AfterViewChecked,
  ChangeDetectorRef,
  Component,
  ElementRef,
  EventEmitter,
  Input,
  OnDestroy,
  OnInit,
  Output,
  ViewChild,
} from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { HttpClient } from '@angular/common/http';
import { catchError } from 'rxjs/operators';
import { Subscription, of } from 'rxjs';
import { PIPELINES, PipelineDef, PipelineRoute } from '../../pipelines/pipeline-registry';
import {
  AssistantMessage,
  AssistantService,
  AssistantSuggestion,
  Conversation,
} from '../../services/assistant.service';
import { MarkdownService } from '../../services/markdown.service';
import { SafeHtml } from '@angular/platform-browser';

interface RecentResult {
  id: string;
  type: 'video' | 'image';
  url: string;
  title: string;
  pipelineId: string;
  cost?: number;
  duration?: string;
  created_at?: string;
}

interface MonitorSummary {
  authorCount: number;
  workCount: number;
  newWorkCount: number;
  lastCheckedAt?: string;
  hasDailyReport?: boolean;
  dailyReportDate?: string;
}

/**
 * 首屏组件
 *
 * 双视图：
 *   - chatMode=false：Hero / Pipeline 卡带 / 最近作品（默认）
 *   - chatMode=true ：占据主区的全宽 AI 对话页（左 rail = 会话列表）
 *
 * 与浮窗共享同一个 AssistantService。
 */
@Component({
  selector: 'app-home',
  standalone: true,
  imports: [CommonModule, FormsModule],
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.css'],
})
export class HomeComponent implements OnInit, OnDestroy, AfterViewChecked {
  @Input() monitorSummary: MonitorSummary | null = null;
  @Output() navigate = new EventEmitter<{ tab: string; payload?: any }>();
  @Output() suggestionPick = new EventEmitter<AssistantSuggestion>();
  /** chatMode 变化（父组件用来隐藏 task-pill / FAB） */
  @Output() inlineChatChange = new EventEmitter<boolean>();

  @ViewChild('chatList') chatListEl?: ElementRef<HTMLElement>;
  @ViewChild('chatInput') chatInputEl?: ElementRef<HTMLTextAreaElement>;

  // ===== Hero =====
  prompt = '';

  readonly featuredPipelines: PipelineDef[] = PIPELINES.filter((p) =>
    ['topic_to_video', 'image_to_video', 'digital_human', 'action_transfer'].includes(p.id),
  );
  readonly allPipelines = PIPELINES;

  recentResults: RecentResult[] = [];
  recentLoading = true;

  // ===== Chat 视图 =====
  chatMode = false;
  chatDraft = '';
  messages: AssistantMessage[] = [];
  conversations: Conversation[] = [];
  activeId: string | null = null;
  loading = false;

  private subs = new Subscription();
  private shouldScroll = false;

  constructor(
    private http: HttpClient,
    private assistant: AssistantService,
    private cdr: ChangeDetectorRef,
    private md: MarkdownService,
  ) {}

  /** 渲染助手消息为安全 HTML */
  renderMd(text: string): SafeHtml {
    return this.md.render(text);
  }

  ngOnInit(): void {
    this.loadRecentResults();
    // 注意：所有订阅回调都显式 markForCheck + detectChanges，
    // 因为 fetch 路径下回调可能跳出 zone，仅靠 zone 自动 CD 不可靠。
    this.subs.add(this.assistant.activeMessages$.subscribe((list) => {
      this.messages = list;
      this.shouldScroll = true;
      this.cdr.detectChanges();
    }));
    this.subs.add(this.assistant.conversations$.subscribe((c) => {
      this.conversations = c;
      this.cdr.detectChanges();
    }));
    this.subs.add(this.assistant.activeId$.subscribe((id) => {
      this.activeId = id;
      this.cdr.detectChanges();
    }));
    this.subs.add(this.assistant.loading$.subscribe((v) => {
      this.loading = v;
      this.cdr.detectChanges();
    }));
  }

  ngOnDestroy(): void {
    this.subs.unsubscribe();
    // 离开首屏组件时务必关闭内联模式，避免别的页面 FAB 还被隐藏
    this.assistant.setInlineActive(false);
    this.inlineChatChange.emit(false);
  }

  ngAfterViewChecked(): void {
    if (this.shouldScroll && this.chatMode && this.chatListEl) {
      const el = this.chatListEl.nativeElement;
      el.scrollTop = el.scrollHeight;
      this.shouldScroll = false;
    }
  }

