import {
  ChangeDetectionStrategy,
  Component,
  computed,
  HostListener,
  inject,
  input,
  output,
} from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormBuilder, ReactiveFormsModule, Validators } from '@angular/forms';
import {
  passwordMatchValidator,
  PasswordPolicy,
} from './change-password-modal.validators';

export type ChangePasswordMode = 'self' | 'admin-reset';

export interface ChangePasswordSubmitPayload {
  oldPassword: string;
  newPassword: string;
  confirmNewPassword: string;
}

const DEFAULT_POLICY: PasswordPolicy = {
  minLength: 12,
  requireMixed: true,
  description: 'At least 12 characters with upper, lower, digit and symbol',
};

@Component({
  selector: 'app-change-password-modal',
  standalone: true,
  changeDetection: ChangeDetectionStrategy.OnPush,
  imports: [CommonModule, ReactiveFormsModule],
  styles: [`
    .modal-overlay {
      position: fixed; inset: 0; background: rgba(0, 0, 0, 0.9);
      backdrop-filter: blur(4px);
      display: flex; align-items: center; justify-content: center; z-index: 1200;
      padding: 16px;
    }
    .modal-card {
      background: #000000; color: #ffffff;
      border: 3px solid var(--neon-red);
      padding: 28px 24px;
      width: min(440px, 94vw); position: relative;
      box-shadow: 0 10px 40px rgba(0, 0, 0, 0.9), 0 0 25px rgba(255, 0, 51, 0.35);
    }
    h2 {
      font-family: var(--font-heading, 'Chakra Petch', sans-serif);
      font-size: 2rem; font-weight: 900; font-style: italic;
      text-transform: uppercase; color: #ffffff; margin-bottom: 20px;
      letter-spacing: 0.5px;
    }
    .field {
      display: flex; flex-direction: column; gap: 6px;
      margin-bottom: 16px; text-align: left;
    }
    .field span {
      font-family: var(--font-mono); font-size: 0.75rem; font-weight: 800;
      color: #888899; text-transform: uppercase; letter-spacing: 1px;
    }
    .field input {
      font-family: var(--font-mono); background-color: #000000; color: #ffffff;
      border: 2px solid var(--neon-purple); padding: 12px 14px;
      font-size: 0.95rem; outline: none; width: 100%;
    }
    .field input:focus {
      border-color: var(--neon-cyan); box-shadow: 0 0 10px var(--neon-cyan-glow);
    }
    .error {
      color: var(--neon-red); font-family: var(--font-mono); font-size: 0.85rem; font-weight: bold;
    }
    .hint {
      color: #777788; font-family: var(--font-mono); font-size: 0.75rem; margin-bottom: 20px;
    }
    .actions {
      display: flex; justify-content: flex-end; gap: 12px; margin-top: 10px;
    }
    .actions button {
      font-family: var(--font-mono); font-weight: 800; text-transform: uppercase;
      padding: 10px 20px; font-size: 0.9rem; cursor: pointer;
    }
    .btn-cancel {
      background: #000000; color: var(--neon-purple); border: 2px solid var(--neon-purple);
    }
    .btn-cancel:hover:not([disabled]) {
      background: var(--neon-purple); color: #000000;
    }
    .btn-ok {
      background: var(--neon-red); color: #000000; border: 2px solid var(--neon-red);
    }
    .btn-ok:hover:not([disabled]) {
      background: #000000; color: var(--neon-red); box-shadow: 0 0 15px rgba(255, 0, 51, 0.4);
    }
  `],
  template: `
    @if (open()) {
      <div class="modal-overlay" data-testid="change-password-overlay" (click)="onCancel()">
        <div
          class="modal-card"
          role="dialog"
          aria-modal="true"
          aria-labelledby="cp-title"
          data-testid="change-password-modal"
          (click)="$event.stopPropagation()"
        >
          <h2 id="cp-title">CHANGE PASSWORD</h2>

