/**
 * 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, ElementRef, OnDestroy, OnInit, ViewChild, inject } from '@angular/core';
import { formatDate } from '@angular/common';
import { UntypedFormBuilder, UntypedFormGroup, Validators } from '@angular/forms';
import { Observable, concat } from 'rxjs';
import { Router } from '@angular/router';
import { MatIconModule } from '@angular/material/icon';
import { MatButtonModule } from '@angular/material/button';
import { MatTableModule } from '@angular/material/table';
import { MatTabsModule } from '@angular/material/tabs';
import { MatPaginatorModule, PageEvent } from '@angular/material/paginator';
import { MatSnackBar, MatSnackBarModule } from '@angular/material/snack-bar';
import { FaIconComponent } from '@fortawesome/angular-fontawesome';
import lightGallery from 'lightgallery';
import lgZoom from 'lightgallery/plugins/zoom';
import lgFullscreen from 'lightgallery/plugins/fullscreen';
import type { LightGallery } from 'lightgallery/lightgallery';
import type { GalleryItem } from 'lightgallery/lg-utils';
import { STANDALONE_SHARED_IMPORTS } from 'app/standalone-shared.module';

/** Custom Services */
import { CtsClearingService } from '../ctsclearing.service';
import { pillClass, clearingError } from '../../clearing-network/clearing-status';

/**
 * Outward CTS clearing — landing page for the whole outward flow. Capture a cheque, see it sit as
 * "Pending" until a clearing session sends it, then find it as a row in the Batches table below (a real
 * session, one row per shared batchReference) — click a batch to see its cheques and settle/dishonour them.
 * There's no per-cheque "Send" any more: cheques only leave via the 2-hourly session job or the manual
 * "Send Pending Batch" fallback, so batch is always the unit you browse sent cheques by.
 */
@Component({
  selector: 'mifosx-outward-presentment',
  templateUrl: './outward-presentment.component.html',
  styleUrls: ['./outward-presentment.component.scss'],
  imports: [
    ...STANDALONE_SHARED_IMPORTS,
    MatIconModule,
    MatButtonModule,
    MatTableModule,
    MatTabsModule,
    MatPaginatorModule,
    MatSnackBarModule,
    FaIconComponent
  ]
})
export class OutwardPresentmentComponent implements OnInit, OnDestroy {
  private formBuilder = inject(UntypedFormBuilder);
  private ctsService = inject(CtsClearingService);
  private router = inject(Router);
  private snackBar = inject(MatSnackBar);

  @ViewChild('lightboxRoot', { static: true }) lightboxRoot: ElementRef<HTMLElement>;
  private lightboxInstance: LightGallery | null = null;
  private readonly lightboxPlugins = [
    lgZoom,
    lgFullscreen
  ];

  pillClass = pillClass;

  private notify(message: string, isError = false): void {
    this.snackBar.open(message, 'Dismiss', { duration: isError ? 6000 : 3000 });
  }

  busy = false;
  showCaptureForm = false;

  /** Cheque images picked in the capture form itself — uploaded right after creation, in the same Submit. */
  selectedFrontFile: File | null = null;
  selectedBackFile: File | null = null;
  frontPreviewUrl: string | null = null;
  backPreviewUrl: string | null = null;

  captureForm: UntypedFormGroup;
  pendingFilterForm: UntypedFormGroup;
  batchesFilterForm: UntypedFormGroup;

  // ----- Pending cheques (CAPTURED, not yet in any batch) -----

  presentments: any[] = [];
  pendingTotalRecords = 0;
  pendingPageSize = 10;
  pendingPageIndex = 0;
  pageSizeOptions = [
    10,
    25,
    50,
    100
  ];

  pendingColumns = [
    'id',
    'chequeNumber',
    'drawerBank',
    'payeeName',
    'amount',
    'depositedDate',
    'image',
    'status'
  ];

  // ----- Batches (real, already-sent clearing sessions) -----

  batches: any[] = [];
  batchesTotalRecords = 0;
  batchesPageSize = 10;
  batchesPageIndex = 0;

  batchColumns = [
    'batchReference',
    'session',
    'items',
    'amount',
    'progress',
    'actions'
  ];