  // ===== Hero 提交：开启 chatMode 并发起对话 =====
  submitPrompt(): void {
    const text = this.prompt.trim();
    if (!text) return;
    // 每次首屏发起 → 在当前激活会话延续，或没有时由 service 自动建新
    this.assistant.send(text);
    this.prompt = '';
    this.openChat();
  }

  // ===== Chat 视图 =====
  openChat(): void {
    this.chatMode = true;
    this.assistant.setInlineActive(true);
    this.inlineChatChange.emit(true);
    this.shouldScroll = true;
    setTimeout(() => this.chatInputEl?.nativeElement?.focus(), 80);
  }

  backToHero(): void {
    this.chatMode = false;
    this.assistant.setInlineActive(false);
    this.inlineChatChange.emit(false);
  }

  chatSubmit(): void {
    const t = this.chatDraft.trim();
    if (!t || this.loading) return;
    this.assistant.send(t);
    this.chatDraft = '';
  }

  onChatKey(ev: KeyboardEvent): void {
    if (ev.key === 'Enter' && !ev.shiftKey && !ev.altKey) {
      ev.preventDefault();
      this.chatSubmit();
    }
  }

  newChat(): void {
    this.assistant.newConversation();
    setTimeout(() => this.chatInputEl?.nativeElement?.focus(), 60);
  }

  pickConv(id: string): void {
    this.assistant.switchTo(id);
    this.shouldScroll = true;
  }

  deleteConv(id: string, ev: MouseEvent): void {
    ev.stopPropagation();
    if (confirm('删除这条会话？')) this.assistant.deleteConversation(id);
  }

  emitSuggestion(s: AssistantSuggestion): void {
    this.suggestionPick.emit(s);
  }

  // ===== Pipeline 卡带 =====
  enterPipeline(route: PipelineRoute): void {
    this.navigate.emit({ tab: route });
  }

  // ===== 最近作品 =====
  private loadRecentResults(): void {
    this.recentLoading = true;
    this.http
      .get<RecentResult[]>('/backend/api/results')
      .pipe(
        catchError(() => of([] as RecentResult[])),
      )
      .subscribe((results) => {
        this.recentResults = (results || [])
          .filter((r) => r.url)
          .sort((a, b) => (b.created_at || '').localeCompare(a.created_at || ''))
          .slice(0, 8);
        this.recentLoading = false;
      });
  }

  openResult(r: RecentResult): void {
    this.navigate.emit({ tab: 'results', payload: { resultId: r.id } });
  }

  // ===== 辅助 =====
  pipelineShortLabel(pipelineId: string): string {
    const map: Record<string, string> = {
      topic_to_video: '主题',
      image_to_video: '图生',
      digital_human: '数字人',
      action_transfer: '动作',
      asset_remix: '素材',
      video_generation: '视频',
    };
    return map[pipelineId] || pipelineId;
  }

  trackByPipeline = (_: number, p: PipelineDef) => p.id;
  trackByResult = (_: number, r: RecentResult) => r.id;
  trackByMsg = (_: number, m: AssistantMessage) => m.id;
  trackByConv = (_: number, c: Conversation) => c.id;
  trackBySuggest = (_: number, s: AssistantSuggestion) => s.tab + s.label;

  formatTime(ts: number): string {
    if (!ts) return '';
    const d = new Date(ts);
    const now = new Date();
    const isToday = d.toDateString() === now.toDateString();
    const yest = new Date(now.getTime() - 86400000);
    const isYest = d.toDateString() === yest.toDateString();
    const hh = `${d.getHours()}`.padStart(2, '0');
    const mm = `${d.getMinutes()}`.padStart(2, '0');
    if (isToday) return `今天 ${hh}:${mm}`;
    if (isYest) return `昨天 ${hh}:${mm}`;
    return `${d.getMonth() + 1}/${d.getDate()} ${hh}:${mm}`;
  }

  convPreview(c: Conversation): string {
    const lastMsg = [...c.messages].reverse().find((m) => !m.pending && m.content);
    if (!lastMsg) return '（空对话）';
    const txt = lastMsg.content.replace(/\s+/g, ' ').trim();
    return txt.length > 40 ? txt.slice(0, 40) + '…' : txt;
  }
}