/**
 * @copyright 2026 NHCarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */

import { Component, OnInit, inject, signal } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterLink, ActivatedRoute, Router } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { BooksService } from '../../services/books.service';
import { CommentsService } from '../../services/comments.service';
import { AuthService } from '../../services/auth.service';
import { SanitizeService } from '../../services/sanitize.service';
import { CommentDisplayComponent } from '../comment-display/comment-display.component';
import { LikeButtonComponent } from '../shared/like-button.component';
import { BookFormComponent } from '../shared/book-form.component';
import { Book, Comment, BookStatus, UpdateBookDto } from '@library/shared-types';

@Component({
  selector: 'app-book-detail',
  standalone: true,
  imports: [CommonModule, RouterLink, FormsModule, CommentDisplayComponent, LikeButtonComponent, BookFormComponent],
  template: `
    <div class="container">
      <div class="breadcrumb">
        <a routerLink="/books" class="breadcrumb-link">← Back to Books</a>
      </div>

      @if (showEditForm() && authService.user()?.isAdmin && book()) {
        <app-book-form
          mode="edit"
          [book]="book()!"
          (formSubmit)="saveEdit($event)"
          (formCancel)="cancelEdit()"
        ></app-book-form>
      }

      @if (loading()) {
        <div class="loading">Loading book details...</div>
      } @else if (error()) {
        <div class="error-state">
          <h2>Book Not Found</h2>
          <p>{{ error() }}</p>
          <a routerLink="/books" class="btn btn-primary">Return to Books</a>
        </div>
      } @else if (book()) {
        <div class="book-detail-card">
          <div class="book-cover-section">
            <img [src]="book()!.coverImage || '/assets/default-cover.jpg'" [alt]="book()!.title" class="book-cover-large">
          </div>

          <div class="book-content">
            <div class="book-header">
              <h1>{{ book()!.title }}</h1>
              <span class="status status-{{ book()!.status }}">
                {{ getStatusLabel(book()!.status) }}
              </span>
            </div>

            <p class="author">by {{ book()!.author }}</p>
            @if (authService.user()?.isAdmin) {
              <div class="admin-actions">
                <button (click)="editBook()" class="btn btn-edit">✏️ Edit</button>
                <button (click)="deleteBook()" class="btn btn-delete">🗑️ Delete</button>
              </div>
            }

            @if (book()!.series) {
              <p class="series">
                📚 {{ book()!.series }}@if (book()!.seriesOrder) { #{{ book()!.seriesOrder }}}
              </p>
            }

            @if (book()!.isbn) {
              <div class="info-row">
                <span class="info-label">ISBN:</span>
                <span class="info-value">{{ book()!.isbn }}</span>
              </div>
            }

            @if (book()!.rating) {
              <div class="info-row">
                <span class="info-label">Rating:</span>
                <div class="rating">
                  @for (star of [1,2,3,4,5,6,7,8,9,10]; track star) {
                    <span [class.filled]="star <= book()!.rating!">★</span>
                  }
                  <span class="rating-text">({{ book()!.rating }}/10)</span>
                </div>
              </div>
            }

            @if (book()!.timeSpent) {
              <div class="info-row">
                <span class="info-label">Reading Time:</span>
                <span class="info-value time-spent">{{ formatTimeSpent(book()!.timeSpent!) }}</span>
              </div>
            }

            @if (book()!.dateStarted) {
              <div class="info-row">
                <span class="info-label">Started:</span>
                <span class="info-value">{{ formatDate(book()!.dateStarted!) }}</span>
              </div>
            }

            @if (book()!.dateFinished) {
              <div class="info-row">
                <span class="info-label">Finished:</span>
                <span class="info-value">{{ formatDate(book()!.dateFinished!) }}</span>
              </div>
            }

            <div class="info-row">
              <span class="info-label">Added:</span>
              <span class="info-value">{{ formatDate(book()!.createdAt) }}</span>
            </div>

            <div class="info-row">
              <span class="info-label">Last Updated:</span>
              <span class="info-value">{{ formatDate(book()!.updatedAt) }}</span>
            </div>

            <div class="like-section">
              <app-like-button
                entityType="book"
                [entityId]="book()!.id"
              ></app-like-button>
            </div>

            @if (book()!.notes) {
              <div class="notes-section">
                <h3>Notes</h3>
                <p class="notes">{{ book()!.notes }}</p>
              </div>
            }

