import { Component, inject, signal, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { Router, RouterLink } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { NzTableModule, NzTableFilterList } from 'ng-zorro-antd/table';
import { NzButtonModule } from 'ng-zorro-antd/button';
import { NzInputModule } from 'ng-zorro-antd/input';
import { NzTagModule } from 'ng-zorro-antd/tag';
import { NzIconModule } from 'ng-zorro-antd/icon';
import { NzEmptyModule } from 'ng-zorro-antd/empty';
import { NzSpinModule } from 'ng-zorro-antd/spin';
import { NzToolTipModule } from 'ng-zorro-antd/tooltip';
import { NzPaginationModule } from 'ng-zorro-antd/pagination';
import { NzDatePickerModule } from 'ng-zorro-antd/date-picker';
import { NzDropDownModule } from 'ng-zorro-antd/dropdown';
import { ApiService } from '../../../core/services/api.service';
import { AuthService } from '../../../core/services/auth.service';
import { Message, MessageListParams } from '../../../core/models';
import { RelativeTimePipe } from '../../../shared/pipes/relative-time.pipe';

@Component({
  selector: 'app-message-list',
  standalone: true,
  imports: [
    CommonModule,
    FormsModule,
    RouterLink,
    NzTableModule,
    NzButtonModule,
    NzInputModule,
    NzTagModule,
    NzIconModule,
    NzEmptyModule,
    NzSpinModule,
    NzToolTipModule,
    NzPaginationModule,
    NzDatePickerModule,
    NzDropDownModule,
    RelativeTimePipe,
  ],
  templateUrl: './message-list.component.html',
  styleUrl: './message-list.component.scss'
})
export class MessageListComponent implements OnInit {
  private apiService = inject(ApiService);
  private authService = inject(AuthService);
  private router = inject(Router);

  messages = signal<Message[]>([]);
  loading = signal(false);

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

  // Filters
  searchText = '';
  appliedSearchText = '';
  priorityFilter: string[] = [];
  channelFilter: string[] = [];
  senderFilter: string[] = [];
  dateRange: [Date, Date] | null = null;
  dateFilterVisible = false;

  // Filter options
  priorityFilters: NzTableFilterList = [
    { text: 'Low', value: '0' },
    { text: 'Normal', value: '1' },
    { text: 'High', value: '2' },
  ];
  channelFilters = signal<NzTableFilterList>([]);
  senderFilters = signal<NzTableFilterList>([]);

  ngOnInit(): void {
    this.loadChannels();
    this.loadSenders();
    this.loadMessages();
  }

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

    this.apiService.getChannels(userId, 'all_any').subscribe({
      next: (response) => {
        this.channelFilters.set(
          response.channels.map(ch => ({
            text: ch.display_name,
            value: ch.channel_id,
          }))
        );
      }
    });
  }

  loadSenders(): void {
    this.apiService.getSenderNames().subscribe({
      next: (response) => {
        this.senderFilters.set(
          response.sender_names.map(s => ({
            text: s.name,
            value: s.name,
          }))
        );
      }
    });
  }

  loadMessages(): void {
    this.loading.set(true);

    const params: MessageListParams = {
      page_size: this.pageSize,
      trimmed: true,
    };

    if (this.appliedSearchText) {
      params.search = this.appliedSearchText;
    }
    if (this.priorityFilter.length > 0) {
      params.priority = this.priorityFilter.map(p => parseInt(p, 10));
    }
    if (this.channelFilter.length > 0) {
      params.channel_id = this.channelFilter;
    }
    if (this.senderFilter.length > 0) {
      params.sender = this.senderFilter;
    }
    if (this.dateRange) {
      params.after = this.dateRange[0].toISOString();
      params.before = this.dateRange[1].toISOString();
    }

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

    this.apiService.getMessages(params).subscribe({
      next: (response) => {
        this.messages.set(response.messages);
        this.totalCount.set(response.total_count);
        this.loading.set(false);
      },
      error: () => {
        this.loading.set(false);
      }
    });
  }

  applyFilters(): void {
    this.appliedSearchText = this.searchText;
    this.currentPage.set(1);
    this.loadMessages();
  }

  onPriorityFilterChange(filters: string[] | null): void {
    this.priorityFilter = filters ?? [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  onChannelFilterChange(filters: string[] | null): void {
    this.channelFilter = filters ?? [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  onSenderFilterChange(filters: string[] | null): void {
    this.senderFilter = filters ?? [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearSearch(): void {
    this.searchText = '';
    this.appliedSearchText = '';
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearChannelFilter(): void {
    this.channelFilter = [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  removeChannelFilter(channel: string): void {
    this.channelFilter = this.channelFilter.filter(c => c !== channel);
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearSenderFilter(): void {
    this.senderFilter = [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  removeSenderFilter(sender: string): void {
    this.senderFilter = this.senderFilter.filter(s => s !== sender);
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearPriorityFilter(): void {
    this.priorityFilter = [];
    this.currentPage.set(1);
    this.loadMessages();
  }

  onDateRangeChange(dates: [Date, Date] | null): void {
    this.dateRange = dates;
    if (dates) {
      this.dateFilterVisible = false;
    }
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearDateRange(): void {
    this.dateRange = null;
    this.currentPage.set(1);
    this.loadMessages();
  }

  clearAllFilters(): void {
    this.searchText = '';
    this.appliedSearchText = '';
    this.channelFilter = [];
    this.senderFilter = [];
    this.priorityFilter = [];
    this.dateRange = null;
    this.currentPage.set(1);
    this.loadMessages();
  }

  hasActiveFilters(): boolean {
    return !!this.appliedSearchText || this.channelFilter.length > 0 || this.senderFilter.length > 0 || this.priorityFilter.length > 0 || !!this.dateRange;
  }

  getChannelDisplayName(channelId: string): string {
    const filters = this.channelFilters();
    const channel = filters.find(f => f.value === channelId);
    return channel?.text?.toString() ?? channelId;
  }

  getDateRangeDisplay(): string {
    if (!this.dateRange) return '';
    const format = (d: Date) => d.toLocaleDateString();
    return `${format(this.dateRange[0])} - ${format(this.dateRange[1])}`;
  }

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

  viewMessage(message: Message): void {
    this.router.navigate(['/messages', message.message_id]);
  }

  getPriorityLabel(priority: number): string {
    switch (priority) {
      case 0: return 'Low';
      case 1: return 'Normal';
      case 2: return 'High';
      default: return 'Unknown';
    }
  }

  getPriorityColor(priority: number): string {
    switch (priority) {
      case 0: return 'default';
      case 1: return 'blue';
      case 2: return 'red';
      default: return 'default';
    }
  }
}