import { ChangeDetectionStrategy, Component, DestroyRef, inject, signal } from '@angular/core';
import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
import { FormBuilder, ReactiveFormsModule, Validators } from '@angular/forms';
import { ActivatedRoute, RouterLink } from '@angular/router';
import { HttpErrorResponse } from '@angular/common/http';
import { MatButtonModule } from '@angular/material/button';
import { MatCardModule } from '@angular/material/card';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatIconModule } from '@angular/material/icon';
import { MatInputModule } from '@angular/material/input';
import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';

import { ReservationCreatePayload, ShowsApiService } from '../services/shows-api.service';

type ApiValidationErrors = Record<string, string[]>;

@Component({
  standalone: true,
  imports: [
    ReactiveFormsModule,
    RouterLink,
    MatButtonModule,
    MatCardModule,
    MatFormFieldModule,
    MatIconModule,
    MatInputModule,
    MatProgressSpinnerModule,
  ],
  template: `
    <section class="page">
      <header class="page-header">
        <p class="eyebrow">Booking</p>
        <h1>Reserve seats</h1>
        <p class="supporting">
          Performance {{ performanceId }}. Complete the form and we will email a confirmation link before any reservation becomes active.
        </p>
      </header>

      <mat-card class="content-card">
        <mat-card-content>
          @if (isSuccess()) {
            <div class="status-panel success" aria-live="polite">
              <div class="status-icon">
                <mat-icon fontSet="material-symbols-outlined">mark_email_read</mat-icon>
              </div>
              <div>
                <h2>Reservation created</h2>
                <p>Check your email to confirm the booking and unlock the QR code for admission.</p>
                <div class="status-steps">
                  <span><mat-icon fontSet="material-symbols-outlined">mail</mat-icon> Open the confirmation email</span>
                  <span><mat-icon fontSet="material-symbols-outlined">verified</mat-icon> Confirm your reservation</span>
                </div>
              </div>
            </div>
          } @else {
            <form [formGroup]="bookingForm" (ngSubmit)="submit()" novalidate>
              <div class="intro-note">
                <mat-icon fontSet="material-symbols-outlined">info</mat-icon>
                <p>We only ask for the essentials. Your seats are held only after email confirmation.</p>
              </div>

              <div class="form-grid">
                <mat-form-field appearance="outline">
                  <mat-icon matPrefix fontSet="material-symbols-outlined">person</mat-icon>
                  <mat-label>Name</mat-label>
                  <input matInput type="text" formControlName="name" autocomplete="name" />
                  @if (bookingForm.controls.name.touched && bookingForm.controls.name.hasError('required')) {
                    <mat-error>Name is required.</mat-error>
                  }
                </mat-form-field>

                <mat-form-field appearance="outline">
                  <mat-icon matPrefix fontSet="material-symbols-outlined">mail</mat-icon>
                  <mat-label>Email</mat-label>
                  <input matInput type="email" formControlName="email" autocomplete="email" />
                  <mat-hint>We will send the confirmation link here.</mat-hint>
                  @if (bookingForm.controls.email.touched && bookingForm.controls.email.hasError('required')) {
                    <mat-error>Email is required.</mat-error>
                  }
                  @if (bookingForm.controls.email.touched && bookingForm.controls.email.hasError('email')) {
                    <mat-error>Enter a valid email address.</mat-error>
                  }
                </mat-form-field>

                <mat-form-field appearance="outline">
                  <mat-icon matPrefix fontSet="material-symbols-outlined">group</mat-icon>
                  <mat-label>Number of seats</mat-label>
                  <input matInput type="number" min="1" step="1" formControlName="partySize" />
                  <mat-hint>Enter the total number of guests in your party.</mat-hint>
                  @if (bookingForm.controls.partySize.touched && bookingForm.controls.partySize.hasError('required')) {
                    <mat-error>Number of seats is required.</mat-error>
                  }
                  @if (bookingForm.controls.partySize.touched && bookingForm.controls.partySize.hasError('min')) {
                    <mat-error>At least 1 seat is required.</mat-error>
                  }
                </mat-form-field>
              </div>

              @if (submitError()) {
                <div class="message-panel error" aria-live="assertive">
                  <mat-icon fontSet="material-symbols-outlined">error</mat-icon>
                  <p>{{ submitError() }}</p>
                </div>
              }

              @if (fieldErrors().length > 0) {
                <div class="message-panel error field-errors" aria-live="assertive">
                  <mat-icon fontSet="material-symbols-outlined">warning</mat-icon>
                  <div>
                    <p class="message-title">Please check the highlighted details:</p>
                  @for (message of fieldErrors(); track message) {
                    <p>{{ message }}</p>
                  }
                  </div>
                </div>
              }

              <div class="actions">
                <button mat-flat-button type="submit" [disabled]="isSubmitting()">
                  @if (isSubmitting()) {
                    <mat-progress-spinner mode="indeterminate" diameter="18"></mat-progress-spinner>
                    <span>Submitting...</span>
                  } @else {
                    <ng-container>
                      <mat-icon fontSet="material-symbols-outlined">confirmation_number</mat-icon>
                      <span>Reserve</span>
                    </ng-container>
                  }
                </button>
                <a mat-button routerLink="/shows">Back to shows</a>
              </div>
            </form>
          }
        </mat-card-content>
      </mat-card>
    </section>
  `,
  styles: [`
    .page {
      max-width: 760px;
      margin: 0 auto;
    }

