import { AsyncPipe, CurrencyPipe } from '@angular/common';
import { AfterViewInit, Component, ElementRef, OnInit, ViewChild, inject } from '@angular/core';
import { FormControl, FormGroup, ReactiveFormsModule } from '@angular/forms';
import { MatAutocompleteModule, MatAutocompleteSelectedEvent } from '@angular/material/autocomplete';
import { MatButtonModule } from '@angular/material/button';
import { MatCheckboxModule } from '@angular/material/checkbox';
import { MatOptionModule } from '@angular/material/core';
import { MatDialog } from '@angular/material/dialog';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatIconModule } from '@angular/material/icon';
import { MatInputModule } from '@angular/material/input';
import { MatSelectModule } from '@angular/material/select';
import { MatSnackBar } from '@angular/material/snack-bar';
import { MatTableModule } from '@angular/material/table';
import { ActivatedRoute, Router } from '@angular/router';
import { of as observableOf, BehaviorSubject, debounceTime, distinctUntilChanged, Observable, switchMap } from 'rxjs';

import { MenuCategory } from '../../core/menu-category';
import { ProductQuery } from '../../core/product-query';
import { SaleCategory } from '../../core/sale-category';
import { ProductService } from '../../product/product.service';
import { ConfirmDialogComponent } from '../../shared/confirm-dialog/confirm-dialog.component';
import { Bundle, BundleItem } from '../bundle';
import { BundleService } from '../bundle.service';
import { BundleDetailDatasource } from './bundle-detail-datasource';
import { BundleDetailDialogComponent } from './bundle-detail-dialog.component';

@Component({
  selector: 'app-bundle-detail',
  templateUrl: './bundle-detail.component.html',
  styleUrls: ['./bundle-detail.component.css'],
  imports: [
    AsyncPipe,
    CurrencyPipe,
    MatAutocompleteModule,
    MatButtonModule,
    MatCheckboxModule,
    MatFormFieldModule,
    MatIconModule,
    MatInputModule,
    MatOptionModule,
    MatSelectModule,
    MatTableModule,
    ReactiveFormsModule,
  ],
})
export class BundleDetailComponent implements OnInit, AfterViewInit {
  private route = inject(ActivatedRoute);
  private router = inject(Router);
  private dialog = inject(MatDialog);
  private snackBar = inject(MatSnackBar);
  private ser = inject(BundleService);
  private productSer = inject(ProductService);

  @ViewChild('name', { static: true }) nameElement?: ElementRef;

  form: FormGroup<{
    // Bundle header fields
    name: FormControl<string>;
    units: FormControl<string>;
    salePrice: FormControl<number>;
    menuCategory: FormControl<string>;
    saleCategory: FormControl<string>;
    hasHappyHour: FormControl<boolean>;
    isNotAvailable: FormControl<boolean>;

    // Item add row
    addRow: FormGroup<{
      itemId: FormControl<ProductQuery | string>;
      quantity: FormControl<number>;
      salePrice: FormControl<number>;
      printInBill: FormControl<boolean>;
    }>;
  }>;

  menuCategories: MenuCategory[] = [];
  saleCategories: SaleCategory[] = [];
  public items$ = new BehaviorSubject<BundleItem[]>([]);
  dataSource: BundleDetailDatasource = new BundleDetailDatasource(this.items$);

  item: Bundle = new Bundle();

  itemProduct: ProductQuery | null = null;
  itemProducts: Observable<ProductQuery[]>;

  displayedColumns = ['name', 'quantity', 'salePrice', 'printInBill', 'action'];

  constructor() {
    this.form = new FormGroup({
      name: new FormControl<string>('', { nonNullable: true }),
      units: new FormControl<string>('', { nonNullable: true }),
      salePrice: new FormControl<number>(0, { nonNullable: true }),
      menuCategory: new FormControl<string>('', { nonNullable: true }),
      saleCategory: new FormControl<string>('', { nonNullable: true }),
      hasHappyHour: new FormControl<boolean>(false, { nonNullable: true }),
      isNotAvailable: new FormControl<boolean>(false, { nonNullable: true }),

