/**
 * 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 } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import * as ExcelJS from 'exceljs';
import {
  addBanner,
  addLineRows,
  addSectionHeader,
  boxAllCells,
  buildGeneralInfoSheet,
  buildSignatorySheet,
  downloadWorkbook,
  newWorkbook,
  solidFill,
  XL
} from '../oss-workbook';
import { RAL_LIABILITIES } from '../oss1-ral/oss1-ral-data';
import {
  ROE_EARNINGS,
  ROE_EARNINGS_NOTES,
  ROE_GENERAL_INFO,
  ROE_INTEREST_NOT_RECOGNIZED,
  ROE_OTHER_OPERATING_EXPENSES,
  ROE_SIGNATORIES
} from './oss2-roe-data';

type Oss2Tab = 'general' | 'earnings' | 'interest' | 'other-expenses' | 'signatory';

/** One of the two OSS-1 tie-ups printed at the foot of the Earnings sheet. */
interface TieUp {
  label: string;
  oss2Value: number | null;
  oss1Label: string;
  oss1Value: number | null;
  tallies: boolean;
}

@Component({
  selector: 'mifosx-oss2-roe',
  templateUrl: './oss2-roe.component.html',
  styleUrls: ['../oss-return.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    FaIconComponent,
    FormsModule
  ]
})
export class Oss2RoeComponent {
  activeTab: Oss2Tab = 'general';

  generalInfo = ROE_GENERAL_INFO;
  earnings = ROE_EARNINGS;
  earningsNotes = ROE_EARNINGS_NOTES;
  interestNotRecognized = ROE_INTEREST_NOT_RECOGNIZED;
  otherExpenses = ROE_OTHER_OPERATING_EXPENSES;
  signatories = ROE_SIGNATORIES;

  generating = false;
  toastMsg = '';
  toastVisible = false;
  private toastTimer: any;

  showTab(tab: Oss2Tab): void {
    this.activeTab = tab;
  }

  private info(label: string): string {
    return this.generalInfo.find((g) => g.label === label)?.value ?? '';
  }

  get returnName(): string {
    return this.info('Return Name');
  }
  get returnCode(): string {
    return this.info('Return Code');
  }
  get bankName(): string {
    return this.info('Name Of Bank');
  }
  get bankCode(): string {
    return this.info('Bank Code');
  }
  get quarterEndDate(): string {
    return this.info('Quarter End Date');
  }
  get auditFlag(): string {
    return this.info('Audit Flag');
  }

  private earningsValue(prefix: string): number | null {
    return this.earnings.find((l) => l.label.startsWith(prefix))?.value ?? null;
  }

  private liabilityValue(prefix: string): number | null {
    return RAL_LIABILITIES.find((l) => l.label.startsWith(prefix))?.value ?? null;
  }

  get netProfitAfterTax(): number {
    return this.earningsValue('23.') ?? 0;
  }
  get operatingProfit(): number {
    return this.earningsValue('14.') ?? 0;
  }

  /** Sum of the detail sheet — must equal Earnings line 12 ix) Others. */
  get otherExpensesTotal(): number {
    return this.otherExpenses.reduce((sum, e) => sum + (e.amount ?? 0), 0);
  }
  get otherExpensesLineValue(): number | null {
    return this.earningsValue('ix) Others');
  }
  get otherExpensesTally(): boolean {
    return this.otherExpensesTotal === (this.otherExpensesLineValue ?? 0);
  }

  /**
   * The Earnings sheet carries two footnotes requiring 17(i) and 17(ii) to tally
   * with OSS-1 liabilities 12(ii) and 12(i). Checked live rather than left to a
   * reader spotting it in the fine print.
   */
  get oss1TieUps(): TieUp[] {
    const rows: TieUp[] = [
      {
        label: '17 (i) Provision for loan losses (BDDR, Spl. BDDR, etc.)',
        oss2Value: this.earningsValue('i) Provision for loan losses'),
        oss1Label: 'OSS-1 liabilities 12 (ii) BDDR, Spl BDDR',
        oss1Value: this.liabilityValue('ii. BDDR, Spl BDDR'),
        tallies: false
      },
      {
        label: '17 (ii) Provision for depreciation in investments including AFS',
        oss2Value: this.earningsValue('ii) Provision for depreciation in investments'),
        oss1Label: 'OSS-1 liabilities 12 (i) Investment Depreciation Reserve',
        oss1Value: this.liabilityValue('i. For investments (Investment Depreciation Reserve)'),
        tallies: false
      }
    ];
    return rows.map((r) => ({ ...r, tallies: (r.oss2Value ?? 0) === (r.oss1Value ?? 0) }));
  }

  get allTieUpsMatch(): boolean {
    return this.oss1TieUps.every((t) => t.tallies);
  }