    .page-header {
      margin-bottom: 24px;
    }

    .eyebrow {
      margin: 0 0 10px;
      color: var(--azionelab-accent);
      text-transform: uppercase;
      font-size: 0.78rem;
      font-weight: 700;
    }

    h1 {
      margin: 0;
      font-size: clamp(2rem, 4vw, 3rem);
    }

    .supporting {
      color: var(--azionelab-muted);
      line-height: 1.6;
      max-width: 56ch;
      margin: 14px 0 0;
    }

    .content-card {
      border-radius: 20px;
      border: 1px solid var(--azionelab-border);
      background: var(--azionelab-surface-strong);
      box-shadow: var(--azionelab-shadow);
      overflow: hidden;
    }

    mat-card-content {
      padding: 28px !important;
    }

    .intro-note {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-bottom: 20px;
      padding: 14px 16px;
      border-radius: 16px;
      background: rgba(159, 47, 40, 0.06);
      color: var(--azionelab-muted);
    }

    .intro-note p {
      margin: 0;
      line-height: 1.55;
    }

    .intro-note mat-icon {
      color: var(--azionelab-accent);
    }

    .form-grid {
      display: grid;
      gap: 14px;
    }

    mat-form-field {
      width: 100%;
    }

    .message-panel {
      display: flex;
      align-items: flex-start;
      gap: 12px;
      margin-top: 14px;
      padding: 14px 16px;
      border-radius: 16px;
      border: 1px solid transparent;
    }

    .message-panel.error {
      background: var(--azionelab-error-bg);
      border-color: var(--azionelab-error-border);
      color: var(--azionelab-error-ink);
    }

    .message-panel p,
    .field-errors p {
      margin: 0;
      line-height: 1.4;
      font-size: 0.92rem;
    }

    .message-title {
      font-weight: 700;
      margin-bottom: 6px !important;
    }

    .field-errors > div {
      display: grid;
      gap: 6px;
    }

    .actions {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 18px;
      flex-wrap: wrap;
    }

    .actions button[mat-flat-button] {
      min-width: 130px;
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .status-panel {
      display: flex;
      align-items: flex-start;
      gap: 16px;
      padding: 4px 0;
    }

    .status-panel h2 {
      margin: 0 0 6px;
    }

    .status-panel p {
      margin: 0;
      color: var(--azionelab-muted);
      line-height: 1.55;
    }

    .status-panel.success {
      padding: 22px;
      border-radius: 18px;
      background: var(--azionelab-success-bg);
      border: 1px solid var(--azionelab-success-border);
    }

    .status-icon {
      display: grid;
      place-items: center;
      width: 52px;
      height: 52px;
      border-radius: 16px;
      background: rgba(46, 125, 50, 0.12);
    }

    .status-icon mat-icon {
      color: var(--azionelab-success-ink);
    }

    .status-steps {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      margin-top: 14px;
    }

    .status-steps span {
      display: inline-flex;
      align-items: center;
      gap: 6px;
      padding: 8px 12px;
      border-radius: 999px;
      background: rgba(255, 255, 255, 0.72);
      color: var(--azionelab-success-ink);
      font-size: 0.92rem;
    }

    .status-steps mat-icon {
      font-size: 18px;
      width: 18px;
      height: 18px;
    }

    @media (max-width: 640px) {
      mat-card-content {
        padding: 22px !important;
      }

      .status-panel,
      .message-panel,
      .intro-note {
        border-radius: 14px;
      }
    }
  `],
  changeDetection: ChangeDetectionStrategy.OnPush,
})
export class BookingPlaceholderPageComponent {
  private readonly destroyRef = inject(DestroyRef);
  private readonly formBuilder = inject(FormBuilder);
  private readonly route = inject(ActivatedRoute);
  private readonly showsApi = inject(ShowsApiService);

  protected readonly performanceId = this.route.snapshot.paramMap.get('id') ?? '';
  protected readonly isSubmitting = signal(false);
  protected readonly isSuccess = signal(false);
  protected readonly submitError = signal('');
  protected readonly fieldErrors = signal<string[]>([]);

  protected readonly bookingForm = this.formBuilder.nonNullable.group({
    name: ['', [Validators.required, Validators.maxLength(200)]],
    email: ['', [Validators.required, Validators.email]],
    partySize: [1, [Validators.required, Validators.min(1)]],
  });

  protected submit(): void {
    this.submitError.set('');
    this.fieldErrors.set([]);

    if (this.bookingForm.invalid) {
      this.bookingForm.markAllAsTouched();
      return;
    }

    const payload: ReservationCreatePayload = {
      name: this.bookingForm.controls.name.value.trim(),
      email: this.bookingForm.controls.email.value.trim(),
      party_size: this.bookingForm.controls.partySize.value,
    };

    this.isSubmitting.set(true);

    this.showsApi.createReservation(this.performanceId, payload)
      .pipe(takeUntilDestroyed(this.destroyRef))
      .subscribe({
        next: () => {
          this.isSubmitting.set(false);
          this.isSuccess.set(true);
          this.bookingForm.disable();
        },
        error: (error: HttpErrorResponse) => {
          this.isSubmitting.set(false);
          if (error.status === 400 && error.error && typeof error.error === 'object') {
            this.fieldErrors.set(this.flattenValidationErrors(error.error as ApiValidationErrors));
            return;
          }
          this.submitError.set('Could not create reservation. Please try again.');
        },
      });
  }

  private flattenValidationErrors(errors: ApiValidationErrors): string[] {
    return Object.entries(errors).flatMap(([field, messages]) => {
      const label = field === 'party_size' ? 'number of seats' : field;
      return messages.map((message) => `${label}: ${message}`);
    });
  }
}