import { Component, inject, signal, OnInit } from '@angular/core';
import { CommonModule, DatePipe } from '@angular/common';
import { Router, RouterLink } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { NzTableModule } from 'ng-zorro-antd/table';
import { NzButtonModule } from 'ng-zorro-antd/button';
import { NzIconModule } from 'ng-zorro-antd/icon';
import { NzTagModule } from 'ng-zorro-antd/tag';
import { NzEmptyModule } from 'ng-zorro-antd/empty';
import { NzTabsModule } from 'ng-zorro-antd/tabs';
import { NzPopconfirmModule } from 'ng-zorro-antd/popconfirm';
import { NzModalModule } from 'ng-zorro-antd/modal';
import { NzFormModule } from 'ng-zorro-antd/form';
import { NzInputModule } from 'ng-zorro-antd/input';
import { NzToolTipModule } from 'ng-zorro-antd/tooltip';
import { NzAlertModule } from 'ng-zorro-antd/alert';
import { NzPaginationModule } from 'ng-zorro-antd/pagination';
import { ApiService } from '../../../core/services/api.service';
import { AuthService } from '../../../core/services/auth.service';
import { NotificationService } from '../../../core/services/notification.service';
import { SettingsService } from '../../../core/services/settings.service';
import { UserCacheService, ResolvedUser } from '../../../core/services/user-cache.service';
import { Subscription, SubscriptionFilter } from '../../../core/models';
import { RelativeTimePipe } from '../../../shared/pipes/relative-time.pipe';

type SubscriptionTab = 'all' | 'own' | 'deactivated' | 'external' | 'incoming';

interface TabConfig {
  filter: SubscriptionFilter;
}

const TAB_CONFIGS: Record<SubscriptionTab, TabConfig> = {
  all: { filter: {} },
  own: { filter: { direction: 'outgoing', confirmation: 'confirmed', external: 'false' } },
  deactivated: { filter: { direction: 'outgoing', confirmation: 'unconfirmed', external: 'false' } },
  external: { filter: { direction: 'outgoing', confirmation: 'all', external: 'true' } },
  incoming: { filter: { direction: 'incoming', confirmation: 'all', external: 'true' } },
};

@Component({
  selector: 'app-subscription-list',
  standalone: true,
  imports: [
    CommonModule,
    DatePipe,
    FormsModule,
    RouterLink,
    NzTableModule,
    NzButtonModule,
    NzIconModule,
    NzTagModule,
    NzEmptyModule,
    NzTabsModule,
    NzPopconfirmModule,
    NzModalModule,
    NzFormModule,
    NzInputModule,
    NzToolTipModule,
    NzAlertModule,
    NzPaginationModule,
    RelativeTimePipe,
  ],
  templateUrl: './subscription-list.component.html',
  styleUrl: './subscription-list.component.scss'
})
export class SubscriptionListComponent implements OnInit {
  private router = inject(Router);
  private apiService = inject(ApiService);
  private authService = inject(AuthService);
  private notification = inject(NotificationService);
  private settingsService = inject(SettingsService);
  private userCacheService = inject(UserCacheService);

  expertMode = this.settingsService.expertMode;

  subscriptions = signal<Subscription[]>([]);
  userNames = signal<Map<string, ResolvedUser>>(new Map());
  loading = signal(false);
  activeTab: SubscriptionTab = 'all';

  // Pagination
  currentPage = signal(1);
  pageSize = 50;
  totalCount = signal(0);

  // Create subscription modal
  showCreateModal = signal(false);
  newChannelOwner = '';
  newChannelName = '';
  creating = signal(false);

  ngOnInit(): void {
    this.loadSubscriptions();
  }

  loadSubscriptions(): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.loading.set(true);

    const filter: SubscriptionFilter = {
      ...TAB_CONFIGS[this.activeTab].filter,
      page_size: this.pageSize,
    };

    // Use page-index based pagination: $1 = page 1, $2 = page 2, etc.
    const page = this.currentPage();
    if (page > 1) {
      filter.next_page_token = `$${page}`;
    }

    this.apiService.getSubscriptions(userId, filter).subscribe({
      next: (response) => {
        this.subscriptions.set(response.subscriptions);
        this.totalCount.set(response.total_count);
        this.loading.set(false);
        this.resolveUserNames(response.subscriptions);
      },
      error: () => {
        this.loading.set(false);
      }
    });
  }

  private resolveUserNames(subscriptions: Subscription[]): void {
    const userIds = new Set<string>();
    for (const sub of subscriptions) {
      userIds.add(sub.subscriber_user_id);
      userIds.add(sub.channel_owner_user_id);
    }
    for (const id of userIds) {
      this.userCacheService.resolveUser(id).subscribe(resolved => {
        this.userNames.update(map => new Map(map).set(id, resolved));
      });
    }
  }

