/**
 * 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, 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 { FaIconComponent } from '@fortawesome/angular-fontawesome';
import { RbiCircularsService } from '../../../rbi-circulars/rbi-circulars.service';

/** A reserve account as the position screen lists it. */
export interface TransferAccount {
  glAccountId: number;
  glCode: string;
  name: string;
  balance: number;
  item: string;
  head: string;
}

/** What the dialog is opened with: the account clicked, and everything it may move to. */
export interface ReserveTransferData {
  from: TransferAccount;
  accounts: TransferAccount[];
  /** The office the entry posts against, and the date it posts on. */
  officeId: number;
  currencyCode: string;
}

/**
 * Moves money between the accounts the cash reserve is held in.
 *
 * The entry posts through the platform's own journal command, so it goes to maker-checker like any
 * other entry against the ledger. That is deliberate: the amounts settle a statutory requirement,
 * and a transfer that changes whether the bank is compliant is not something one person should be
 * able to post alone.
 *
 * It records the movement; it does not make it. The money reaches the other bank when the treasury
 * desk sends the NEFT or RTGS, and this entry is the bank's own record of having done so — which is
 * why the dialog says as much before it posts.
 */
@Component({
  selector: 'mifosx-reserve-transfer-dialog',
  standalone: true,
  templateUrl: './reserve-transfer-dialog.component.html',
  styleUrls: ['./reserve-transfer-dialog.component.scss'],
  imports: [
    CommonModule,
    FormsModule,
    MatDialogModule,
    MatButtonModule,
    FaIconComponent
  ]
})
export class ReserveTransferDialogComponent {
  private dialogRef = inject(MatDialogRef<ReserveTransferDialogComponent>);
  private rbi = inject(RbiCircularsService);

  /** The account money leaves. Fixed — the dialog is opened from its row. */
  readonly from: TransferAccount;
  /** Everything it can move to: the other reserve accounts, never itself. */
  readonly destinations: TransferAccount[];

  toAccountId: number | null = null;
  amount: number | null = null;
  reference = '';
  comments = '';

  submitting = false;
  error = '';

  readonly data = inject<ReserveTransferData>(MAT_DIALOG_DATA);

  constructor() {
    this.from = this.data.from;
    this.destinations = (this.data.accounts ?? []).filter((a) => a.glAccountId !== this.data.from.glAccountId);
  }

  /** The account chosen to receive the money, while one is chosen. */
  get to(): TransferAccount | null {
    return this.destinations.find((a) => a.glAccountId === this.toAccountId) ?? null;
  }

  /** What the source would hold once this posts — the figure that decides whether it may. */
  get fromAfter(): number {
    return this.from.balance - (this.amount ?? 0);
  }

  get toAfter(): number {
    return (this.to?.balance ?? 0) + (this.amount ?? 0);
  }

  /**
   * Whether the amount can actually be sent.
   *
   * An account cannot send more than it holds: the ledger would carry a negative balance on a cash
   * or bank account, which is not a position that exists.
   */
  get overdrawn(): boolean {
    return this.amount !== null && this.amount > this.from.balance;
  }

  get canSubmit(): boolean {
    return !this.submitting && this.toAccountId !== null && (this.amount ?? 0) > 0 && !this.overdrawn;
  }

  money(value: number | null | undefined): string {
    if (value === null || value === undefined) {
      return '—';
    }
    return `₹${value.toLocaleString('en-IN', { minimumFractionDigits: 2, maximumFractionDigits: 2 })}`;
  }

  /**
   * Posts the transfer as a single journal entry.
   *
   * These are asset accounts, so the one money LEAVES is credited and the one it arrives in is
   * debited — the opposite of how the screen words it, and deliberately so: a treasury user thinks
   * "send from here, receive there", and making them think in debits and credits to move their own
   * money would be asking them to do the ledger's job.
   */
  submit(): void {
    if (!this.canSubmit || !this.to) {
      return;
    }
    this.submitting = true;
    this.error = '';

    // The reserve endpoint, not the manual journal entry one: that is turned off at the HTTP edge
    // on this installation. The sides are named from and to, as a desk thinks of them; the debit
    // and credit are worked out on the server, where the accounts can also be checked.
    const transfer = {
      fromGlAccountId: this.from.glAccountId,
      toGlAccountId: this.to.glAccountId,
      amount: this.amount as number,
      officeId: this.data.officeId,
      reference: this.reference || undefined,
      comments:
        this.comments || `Reserve transfer: ${this.from.glCode} ${this.from.name} to ${this.to.glCode} ${this.to.name}`
    };

    this.rbi.transferReserve(transfer).subscribe({
      next: () => this.dialogRef.close(true),
      error: (err: any) => {
        this.submitting = false;
        // The platform's own message, not a rewritten one: it names the rule that stopped the
        // entry — a closed accounting period, a disabled account — and a generic "could not post"
        // sends the user to look for a fault that has already been explained.
        this.error =
          err?.error?.developerMessage ||
          err?.error?.defaultUserMessage ||
          err?.error?.errors?.[0]?.defaultUserMessage ||
          'The transfer could not be posted.';
      }
    });
  }

  close(): void {
    this.dialogRef.close(false);
  }
}