import { ChangeDetectionStrategy, ChangeDetectorRef, Component, computed, effect, inject, signal, OnDestroy } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { ActivatedRoute, Router, RouterLink } from '@angular/router';
import { InstanceService, Provider } from '../../services/instance.service';
import { ThemesService } from '../../services/themes.service';
import { YoutubeApiService } from '../../services/youtube-api.service';
import { Video } from '../../models/video.model';
import { TranslatePipe } from '../../pipes/translate.pipe';
import { LikeButtonComponent } from '../shared/components/like-button/like-button.component';
import { DurationPipe } from '../../app/shared/pipes/duration.pipe';
import { ProviderBadgeComponent } from '../../app/shared/components/provider-badge/provider-badge.component';
import { ChannelIdentityComponent } from '../../app/shared/components/channel-identity/channel-identity.component';
import { classifyVideo, isShortVideo } from '../../app/shared/utils/video-kind';
import { map, of, switchMap, catchError, Observable } from 'rxjs';
import { PagedResult } from '../../services/youtube-api.service';

const TWITCH_THEME_KEYWORDS: Record<string, string[]> = {
  trending: ['just chatting', 'highlights'],
  live: ['live', 'stream'],
  gaming: ['gaming', 'playthrough'],
  sports: ['sports', 'esports'],
  'finance-crypto': ['finance', 'crypto'],
  business: ['business', 'entrepreneur'],
  tech: ['technology', 'coding'],
  science: ['science', 'space'],
  health: ['fitness', 'wellness'],
  music: ['music', 'performance'],
  podcasts: ['podcast', 'talk show'],
  'movies-tv': ['movie review', 'tv discussion'],
  education: ['education', 'tutorial'],
  travel: ['travel vlog'],
  food: ['cooking', 'food'],
  'diy-makers': ['diy', 'maker'],
  autos: ['car build', 'automotive'],
  'nature-animals': ['outdoors', 'wildlife'],
  comedy: ['comedy', 'standup'],
  'art-design': ['art stream', 'drawing'],
  vlogs: ['vlog', 'lifestyle'],
  reviews: ['tech review', 'unboxing'],
  documentary: ['history', 'documentary'],
  'family-kids': ['family', 'kids'],
  news: ['news', 'politics'],
};
@Component({
  selector: 'app-provider-theme',
  standalone: true,
  templateUrl: './provider-theme-page.component.html',
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [CommonModule, FormsModule, RouterLink, TranslatePipe, LikeButtonComponent, DurationPipe, ProviderBadgeComponent, ChannelIdentityComponent]
})
export class ProviderThemePageComponent implements OnDestroy {
  private route = inject(ActivatedRoute);
  private router = inject(Router);
  private instances = inject(InstanceService);
  themes = inject(ThemesService);
  private api = inject(YoutubeApiService);
  private cdr = inject(ChangeDetectorRef);

  provider = signal<Provider>('youtube');
  theme = signal<string>('trending');

  // Guard to ignore stale async responses
  private version = 0;

  // Filters state
  sort = signal<'recent' | 'viewed' | 'longest'>('recent');
  duration = signal<'any' | 'short' | 'medium' | 'long'>('any');
  type = signal<'any' | 'video' | 'live' | 'recorded' | 'short'>('any');
  language = signal<'any' | 'en' | 'fr'>('any');
  date = signal<'any' | 'day' | 'week' | 'month' | 'year'>('any');

  // Data state
  allVideos = signal<Video[]>([]);
  nextCursor = signal<string | null>(null);
  loading = signal(false);
  error = signal<string | null>(null);

  // Derived state for the UI
  providersList = computed(() => this.instances.providers());
  videos = computed(() => this.applyFilters(this.allVideos()));

  constructor() {
    this.route.paramMap.subscribe(pm => {
      const provider = (pm.get('provider') as Provider) || 'youtube';
      const theme = pm.get('theme') || 'trending';
      this.provider.set(provider);
      this.theme.set(theme);
      this.instances.setSelectedProvider(provider);
      this.resetAndLoad();
    });

