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

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

export interface RiskChangeDialogData {
  clientId: number;
  customerName: string;
  /** 1 Low, 2 Medium, 3 High; null where the customer carries no rating yet. */
  currentCategory: number | null;
  /** What the report's own computation says the rating should be, used as the default. */
  recommendedCategory: number | null;
  /** The one-line explanation the report already shows against the row. */
  recommendationReason: string;
}

/**
 * Raises a change to a customer's KYC risk category for approval.
 *
 * <p>
 * The rating governs how often the customer is re-KYC'd and what AML thresholds they are measured
 * against, so it is not something one officer moves on their own. The dialog collects what it
 * should become and why; a checker applies it.
 */
@Component({
  selector: 'mifosx-risk-change-dialog',
  standalone: true,
  imports: [
    CommonModule,
    ReactiveFormsModule,
    MatDialogModule,
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatSelectModule
  ],
  template: `
    <h2 mat-dialog-title>Change Risk Category</h2>
    <mat-dialog-content>
      <div class="rc-summary">
        <div class="rc-row">
          <span class="rc-label">Customer</span>
          <strong class="rc-value">{{ data.customerName }}</strong>
        </div>
        <div class="rc-row">
          <span class="rc-label">Rating on file</span>
          <strong class="rc-value">{{ labelOf(data.currentCategory) }}</strong>
        </div>
      </div>

      <!-- The report already worked this out; showing it saves the reviewer re-deriving it, and
           says plainly that the figure is a recommendation rather than a decision. -->
      <p class="rc-reason" *ngIf="data.recommendationReason">
        <span class="rc-label">Why this came up</span><br />{{ data.recommendationReason }}
      </p>

      <form [formGroup]="form" class="rc-form">
        <mat-form-field appearance="outline" class="rc-full">
          <mat-label>New risk category</mat-label>
          <mat-select formControlName="requestedCategory">
            <mat-option [value]="1">Low</mat-option>
            <mat-option [value]="2">Medium</mat-option>
            <mat-option [value]="3">High</mat-option>
          </mat-select>
          <mat-error *ngIf="form.get('requestedCategory')?.hasError('required')">Pick the new category</mat-error>
        </mat-form-field>

        <mat-form-field appearance="outline" class="rc-full">
          <mat-label>Reason</mat-label>
          <textarea
            matInput
            formControlName="reason"
            rows="3"
            placeholder="e.g. Repeated large cash deposits inconsistent with declared income"
          ></textarea>
          <mat-hint>Recorded against the customer's risk history</mat-hint>
          <mat-error *ngIf="form.get('reason')?.hasError('required')">A reason is required</mat-error>
        </mat-form-field>
      </form>

      <p class="rc-effect">
        The rating does not move now. It goes to a checker, and on approval the customer's KYC record and re-KYC due
        date are updated together.
      </p>

      <p class="rc-error" *ngIf="errorMessage">{{ errorMessage }}</p>
    </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="primary" type="button" [disabled]="form.invalid || submitting" (click)="submit()">
        {{ submitting ? 'Sending…' : 'Send for Approval' }}
      </button>
    </mat-dialog-actions>
  `,
  styles: [
    `
      .rc-summary {
        border: 1px solid #e2e8f0;
        border-radius: 8px;
        padding: 12px 14px;
        margin-bottom: 14px;
        background: #f8fafc;
      }
      .rc-row {
        display: flex;
        justify-content: space-between;
        align-items: baseline;
        gap: 16px;
        padding: 3px 0;
      }
      .rc-label {
        color: #64748b;
        font-size: 12.5px;
      }
      .rc-value {
        color: #1e293b;
        font-size: 13.5px;
      }
      .rc-reason {
        font-size: 12.5px;
        line-height: 1.5;
        color: #334155;
        margin: 0 0 14px;
      }
      .rc-form {
        display: flex;
        flex-direction: column;
      }
      .rc-full {
        width: 100%;
      }
      .rc-effect {
        font-size: 12.5px;
        line-height: 1.55;
        color: #1e3a8a;
        background: #eff6ff;
        border: 1px solid #bfdbfe;
        border-radius: 6px;
        padding: 10px 12px;
        margin: 4px 0 0;
      }
      .rc-error {
        margin: 12px 0 0;
        padding: 10px 12px;
        border: 1px solid #fecaca;
        border-radius: 6px;
        background: #fef2f2;
        color: #b91c1c;
        font-size: 12.5px;
      }
    `
  ]
})
export class RiskChangeDialogComponent {
  private fb = inject(FormBuilder);
  private amlService = inject(AmlService);
  private snackBar = inject(MatSnackBar);
  dialogRef = inject(MatDialogRef<RiskChangeDialogComponent>);

  form: FormGroup;
  submitting = false;
  errorMessage = '';

  constructor(@Inject(MAT_DIALOG_DATA) public data: RiskChangeDialogData) {
    this.form = this.fb.group({
      // Defaulted to what the report recommends, but left editable: the reviewer has seen the
      // customer and the computation has not.
      requestedCategory: [
        data.recommendedCategory ?? null,
        Validators.required
      ],
      reason: [
        '',
        Validators.required
      ]
    });
  }

  labelOf(category: number | null): string {
    return category === 1 ? 'Low' : category === 2 ? 'Medium' : category === 3 ? 'High' : 'Unrated';
  }

  submit(): void {
    if (this.form.invalid) {
      this.form.markAllAsTouched();
      return;
    }
    this.submitting = true;
    this.errorMessage = '';
    const v = this.form.value;
    this.amlService.requestRiskChange(this.data.clientId, v.requestedCategory, (v.reason || '').trim()).subscribe({
      next: () => {
        this.submitting = false;
        this.snackBar.open(
          `Risk change to ${this.labelOf(v.requestedCategory)} sent for approval — ${this.data.customerName}`,
          'Close',
          { duration: 5000 }
        );
        this.dialogRef.close(true);
      },
      error: (err: any) => {
        this.submitting = false;
        this.errorMessage = err?.error?.defaultUserMessage || err?.error?.message || 'Could not send the request.';
      }
    });
  }
}