/**
 * 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 { MAT_DIALOG_DATA, MatDialogRef, MatDialogModule } from '@angular/material/dialog';
import { MatButtonModule } from '@angular/material/button';
import { MatIconModule } from '@angular/material/icon';
import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
import { catchError } from 'rxjs/operators';
import { of } from 'rxjs';
import { OrganizationService } from 'app/organization/organization.service';
import { SettingsService } from 'app/settings/settings.service';

/** One day of an agent's outstanding entries, as the dialog lists them. */
export interface EntryDay {
  date: string;
  entries: any[];
  total: number;
}

/**
 * Applies the cashier's DDS receipts to an agent's outstanding collections.
 *
 * The agent's cash is already in the bank: the cashier took it at the counter into the agent's own GL
 * account, tagged DDS, and the manager approved it. Applying it here hands the money on to the
 * customers the agent wrote down - Dr the agent's GL, Cr DDS Customer Deposits - and each entry is
 * settled against the application. The same screen as Apply Additional Shares.
 *
 * Everything outstanding up to the day chosen on the screen, shown a day at a time - nothing to tick,
 * because what the agent wrote down is settled whole, and an agent who comes in after several days
 * brings several days' cash. The vouchers are ticked, since a day's
 * cash can come in more than one visit. They have to agree exactly: what the agent wrote down is what
 * each customer is owed, so vouchers short of it leave somebody uncredited and vouchers over it leave
 * money nobody can place.
 *
 * The day is shown totalled and its lines opened only when asked for - an agent with a thousand
 * customers is a thousand lines, and the day's total is what the counter is checking.
 */
@Component({
  selector: 'mifosx-apply-dds-receipt-dialog',
  templateUrl: './apply-dds-receipt-dialog.component.html',
  styleUrls: ['./apply-dds-receipt-dialog.component.scss'],
  standalone: true,
  imports: [
    CommonModule,
    FormsModule,
    MatDialogModule,
    MatButtonModule,
    MatIconModule,
    MatProgressSpinnerModule
  ]
})
export class ApplyDdsReceiptDialogComponent implements OnInit {
  private organizationService = inject(OrganizationService);
  private settingsService = inject(SettingsService);

  public dialogRef = inject(MatDialogRef<ApplyDdsReceiptDialogComponent>);
  public data = inject<{
    agentId: number;
    agentCode: string;
    agentName: string;
    glCode: string | null;
    entryDate: string;
  }>(MAT_DIALOG_DATA);

  loadingEntries = true;
  loadingReceipts = true;
  submitting = false;
  errorMsg = '';

  /** The chosen day's outstanding entries - one day, or none when nothing is outstanding on it. */
  days: EntryDay[] = [];

  /** DDS receipts on the agent's GL account, approved and not yet applied. */
  available: any[] = [];

  /**
   * The day is settled whole, so it is always included. The vouchers are the clerk's choice, and none
   * is picked for them even when only one is listed.
   */
  pickedDays = new Set<string>();
  pickedReceipts = new Set<number>();

  /** The day whose lines are open, and the search within it. */
  openDay: string | null = null;
  daySearch = '';

  get loading(): boolean {
    return this.loadingEntries || this.loadingReceipts;
  }

  ngOnInit(): void {
    // Everything outstanding up to the chosen date, whatever day it was written - an agent's cash for
    // several days arrives in one visit, and all of it is settled together.
    this.organizationService
      .getAgentPendingCollections(this.data.agentId)
      .pipe(
        catchError((err) => {
          this.errorMsg = this.readError(err, "Could not load the agent's entries.");
          return of(null);
        })
      )
      .subscribe((res: any) => {
        this.days = groupByDay(
          (res?.entries || []).filter(
            (entry: any) => entry.status === 'PENDING' && String(entry.entryDate) <= this.data.entryDate
          )
        );
        this.pickedDays = new Set(this.days.map((day) => day.date));
        this.loadingEntries = false;
      });

    this.organizationService
      .getAgentCashReceipts(this.data.agentId)
      .pipe(
        catchError((err) => {
          this.errorMsg = this.readError(err, 'Could not load the available receipts.');
          return of([]);
        })
      )
      .subscribe((rows: any) => {
        this.available = Array.isArray(rows) ? rows : [];
        this.loadingReceipts = false;
      });
  }

  // ── Picking ─────────────────────────────────────────────────────────────────────────────────

  toggleReceipt(receipt: any): void {
    if (this.submitting) {
      return;
    }
    this.pickedReceipts.has(receipt.id) ? this.pickedReceipts.delete(receipt.id) : this.pickedReceipts.add(receipt.id);
  }

  toggleOpen(day: EntryDay, event: Event): void {
    event.stopPropagation();
    this.openDay = this.openDay === day.date ? null : day.date;
    this.daySearch = '';
  }

  /** The open day's lines, narrowed by party code or name. */
  visibleEntries(day: EntryDay): any[] {
    const term = this.daySearch.trim().toLowerCase();
    if (!term) {
      return day.entries;
    }
    return day.entries.filter(
      (entry: any) =>
        String(entry.partyCode || '')
          .toLowerCase()
          .includes(term) ||
        String(entry.partyName || '')
          .toLowerCase()
          .includes(term)
    );
  }

