import { CdkScrollableModule } from '@angular/cdk/scrolling';
import { Component, computed, inject, linkedSignal } from '@angular/core';
import { form, FormField, FormRoot } from '@angular/forms/signals';
import { MatAutocompleteModule } from '@angular/material/autocomplete';
import { MatButtonModule } from '@angular/material/button';
import { MatOptionModule } from '@angular/material/core';
import { MAT_DIALOG_DATA, MatDialogModule, MatDialogRef } from '@angular/material/dialog';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';
import { round } from 'mathjs';

import { Batch } from '../core/batch';
import { BatchService } from '../core/batch.service';
import { Inventory } from '../core/inventory';
import { MathService } from '../shared/math.service';

export interface IssueDialogFormData {
  batch: Batch | string | null;
  quantity: string;
}

@Component({
  selector: 'app-issue-dialog',
  templateUrl: './issue-dialog.component.html',
  styleUrls: ['./issue-dialog.component.css'],
  imports: [
    MatDialogModule,
    CdkScrollableModule,
    FormField,
    FormRoot,
    MatFormFieldModule,
    MatInputModule,
    MatAutocompleteModule,
    MatOptionModule,
    MatButtonModule,
  ],
})
export class IssueDialogComponent {
  readonly dialogRef = inject<MatDialogRef<IssueDialogComponent, Inventory>>(MatDialogRef);
  data = inject<{
    inventory: Inventory;
    date: string;
  }>(MAT_DIALOG_DATA);

  private math = inject(MathService);
  private batchSer = inject(BatchService);

  formModel = linkedSignal<
    {
      inventory: Inventory;
      date: string;
    },
    IssueDialogFormData
  >({
    source: () => this.data,
    computation: (data: { inventory: Inventory; date: string }): IssueDialogFormData => ({
      batch: data.inventory.batch ?? null,
      quantity: `${data.inventory.quantity}`,
    }),
  });

  form = form(this.formModel);

  batchSearch = computed(() => {
    const v = this.form.batch().value();
    return typeof v === 'string' ? v : null;
  });

  batchesResource = this.batchSer.autocomplete(
    computed(() => this.data.date),
    this.batchSearch,
  );

  batches = computed(() => this.batchesResource.value() ?? []);

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

  accept(): void {
    const formValue = this.form().value();
    const batch = typeof formValue.batch === 'string' ? null : formValue.batch;
    if (!batch || !batch.id) {
      return;
    }
    const quantity = this.math.parseAmount(formValue.quantity ?? '0', 2);
    this.data.inventory.batch = batch;
    this.data.inventory.quantity = quantity;
    this.data.inventory.rate = batch.rate;
    this.data.inventory.tax = batch.tax;
    this.data.inventory.discount = batch.discount;
    this.data.inventory.amount = round(quantity * batch.rate * (1 + batch.tax) * (1 - batch.discount), 2);
    this.dialogRef.close(this.data.inventory);
  }
}