/**
 * 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, inject } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormBuilder, FormGroup, ReactiveFormsModule, Validators } from '@angular/forms';
import { MatButtonModule } from '@angular/material/button';
import { MAT_DIALOG_DATA, MatDialog, MatDialogModule, MatDialogRef } from '@angular/material/dialog';
import { MatFormFieldModule } from '@angular/material/form-field';
import { MatInputModule } from '@angular/material/input';
import { MatSnackBar, MatSnackBarModule } from '@angular/material/snack-bar';

import { AmlService } from 'app/aml/aml.service';

const CATEGORY_LABEL: Record<number, string> = { 1: 'Low', 2: 'Medium', 3: 'High' };

/**
 * The approval queue for risk-category changes raised from the Risk Review Report.
 *
 * <p>
 * Approving here moves the customer's KYC rating and their re-KYC due date together, so the row
 * shows where the rating is going from and to, and why the reviewer asked - the checker is deciding
 * how closely the bank watches that customer, not clearing a queue item.
 */
@Component({
  selector: 'mifosx-risk-change-approvals',
  standalone: true,
  imports: [
    CommonModule,
    MatButtonModule,
    MatDialogModule,
    MatSnackBarModule
  ],
  template: `
    <div class="rca-root">
      <div class="rca-head">
        <div>
          <h2 class="rca-title">Risk Category Approvals</h2>
          <p class="rca-sub">
            Changes to a customer's KYC risk category, raised from the Risk Review Report. Approving moves the rating
            and the re-KYC due date together, and writes the reason into the customer's risk history.
          </p>
        </div>
      </div>

      <div class="rca-filters">
        <button
          *ngFor="let s of statuses"
          type="button"
          class="rca-chip"
          [class.rca-chip--on]="selectedStatus === s"
          (click)="filterBy(s)"
        >
          {{ s === '' ? 'All' : s }} <span class="rca-count">({{ countOf(s) }})</span>
        </button>
      </div>

      <div class="rca-table-wrap">
        <table class="rca-table">
          <thead>
            <tr>
              <th>Req. ID</th>
              <th>Customer</th>
              <th>CIF</th>
              <th>Branch</th>
              <th>Rating change</th>
              <th>Reason</th>
              <th>Status</th>
              <th>Requested By</th>
              <th>Requested On</th>
              <th>Action</th>
            </tr>
          </thead>
          <tbody>
            <tr *ngFor="let r of filtered">
              <td class="mono">{{ r.id }}</td>
              <td>
                <strong>{{ r.clientName }}</strong>
              </td>
              <td class="mono">{{ r.cifNumber || '—' }}</td>
              <td>{{ r.officeName || '—' }}</td>
              <td>
                <span class="rca-move">
                  {{ labelOf(r.currentCategory) }} <span class="rca-arrow">&rarr;</span>
                  <strong>{{ labelOf(r.requestedCategory) }}</strong>
                </span>
              </td>
              <td class="rca-reason">{{ r.reason }}</td>
              <td>
                <span class="rca-status" [ngClass]="'rca-status--' + (r.status || '').toLowerCase()">{{
                  r.status
                }}</span>
              </td>
              <td>{{ r.makerUsername }}</td>
              <td class="mono">{{ r.createdDate }}</td>
              <td>
                <div class="rca-actions" *ngIf="r.status === 'PENDING'">
                  <button mat-flat-button color="primary" type="button" (click)="approve(r)">Approve</button>
                  <button mat-stroked-button color="warn" type="button" (click)="reject(r)">Reject</button>
                </div>
                <span class="rca-done" *ngIf="r.status === 'APPROVED'">
                  by {{ r.checkerUsername }}, {{ r.checkerDate }}
                </span>
                <span class="rca-done" *ngIf="r.status === 'REJECTED'">{{ r.rejectionReason }}</span>
              </td>
            </tr>
            <tr *ngIf="!filtered.length">
              <td colspan="10" class="rca-empty">No risk category change matches this filter.</td>
            </tr>
          </tbody>
        </table>
      </div>
    </div>
  `,
  styles: [
    `
      .rca-root {
        padding: 20px 24px 40px;
        background: #f8fafc;
        min-height: 100%;
      }
      .rca-head {
        margin-bottom: 16px;
      }
      .rca-title {
        margin: 0 0 3px;
        font-size: 20px;
        font-weight: 700;
        color: #1e293b;
      }
      .rca-sub {
        margin: 0;
        max-width: 800px;
        font-size: 13px;
        line-height: 1.5;
        color: #64748b;
      }
      .rca-filters {
        display: flex;
        gap: 8px;
        margin-bottom: 14px;
        flex-wrap: wrap;
      }
      .rca-chip {
        height: 32px;
        padding: 0 14px;
        border: 1px solid #cbd5e1;
        border-radius: 999px;
        background: #fff;
        font: inherit;
        font-size: 12.5px;
        font-weight: 600;
        color: #334155;
        cursor: pointer;
      }
      .rca-chip--on {
        border-color: #1e3a8a;
        background: #eff6ff;
        color: #1e3a8a;
      }
      .rca-count {
        color: #94a3b8;
        font-weight: 500;
      }
      .rca-table-wrap {
        background: #fff;
        border: 1px solid #e2e8f0;
        border-radius: 11px;
        overflow-x: auto;
      }
      .rca-table {
        width: 100%;
        border-collapse: collapse;
        font-size: 12.5px;
      }
      .rca-table th {
        text-align: left;
        padding: 10px;
        background: #f1f5f9;
        font-size: 10.5px;
        font-weight: 700;
        text-transform: uppercase;
        letter-spacing: 0.04em;
        color: #475569;
        white-space: nowrap;
        border-bottom: 1px solid #e2e8f0;
      }
      .rca-table td {
        padding: 11px 10px;
        border-bottom: 1px solid #f1f5f9;
        vertical-align: middle;
        color: #334155;
      }
      .mono {
        font-family: 'DM Mono', monospace;
      }
      .rca-move {
        white-space: nowrap;
      }
      .rca-arrow {
        color: #94a3b8;
        margin: 0 4px;
      }
      .rca-reason {
        max-width: 280px;
      }
      .rca-status {
        display: inline-block;
        padding: 2px 9px;
        border-radius: 999px;
        font-size: 11px;
        font-weight: 700;
        background: #f1f5f9;
        color: #475569;
      }
      .rca-status--pending {
        background: #fef3c7;
        color: #b45309;
      }
      .rca-status--approved {
        background: #dcfce7;
        color: #15803d;
      }
      .rca-status--rejected {
        background: #fee2e2;
        color: #b91c1c;
      }
      .rca-actions {
        display: flex;
        gap: 8px;
      }
      .rca-done {
        font-size: 11.5px;
        color: #64748b;
      }
      .rca-empty {
        padding: 30px;
        text-align: center;
        color: #94a3b8;
      }
    `
  ]
})
export class RiskChangeApprovalsComponent implements OnInit {
  private amlService = inject(AmlService);
  private dialog = inject(MatDialog);
  private snackBar = inject(MatSnackBar);

