/**
 * 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, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import { MatDialog } from '@angular/material/dialog';
import { MatSnackBar } from '@angular/material/snack-bar';
import { MatTooltip } from '@angular/material/tooltip';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';

import {
  CertificatePreviewDialogComponent,
  CertificatePreviewDialogData
} from '../certificate-preview-dialog/certificate-preview-dialog.component';
import { downloadLoanInterestPdf } from '../certificate-pdf';

export type LoanProductType = 'HOUSING' | 'PERSONAL' | 'AUTO' | 'EDUCATION' | 'GOLD' | 'BUSINESS';

export interface FyInterestBreakup {
  /** Financial year label e.g. "FY 2024-25". */
  fy: string;
  openingBalance: number;
  closingBalance: number;
  principalPaid: number;
  interestPaid: number;
}

export interface LoanInterestRecord {
  accountNo: string;
  customerId: string;
  customerName: string;
  customerPan: string;
  customerAddress: string;
  branch: string;
  loanType: LoanProductType;
  sanctionedAmount: number;
  disbursementDate: string;
  /** Interest rate p.a. (e.g. 8.65) */
  interestRate: number;
  fy: FyInterestBreakup[];
}

@Component({
  selector: 'mifosx-loan-interest-certificate',
  templateUrl: './loan-interest.component.html',
  styleUrls: ['../certificates.shared.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    CommonModule,
    FormsModule,
    FaIconComponent,
    MatTooltip
  ]
})
export class LoanInterestCertificateComponent implements OnInit {
  private dialog = inject(MatDialog);
  private snack = inject(MatSnackBar);

  // ── Filters ──
  search = '';
  fyFilter = '';
  loanTypeFilter: '' | LoanProductType = '';

  loans: LoanInterestRecord[] = [];

  /** All financial years present across the dataset (newest first). */
  fyOptions: string[] = [];

  readonly loanTypeOptions: { value: LoanProductType; label: string }[] = [
    { value: 'HOUSING', label: 'Housing Loan' },
    { value: 'PERSONAL', label: 'Personal Loan' },
    { value: 'AUTO', label: 'Auto Loan' },
    { value: 'EDUCATION', label: 'Education Loan' },
    { value: 'GOLD', label: 'Gold Loan' },
    { value: 'BUSINESS', label: 'Business Loan' }
  ];

  ngOnInit(): void {
    this.loans = seedLoanInterestRecords();
    this.fyOptions = Array.from(new Set(this.loans.flatMap((l) => l.fy.map((f) => f.fy))))
      .sort()
      .reverse();
    // Default to most-recent FY
    if (this.fyOptions.length) {
      this.fyFilter = this.fyOptions[0];
    }
  }

  // ── Derived list ──
  get filteredLoans(): LoanInterestRecord[] {
    const q = this.search.trim().toLowerCase();
    return this.loans.filter((l) => {
      if (this.loanTypeFilter && l.loanType !== this.loanTypeFilter) return false;
      if (!q) return true;
      return (
        l.accountNo.toLowerCase().includes(q) ||
        l.customerName.toLowerCase().includes(q) ||
        l.customerId.toLowerCase().includes(q) ||
        l.customerPan.toLowerCase().includes(q)
      );
    });
  }

  loanTypeLabel(t: LoanProductType): string {
    return this.loanTypeOptions.find((o) => o.value === t)?.label || t;
  }

  selectedFyData(l: LoanInterestRecord): FyInterestBreakup | undefined {
    return l.fy.find((f) => f.fy === this.fyFilter) || l.fy[0];
  }

  totalInterestForFy(): number {
    return this.filteredLoans.reduce((s, l) => s + (this.selectedFyData(l)?.interestPaid || 0), 0);
  }

  totalPrincipalForFy(): number {
    return this.filteredLoans.reduce((s, l) => s + (this.selectedFyData(l)?.principalPaid || 0), 0);
  }

  outstandingPrincipal(l: LoanInterestRecord): number {
    return this.selectedFyData(l)?.closingBalance ?? 0;
  }

  // ── Actions ──
  clearFilters(): void {
    this.search = '';
    this.loanTypeFilter = '';
    if (this.fyOptions.length) this.fyFilter = this.fyOptions[0];
  }

  viewCertificate(l: LoanInterestRecord): void {
    const fy = this.selectedFyData(l);
    if (!fy) {
      this.snack.open('No interest data on file for the selected financial year.', 'OK', { duration: 2500 });
      return;
    }
    const data: CertificatePreviewDialogData = {
      kind: 'interest',
      loanInterest: { record: l, fy }
    };
    this.dialog.open(CertificatePreviewDialogComponent, {
      width: '880px',
      maxWidth: '96vw',
      maxHeight: '92vh',
      autoFocus: false,
      panelClass: 'cert-preview-dialog',
      data
    });
  }

  downloadCertificate(l: LoanInterestRecord): void {
    const fy = this.selectedFyData(l);
    if (!fy) {
      this.snack.open('No interest data on file for the selected financial year.', 'OK', { duration: 2500 });
      return;
    }
    downloadLoanInterestPdf(l, fy);
    this.snack.open(`Interest Certificate (${fy.fy}) downloaded.`, 'OK', { duration: 2400 });
  }
}