            @if (book()!.tags && book()!.tags.length > 0) {
              <div class="tags-section">
                <h3>Tags</h3>
                <div class="tags-display">
                  @for (tag of book()!.tags; track tag) {
                    <span class="tag-chip">{{ tag }}</span>
                  }
                </div>
              </div>
            }

            @if (book()!.links && book()!.links.length > 0) {
              <div class="links-section">
                <h3>External Links</h3>
                <div class="links-display">
                  @for (link of book()!.links; track link.url) {
                    <a [href]="link.url" target="_blank" rel="noopener noreferrer" class="external-link">
                      {{ link.title }} ↗
                    </a>
                  }
                </div>
              </div>
            }

            <div class="comments-section">
              <h3>Comments</h3>
              @if (authService.isAuthenticated()) {
                @if (authService.user()?.isBanned) {
                  <div class="banned-notice">
                    You have been banned from commenting.
                  </div>
                } @else {
                  <form (ngSubmit)="addComment()" class="comment-form">
                    <textarea
                      [(ngModel)]="newCommentContent"
                      name="comment"
                      placeholder="Add a comment (Markdown supported)..."
                      rows="3"
                    ></textarea>
                    <button type="submit" class="btn btn-primary">Post Comment</button>
                  </form>
                }
              } @else {
                <div class="auth-prompt">
                  <p>Please sign in to comment.</p>
                </div>
              }

              @if (commentsLoading()) {
                <div class="comments-loading">Loading comments...</div>
              } @else {
                <app-comment-display
                  [comments]="comments"
                  (edit)="handleCommentEdit($event)"
                  (delete)="deleteComment($event)"
                />
              }
            </div>
          </div>
        </div>
      }
    </div>
  `,
  styles: [`
    .container {
      max-width: 900px;
      margin: 0 auto;
      padding: 2rem;
    }

    .breadcrumb {
      margin-bottom: 1.5rem;
    }

    .breadcrumb-link {
      color: #8b6f47;
      text-decoration: none;
      font-weight: 500;
      transition: opacity 0.3s;
    }

    .breadcrumb-link:hover {
      opacity: 0.8;
    }

    .loading {
      text-align: center;
      padding: 3rem;
      color: #666;
      font-size: 1.1rem;
    }

    .error-state {
      text-align: center;
      padding: 3rem;
      background: #fef2f2;
      border: 1px solid #fecaca;
      border-radius: 8px;
    }

    .error-state h2 {
      color: #991b1b;
      margin-bottom: 1rem;
    }

    .error-state p {
      color: #dc2626;
      margin-bottom: 1.5rem;
    }

    .book-detail-card {
      background: white;
      border: 1px solid #e5e7eb;
      border-radius: 8px;
      overflow: hidden;
      box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    }

    .book-cover-section {
      width: 100%;
      background: #f3f4f6;
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 2rem;
    }

    .book-cover-large {
      max-width: 100%;
      max-height: 400px;
      object-fit: contain;
      border-radius: 4px;
    }

    .book-content {
      padding: 2rem;
    }

    .book-header {
      display: flex;
      align-items: center;
      gap: 1rem;
      margin-bottom: 1rem;
      flex-wrap: wrap;
    }

    .book-header h1 {
      margin: 0;
      font-size: 2rem;
      color: #1f2937;
    }

    .author {
      color: #6b7280;
      font-style: italic;
      font-size: 1.1rem;
      margin: 0 0 1rem 0;
    }

    .status {
      display: inline-block;
      padding: 0.5rem 1rem;
      border-radius: 4px;
      font-size: 0.9rem;
      font-weight: 500;
    }

    .status-reading {
      background: #fef3c7;
      color: #92400e;
    }

    .status-finished {
      background: #d1fae5;
      color: #065f46;
    }

    .status-toRead {
      background: #e0e7ff;
      color: #3730a3;
    }

    .status-retired {
      background: #f3f4f6;
      color: #4b5563;
    }


    .admin-actions {
      display: flex;
      gap: 0.75rem;
      margin-bottom: 1.5rem;
      padding: 1rem;
      background: #fef3c7;
      border-radius: 4px;
      border: 1px solid #fbbf24;
    }

