import {ChangeDetectionStrategy, Component, inject, OnInit, signal, computed} from '@angular/core';
import {CommonModule} from '@angular/common';
import {MatIconModule} from '@angular/material/icon';
import {RouterModule, Router} from '@angular/router';
import {ReactiveFormsModule, FormBuilder, FormGroup, Validators, FormControl} from '@angular/forms';
import {GroupService} from '../../services/group';
import {UserService} from '../../services/user';
import {User, Group} from '../../models/data.models';
import {debounceTime, distinctUntilChanged, switchMap, of} from 'rxjs';

@Component({
  selector: 'app-create-group',
  standalone: true,
  imports: [CommonModule, MatIconModule, RouterModule, ReactiveFormsModule],
  templateUrl: './create-group.html',
  styleUrl: './create-group.css',
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class CreateGroup implements OnInit {
  private fb = inject(FormBuilder);
  private router = inject(Router);
  private groupService = inject(GroupService);
  private userService = inject(UserService);

  groupForm: FormGroup = this.fb.group({
    name: ['', [Validators.required]],
    description: [''],
    isPrivate: [false],
    avatarUrl: ['https://picsum.photos/seed/avatar/200/200']
  });

  searchControl = new FormControl('');
  searchResults = signal<User[]>([]);
  selectedMembers = signal<User[]>([]);
  
  groupAvatar = computed(() => this.groupForm.get('avatarUrl')?.value);

  isEditing = false;
  editingId: number | null = null;

  ngOnInit() {
    // Ricerca utenti per i membri
    this.searchControl.valueChanges.pipe(
      debounceTime(300),
      distinctUntilChanged(),
      switchMap(query => {
        if (!query || query.length < 2) return of([]);
        return this.userService.searchUsers(query);
      })
    ).subscribe(users => {
      this.searchResults.set(users);
    });

    const navigation = this.router.getCurrentNavigation();
    const state = navigation?.extras.state as { group: Group };
    
    const historyState = typeof window !== 'undefined' ? window.history.state as { group?: Group } : null;
    const group = state?.group || historyState?.group;

    if (group) {
      this.isEditing = true;
      this.editingId = group.id;
      this.groupForm.patchValue({
        name: group.name,
        description: group.description,
        isPrivate: group.isPrivate,
        avatarUrl: group.avatarUrl
      });
      if (group.members) {
        this.selectedMembers.set(group.members);
      }
    }
  }

  addMember(user: User) {
    if (!this.selectedMembers().find(m => m.id === user.id)) {
      this.selectedMembers.update(prev => [...prev, user]);
    }
    this.searchControl.setValue('');
    this.searchResults.set([]);
  }

  removeMember(userId: string) {
    this.selectedMembers.update(prev => prev.filter(m => m.id !== userId));
  }

  onSubmit() {
    if (this.groupForm.valid) {
      const formValue = this.groupForm.value;
      const memberIds = this.selectedMembers().map(m => m.id);

      const payload = {
        name: formValue.name,
        description: formValue.description,
        isPrivate: formValue.isPrivate,
        avatarUrl: formValue.avatarUrl,
        members: memberIds
      };

      if (this.isEditing && this.editingId) {
        this.groupService.updateGroup(this.editingId, payload).subscribe({
          next: () => this.router.navigate(['/groups']),
          error: (err) => console.error('Error updating group:', err)
        });
      } else {
        this.groupService.createGroup(payload).subscribe({
          next: () => this.router.navigate(['/groups']),
          error: (err) => console.error('Error creating group:', err)
        });
      }
    }
  }
}