/**
 * 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/.
 */

/** Angular Imports */
import { Component, OnInit, inject } from '@angular/core';
import { MatTableModule, MatTableDataSource } from '@angular/material/table';
import { MatIconModule } from '@angular/material/icon';
import { MatButtonModule } from '@angular/material/button';
import { MatTooltipModule } from '@angular/material/tooltip';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatSelectModule } from '@angular/material/select';
import { MatCheckboxModule } from '@angular/material/checkbox';
import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
import { MatDialog, MatDialogModule } from '@angular/material/dialog';
import { FormsModule } from '@angular/forms';
import { CommonModule } from '@angular/common';

/** Custom Services */
import { AmlService } from '../../../aml/aml.service';
import { AlertService } from '../../../core/alert/alert.service';
import { HasPermissionDirective } from '../../../directives/has-permission/has-permission.directive';
import { AmlRecurringReviewDialogComponent } from './aml-recurring-review-dialog.component';

/**
 * Customers whose transactions keep tripping the AML engine, queued for an employee to review why.
 *
 * A single alert is a transaction question and is handled on the Flagged Transactions tab. This tab
 * asks a different question — is this *customer's* pattern of behaviour acceptable — which no single
 * alert can answer. Reviews are recorded against the alert count seen, so a customer leaves the
 * queue once reviewed and only returns when the engine flags them again.
 */
@Component({
  selector: 'mifosx-aml-recurring-alerts',
  templateUrl: './aml-recurring-alerts.component.html',
  styleUrls: ['./aml-recurring-alerts.component.scss'],
  standalone: true,
  imports: [
    CommonModule,
    FormsModule,
    MatTableModule,
    MatIconModule,
    MatButtonModule,
    MatTooltipModule,
    MatFormFieldModule,
    MatSelectModule,
    MatCheckboxModule,
    MatProgressSpinnerModule,
    MatDialogModule,
    HasPermissionDirective
  ]
})
export class AmlRecurringAlertsComponent implements OnInit {
  private amlService = inject(AmlService);
  private dialog = inject(MatDialog);
  private alertService = inject(AlertService);

  rows = new MatTableDataSource<any>([]);
  displayedColumns: string[] = [
    'customer',
    'alertCount',
    'severity',
    'rules',
    'totalAmount',
    'lastAlert',
    'reviewState',
    'actions'
  ];

  /**
   * Matches ClientRiskEscalationServiceImpl.ESCALATION_THRESHOLD, which already treats 3 cumulative
   * AML events as the point a customer's risk rating is reconsidered.
   */
  minAlerts = 3;
  windowDays = 90;
  onlyNeedingReview = false;

  readonly thresholdOptions = [
    2,
    3,
    5,
    10
  ];
  readonly windowOptions = [
    { value: 30, label: 'Last 30 days' },
    { value: 90, label: 'Last 90 days' },
    { value: 180, label: 'Last 6 months' },
    { value: 365, label: 'Last 12 months' }
  ];

  loading = false;
  loadFailed = false;
  /** Which customer's alert detail is expanded inline. */
  expandedClientId: number | null = null;

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

  load(): void {
    this.loading = true;
    this.loadFailed = false;
    this.expandedClientId = null;
    this.amlService.getRecurringAlerts(this.minAlerts, this.windowDays, this.onlyNeedingReview).subscribe({
      next: (data) => {
        this.loading = false;
        this.rows.data = this.mapRows(data || []);
      },
      error: () => {
        this.loading = false;
        this.loadFailed = true;
        // An AML review queue shows what the engine found or nothing at all. Standing in sample
        // customers when the call fails invents suspicious activity against names that are not
        // the bank's, which is worse than an empty table saying the load failed.
        this.rows.data = [];
      }
    });
  }

  /** Parses the date fields the template renders. */
  private mapRows(rows: any[]): any[] {
    return rows.map((r: any) => ({
      ...r,
      firstAlertOnDate: this.toDate(r.firstAlertOn),
      lastAlertOnDate: this.toDate(r.lastAlertOn),
      lastReviewedOnDate: this.toDate(r.lastReviewedOn),
      alerts: (r.alerts || []).map((a: any) => ({ ...a, raisedOnDate: this.toDate(a.raisedOn) }))
    }));
  }

  toggleExpanded(row: any): void {
    this.expandedClientId = this.expandedClientId === row.clientId ? null : row.clientId;
  }

  isExpanded(row: any): boolean {
    return this.expandedClientId === row.clientId;
  }

  get needingReviewCount(): number {
    return this.rows.data.filter((r) => r.needsReview).length;
  }

  review(row: any): void {
    const dialogRef = this.dialog.open(AmlRecurringReviewDialogComponent, {
      width: '780px',
      maxWidth: '95vw',
      autoFocus: false,
      disableClose: true,
      data: { row, windowDays: this.windowDays }
    });

    dialogRef.afterClosed().subscribe((outcome: string | undefined) => {
      if (!outcome) {
        return;
      }
      this.alertService.alert({
        type: 'Review Recorded',
        message: `${row.clientDisplayName} reviewed as ${outcome}.`
      });
      // Re-read: the review changes needsReview, and the count recorded server-side is what the
      // row must now reflect.
      this.load();
    });
  }

  amount(value: any): string {
    return '₹' + (Number(value) || 0).toLocaleString('en-IN');
  }

  riskLabel(category: any): string {
    switch (Number(category)) {
      case 1:
        return 'Low';
      case 2:
        return 'Medium';
      case 3:
        return 'High';
      default:
        return 'Unrated';
    }
  }

  riskClass(category: any): string {
    switch (Number(category)) {
      case 1:
        return 'ra-risk ra-risk-low';
      case 2:
        return 'ra-risk ra-risk-medium';
      case 3:
        return 'ra-risk ra-risk-high';
      default:
        return 'ra-risk ra-risk-none';
    }
  }

  /**
   * Fineract's Gson adapter emits LocalDateTime as [y, M, d, H, m, s] rather than an ISO string, so
   * the date pipe renders nothing unless it is converted first. Month is 1-based there, 0-based in Date.
   */
  private toDate(value: any): Date | null {
    if (!value) {
      return null;
    }
    if (Array.isArray(value)) {
      const [
        y,
        M,
        d,
        H = 0,
        m = 0,
        s = 0
      ] = value;
      if (y == null || M == null || d == null) {
        return null;
      }
      return new Date(y, M - 1, d, H, m, s);
    }
    const parsed = new Date(value);
    return isNaN(parsed.getTime()) ? null : parsed;
  }
}