// ───────────────────── Mock seed (top-level export) ─────────────────────
export function seedLoanInterestRecords(): LoanInterestRecord[] {
  return [
    {
      accountNo: 'LN10029384',
      customerId: 'CUST112233',
      customerName: 'Rohan S. Mehta',
      customerPan: 'ABCPM1234E',
      customerAddress: 'Flat 902, Skyline Apt, Andheri (E), Mumbai 400069',
      branch: 'Mumbai — Andheri (E)',
      loanType: 'HOUSING',
      sanctionedAmount: 4500000,
      disbursementDate: '2021-06-15',
      interestRate: 8.65,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 3620000,
          closingBalance: 3380000,
          principalPaid: 240000,
          interestPaid: 312500
        },
        {
          fy: 'FY 2023-24',
          openingBalance: 3840000,
          closingBalance: 3620000,
          principalPaid: 220000,
          interestPaid: 328200
        },
        {
          fy: 'FY 2022-23',
          openingBalance: 4050000,
          closingBalance: 3840000,
          principalPaid: 210000,
          interestPaid: 342800
        }
      ]
    },
    {
      accountNo: 'LN20034112',
      customerId: 'CUST334455',
      customerName: 'Anita Verma',
      customerPan: 'EFGHV5678A',
      customerAddress: 'B-12, Connaught Pl, New Delhi 110001',
      branch: 'New Delhi — Connaught Place',
      loanType: 'PERSONAL',
      sanctionedAmount: 600000,
      disbursementDate: '2022-09-10',
      interestRate: 12.5,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 380000,
          closingBalance: 220000,
          principalPaid: 160000,
          interestPaid: 41200
        },
        { fy: 'FY 2023-24', openingBalance: 520000, closingBalance: 380000, principalPaid: 140000, interestPaid: 56800 }
      ]
    },
    {
      accountNo: 'LN50200077',
      customerId: 'CUST556677',
      customerName: 'Karthik Rao',
      customerPan: 'PQRSR2233Z',
      customerAddress: '24, MG Road, Bengaluru 560001',
      branch: 'Bengaluru — MG Road',
      loanType: 'AUTO',
      sanctionedAmount: 850000,
      disbursementDate: '2023-01-20',
      interestRate: 9.4,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 620000,
          closingBalance: 480000,
          principalPaid: 140000,
          interestPaid: 58800
        },
        { fy: 'FY 2023-24', openingBalance: 780000, closingBalance: 620000, principalPaid: 160000, interestPaid: 71200 }
      ]
    },
    {
      accountNo: 'LN70010023',
      customerId: 'CUST889900',
      customerName: 'Vikram Joshi',
      customerPan: 'LMNOJ9988X',
      customerAddress: 'Office 3B, Koregaon Park Road, Pune 411001',
      branch: 'Pune — Koregaon Park',
      loanType: 'BUSINESS',
      sanctionedAmount: 5500000,
      disbursementDate: '2020-11-05',
      interestRate: 11.0,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 4200000,
          closingBalance: 3950000,
          principalPaid: 250000,
          interestPaid: 464800
        },
        {
          fy: 'FY 2023-24',
          openingBalance: 4480000,
          closingBalance: 4200000,
          principalPaid: 280000,
          interestPaid: 488600
        },
        {
          fy: 'FY 2022-23',
          openingBalance: 4760000,
          closingBalance: 4480000,
          principalPaid: 280000,
          interestPaid: 522300
        }
      ]
    },
    {
      accountNo: 'LN88990022',
      customerId: 'CUST990011',
      customerName: 'Arjun Banerjee',
      customerPan: 'TUVWB4455F',
      customerAddress: '42, Park Street, Kolkata 700016',
      branch: 'Kolkata — Park Street',
      loanType: 'EDUCATION',
      sanctionedAmount: 1200000,
      disbursementDate: '2022-04-22',
      interestRate: 9.85,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 920000,
          closingBalance: 790000,
          principalPaid: 130000,
          interestPaid: 93500
        },
        {
          fy: 'FY 2023-24',
          openingBalance: 1080000,
          closingBalance: 920000,
          principalPaid: 160000,
          interestPaid: 102200
        }
      ]
    },
    {
      accountNo: 'LN50200099',
      customerId: 'CUST667788',
      customerName: 'Lakshmi Naidu',
      customerPan: 'XYZAN7788Q',
      customerAddress: 'Plot 14, Road No. 3, Banjara Hills, Hyderabad 500034',
      branch: 'Hyderabad — Banjara Hills',
      loanType: 'GOLD',
      sanctionedAmount: 450000,
      disbursementDate: '2023-08-18',
      interestRate: 10.25,
      fy: [
        {
          fy: 'FY 2024-25',
          openingBalance: 320000,
          closingBalance: 180000,
          principalPaid: 140000,
          interestPaid: 28400
        }
      ]
    }
  ];
}