    .btn-edit {
      background: #3b82f6;
      color: white;
    }

    .btn-edit:hover {
      background: #2563eb;
    }

    .btn-delete {
      background: #ef4444;
      color: white;
    }

    .btn-delete:hover {
      background: #dc2626;
    }

    .series {
      color: #8b6f47;
      font-size: 1rem;
      margin: 0.5rem 0 1.5rem 0;
      font-weight: 500;
      font-style: italic;
    }

    .info-row {
      display: flex;
      align-items: center;
      gap: 1rem;
      margin-bottom: 0.75rem;
      padding: 0.5rem 0;
      border-bottom: 1px solid #f3f4f6;
    }

    .info-label {
      font-weight: 600;
      color: #4b5563;
      min-width: 120px;
    }

    .info-value {
      color: #1f2937;
    }

    .time-spent {
      color: #10b981;
      font-weight: 600;
    }

    .rating {
      display: flex;
      align-items: center;
      gap: 0.25rem;
    }

    .rating span {
      color: #e5e7eb;
      font-size: 1.2rem;
    }

    .rating span.filled {
      color: #f59e0b;
    }

    .rating-text {
      margin-left: 0.5rem;
      font-size: 1rem;
      color: #6b7280;
      font-weight: 500;
    }

    .like-section {
      margin: 1.5rem 0;
    }

    .notes-section,
    .tags-section,
    .links-section {
      margin-top: 2rem;
    }

    .notes-section h3,
    .tags-section h3,
    .links-section h3,
    .comments-section h3 {
      font-size: 1.25rem;
      color: #1f2937;
      margin-bottom: 1rem;
    }

    .notes {
      font-size: 1rem;
      color: #4b5563;
      line-height: 1.6;
      white-space: pre-wrap;
    }

    .tags-display {
      display: flex;
      flex-wrap: wrap;
      gap: 0.5rem;
    }

    .tag-chip {
      background: #8b6f47;
      color: white;
      padding: 0.375rem 0.875rem;
      border-radius: 12px;
      font-size: 0.875rem;
      font-weight: 500;
    }

    .links-display {
      display: flex;
      flex-wrap: wrap;
      gap: 0.75rem;
    }

    .external-link {
      color: #8b6f47;
      text-decoration: none;
      font-size: 0.95rem;
      padding: 0.5rem 1rem;
      border: 2px solid #8b6f47;
      border-radius: 4px;
      transition: all 0.2s;
      font-weight: 500;
    }

    .external-link:hover {
      background: #8b6f47;
      color: white;
    }

    .comments-section {
      margin-top: 2rem;
      padding-top: 2rem;
      border-top: 2px solid #e5e7eb;
    }

    .comment-form {
      margin-bottom: 1.5rem;
    }

    .comment-form textarea {
      width: 100%;
      padding: 0.75rem;
      border: 1px solid #d1d5db;
      border-radius: 4px;
      font-size: 1rem;
      resize: vertical;
      margin-bottom: 0.75rem;
      font-family: inherit;
    }

    .comment-form textarea:focus {
      outline: none;
      border-color: #8b6f47;
    }

    .banned-notice {
      background: #fef2f2;
      border: 1px solid #fecaca;
      color: #991b1b;
      padding: 1rem;
      border-radius: 4px;
      text-align: center;
      margin-bottom: 1.5rem;
      font-size: 0.95rem;
    }

    .auth-prompt {
      background: #f3f4f6;
      padding: 1rem;
      border-radius: 4px;
      text-align: center;
      margin-bottom: 1.5rem;
    }

    .auth-prompt p {
      margin: 0;
      color: #4b5563;
    }

    .comments-loading {
      text-align: center;
      padding: 1.5rem;
      color: #6b7280;
      font-size: 0.95rem;
    }

    .btn {
      padding: 0.625rem 1.25rem;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      font-size: 1rem;
      transition: all 0.3s;
      font-weight: 500;
    }

    .btn:hover {
      opacity: 0.9;
    }

    .btn-primary {
      background: #8b6f47;
      color: white;
    }

    @media (max-width: 640px) {
      .container {
        padding: 1rem;
      }

      .book-header {
        flex-direction: column;
        align-items: flex-start;
      }

