import { Injectable } from '@angular/core';
import { MatDialog } from '@angular/material';
import { BehaviorSubject } from 'rxjs';
import { Observable } from 'rxjs/internal/Observable';
import * as math from 'mathjs';
import { Product } from '../core/product';
import { ModifiersComponent } from './modifiers/modifiers.component';
import { ModifierCategoryService } from '../modifier-categories/modifier-category.service';
import { ModifierCategory } from '../core/modifier-category';
import { Bill, Inventory, Kot, PrintType } from './bills/bill';
import { VoucherService } from './bills/voucher.service';
import { ToasterService } from '../core/toaster.service';
import { Table } from '../core/table';
import { SelectionModel } from '@angular/cdk/collections';

@Injectable()
export class BillService {
  public dataObs;
  public data: any[];
  public bill;
  public netAmount: BehaviorSubject<number>;
  public discountAmount: BehaviorSubject<number>;
  public taxAmount: BehaviorSubject<number>;
  public amount: BehaviorSubject<number>;
  public selection = new SelectionModel<any>(true, []);

  constructor(
    private dialog: MatDialog,
    private toaster: ToasterService,
    private ser: VoucherService,
    private modifierCategoryService: ModifierCategoryService
  ) {
    this.data = [];
    this.dataObs = new BehaviorSubject<any[]>(this.data);
    this.netAmount = new BehaviorSubject(0);
    this.discountAmount = new BehaviorSubject(0);
    this.taxAmount = new BehaviorSubject(0);
    this.amount = new BehaviorSubject(0);
  }

  loadData(bill: Bill): void {
    this.bill = bill;
    const view = this.bill.kots.map(k => {
      return [{
        id: k.id,
        isKot: true,
        oldKot: true,
        info: `Kot: ${k.code} / ${k.date} (${k.user.name}) `
      }, ...k.inventories.map(i => {
        return {
          id: i.id,
          kotId: k.id,
          isKot: false,
          product: i.product,
          productId: i.product.id,
          isHappyHour: i.isHappyHour,
          isPrinted: true,
          info: `${i.product.name} @ ${i.price} - ${math.round(i.discount * 100, 2)}%`,
          price: i.price,
          quantity: i.quantity,
          discount: i.discount,
          taxRate: i.taxRate,
          tax: i.tax,
          modifiers: i.modifiers
        };
      })];
    });
    this.data = view.reduce((a, c) => a.concat(c) , []);
    this.data.push({isKot: true, newKot: true, info: '== New Kot =='});
    this.dataObs.next(this.data);
    this.updateAmounts();

  }
  addProduct(product: Product): void {
    const old = this.data.find(
      x => !x.isKot && !x.id && x.productId === product.id && x.isHappyHour === product.hasHappyHour
    );
    if (old !== undefined) {
      old.quantity += 1;
    } else {
      const item = {
        isKot: false,
        product: product,
        productId: product.id,
        isHappyHour: product.hasHappyHour,
        info: `${product.name} @ ${product.price} - ${0}%`,
        price: product.price,
        quantity: 1,
        discount: 0,
        taxRate: product.tax.rate,
        tax: product.tax,
        modifiers: []
      };
      this.data.push(item);
      this.modifierCategoryService.listIsActiveOfProduct(product.id).subscribe(result => {
        if (result.reduce((a: any, c: ModifierCategory) => {
          return a + c.minimum;
        }, 0)) {
          this.showModifier(item);
        }
      });
    }
    this.dataObs.next(this.data);
    this.updateAmounts();
  }

  showModifier(item: any): void {
    // [routerLink]="['/sales', 'modifiers', item.id]"
    const dialogRef = this.dialog.open(ModifiersComponent, {
      position: {
        top: '10vh'
      },
      data: {
        list: this.modifierCategoryService.listIsActiveOfProduct(item.productId),
        selected: item.modifiers
      }
    });

    dialogRef.afterClosed().subscribe(result => {
      if (result !== undefined) {
        item.modifiers = result;
      }
    });
  }

  addOne(item: any): void {
    item.quantity += 1;
    this.dataObs.next(this.data);
    this.updateAmounts();
  }

  quantity(item: any, quantity: number): void {
    item.quantity = quantity;
    this.dataObs.next(this.data);
    this.updateAmounts();
  }

  subtractOne(item: any): void {
    if (item.quantity > 1) {
      item.quantity -= 1;
      this.dataObs.next(this.data);
      this.updateAmounts();
    } else if (item.quantity === 0) {
      this.removeItem(item);
    }
  }