  /**
   * Defaults to today on first load so this isn't every session ever sent — "All" widens it. Persisted on
   * the singleton service so opening a batch and navigating back doesn't silently reset the choice.
   */
  get batchDateFilter(): 'today' | 'all' {
    return this.ctsService.outwardBatchesDateFilter;
  }

  constructor() {
    this.captureForm = this.formBuilder.group({
      depositingAccountType: [
        'SAVINGS',
        Validators.required
      ],
      depositingAccountId: [
        '',
        Validators.required
      ],
      chequeNumber: [
        '',
        Validators.required
      ],
      amount: [
        '',
        Validators.required
      ],
      payeeName: [''],
      drawerBankName: [''],
      drawerBankMicr: [''],
      drawerIfsc: [''],
      depositedDate: [
        '',
        Validators.required
      ],
      stopPaymentFlag: [false],
      iqaStatus: ['PASS'],
      iqaDetail: [''],
      drawerAccountNumber: ['']
    });
    this.pendingFilterForm = this.formBuilder.group({
      fromDate: [''],
      toDate: [''],
      chequeNumber: [''],
      drawerBankName: [''],
      payeeName: ['']
    });
    // Batches defaults to today on first load — matches the persisted Today/All quick toggle below.
    const initialBatchDate = this.batchDateFilter === 'today' ? new Date() : null;
    this.batchesFilterForm = this.formBuilder.group({
      fromDate: [initialBatchDate],
      toDate: [initialBatchDate],
      batchReference: ['']
    });
  }

  ngOnInit(): void {
    this.loadPresentments();
    this.loadBatches();
  }

  ngOnDestroy(): void {
    this.destroyLightbox();
  }

  /** Cheque image data URLs, keyed "<presentmentId>_<side>" — populated once fetched. */
  imageUrls: { [key: string]: string } = {};

  loadPresentments(): void {
    const f = this.pendingFilterForm.value;
    const filters = {
      fromDate: this.toApiDate(f.fromDate),
      toDate: this.toApiDate(f.toDate),
      chequeNumber: f.chequeNumber || undefined,
      drawerBankName: f.drawerBankName || undefined,
      payeeName: f.payeeName || undefined
    };
    this.ctsService
      .getOutwardPresentments('CAPTURED', this.pendingPageIndex * this.pendingPageSize, this.pendingPageSize, filters)
      .subscribe((res: any) => {
        this.presentments = res?.pageItems ?? (Array.isArray(res) ? res : []);
        this.pendingTotalRecords = Number(res?.totalFilteredRecords ?? this.presentments.length);
        this.presentments.forEach((p: any) => {
          this.loadItemImage(p, 'front');
          this.loadItemImage(p, 'back');
        });
      });
  }

  applyPendingFilters(): void {
    this.pendingPageIndex = 0;
    this.loadPresentments();
  }

  clearPendingFilters(): void {
    this.pendingFilterForm.reset({ fromDate: '', toDate: '', chequeNumber: '', drawerBankName: '', payeeName: '' });
    this.pendingPageIndex = 0;
    this.loadPresentments();
  }

  onPendingPageChange(event: PageEvent): void {
    this.pendingPageSize = event.pageSize;
    this.pendingPageIndex = event.pageIndex;
    this.loadPresentments();
  }

  loadBatches(): void {
    const f = this.batchesFilterForm.value;
    const filters = {
      fromDate: this.toApiDate(f.fromDate),
      toDate: this.toApiDate(f.toDate),
      batchReference: f.batchReference || undefined
    };
    this.ctsService
      .getOutwardBatches(this.batchesPageIndex * this.batchesPageSize, this.batchesPageSize, filters)
      .subscribe((res: any) => {
        this.batches = res?.pageItems ?? (Array.isArray(res) ? res : []);
        this.batchesTotalRecords = Number(res?.totalFilteredRecords ?? this.batches.length);
      });
  }

  applyBatchesFilters(): void {
    // A manual date edit no longer matches a plain "today"/"all" quick state — treat it as custom.
    this.ctsService.outwardBatchesDateFilter = 'all';
    this.batchesPageIndex = 0;
    this.loadBatches();
  }

  clearBatchesFilters(): void {
    this.ctsService.outwardBatchesDateFilter = 'all';
    this.batchesFilterForm.reset({ fromDate: '', toDate: '', batchReference: '' });
    this.batchesPageIndex = 0;
    this.loadBatches();
  }

  setBatchDateFilter(filter: 'today' | 'all'): void {
    this.ctsService.outwardBatchesDateFilter = filter;
    const day = filter === 'today' ? new Date() : null;
    this.batchesFilterForm.patchValue({ fromDate: day, toDate: day });
    this.batchesPageIndex = 0;
    this.loadBatches();
  }

  onBatchesPageChange(event: PageEvent): void {
    this.batchesPageSize = event.pageSize;
    this.batchesPageIndex = event.pageIndex;
    this.loadBatches();
  }

  openBatch(batch: any): void {
    this.router.navigate([
      '/ctsclearing',
      'outward-batches',
      batch.batchReference
    ]);
  }

