/**
 * 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 { CommonModule } from '@angular/common';
import { RouterLink } from '@angular/router';
import {
  ALL_HOLDINGS,
  ALLOCATION_TARGET_IS_RBI_LINKED,
  INSTRUMENT_LABELS,
  InstrumentType,
  InvestmentHolding,
  TARGET_ALLOCATION_PCT,
  accruedInterest,
  daysToMaturity,
  maturityAmount
} from '../investment-data';
import { exportWorkbook } from '../investment-export';

interface InstrumentSummary {
  type: InstrumentType;
  label: string;
  route: string;
  count: number;
  faceValue: number;
  accruedInterest: number;
  maturityValue: number;
}

interface AllocationRow {
  type: InstrumentType;
  label: string;
  targetPct: number;
  actualPct: number;
  actualValue: number;
  variancePct: number;
  statusLabel: 'Within Target' | 'Over-Allocated' | 'Under-Allocated';
  /** True when the target itself traces to an RBI SLR/Non-SLR rule rather than being a
   *  board-only policy choice — see TARGET_ALLOCATION_PCT's doc comment in investment-data.ts. */
  isRbiLinked: boolean;
}

/** Cross-instrument portfolio dashboard — every figure is derived from ALL_HOLDINGS, never
 *  hand-duplicated, so it can never drift from the per-instrument screens or Reports. */
@Component({
  selector: 'mifosx-investment-dashboard',
  templateUrl: './investment-dashboard.component.html',
  styleUrls: [
    '../../cashier/cashier-shared.scss',
    '../investment-shared.scss'
  ],
  standalone: true,
  imports: [
    CommonModule,
    RouterLink
  ]
})
export class InvestmentDashboardComponent {
  asOnDate = '';
  generating = false;
  toastMsg = '';
  toastVisible = false;
  private toastTimer: ReturnType<typeof setTimeout> | undefined;
  private readonly types: Array<{ type: InstrumentType; route: string }> = [
    { type: 'FD', route: '/investment/fd' },
    { type: 'GOVT_SECURITY', route: '/investment/bonds' },
    { type: 'NON_SLR', route: '/investment/bonds' },
    { type: 'BOND', route: '/investment/bonds' },
    { type: 'MUTUAL_FUND', route: '/investment/bonds' },
    { type: 'SHARE', route: '/investment/share' }
  ];

  constructor() {
    const d = new Date();
    this.asOnDate = `${String(d.getDate()).padStart(2, '0')}-${String(d.getMonth() + 1).padStart(2, '0')}-${d.getFullYear()}`;
  }

  private holdingsOf(type: InstrumentType): InvestmentHolding[] {
    return ALL_HOLDINGS.filter((h) => h.instrumentType === type);
  }

  get summaries(): InstrumentSummary[] {
    return this.types.map(({ type, route }) => {
      const holdings = this.holdingsOf(type);
      return {
        type,
        label: INSTRUMENT_LABELS[type],
        route,
        count: holdings.length,
        faceValue: holdings.reduce((s, h) => s + h.faceValue, 0),
        accruedInterest: holdings.reduce((s, h) => s + accruedInterest(h, this.asOnDate), 0),
        maturityValue: holdings.reduce((s, h) => s + maturityAmount(h), 0)
      };
    });
  }

  /** Board-approved policy target % per instrument type vs the portfolio's actual allocation
   *  (by invested/face value) — a ±2 percentage-point band is treated as "Within Target" since
   *  a treasury desk can't rebalance to the exact decimal every day. */
  get allocationVsTarget(): AllocationRow[] {
    const total = this.totalFaceValue;
    return this.types.map(({ type }) => {
      const value = this.holdingsOf(type).reduce((s, h) => s + h.faceValue, 0);
      const actualPct = total ? (value / total) * 100 : 0;
      const targetPct = TARGET_ALLOCATION_PCT[type];
      const variancePct = +(actualPct - targetPct).toFixed(1);
      const statusLabel: AllocationRow['statusLabel'] =
        Math.abs(variancePct) <= 2 ? 'Within Target' : variancePct > 0 ? 'Over-Allocated' : 'Under-Allocated';
      return {
        type,
        label: INSTRUMENT_LABELS[type],
        targetPct,
        actualPct: +actualPct.toFixed(1),
        actualValue: value,
        variancePct,
        statusLabel,
        isRbiLinked: ALLOCATION_TARGET_IS_RBI_LINKED[type]
      };
    });
  }

  get totalHoldings(): number {
    return ALL_HOLDINGS.length;
  }

  get totalFaceValue(): number {
    return ALL_HOLDINGS.reduce((s, h) => s + h.faceValue, 0);
  }

  get totalAccruedInterest(): number {
    return ALL_HOLDINGS.reduce((s, h) => s + accruedInterest(h, this.asOnDate), 0);
  }

  get totalMaturityValue(): number {
    return ALL_HOLDINGS.reduce((s, h) => s + maturityAmount(h), 0);
  }

  get activeCount(): number {
    return ALL_HOLDINGS.filter((h) => h.status === 'ACTIVE').length;
  }

  get maturedCount(): number {
    return ALL_HOLDINGS.filter((h) => h.status === 'MATURED').length;
  }

  /** Holdings maturing within the next 90 days — a "due-date diary" style widget. */
  get maturingSoon(): InvestmentHolding[] {
    return ALL_HOLDINGS.filter((h) => h.status === 'ACTIVE' && daysToMaturity(h, this.asOnDate) <= 90).sort(
      (a, b) => daysToMaturity(a, this.asOnDate) - daysToMaturity(b, this.asOnDate)
    );
  }

  daysLeft(h: InvestmentHolding): number {
    return daysToMaturity(h, this.asOnDate);
  }

  instrumentLabel(type: InstrumentType): string {
    return INSTRUMENT_LABELS[type];
  }

  async exportExcel(): Promise<void> {
    this.generating = true;
    try {
      await exportWorkbook(
        [
          {
            sheetName: 'Instrument Breakup',
            title: 'Investment Portfolio — Instrument-wise Break-up',
            subtitle: `As on ${this.asOnDate}`,
            headers: [
              'Instrument Type',
              'Holdings',
              'Face Value',
              'Accrued Interest',
              'Maturity Value'
            ],
            widths: [
              26,
              12,
              18,
              18,
              18
            ],
            rows: this.summaries.map((s) => [
              s.label,
              s.count,
              s.faceValue,
              s.accruedInterest,
              s.maturityValue
            ])
          },
          {
            sheetName: 'Portfolio Allocation',
            title: 'Portfolio Allocation — Target vs Actual',
            subtitle: `As on ${this.asOnDate}`,
            headers: [
              'Instrument Type',
              'Target Basis',
              'Target %',
              'Actual %',
              'Actual Value',
              'Variance %',
              'Status'
            ],
            widths: [
              26,
              20,
              12,
              12,
              18,
              12,
              18
            ],
            rows: this.allocationVsTarget.map((a) => [
              a.label,
              a.isRbiLinked ? 'RBI SLR / Non-SLR Norm' : 'Board Policy',
              a.targetPct,
              a.actualPct,
              a.actualValue,
              a.variancePct,
              a.statusLabel
            ])
          }
        ],
        `Investment-Dashboard-${this.asOnDate}`
      );
      this.toast('Investment Dashboard exported.');
    } catch (err) {
      console.error('Investment Dashboard export failed', err);
      this.toast('Could not generate the workbook — please retry.');
    } finally {
      this.generating = false;
    }
  }

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