  getUserDisplayName(userId: string): string {
    const resolved = this.userNames().get(userId);
    return resolved?.displayName || userId;
  }

  onTabChange(index: number): void {
    const tabs: SubscriptionTab[] = ['all', 'own', 'deactivated', 'external', 'incoming'];
    this.activeTab = tabs[index];
    this.currentPage.set(1);
    this.loadSubscriptions();
  }

  goToPage(page: number): void {
    this.currentPage.set(page);
    this.loadSubscriptions();
  }

  isOutgoing(sub: Subscription): boolean {
    const userId = this.authService.getUserId();
    return sub.subscriber_user_id === userId;
  }

  isOwner(sub: Subscription): boolean {
    const userId = this.authService.getUserId();
    return sub.channel_owner_user_id === userId;
  }

  isOwnSubscription(sub: Subscription): boolean {
    const userId = this.authService.getUserId();
    return sub.subscriber_user_id === userId && sub.channel_owner_user_id === userId;
  }

  viewSubscription(sub: Subscription): void {
    this.router.navigate(['/subscriptions', sub.subscription_id]);
  }

  // Actions
  acceptSubscription(sub: Subscription): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.apiService.confirmSubscription(userId, sub.subscription_id, { confirmed: true }).subscribe({
      next: () => {
        this.notification.success('Subscription accepted');
        this.loadSubscriptions();
      }
    });
  }

  denySubscription(sub: Subscription): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.apiService.deleteSubscription(userId, sub.subscription_id).subscribe({
      next: () => {
        this.notification.success('Subscription denied');
        this.loadSubscriptions();
      }
    });
  }

  revokeSubscription(sub: Subscription): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.apiService.deleteSubscription(userId, sub.subscription_id).subscribe({
      next: () => {
        this.notification.success('Subscription revoked');
        this.loadSubscriptions();
      }
    });
  }

  activateSubscription(sub: Subscription): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.apiService.confirmSubscription(userId, sub.subscription_id, { active: true }).subscribe({
      next: () => {
        this.notification.success('Subscription activated');
        this.loadSubscriptions();
      }
    });
  }

  deactivateSubscription(sub: Subscription): void {
    const userId = this.authService.getUserId();
    if (!userId) return;

    this.apiService.confirmSubscription(userId, sub.subscription_id, { active: false }).subscribe({
      next: () => {
        this.notification.success('Subscription deactivated');
        this.loadSubscriptions();
      }
    });
  }

  // Create subscription
  openCreateModal(): void {
    this.newChannelOwner = '';
    this.newChannelName = '';
    this.showCreateModal.set(true);
  }

  closeCreateModal(): void {
    this.showCreateModal.set(false);
  }

  createSubscription(): void {
    const userId = this.authService.getUserId();
    if (!userId || !this.newChannelOwner.trim() || !this.newChannelName.trim()) return;

    this.creating.set(true);
    this.apiService.createSubscription(userId, {
      channel_owner_user_id: this.newChannelOwner.trim(),
      channel_internal_name: this.newChannelName.trim()
    }).subscribe({
      next: () => {
        this.notification.success('Subscription request sent');
        this.closeCreateModal();
        this.creating.set(false);
        this.loadSubscriptions();
      },
      error: () => {
        this.creating.set(false);
      }
    });
  }

  getConfirmationInfo(sub: Subscription): { label: string; color: string } {
    if (sub.confirmed) {
      return { label: 'Confirmed', color: 'green' };
    }
    return { label: 'Pending', color: 'orange' };
  }

  getActiveInfo(sub: Subscription): { label: string; color: string } {
    if (sub.active) {
      return { label: 'Active', color: 'green' };
    }
    return { label: 'Inactive', color: 'default' };
  }

  getTypeLabel(sub: Subscription): { label: string; color: string } {
    const userId = this.authService.getUserId();
    if (sub.subscriber_user_id === sub.channel_owner_user_id) {
      return { label: 'Own', color: 'green' };
    }
    if (sub.subscriber_user_id === userId) {
      return { label: 'External', color: 'blue' };
    }
    return { label: 'Incoming', color: 'purple' };
  }

  getTabDescription(): string | null {
    switch (this.activeTab) {
      case 'own':
        return 'Active subscriptions to your channels.';
      case 'deactivated':
        return 'Deactivated subscriptions to your channels. These can be reactivated by you.';
      case 'external':
        return 'Your subscriptions to channels owned by other users.';
      case 'incoming':
        return 'Subscription from other users to your channels.';
      default:
        return null;
    }
  }
}