      .book-header h1 {
        font-size: 1.5rem;
      }

      .info-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
      }

      .info-label {
        min-width: auto;
      }
    }
  `]
})
export class BookDetailComponent implements OnInit {
  private readonly booksService = inject(BooksService);
  private readonly commentsService = inject(CommentsService);
  readonly authService = inject(AuthService);
  private readonly sanitizeService = inject(SanitizeService);
  private readonly route = inject(ActivatedRoute);
  private readonly router = inject(Router);

  book = signal<Book | null>(null);
  comments = signal<Comment[]>([]);
  loading = signal(true);
  commentsLoading = signal(false);
  error = signal<string | null>(null);
  newCommentContent = '';
  showEditForm = signal(false);

  ngOnInit() {
    const bookId = this.route.snapshot.paramMap.get('id');
    if (!bookId) {
      this.error.set('No book ID provided');
      this.loading.set(false);
      return;
    }

    this.loadBook(bookId);
    this.loadComments(bookId);
  }

  private loadBook(bookId: string) {
    this.loading.set(true);
    this.booksService.getBookById(bookId).subscribe({
      next: (book) => {
        if (!book) {
          this.error.set('Book not found');
        } else {
          this.book.set(book);
        }
        this.loading.set(false);
      },
      error: () => {
        this.error.set('Failed to load book. It may not exist or there was an error.');
        this.loading.set(false);
      }
    });
  }

  private loadComments(bookId: string) {
    this.commentsLoading.set(true);
    this.commentsService.getCommentsForBook(bookId).subscribe({
      next: (comments) => {
        this.comments.set(comments);
        this.commentsLoading.set(false);
      },
      error: () => {
        this.commentsLoading.set(false);
      }
    });
  }

  addComment() {
    const book = this.book();
    if (!book || !this.newCommentContent.trim()) return;

    this.commentsService.addCommentToBook(book.id, { content: this.newCommentContent }).subscribe({
      next: (comment) => {
        this.comments.set([comment, ...this.comments()]);
        this.newCommentContent = '';
      }
    });
  }

  handleCommentEdit(event: { commentId: string; content: string }) {
    const book = this.book();
    if (!book) return;

    this.commentsService.updateCommentOnBook(book.id, event.commentId, event.content).subscribe({
      next: (updatedComment) => {
        this.comments.set(
          this.comments().map(c => c.id === event.commentId ? updatedComment : c)
        );
      }
    });
  }

  deleteComment(commentId: string) {
    const book = this.book();
    if (!book || !confirm('Are you sure you want to delete this comment?')) return;

    this.commentsService.deleteCommentFromBook(book.id, commentId).subscribe({
      next: () => {
        this.comments.set(this.comments().filter(c => c.id !== commentId));
      }
    });
  }

  getStatusLabel(status: BookStatus): string {
    switch (status) {
      case BookStatus.reading: return 'Currently Reading';
      case BookStatus.finished: return 'Finished';
      case BookStatus.toRead: return 'To Read';
      case BookStatus.retired: return 'Retired';
    }
  }

  formatDate(date: Date | string): string {
    return new Date(date).toLocaleDateString('en-GB', {
      year: 'numeric',
      month: 'long',
      day: 'numeric'
    });
  }

  formatTimeSpent(minutes: number): string {
    const hours = Math.floor(minutes / 60);
    const mins = minutes % 60;

    if (hours === 0) {
      return `${mins} minutes`;
    } else if (mins === 0) {
      return `${hours} hour${hours === 1 ? '' : 's'}`;
    } else {
      return `${hours} hour${hours === 1 ? '' : 's'} ${mins} minute${mins === 1 ? '' : 's'}`;
    }
  }

  editBook() {
    this.showEditForm.set(true);
  }

  cancelEdit() {
    this.showEditForm.set(false);
  }

  saveEdit(data: UpdateBookDto) {
    const book = this.book();
    if (!book) return;

    this.booksService.updateBook(book.id, data).subscribe({
      next: (updatedBook) => {
        this.book.set(updatedBook);
        this.showEditForm.set(false);
      },
      error: (err) => {
        alert('Failed to update book: ' + (err.error?.message || 'Unknown error'));
      }
    });
  }

  deleteBook() {
    const book = this.book();
    if (!book) return;

    if (!confirm(`Are you sure you want to delete "${book.title}"? This action cannot be undone.`)) {
      return;
    }

    this.booksService.deleteBook(book.id).subscribe({
      next: () => {
        this.router.navigate(['/books']);
      },
      error: (err) => {
        alert('Failed to delete book: ' + (err.error?.message || 'Unknown error'));
      }
    });
  }
}