  rows: any[] = [];
  readonly statuses = [
    'PENDING',
    'APPROVED',
    'REJECTED',
    ''
  ];
  selectedStatus = 'PENDING';

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

  load(): void {
    this.amlService.getRiskChangeRequests().subscribe({
      next: (rows) => (this.rows = rows || []),
      error: (err: any) =>
        this.snackBar.open('Could not load requests: ' + (err?.error?.defaultUserMessage || err.message), 'Close', {
          duration: 5000
        })
    });
  }

  get filtered(): any[] {
    return this.selectedStatus ? this.rows.filter((r) => r.status === this.selectedStatus) : this.rows;
  }

  countOf(status: string): number {
    return status ? this.rows.filter((r) => r.status === status).length : this.rows.length;
  }

  filterBy(status: string): void {
    this.selectedStatus = status;
  }

  labelOf(category: number | null): string {
    return category == null ? 'Unrated' : CATEGORY_LABEL[category] || '—';
  }

  approve(r: any): void {
    this.amlService.approveRiskChange(r.id).subscribe({
      next: () => {
        this.snackBar.open(
          `${r.clientName} moved to ${this.labelOf(r.requestedCategory)} — re-KYC due date updated.`,
          'Close',
          { duration: 6000 }
        );
        this.load();
      },
      error: (err: any) =>
        this.snackBar.open('Error: ' + (err?.error?.defaultUserMessage || err.message), 'Close', { duration: 7000 })
    });
  }

  reject(r: any): void {
    this.dialog
      .open(RejectRiskChangeDialogComponent, { width: '450px', data: { request: r }, disableClose: true })
      .afterClosed()
      .subscribe((done) => {
        if (done) {
          this.load();
        }
      });
  }
}

// ── REJECT DIALOG ──
@Component({
  selector: 'mifosx-reject-risk-change-dialog',
  standalone: true,
  imports: [
    CommonModule,
    ReactiveFormsModule,
    MatDialogModule,
    MatFormFieldModule,
    MatInputModule,
    MatButtonModule
  ],
  template: `
    <h2 mat-dialog-title>Reject Risk Category Change</h2>
    <mat-dialog-content>
      <p class="hint">
        {{ data.request.clientName }} stays on their current rating. The reason is shown to the reviewer who raised it.
      </p>
      <form [formGroup]="form">
        <mat-form-field appearance="outline" class="full">
          <mat-label>Rejection reason</mat-label>
          <textarea matInput formControlName="rejectionReason" rows="3"></textarea>
          <mat-error *ngIf="form.get('rejectionReason')?.hasError('required')">A reason is required</mat-error>
        </mat-form-field>
      </form>
    </mat-dialog-content>
    <mat-dialog-actions align="end">
      <button mat-stroked-button type="button" (click)="dialogRef.close(false)">Cancel</button>
      <button mat-flat-button color="warn" type="button" [disabled]="form.invalid || busy" (click)="submit()">
        Reject
      </button>
    </mat-dialog-actions>
  `,
  styles: [
    `
      .full {
        width: 100%;
      }
      .hint {
        font-size: 13px;
        color: #64748b;
        margin: 0 0 12px;
        line-height: 1.5;
      }
    `
  ]
})
export class RejectRiskChangeDialogComponent {
  private fb = inject(FormBuilder);
  private amlService = inject(AmlService);
  private snackBar = inject(MatSnackBar);
  dialogRef = inject(MatDialogRef<RejectRiskChangeDialogComponent>);

  data: { request: any } = inject(MAT_DIALOG_DATA);
  form: FormGroup;
  busy = false;

  constructor() {
    this.form = this.fb.group({ rejectionReason: [
        '',
        Validators.required
      ] });
  }

  submit(): void {
    if (this.form.invalid) {
      return;
    }
    this.busy = true;
    this.amlService.rejectRiskChange(this.data.request.id, this.form.value.rejectionReason).subscribe({
      next: () => {
        this.busy = false;
        this.snackBar.open('Risk category change rejected', 'Close', { duration: 3000 });
        this.dialogRef.close(true);
      },
      error: (err: any) => {
        this.busy = false;
        this.snackBar.open('Error: ' + (err?.error?.defaultUserMessage || err.message), 'Close', { duration: 6000 });
      }
    });
  }
}