  // ── What has to be covered ──────────────────────────────────────────────────────────────────

  get entryCount(): number {
    return this.days.reduce((sum, day) => sum + day.entries.length, 0);
  }

  get outstandingTotal(): number {
    return this.days.reduce((sum, day) => sum + day.total, 0);
  }

  get pickedEntryCount(): number {
    return this.days.filter((day) => this.pickedDays.has(day.date)).reduce((sum, day) => sum + day.entries.length, 0);
  }

  get required(): number {
    return round2(this.days.filter((day) => this.pickedDays.has(day.date)).reduce((sum, day) => sum + day.total, 0));
  }

  get received(): number {
    return round2(
      this.available.filter((r) => this.pickedReceipts.has(r.id)).reduce((sum, r) => sum + Number(r.amount || 0), 0)
    );
  }

  /** Vouchers less entries: below zero they are short, above zero they are over. */
  get difference(): number {
    return round2(this.received - this.required);
  }

  get canApply(): boolean {
    return this.pickedDays.size > 0 && this.pickedReceipts.size > 0 && this.difference === 0 && !this.submitting;
  }

  glLabel(option: any): string {
    return [
      option?.glCode,
      option?.glName
    ]
      .filter(Boolean)
      .join(' — ');
  }

  // ── Voucher search, for a receipt the list does not carry ───────────────────────────────────

  searching = false;
  searchOpen = false;
  searchVoucherNo = '';

  openSearch(): void {
    this.searchOpen = true;
    this.searchVoucherNo = '';
    this.errorMsg = '';
  }

  closeSearch(): void {
    this.searchOpen = false;
    this.errorMsg = '';
  }

  /**
   * Finds one voucher on the agent's GL account and, when it cannot be used, says why - not taken as
   * DDS, not approved yet, or already applied - rather than simply not finding it.
   */
  runSearch(): void {
    const voucher = this.searchVoucherNo.trim();
    if (!voucher || this.searching) {
      return;
    }
    this.searching = true;
    this.errorMsg = '';
    this.organizationService
      .getAgentCashReceipts(this.data.agentId, voucher)
      .pipe(
        catchError((err) => {
          this.errorMsg = this.readError(err, `Voucher ${voucher} could not be looked up.`);
          return of(null);
        })
      )
      .subscribe((rows: any) => {
        this.searching = false;
        if (rows === null) {
          return;
        }
        const found = (Array.isArray(rows) ? rows : [])[0];
        if (!found) {
          this.errorMsg = `Voucher ${voucher} is not on ${this.data.agentCode}'s GL account ${this.data.glCode || ''}.`;
        } else if (found.entryType !== 'DDS') {
          this.errorMsg = `Voucher ${voucher} was taken as "${found.entryType || 'untagged'}", not DDS. Ask the cashier to correct the entry type.`;
        } else if (found.status !== 'APPROVED') {
          this.errorMsg = `Voucher ${voucher} is ${found.status}. It can be applied once the manager approves it.`;
        } else if (found.applied) {
          this.errorMsg = `Voucher ${voucher} has already been applied.`;
        } else {
          this.available = [
            found,
            ...this.available.filter((entry) => entry.id !== found.id)
          ];
          this.pickedReceipts.add(found.id);
          this.searchOpen = false;
        }
      });
  }

  // ── A receipt's own GL entries ──────────────────────────────────────────────────────────────

  viewing: any = null;
  viewingGlEntries: any[] | null = null;
  loadingGlEntries = false;

  openDetail(option: any, event: Event): void {
    event.stopPropagation();
    this.viewing = option;
    this.viewingGlEntries = null;
    this.loadingGlEntries = true;
    this.organizationService
      .getCashReceiptGlEntries(option.id)
      .pipe(catchError(() => of([])))
      .subscribe((rows: any) => {
        this.viewingGlEntries = Array.isArray(rows) ? rows : [];
        this.loadingGlEntries = false;
      });
  }

  closeDetail(): void {
    this.viewing = null;
    this.viewingGlEntries = null;
  }

  // ── Submission ──────────────────────────────────────────────────────────────────────────────

  apply(): void {
    if (!this.canApply) {
      return;
    }
    this.submitting = true;
    this.errorMsg = '';
    const vouchers = this.available.filter((r) => this.pickedReceipts.has(r.id)).map((r) => r.voucherNo);
    const entries = this.pickedEntryCount;
    const amount = this.required;
    this.organizationService
      .settleAgentCollections({
        agentId: Number(this.data.agentId),
        cashierDepositRequestIds: Array.from(this.pickedReceipts),
        entryDates: Array.from(this.pickedDays),
        locale: this.settingsService.language.code
      })
      .pipe(
        catchError((err) => {
          this.errorMsg = this.readError(err, 'The receipts could not be applied.');
          this.submitting = false;
          return of(null);
        })
      )
      .subscribe((res: any) => {
        if (res) {
          this.dialogRef.close({ vouchers, entries, amount, response: res });
        }
      });
  }

  private readError(err: any, fallback: string): string {
    return (
      err?.error?.errors?.[0]?.defaultUserMessage ??
      err?.error?.defaultUserMessage ??
      err?.error?.developerMessage ??
      fallback
    );
  }
}

/** Entries grouped by the day they were collected, oldest first, each day totalled. */
export function groupByDay(entries: any[]): EntryDay[] {
  const byDay = new Map<string, EntryDay>();
  for (const entry of entries) {
    const date = String(entry.entryDate);
    const day = byDay.get(date) ?? { date, entries: [], total: 0 };
    day.entries.push(entry);
    day.total = round2(day.total + Number(entry.amount || 0));
    byDay.set(date, day);
  }
  return Array.from(byDay.values()).sort((a, b) => a.date.localeCompare(b.date));
}

function round2(value: number): number {
  return Math.round(value * 100) / 100;
}