  // ══════════════ Excel generation ══════════════

  /** Rebuilds the RBI workbook: one sheet per section, original layout and styling. */
  async generateExcel(): Promise<void> {
    this.generating = true;
    try {
      const wb = newWorkbook();

      buildGeneralInfoSheet(wb, this.generalInfo);
      this.buildEarningsSheet(wb);
      this.buildInterestSheet(wb);
      this.buildOtherExpensesSheet(wb);
      buildSignatorySheet(wb, this.signatories, 'Signatory Information');

      await downloadWorkbook(wb, `Form OSS-2_CIMS ${this.returnCode} - ${this.quarterEndDate}.xlsx`);
      this.toast(`${this.returnCode} workbook generated for quarter ending ${this.quarterEndDate}`);
    } catch {
      this.toast('Could not generate the workbook — please retry');
    } finally {
      this.generating = false;
    }
  }

  private buildEarningsSheet(wb: ExcelJS.Workbook): void {
    const sheet = wb.addWorksheet('Earnings');
    sheet.columns = [
      { width: 90 },
      { width: 20 }
    ];
    addBanner(sheet, 'Earnings', 'B');

    const first = sheet.rowCount + 1;
    addSectionHeader(sheet, '', 'Rs in Thousand');
    addLineRows(sheet, this.earnings);
    boxAllCells(sheet, first, sheet.rowCount, 2);

    sheet.addRow([]);
    const notesStart = sheet.rowCount + 1;
    for (const note of this.earningsNotes) {
      const row = sheet.addRow([note]);
      sheet.mergeCells(`A${row.number}:B${row.number}`);
      row.font = { bold: true, italic: true, size: 10 };
      row.alignment = { wrapText: true };
      row.getCell(1).fill = solidFill(XL.headerGrey);
    }
    boxAllCells(sheet, notesStart, sheet.rowCount, 2);

    sheet.views = [{ state: 'frozen', ySplit: 3 }];
  }

  private buildInterestSheet(wb: ExcelJS.Workbook): void {
    const sheet = wb.addWorksheet('Interest Receivable Not Recog');
    sheet.columns = [
      { width: 72 },
      { width: 22 }
    ];
    addBanner(sheet, 'Interest Receivable Not Recognized', 'B');

    const start = sheet.rowCount + 1;
    const unit = sheet.addRow(['', 'Rs in Thousand']);
    unit.font = { bold: true };
    unit.alignment = { horizontal: 'center' };
    unit.eachCell((c) => (c.fill = solidFill(XL.headerGrey)));

    const head = sheet.addRow(['Interest receivable on NPAs not recognized as income', this.quarterEndDate]);
    head.font = { bold: true };
    head.getCell(2).alignment = { horizontal: 'center' };
    head.eachCell((c) => (c.fill = solidFill(XL.headerGrey)));

    for (const r of this.interestNotRecognized) {
      const row = sheet.addRow([r.label, r.value]);
      row.getCell(1).alignment = { wrapText: true, vertical: 'middle' };
      row.getCell(1).fill = solidFill(XL.headerGrey);
      row.getCell(2).numFmt = '#,##0.00';
      if (r.total) {
        row.getCell(2).fill = solidFill(XL.derivedBlue);
        row.getCell(2).font = { bold: true };
      }
    }
    boxAllCells(sheet, start, sheet.rowCount, 2);
  }

  private buildOtherExpensesSheet(wb: ExcelJS.Workbook): void {
    const sheet = wb.addWorksheet('Other Operating Expenses');
    sheet.columns = [
      { width: 10 },
      { width: 56 },
      { width: 20 }
    ];
    addBanner(sheet, 'Other Operating Expenses', 'C');

    const start = sheet.rowCount + 1;
    const title = sheet.addRow(['Details of Other Operating Expenses', '', 'Rs in Thousand']);
    sheet.mergeCells(`A${title.number}:B${title.number}`);
    title.font = { bold: true };
    title.eachCell((c) => (c.fill = solidFill(XL.headerGrey)));
    title.getCell(3).alignment = { horizontal: 'center' };

    const head = sheet.addRow(['Sr No', 'Particulars', 'Amount']);
    head.font = { bold: true };
    head.alignment = { horizontal: 'center' };
    head.eachCell((c) => (c.fill = solidFill(XL.headerGrey)));

    for (const e of this.otherExpenses) {
      const row = sheet.addRow([e.srNo, e.particulars, e.amount]);
      row.getCell(3).numFmt = '#,##0.00';
    }

    const total = sheet.addRow(['Total', '', this.otherExpensesTotal]);
    sheet.mergeCells(`A${total.number}:B${total.number}`);
    total.font = { bold: true };
    total.getCell(1).fill = solidFill(XL.headerGrey);
    total.getCell(3).numFmt = '#,##0.00';
    total.getCell(3).fill = solidFill(XL.derivedBlue);

    boxAllCells(sheet, start, sheet.rowCount, 3);

    const ref = sheet.addRow(['', '', 'Refer Earnings Sheet — line 12 ix) Others']);
    ref.getCell(3).font = { italic: true, size: 10 };
  }

  private toast(msg: string): void {
    this.toastMsg = msg;
    this.toastVisible = true;
    if (this.toastTimer) {
      clearTimeout(this.toastTimer);
    }
    this.toastTimer = setTimeout(() => (this.toastVisible = false), 3200);
  }
}