      addRow: new FormGroup({
        itemId: new FormControl<ProductQuery | string>('', { nonNullable: true }),
        quantity: new FormControl<number>(1, { nonNullable: true }),
        salePrice: new FormControl<number>(0, { nonNullable: true }),
        printInBill: new FormControl<boolean>(true, { nonNullable: true }),
      }),
    });
    this.itemProducts = this.form.controls.addRow.controls.itemId.valueChanges.pipe(
      debounceTime(150),
      distinctUntilChanged(),
      switchMap((x) => {
        // if user types, x is string; if user selects, x is Product
        if (typeof x !== 'string') {
          return observableOf([]);
        }
        return x.trim() === '' ? observableOf([]) : this.productSer.query(x);
      }),
    );
    this.form.controls.addRow.controls.itemId.valueChanges.subscribe((x) => {
      if (typeof x === 'string') {
        this.itemProduct = null;
      }
    });
  }

  ngOnInit() {
    this.route.data.subscribe((value) => {
      const data = value as {
        item: Bundle;
        menuCategories: MenuCategory[];
        saleCategories: SaleCategory[];
      };
      this.menuCategories = data.menuCategories;
      this.saleCategories = data.saleCategories;
      this.showItem(data.item);
    });
  }

  displayFn(product?: ProductQuery | string): string {
    return !product ? '' : typeof product === 'string' ? product : product.name;
  }

  bundleSelected(event: MatAutocompleteSelectedEvent): void {
    const product = event.option.value as ProductQuery;
    this.itemProduct = product;
    this.form.controls.addRow.controls.salePrice.setValue(product.price ?? 0);
  }

  private recalcBundleSalePrice(): void {
    const total = (this.item.items ?? []).reduce((sum, x) => {
      const qty = Number(x.quantity ?? 0);
      const price = Number(x.salePrice ?? 0);
      if (Number.isNaN(qty) || Number.isNaN(price)) return sum;
      return sum + qty * price;
    }, 0);

    // keep model + form in sync
    this.item.salePrice = Number(total.toFixed(2));

    // if the control is disabled, use patchValue
    this.form.controls.salePrice.patchValue(this.item.salePrice);
  }

  showItem(item: Bundle) {
    this.item = item;

    this.form.setValue({
      name: this.item.name ?? '',
      units: this.item.units ?? '',
      salePrice: Number(this.item.salePrice ?? 0),
      menuCategory: this.item.menuCategory?.id ?? '',
      saleCategory: this.item.saleCategory?.id ?? '',
      hasHappyHour: this.item.hasHappyHour ?? false,
      isNotAvailable: this.item.isNotAvailable ?? false,

      addRow: {
        itemId: '',
        quantity: 1,
        salePrice: 0,
        printInBill: true,
      },
    });
    this.itemProduct = null;
    this.form.controls.salePrice.disable({ emitEvent: false });

    this.items$.next(this.item.items ?? []);
    this.recalcBundleSalePrice();
  }

  ngAfterViewInit() {
    setTimeout(() => {
      if (this.nameElement !== undefined) {
        this.nameElement.nativeElement.focus();
      }
    }, 0);
  }

  resetAddRow() {
    this.form.controls.addRow.reset();
    this.itemProduct = null;
  }

  addRow() {
    const v = this.form.value.addRow;
    if (!v) {
      return;
    }

    if (!this.itemProduct?.id) {
      this.snackBar.open('Please select a product', 'Error');
      return;
    }

    const quantity = Number(v.quantity ?? 0);
    if (Number.isNaN(quantity) || quantity <= 0) {
      this.snackBar.open('Quantity has to be > 0', 'Error');
      return;
    }

    const salePrice = Number(v.salePrice ?? 0);
    if (Number.isNaN(salePrice) || salePrice < 0) {
      this.snackBar.open('Sale Price has to be >= 0', 'Error');
      return;
    }