  removeItem(item: any): void {
    this.data.splice(this.data.indexOf(item), 1);
    this.dataObs.next(this.data);
    this.updateAmounts();
  }

  modifier(item: any): void {
    this.showModifier(item);
  }

  discount(discounts: {id: string, name: string, discount: number}[]): void {
    this.data.forEach(x => {
      if (!x.isKot) {
        x.discount = discounts.find(d => d.id === x.product.saleCategory.id).discount / 100;
        x.info = `${x.product.name} @ ${x.price} - ${math.round(x.discount * 100, 2)}%`;
      }
    });
    this.dataObs.next(this.data);
    this.updateAmounts();
  }

  private getKot(): Kot {
    return new Kot({
      inventories: this.data.filter(x => !x.isKot && !x.isPrinted).map(y => new Inventory({
        product: y.product,
        quantity: y.quantity,
        price: y.price,
        isHappyHour: y.isHappyHour,
        discount: y.discount,
        modifiers: y.modifiers,
        taxRate: y.taxRate,
        tax: y.tax
      }))
    });
  }

  printKot(guest_book_id: string): Observable<boolean> {
    const item = JSON.parse(JSON.stringify(this.bill));
    const newKot = this.getKot();
    if (newKot.inventories.length === 0) {
      this.toaster.show('Error', 'Cannot print a blank KOT\nPlease add some products!');
    }
    item.kots.push(newKot);
    return this.ser.saveOrUpdate(item, PrintType.Kot, guest_book_id, true);
  }

  printBill(guest_book_id: string, printType: PrintType): Observable<boolean> {
    const item = JSON.parse(JSON.stringify(this.bill));
    item.kots.forEach(k => {
      k.inventories.forEach(i => {
        i.discount = this.data.find(x => !x.isKot && x.id === i.id).discount;
      });
    });
    item.kots.push(this.getKot());
    return this.ser.saveOrUpdate(item, printType, guest_book_id, true);
  }

  type() {
    return this.bill.voucherType;
  }

  receivePayment(amounts: { id: string; name: string; amount: number }[]): Observable<boolean> {
    return this.ser.receivePayment(this.bill.id, amounts, true);
  }

  moveTable(table: Table): Observable<boolean> {
    return this.ser.moveTable(this.bill.id, table);
  }

  mergeTable(table: Table): Observable<boolean> {
    return this.ser.mergeTable(this.bill.id, table);
  }

  moveKot(kotId: string, table: Table): Observable<boolean> {
    return this.ser.moveKotToNewTable(this.bill.id, kotId, table);
  }

  mergeKot(kotId: string, table: Table): Observable<boolean> {
    return this.ser.mergeKotWithOldBill(this.bill.id, kotId, table);
  }

  voidBill(reason: string): Observable<boolean> {
    return this.ser.voidBill(this.bill.id, reason, true);
  }

  updateAmounts() {
    this.netAmount.next(
      math.round(this.data.filter(x => !x.isKot).reduce(
        (ca: number, c: any) => ca + ((c.isHappyHour ? 0 : c.price) * c.quantity)
        , 0))
    );
    this.discountAmount.next(
      math.round(this.data.filter(x => !x.isKot).reduce(
        (ca: number, c: Inventory) => ca + ((c.isHappyHour ? 0 : c.price) * c.quantity * c.discount)
        , 0))
    );
    this.taxAmount.next(
      math.round(this.data.filter(x => !x.isKot).reduce(
        (ca: number, c: Inventory) => ca + ((c.isHappyHour ? 0 : c.price) * c.quantity * (1 - c.discount) * c.taxRate)
        , 0))
    );
    this.amount.next(
      math.round(this.data.filter(x => !x.isKot).reduce(
        (ca: number, c: Inventory) => ca + ((c.isHappyHour ? 0 : c.price) * c.quantity * (1 - c.discount) * (1 + c.taxRate))
        , 0))
    );
  }

  amountVal(): number {
    return math.round(this.bill.kots.reduce(
      (ka: number, k: Kot) => ka + k.inventories.reduce(
        (ca: number, c: Inventory) => ca + ((c.isHappyHour ? 0 : c.price) * c.quantity * (1 - c.discount) * (1 + c.taxRate))
        , 0)
      , 0));
  }

  splitBill(table: Table): Observable<boolean> {
    const inventoriesToMove: string[] = this.selection.selected.map((x: any) => x.id);
    return this.ser.splitBill(this.bill.id, inventoriesToMove, table);
  }
}