    // Re-apply filters on change
    effect(() => {
      this.sort();
      this.duration();
      this.type();
      this.language();
      this.date();
      this.cdr.markForCheck();
    });
  }

  private resetAndLoad() {
    this.version++;
    this.allVideos.set([]);
    this.nextCursor.set(null);
    this.error.set(null);
    this.loadMore();
  }

  private buildQuery(provider: Provider): string {
    const slug = this.theme();
    const baseTokens = this.themes.tokensFor(slug);

    if (provider === 'twitch') {
      const twitchTokens = TWITCH_THEME_KEYWORDS[slug] || [];
      const merged = [...new Set([...twitchTokens, ...baseTokens])];
      const value = merged.join(' ').trim();
      if (value) return value;
      if (twitchTokens.length) return twitchTokens.join(' ');
      return slug.replace(/-/g, ' ');
    }

    const value = baseTokens.join(' ').trim();
    return value || slug.replace(/-/g, ' ');
  }

  loadMore() {
    if (this.loading()) return;

    const readiness = this.instances.getProviderReadiness(this.provider());
    if (!readiness.ready) {
      this.error.set(readiness.reason || 'Provider not ready');
      return;
    }

    this.loading.set(true);
    this.error.set(null);
    const snapshotVersion = this.version;
    const provider = this.provider();
    const query = this.buildQuery(provider);
    const cursor = this.nextCursor();
    const themeSlug = this.theme();
    const isLiveTheme = themeSlug === 'live';

    let apiCall: Observable<PagedResult<Video>>;
    if (provider === 'twitch') {
      if (isLiveTheme) {
        // Thème live : top streams (jamais vide quand Twitch est configuré).
        apiCall = this.api.getTwitchTopStreamsPage(cursor || undefined);
      } else {
        // Thème classique : VODs puis clips, puis top streams en filet de sécurité.
        apiCall = this.api.searchTwitchVodsPage(query, cursor || undefined).pipe(
          switchMap((res) => {
            if ((res?.items?.length || 0) >= 8) {
              return of(res);
            }
            return this.api.searchTwitchClipsPage(query, cursor || undefined).pipe(
              map((clips) => ({ ...clips, items: [...(res?.items || []), ...(clips.items || [])] })),
              switchMap((merged: any) => {
                if (((merged?.items?.length) || 0) >= 4) return of(merged);
                return this.api.getTwitchTopStreamsPage(cursor || undefined).pipe(
                  map((top) => {
                    const seen = new Set((merged?.items || []).map((v: Video) => v.videoId));
                    const extra = (top?.items || []).filter((v: Video) => !seen.has(v.videoId));
                    return { items: [...(merged?.items || []), ...extra], nextCursor: top?.nextCursor || merged?.nextCursor || null };
                  }),
                  // En cas d'échec du fallback, garder au moins VODs+clips.
                  catchError(() => of(merged))
                );
              })
            );
          })
        );
      }
    } else {
      apiCall = query
        ? this.api.searchVideosPage(query, cursor, provider)
        : this.api.getTrendingPage(cursor, provider);
    }

    apiCall.subscribe({
      next: (res: PagedResult<Video>) => {
        if (snapshotVersion !== this.version) return;

        const existingIds = new Set(this.allVideos().map((v: Video) => v.videoId));
        const newVideos = (res.items || []).filter((v: Video) => !existingIds.has(v.videoId));

        this.allVideos.update(current => [...current, ...newVideos]);
        this.nextCursor.set(res.nextCursor || null);
        this.loading.set(false);
        this.cdr.markForCheck();
      },
      error: (e) => {
        if (snapshotVersion !== this.version) return;
        this.error.set(e.message || 'Failed to load videos');
        this.loading.set(false);
        this.cdr.markForCheck();
      }
    });
  }

  private applyFilters(list: Video[]): Video[] {
    let arr = [...list];
    const durationFilter = this.duration();
    if (durationFilter !== 'any') {
      arr = arr.filter(v => {
        const dur = v.duration || 0;
        if (durationFilter === 'short') return dur > 0 && dur < 240; // < 4 min
        if (durationFilter === 'medium') return dur >= 240 && dur < 1200; // 4-20 min
        if (durationFilter === 'long') return dur >= 1200; // > 20 min
        return true;
      });
    }