    // name is expected from backend as "name (units)" on GET;
    // for new rows we keep it blank (or you can set placeholder)
    const bi = new BundleItem({
      itemId: this.itemProduct?.id,
      name: this.itemProduct?.name ?? '',
      quantity,
      salePrice,
      printInBill: v.printInBill || false,
    });

    this.item.items.push(bi);
    this.items$.next(this.item.items);
    this.resetAddRow();

    this.recalcBundleSalePrice();
  }

  editRow(row: BundleItem) {
    const dialogRef = this.dialog.open(BundleDetailDialogComponent, {
      width: '650px',
      data: {
        item: JSON.parse(JSON.stringify(row)) as BundleItem,
      },
    });

    dialogRef.afterClosed().subscribe((result: boolean | BundleItem) => {
      if (!result) {
        return;
      }
      Object.assign(row, result as BundleItem);
      this.items$.next(this.item.items);
      this.resetAddRow();
      this.recalcBundleSalePrice();
    });
  }

  deleteRow(row: BundleItem) {
    this.item.items.splice(this.item.items.indexOf(row), 1);
    this.items$.next(this.item.items);
    this.recalcBundleSalePrice();
  }

  save() {
    if (!this.item.items || this.item.items.length === 0) {
      this.snackBar.open('Bundle must contain at least one item', 'Error');
      return;
    }
    this.ser.saveOrUpdate(this.getItem()).subscribe({
      next: () => {
        this.snackBar.open('', 'Success');
        this.router.navigateByUrl('/bundles');
      },
      error: (error) => {
        this.snackBar.open(error, 'Error');
      },
    });
  }

  delete() {
    this.ser.delete(this.item.id as string).subscribe({
      next: () => {
        this.snackBar.open('', 'Success');
        this.router.navigateByUrl('/bundles');
      },
      error: (error) => {
        this.snackBar.open(error, 'Error');
      },
    });
  }

  confirmDelete(): void {
    const dialogRef = this.dialog.open(ConfirmDialogComponent, {
      width: '250px',
      data: { title: 'Delete Bundle?', content: 'Are you sure? This cannot be undone.' },
    });

    dialogRef.afterClosed().subscribe((result: boolean) => {
      if (result) {
        this.delete();
      }
    });
  }

  getItem(): Bundle {
    const v = this.form.value;

    this.item.name = v.name ?? '';
    this.item.units = v.units ?? '';
    this.item.salePrice = Number(v.salePrice ?? 0);
    this.item.hasHappyHour = v.hasHappyHour ?? false;
    this.item.isNotAvailable = v.isNotAvailable ?? false;
    this.item.sortOrder = this.item.sortOrder ?? 0;

    // menu category
    const menuCategoryId = v.menuCategory ?? '';
    if (!menuCategoryId) {
      // keep it as-is; backend will 422 anyway, but we can show UI error too
      this.snackBar.open('Menu Category is required', 'Error');
      return this.item;
    }

    if (this.item.menuCategory === null || this.item.menuCategory === undefined) {
      this.item.menuCategory = new MenuCategory();
    }
    this.item.menuCategory.id = menuCategoryId;

    // sale category
    const saleCategoryId = v.saleCategory ?? '';
    if (!saleCategoryId) {
      // keep it as-is; backend will 422 anyway, but we can show UI error too
      this.snackBar.open('Menu Category is required', 'Error');
      return this.item;
    }

    if (this.item.saleCategory === null || this.item.saleCategory === undefined) {
      this.item.saleCategory = new SaleCategory();
    }
    this.item.saleCategory.id = saleCategoryId;

    // ensure items array exists
    if (!this.item.items) {
      this.item.items = [];
    }

    return this.item;
  }
}