/**
 * 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, ViewChild, inject } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { Router, RouterLink } from '@angular/router';
import {
  MatTableDataSource,
  MatTable,
  MatColumnDef,
  MatHeaderCellDef,
  MatHeaderCell,
  MatCellDef,
  MatCell,
  MatHeaderRowDef,
  MatHeaderRow,
  MatRowDef,
  MatRow
} from '@angular/material/table';
import { MatPaginator, PageEvent } from '@angular/material/paginator';
import { MatSort } from '@angular/material/sort';
import { MatProgressBar } from '@angular/material/progress-bar';
import { MatButton, MatIconButton } from '@angular/material/button';
import { MatIcon } from '@angular/material/icon';
import { MatFormField, MatLabel, MatPrefix } from '@angular/material/form-field';
import { MatInput } from '@angular/material/input';
import { MatSelect } from '@angular/material/select';
import { MatOption } from '@angular/material/core';
import { MatDatepicker, MatDatepickerInput, MatDatepickerToggle } from '@angular/material/datepicker';
import { MatNativeDateModule } from '@angular/material/core';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';
import { OtpAuditLogsService, OtpLog, OtpLogPage } from './otp-audit-logs.service';

@Component({
  selector: 'mifosx-otp-audit-logs',
  templateUrl: './otp-audit-logs.component.html',
  styleUrls: ['./otp-audit-logs.component.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    FormsModule,
    RouterLink,
    MatTable,
    MatColumnDef,
    MatHeaderCellDef,
    MatHeaderCell,
    MatCellDef,
    MatCell,
    MatHeaderRowDef,
    MatHeaderRow,
    MatRowDef,
    MatRow,
    MatPaginator,
    MatProgressBar,
    MatButton,
    MatIconButton,
    MatIcon,
    MatFormField,
    MatLabel,
    MatPrefix,
    MatInput,
    MatSelect,
    MatOption,
    MatDatepicker,
    MatDatepickerInput,
    MatDatepickerToggle,
    MatNativeDateModule,
    FaIconComponent
  ]
})
export class OtpAuditLogsComponent implements OnInit {
  private service = inject(OtpAuditLogsService);
  private router = inject(Router);

  @ViewChild(MatPaginator) paginator!: MatPaginator;

  loading = false;
  totalElements = 0;
  dataSource = new MatTableDataSource<OtpLog>([]);
  /** Last error returned by the listing endpoint (if any) */
  errorStatus = 0;
  errorMsg = '';

  displayedColumns: string[] = [
    'id',
    'createdOn',
    'username',
    'channel',
    'destination',
    'status',
    'attempts',
    'verifiedOn',
    'actions'
  ];

  /** Filter state */
  search = '';
  status = '';
  channel = '';
  dateFrom: Date | null = null;
  dateTo: Date | null = null;
  pageSize = 25;
  pageIndex = 0;

  readonly statusOptions = [
    { value: '', label: 'All' },
    { value: 'PENDING', label: 'Pending' },
    { value: 'VERIFIED', label: 'Verified' },
    { value: 'FAILED', label: 'Failed' },
    { value: 'EXPIRED', label: 'Expired' },
    { value: 'LOCKED', label: 'Locked' }
  ];

  readonly channelOptions = [
    { value: '', label: 'All' },
    { value: 'SMS', label: 'SMS' },
    { value: 'EMAIL', label: 'Email' },
    { value: 'TOTP', label: 'Authenticator' }
  ];

  ngOnInit(): void {
    this.fetch();
  }

  fetch(): void {
    this.loading = true;
    this.errorStatus = 0;
    this.errorMsg = '';
    this.service
      .list({
        page: this.pageIndex,
        pageSize: this.pageSize,
        search: this.search?.trim() || undefined,
        status: this.status || undefined,
        channel: this.channel || undefined,
        dateFrom: this.toIso(this.dateFrom),
        dateTo: this.toIso(this.dateTo)
      })
      .subscribe({
        next: (res: OtpLogPage | OtpLog[]) => {
          this.loading = false;
          if (Array.isArray(res)) {
            this.totalElements = res.length;
            this.dataSource.data = res;
          } else {
            this.totalElements = res?.totalElements ?? res?.pageItems?.length ?? 0;
            this.dataSource.data = res?.pageItems || [];
          }
        },
        error: (err) => {
          this.loading = false;
          this.dataSource.data = [];
          this.totalElements = 0;
          this.errorStatus = err?.status || 0;
          this.errorMsg =
            err?.error?.defaultUserMessage || err?.error?.message || err?.message || 'Failed to load OTP audit logs.';
        }
      });
  }

  applyFilters(): void {
    this.pageIndex = 0;
    if (this.paginator) this.paginator.firstPage();
    this.fetch();
  }

  clearFilters(): void {
    this.search = '';
    this.status = '';
    this.channel = '';
    this.dateFrom = null;
    this.dateTo = null;
    this.applyFilters();
  }

  onPage(e: PageEvent): void {
    this.pageIndex = e.pageIndex;
    this.pageSize = e.pageSize;
    this.fetch();
  }

  view(log: OtpLog): void {
    if (log?.id != null)
      this.router.navigate([
        '/otp-audit-logs',
        log.id
      ]);
  }

  refresh(): void {
    this.fetch();
  }

  /** Export the currently displayed page as a CSV file. */
  downloadCsv(): void {
    const rows = this.dataSource.data || [];
    if (!rows.length) return;
    const headers = [
      'ID',
      'Created',
      'User',
      'Channel',
      'Destination',
      'Status',
      'Purpose',
      'Attempts',
      'Verified On',
      'IP',
      'Reference'
    ];
    const escape = (v: any) => {
      if (v == null) return '';
      const s = String(v).replace(/"/g, '""');
      return /[",\n]/.test(s) ? `"${s}"` : s;
    };
    const lines = [headers.join(',')];
    for (const r of rows) {
      lines.push(
        [
          r.id,
          this.formatDate(r.createdOn),
          r.username,
          r.channel,
          r.destination,
          r.status,
          r.purpose,
          r.attempts,
          this.formatDate(r.verifiedOn),
          r.ipAddress,
          r.otpReference
        ]
          .map(escape)
          .join(',')
      );
    }
    const blob = new Blob([lines.join('\n')], { type: 'text/csv;charset=utf-8;' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = `otp-audit-logs-${new Date().toISOString().slice(0, 10)}.csv`;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
  }

  /** Format date arrays/strings into a friendly local string */
  formatDate(value: any): string {
    if (!value) return '—';
    if (Array.isArray(value) && value.length >= 3) {
      const [
        y,
        m,
        d,
        h = 0,
        mi = 0,
        s = 0
      ] = value;
      const dt = new Date(y, m - 1, d, h, mi, s);
      return dt.toLocaleString();
    }
    if (typeof value === 'string') {
      const dt = new Date(value);
      return isNaN(dt.getTime()) ? value : dt.toLocaleString();
    }
    return String(value);
  }

  statusClass(status?: string): string {
    if (!status) return '';
    const s = status.toUpperCase();
    if (s === 'VERIFIED') return 'is-ok';
    if (s === 'PENDING') return 'is-warn';
    if (s === 'FAILED' || s === 'EXPIRED' || s === 'LOCKED') return 'is-bad';
    return '';
  }

  private toIso(d: Date | null): string | undefined {
    if (!d) return undefined;
    const yyyy = d.getFullYear();
    const mm = String(d.getMonth() + 1).padStart(2, '0');
    const dd = String(d.getDate()).padStart(2, '0');
    return `${yyyy}-${mm}-${dd}`;
  }
}