          <form [formGroup]="form" (ngSubmit)="onSubmit()">
            @if (mode() === 'self') {
              <label class="field">
                <span>OLD PASSWORD</span>
                <input
                  type="password"
                  autocomplete="current-password"
                  formControlName="oldPassword"
                  placeholder="CURRENT PASSWORD"
                  data-testid="cp-old"
                />
              </label>
            }

            <label class="field">
              <span>NEW PASSWORD</span>
              <input
                type="password"
                autocomplete="new-password"
                formControlName="newPassword"
                placeholder="NEW PASSWORD"
                data-testid="cp-new"
              />
              @if (fieldErrorFor('newPassword'); as msg) {
                <span class="error" data-testid="cp-new-error">{{ msg }}</span>
              }
            </label>

            <label class="field">
              <span>CONFIRM NEW PASSWORD</span>
              <input
                type="password"
                autocomplete="new-password"
                formControlName="confirmNewPassword"
                placeholder="CONFIRM NEW PASSWORD"
                data-testid="cp-confirm"
              />
              @if (fieldErrorFor('confirmPassword'); as msg) {
                <span class="error" data-testid="cp-confirm-error">{{ msg }}</span>
              }
              @if (fieldErrorFor('confirmNewPassword'); as msg) {
                <span class="error" data-testid="cp-confirm-error">{{ msg }}</span>
              }
            </label>

            @if (errorMessage()) {
              <p class="error" data-testid="cp-error">{{ errorMessage() }}</p>
            }
            @if (formError()) {
              <p class="error" data-testid="cp-form-error">{{ formError() }}</p>
            }
            <p class="hint" data-testid="cp-policy">{{ policy().description }}</p>

            <div class="actions">
              <button
                type="button"
                class="btn-cancel"
                data-testid="cp-cancel"
                (click)="onCancel()"
                [disabled]="submitting()"
              >
                CANCEL
              </button>
              <button
                type="submit"
                class="btn-ok"
                data-testid="cp-ok"
                [disabled]="submitting()"
              >
                {{ submitting() ? 'SAVING...' : 'OK' }}
              </button>
            </div>
          </form>
        </div>
      </div>
    }
  `,
})
export class ChangePasswordModalComponent {
  private readonly fb = inject(FormBuilder);

  readonly open = input<boolean>(false);
  readonly mode = input<ChangePasswordMode>('self');
  readonly policy = input<PasswordPolicy>(DEFAULT_POLICY);
  readonly errorMessage = input<string | null>(null);
  readonly submitting = input<boolean>(false);
  readonly fieldErrors = input<Record<string, string> | null>(null);

  readonly cancel = output<void>();
  readonly submit = output<ChangePasswordSubmitPayload>();

  readonly form = this.fb.nonNullable.group(
    {
      oldPassword: this.fb.nonNullable.control(''),
      newPassword: this.fb.nonNullable.control('', [Validators.required]),
      confirmNewPassword: this.fb.nonNullable.control('', [Validators.required]),
    },
    { validators: passwordMatchValidator },
  );

  readonly formError = computed<string | null>(() => {
    const errs = this.form.errors;
    if (errs?.['passwordMismatch']) return 'Passwords do not match';
    return null;
  });

  fieldErrorFor(path: string): string | null {
    const map = this.fieldErrors();
    if (!map) return null;
    return map[path] ?? null;
  }

  @HostListener('document:keydown.escape')
  onEscape(): void {
    if (this.open() && !this.submitting()) this.onCancel();
  }

  onCancel(): void {
    if (this.submitting()) return;
    this.form.reset({ oldPassword: '', newPassword: '', confirmNewPassword: '' });
    this.cancel.emit();
  }

  onSubmit(): void {
    if (this.submitting()) return;
    const v = this.form.getRawValue();
    if (this.mode() === 'self' && !v.oldPassword) return;
    if (!v.newPassword || !v.confirmNewPassword) return;
    if (this.form.invalid) return;
    this.submit.emit({
      oldPassword: v.oldPassword,
      newPassword: v.newPassword,
      confirmNewPassword: v.confirmNewPassword,
    });
  }
}