    const typeFilter = this.type();
    if (typeFilter !== 'any') {
      const p = this.provider();
      arr = arr.filter(v => {
        const withProvider = { ...v, provider: (v.provider as string) || p };
        if (typeFilter === 'video') return !isShortVideo(withProvider) && (v.type === 'video' || v.type === 'recorded');
        if (typeFilter === 'live') return v.type === 'live' || v.type === 'channel' || v.type === 'stream' || (v as any).isLive === true;
        if (typeFilter === 'recorded') return v.type === 'recorded' || (v.type === 'video' && !isShortVideo(withProvider));
        // Shorts : classification partagée (durée 0/absente ⇒ jamais un Short).
        if (typeFilter === 'short') return isShortVideo(withProvider);
        return true;
      });
    }

    const langFilter = this.language();
    if (langFilter !== 'any') {
      // Simple heuristic, can be improved
      const isFr = (s: string) => /[éèêàùçîïô]/.test(s) || /\b(le|la|les|un|une)\b/i.test(s);
      const isEn = (s: string) => /\b(the|a|an|and|for)\b/i.test(s);
      arr = arr.filter(v => {
        const text = `${v.title} ${v.uploaderName}`.toLowerCase();
        if (langFilter === 'fr') return isFr(text);
        if (langFilter === 'en') return isEn(text) && !isFr(text);
        return true;
      });
    }

    const dateFilter = this.date();
    if (dateFilter !== 'any') {
      const now = Date.now();
      const cutoff = {
        day: now - 24 * 3600 * 1000,
        week: now - 7 * 24 * 3600 * 1000,
        month: now - 30 * 24 * 3600 * 1000,
        year: now - 365 * 24 * 3600 * 1000,
      }[dateFilter] || 0;
      if (cutoff > 0) {
        arr = arr.filter(v => (v.uploaded || 0) >= cutoff);
      }
    }

    const sortOrder = this.sort();
    if (sortOrder === 'recent') arr.sort((a, b) => (b.uploaded || 0) - (a.uploaded || 0));
    if (sortOrder === 'viewed') arr.sort((a, b) => (b.views || 0) - (a.views || 0));
    if (sortOrder === 'longest') arr.sort((a, b) => (b.duration || 0) - (a.duration || 0));

    return arr;
  }

  changeProvider(p: any) {
    const provider = String(p) as Provider;
    this.instances.setSelectedProvider(provider);
    this.router.navigate(['/p', provider, 't', this.theme()]);
  }

  onSortChange(val: any) { this.sort.set(val as any); }
  onDurationChange(val: any) { this.duration.set(val as any); }
  onTypeChange(val: any) { this.type.set(val as any); }

  // Raccourci Vidéos / Shorts synchronisé avec le filtre "type" existant.
  contentFilter = computed<'all' | 'videos' | 'shorts'>(() => {
    const t = this.type();
    if (t === 'short') return 'shorts';
    if (t === 'video') return 'videos';
    return 'all';
  });
  setContentFilter(v: 'all' | 'videos' | 'shorts'): void {
    this.type.set(v === 'shorts' ? 'short' : v === 'videos' ? 'video' : 'any');
  }

  kindOf(v: Video): string {
    const p = this.provider();
    return classifyVideo({ ...v, provider: (v.provider as string) || p });
  }

  shortsCount(): number {
    const p = this.provider();
    return this.allVideos().filter(v => isShortVideo({ ...v, provider: (v.provider as string) || p })).length;
  }
  onLanguageChange(val: any) { this.language.set(val as any); }
  onDateChange(val: any) { this.date.set(val as any); }

  retry() {
    this.error.set(null);
    this.loadMore();
  }

  watchQueryParams(v: Video): Record<string, any> | null {
    const p = this.provider();
    const qp: any = { p };
    if (p === 'odysee' && v.url?.startsWith('https://odysee.com/')) {
      let slug = v.url.substring('https://odysee.com/'.length);
      if (slug.startsWith('/')) slug = slug.slice(1);
      qp.slug = slug;
    }
    if (p === 'twitch' && v.type === 'channel') qp.channel = v.videoId;
    return qp;
  }

  trackByVideo(_idx: number, v: Video) { return v.videoId || v.url; }

  ngOnDestroy(): void {
    this.version++; // Invalidate any pending requests
  }
}