/**
 * Copyright since 2025 Mifos Initiative
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

import { Component, OnInit, inject } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { MatIconModule } from '@angular/material/icon';
import { MatSnackBar, MatSnackBarModule } from '@angular/material/snack-bar';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';
import { MatTabsModule } from '@angular/material/tabs';
import { forkJoin, of } from 'rxjs';
import { catchError } from 'rxjs/operators';
import { CashierService } from '../cashier.service';
import { businessToday } from 'app/core/utils/business-today';

interface DenomRow {
  denominationId: number;
  denominationValue: number;
  kind: string;
  morningCount: number;
  expectedCount: number;
  physicalCount: number;
  varianceCount: number;
}

interface ReconRecord {
  id: number;
  reconDate: string;
  cashierId: number;
  cashierName: string;
  expectedAmount: number;
  physicalAmount: number;
  variance: number;
  status: 'OK' | 'SHORT' | 'EXCESS';
  performedByUsername: string;
  createdAt: string;
}

/** Denomination-wise reconciliation — expected vs physical count per cashier. */
@Component({
  selector: 'mifosx-reconciliation',
  templateUrl: './reconciliation.component.html',
  styleUrls: [
    '../cashier-shared.scss',
    './reconciliation.component.scss'
  ],
  standalone: true,
  imports: [
    CommonModule,
    FormsModule,
    MatIconModule,
    MatSnackBarModule,
    MatFormFieldModule,
    MatInputModule,
    MatTabsModule
  ]
})
export class ReconciliationComponent implements OnInit {
  private service = inject(CashierService);
  private snackBar = inject(MatSnackBar);

  /**
   * A reconciliation is the cashier's own count of their own drawer, so nobody else makes one and there is
   * no cashier to pick: the screen is fixed to the logged-in cashier. The server refuses anything else.
   */
  ownCashierMissing = false;
  ownTellerName = '';

  // ── Entry form ──
  selectedTellerId: number | null = null;
  selectedCashierId: number | null = null;
  cashierName = '';
  reconDate = '';
  note = '';
  varianceReason = '';
  rows: DenomRow[] = [];
  morningTotal = 0;
  loadingExpected = false;
  saving = false;

  // ── History list ──
  history: ReconRecord[] = [];
  loadingHistory = false;

  ngOnInit(): void {
    const d = businessToday();
    this.reconDate = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
    this.lockToOwnCashier();
    this.loadHistory();
  }

  /** Take the logged-in cashier as the one being reconciled, with their counter for the record. */
  private lockToOwnCashier(): void {
    this.service.getCurrentCashierInfo().subscribe((info) => {
      if (!info) {
        this.ownCashierMissing = true;
        return;
      }
      this.selectedCashierId = info.cashierId;
      this.cashierName = info.cashierName;
      this.service
        .getInterCashierCashierSummary(info.cashierId, this.reconDate)
        .pipe(catchError(() => of(null)))
        .subscribe((r: any) => {
          this.selectedTellerId = r?.tellerId ?? null;
          this.ownTellerName = r?.tellerName || '';
        });
      this.fetchExpected();
    });
  }

  fetchExpected(): void {
    if (!this.selectedCashierId) return;
    this.loadingExpected = true;
    forkJoin({
      expected: this.service
        .getExpectedBalance(this.selectedCashierId, this.reconDate)
        .pipe(catchError(() => of(null))),
      morning: this.service
        .getCashierMorningBalance(this.selectedCashierId, this.reconDate)
        .pipe(catchError(() => of(null)))
    }).subscribe(({ expected, morning }) => {
      this.loadingExpected = false;
      const morningMap = new Map<number, number>();
      ((morning?.denominations || []) as any[]).forEach((d: any) =>
        morningMap.set(d.denominationId, d.morningCount ?? 0)
      );
      this.morningTotal = Number(morning?.totalMorning ?? 0);
      if (!expected) return;
      this.rows = ((expected.denominations || []) as any[])
        .sort((a: any, b: any) => b.denominationValue - a.denominationValue)
        .map((d: any) => ({
          denominationId: d.denominationId || null,
          denominationValue: d.denominationValue,
          kind: d.kind || 'note',
          morningCount: morningMap.get(d.denominationId) ?? 0,
          expectedCount: d.expectedCount || 0,
          physicalCount: d.expectedCount || 0,
          varianceCount: 0
        }));
    });
  }

  updatePhysical(row: DenomRow, raw: any): void {
    row.physicalCount = Math.max(0, Math.floor(Number(raw) || 0));
    row.varianceCount = row.physicalCount - row.expectedCount;
  }

  get noteRows(): DenomRow[] {
    return this.rows.filter((r) => r.kind !== 'coin');
  }
  get coinRows(): DenomRow[] {
    return this.rows.filter((r) => r.kind === 'coin');
  }
  get morningNoteTotal(): number {
    return this.noteRows.reduce((s, r) => s + r.morningCount * r.denominationValue, 0);
  }
  get morningCoinTotal(): number {
    return this.coinRows.reduce((s, r) => s + r.morningCount * r.denominationValue, 0);
  }

  get totalExpected(): number {
    return this.rows.reduce((s, r) => s + r.denominationValue * r.expectedCount, 0);
  }
  get totalPhysical(): number {
    return this.rows.reduce((s, r) => s + r.denominationValue * r.physicalCount, 0);
  }
  get totalVariance(): number {
    return this.totalPhysical - this.totalExpected;
  }
  get statusLabel(): string {
    const v = this.totalVariance;
    return v === 0 ? 'OK' : v > 0 ? 'EXCESS' : 'SHORT';
  }
  get valid(): boolean {
    return (
      !!this.selectedCashierId &&
      this.rows.length > 0 &&
      (this.totalVariance === 0 || this.varianceReason.trim().length > 0)
    );
  }

  submit(): void {
    if (!this.valid || this.saving) return;
    this.saving = true;
    const payload = {
      cashierId: this.selectedCashierId,
      tellerId: this.selectedTellerId,
      cashierName: this.cashierName,
      reconDate: this.reconDate,
      note:
        [
          this.note,
          this.totalVariance !== 0 ? `Variance reason: ${this.varianceReason}` : null
        ]
          .filter(Boolean)
          .join(' | ') || null,
      denominations: this.rows.map((r) => ({
        denominationId: r.denominationId,
        denominationValue: r.denominationValue,
        expectedCount: r.expectedCount,
        physicalCount: r.physicalCount
      }))
    };
    this.service.createReconciliation(payload).subscribe({
      next: (res: any) => {
        const status = res?.status || 'OK';
        this.snackBar.open(`Reconciliation saved — Status: ${status}`, 'Close', {
          duration: 4000,
          panelClass: status === 'OK' ? ['snack-ok'] : ['snack-warn']
        });
        this.rows = [];
        this.note = '';
        this.varianceReason = '';
        this.saving = false;
        this.loadHistory();
      },
      error: () => {
        this.saving = false;
      }
    });
  }

  loadHistory(): void {
    this.loadingHistory = true;
    this.service
      .getReconciliations()
      .pipe(catchError(() => of([])))
      .subscribe((list: any[]) => {
        this.history = list || [];
        this.loadingHistory = false;
      });
  }

  statusClass(status: string): string {
    return status === 'OK' ? 'badge-ok' : status === 'EXCESS' ? 'badge-excess' : 'badge-short';
  }
}