import { Component, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormBuilder, FormGroup, Validators, ReactiveFormsModule } from '@angular/forms';
import { ActivatedRoute, Router } from '@angular/router';
import { InputsModule } from '@progress/kendo-angular-inputs';
import { LabelModule } from '@progress/kendo-angular-label';
import { ButtonsModule } from '@progress/kendo-angular-buttons';
import { IndicatorsModule } from '@progress/kendo-angular-indicators';
import { AuthService } from '../../shared/services/auth.service';
import {
  passwordStrengthValidator,
  passwordMatchValidator,
} from '../account/validators/password.validators';

type Step = 'loading' | 'invalid' | 'form';

@Component({
  selector: 'app-accept-invitation',
  standalone: true,
  imports: [
    CommonModule, ReactiveFormsModule,
    InputsModule, LabelModule, ButtonsModule, IndicatorsModule,
  ],
  template: `
<div class="min-h-screen flex items-center justify-center p-4">
  <div class="w-full max-w-md rounded-lg border border-gray-200 bg-white p-6 shadow-sm">

    <h1 class="text-xl font-semibold mb-1">River Of Life Christian Church</h1>

    <!-- Validating the link -->
    <ng-container *ngIf="step === 'loading'">
      <div class="text-center py-6">
        <kendo-loader></kendo-loader>
        <p class="mt-2 text-gray-600">Checking your invitation…</p>
      </div>
    </ng-container>

    <!-- Invalid / expired link -->
    <ng-container *ngIf="step === 'invalid'">
      <p class="text-base font-medium mb-2">This invitation can't be used</p>
      <p class="text-gray-600 mb-4">{{ invalidMessage }}</p>
      <button kendoButton themeColor="primary" (click)="goToLogin()">Go to sign in</button>
    </ng-container>

    <!-- Set password form -->
    <ng-container *ngIf="step === 'form'">
      <p class="text-gray-600 mb-4">
        Welcome<span *ngIf="memberName">, <strong>{{ memberName }}</strong></span>. Set a password to
        finish creating your account and sign in.
      </p>

      <form [formGroup]="form" class="k-form k-form-vertical" (ngSubmit)="onSubmit()">
        <div class="grid grid-cols-1 gap-y-3">

          <kendo-formfield>
            <kendo-label text="New Password *"></kendo-label>
            <kendo-textbox formControlName="newPassword" type="password" [clearButton]="false"></kendo-textbox>
            <kendo-formerror *ngIf="form.get('newPassword')?.errors?.['required']">Required.</kendo-formerror>
            <kendo-formerror *ngIf="form.get('newPassword')?.errors?.['passwordStrength']">
              Must be at least 8 characters with an uppercase letter, a lowercase letter,
              a digit, and a special character.
            </kendo-formerror>
          </kendo-formfield>

          <kendo-formfield>
            <kendo-label text="Confirm Password *"></kendo-label>
            <kendo-textbox formControlName="confirmPassword" type="password" [clearButton]="false"></kendo-textbox>
            <kendo-formerror *ngIf="form.get('confirmPassword')?.errors?.['required']">Required.</kendo-formerror>
            <kendo-formerror *ngIf="form.errors?.['mismatch'] && form.get('confirmPassword')?.touched">
              Passwords do not match.
            </kendo-formerror>
          </kendo-formfield>

          <p *ngIf="errorMessage" class="k-color-error">{{ errorMessage }}</p>

          <div class="mt-2">
            <button kendoButton themeColor="primary" type="submit" [disabled]="form.invalid || submitting">
              <span *ngIf="submitting">…</span>
              Set password &amp; sign in
            </button>
          </div>

        </div>
      </form>
    </ng-container>

  </div>
</div>
  `,
})
export class AcceptInvitationComponent implements OnInit {
  step: Step = 'loading';
  form: FormGroup;
  submitting = false;
  memberName: string | null = null;
  invalidMessage = 'This invitation link is invalid or has already been used.';
  errorMessage = '';

  private token = '';

  constructor(
    private fb: FormBuilder,
    private auth: AuthService,
    private route: ActivatedRoute,
    private router: Router,
  ) {
    this.form = this.fb.group(
      {
        newPassword:     ['', [Validators.required, passwordStrengthValidator()]],
        confirmPassword: ['', [Validators.required]],
      },
      { validators: passwordMatchValidator() },
    );
  }

  ngOnInit(): void {
    this.token = this.route.snapshot.queryParamMap.get('token') ?? '';
    if (!this.token) {
      this.step = 'invalid';
      return;
    }

    this.auth.validateInvitation(this.token).subscribe({
      next: (result) => {
        if (result.valid) {
          this.memberName = result.memberName ?? null;
          this.step = 'form';
        } else {
          this.invalidMessage = result.expired
            ? 'This invitation link has expired. Please ask for a new one.'
            : 'This invitation link is invalid or has already been used.';
          this.step = 'invalid';
        }
      },
      error: () => { this.step = 'invalid'; },
    });
  }

  onSubmit(): void {
    if (this.form.invalid) { this.form.markAllAsTouched(); return; }
    this.submitting = true;
    this.errorMessage = '';

    this.auth.acceptInvitation(this.token, this.form.value.newPassword).subscribe({
      next: () => {
        this.router.navigate(['/user-portal/dashboard']);
      },
      error: (err) => {
        this.errorMessage = err.error?.message ?? 'Could not set your password. The link may have expired.';
        this.submitting = false;
      },
    });
  }

  goToLogin(): void {
    this.router.navigate(['/login']);
  }
}