import { Component, EventEmitter, inject, Input, OnChanges, Output, SimpleChanges } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { firstValueFrom } from 'rxjs';

import { Show } from '../interfaces/show';
import { ShowService, ShowScheduleCreate, ShowCreatePayload, ShowUpdatePayload } from '../services/show.service';
import { UploadService } from '../services/upload.service';
import { getAppConfig } from '../services/app-config.service';

@Component({
  selector: 'app-admin-show-form',
  standalone: true,
  imports: [CommonModule, FormsModule],
  templateUrl: './admin-show-form.component.html',
  styleUrl: './admin-show-form.component.scss',
})
export class AdminShowFormComponent implements OnChanges {
  private showService = inject(ShowService);
  private uploadService = inject(UploadService);

  @Input() editItem: Show | null = null;
  @Output() saved = new EventEmitter<void>();
  @Output() closed = new EventEmitter<void>();

  readonly days = [
    { value: 1, label: 'Monday' },
    { value: 2, label: 'Tuesday' },
    { value: 3, label: 'Wednesday' },
    { value: 4, label: 'Thursday' },
    { value: 5, label: 'Friday' },
    { value: 6, label: 'Saturday' },
    { value: 7, label: 'Sunday' },
  ];

  id: number | null = null;
  title = '';
  description = '';
  host = '';
  genre = '';
  show_art_url = '';
  hero_image_url = '';
  display_order = 0;
  schedules: ShowScheduleCreate[] = [
    { day_of_week: 1, time: '' },
  ];

  loading = false;
  uploading = false;
  error = '';
  success = '';
  submitted = false;

  ngOnChanges(changes: SimpleChanges): void {
    if (changes['editItem'] && this.editItem) {
      this.edit(this.editItem);
    }
  }

  edit(show: Show): void {
    this.id = show.id;
    this.title = show.title;
    this.description = show.description;
    this.host = show.host;
    this.genre = show.genre;
    this.show_art_url = show.show_art_url || '';
    this.hero_image_url = show.hero_image_url || '';
    this.display_order = show.display_order;
    this.schedules = show.schedules.map((s) => ({
      day_of_week: s.day_of_week,
      time: s.time,
    }));
  }

  formatError(err: any): string {
    if (err?.error?.detail) return err.error.detail;
    if (err?.error?.message) return err.error.message;
    if (err?.message) return err.message;
    return 'Failed to save. Please try again.';
  }

  reset(): void {
    this.id = null;
    this.title = '';
    this.description = '';
    this.host = '';
    this.genre = '';
    this.show_art_url = '';
    this.hero_image_url = '';
    this.display_order = 0;
    this.schedules = [{ day_of_week: 1, time: '' }];
    this.error = '';
    this.success = '';
    this.submitted = false;
  }

  onClose(): void {
    this.closed.emit();
    this.reset();
  }

  /** Add a new empty schedule slot row. */
  addScheduleSlot(): void {
    this.schedules.push({ day_of_week: 1, time: '' });
  }

  /** Remove a schedule slot row by index. */
  removeScheduleSlot(index: number): void {
    this.schedules.splice(index, 1);
  }

  /** Handle image file upload and set the URL field. */
  async onImageUpload(event: Event, field: string): Promise<void> {
    const input = event.target as HTMLInputElement;
    if (!input?.files?.length) return;

    const file = input.files[0];
    if (!file.type.startsWith('image/')) {
      this.error = 'Only image files are allowed.';
      return;
    }
    if (file.size > 5 * 1024 * 1024) {
      this.error = 'File size exceeds 5 MB limit.';
      return;
    }

    this.uploading = true;
    this.error = '';

    try {
      const url = await this.uploadService.uploadImage(file);
      (this as any)[field] = url;
      this.success = 'Image uploaded successfully.';
    } catch (err: any) {
      this.error = this.formatError(err);
    } finally {
      this.uploading = false;
    }
  }

  /** Resolve a relative uploads/… path to an absolute URL for preview. */
  getPreviewUrl(url: string): string {
    if (!url) return '';
    if (url.startsWith('http://') || url.startsWith('https://')) return url;
    return `${getAppConfig().apiBaseUrl}/${url}`;
  }

  async onSubmit(): Promise<void> {
    this.submitted = true;

    // Validate required fields
    if (!this.title || !this.host || !this.genre) {
      this.error = 'Please fill in all required fields.';
      return;
    }

    // Validate schedules
    const validSchedules = this.schedules.filter(
      (s) => s.day_of_week && s.time,
    );
    if (validSchedules.length === 0) {
      this.error = 'Add at least one schedule slot with a day and time.';
      return;
    }

    this.loading = true;
    this.error = '';

    const payload = {
      title: this.title,
      description: this.description,
      host: this.host,
      genre: this.genre,
      show_art_url: this.show_art_url || null,
      hero_image_url: this.hero_image_url || null,
      display_order: this.display_order,
      schedules: validSchedules,
    };

    try {
      if (this.id) {
        const updatePayload: ShowUpdatePayload = { ...payload };
        await firstValueFrom(this.showService.updateShow(this.id, updatePayload));
      } else {
        await firstValueFrom(this.showService.createShow(payload as ShowCreatePayload));
      }
      this.saved.emit();
      this.reset();
    } catch (err: any) {
      this.error = this.formatError(err);
    } finally {
      this.loading = false;
    }
  }
}