  /** Fetches the image as an authenticated base64 data URL and caches it — 404 (no upload yet) is expected and silent. */
  loadItemImage(presentment: any, side: 'front' | 'back'): void {
    this.ctsService.getOutwardPresentmentImage(presentment.id, side).subscribe({
      next: (dataUrl: string) => (this.imageUrls[`${presentment.id}_${side}`] = dataUrl),
      error: () => {
        /* no image uploaded for this side yet */
      }
    });
  }

  getItemImageUrl(presentment: any, side: 'front' | 'back'): string | null {
    return this.imageUrls[`${presentment.id}_${side}`] || null;
  }

  /** Opens the front/back cheque image(s) in a zoomable, pannable lightbox — same lightgallery setup used app-wide. */
  openImageZoom(presentment: any, side: 'front' | 'back'): void {
    const frontUrl = this.getItemImageUrl(presentment, 'front');
    const backUrl = this.getItemImageUrl(presentment, 'back');
    const items: GalleryItem[] = [];
    if (frontUrl) {
      items.push({
        src: frontUrl,
        thumb: frontUrl,
        subHtml: `<div class="lg-caption"><h4>Front — Cheque ${presentment.chequeNumber}</h4></div>`
      });
    }
    if (backUrl) {
      items.push({
        src: backUrl,
        thumb: backUrl,
        subHtml: `<div class="lg-caption"><h4>Back — Cheque ${presentment.chequeNumber}</h4></div>`
      });
    }
    if (!items.length) {
      return;
    }
    const startIndex = side === 'back' && frontUrl ? 1 : 0;
    this.destroyLightbox();
    this.lightboxInstance = lightGallery(this.lightboxRoot.nativeElement, {
      dynamic: true,
      dynamicEl: items,
      plugins: this.lightboxPlugins,
      download: false,
      closable: true,
      escKey: true,
      zoomFromOrigin: true
    });
    this.lightboxInstance.openGallery(startIndex);
  }

  private destroyLightbox(): void {
    if (this.lightboxInstance) {
      this.lightboxInstance.destroy();
      this.lightboxInstance = null;
    }
  }

  uploadItemImage(presentment: any, side: 'front' | 'back', event: Event): void {
    const input = event.target as HTMLInputElement;
    const file = input.files && input.files[0];
    if (!file) {
      return;
    }
    this.ctsService.uploadOutwardPresentmentImage(presentment.id, side, file).subscribe({
      next: () => {
        this.notify(side === 'front' ? 'Front image uploaded' : 'Back image uploaded');
        this.loadItemImage(presentment, side);
      },
      error: (err: any) => this.notify(clearingError(err, 'Image upload failed'), true)
    });
    input.value = '';
  }

  private toApiDate(value: any): string | undefined {
    if (!value) {
      return undefined;
    }
    return formatDate(value, 'yyyy-MM-dd', 'en');
  }

  /** Picks a front/back cheque image right in the capture form — uploaded once the cheque is created below. */
  onCaptureFileSelected(side: 'front' | 'back', event: Event): void {
    const input = event.target as HTMLInputElement;
    const file = input.files && input.files[0];
    if (!file) {
      return;
    }
    const previewUrl = URL.createObjectURL(file);
    if (side === 'front') {
      if (this.frontPreviewUrl) {
        URL.revokeObjectURL(this.frontPreviewUrl);
      }
      this.selectedFrontFile = file;
      this.frontPreviewUrl = previewUrl;
    } else {
      if (this.backPreviewUrl) {
        URL.revokeObjectURL(this.backPreviewUrl);
      }
      this.selectedBackFile = file;
      this.backPreviewUrl = previewUrl;
    }
  }

  private resetCaptureFiles(): void {
    if (this.frontPreviewUrl) {
      URL.revokeObjectURL(this.frontPreviewUrl);
    }
    if (this.backPreviewUrl) {
      URL.revokeObjectURL(this.backPreviewUrl);
    }
    this.selectedFrontFile = null;
    this.selectedBackFile = null;
    this.frontPreviewUrl = null;
    this.backPreviewUrl = null;
  }

  /** Front + back cheque image are mandatory before a cheque can be captured — checked in the template too. */
  canSubmitCapture(): boolean {
    return this.captureForm.valid && !!this.selectedFrontFile && !!this.selectedBackFile && !this.busy;
  }

  submitCapture(): void {
    if (!this.canSubmitCapture()) {
      if (this.captureForm.valid && (!this.selectedFrontFile || !this.selectedBackFile)) {
        this.notify('Front and back cheque image are both required', true);
      }
      return;
    }
    this.busy = true;
    const raw = this.captureForm.value;
    const payload = {
      depositingAccountType: raw.depositingAccountType,
      depositingAccountId: raw.depositingAccountId,
      chequeNumber: raw.chequeNumber,
      amount: raw.amount,
      payeeName: raw.payeeName || undefined,
      drawerBankName: raw.drawerBankName || undefined,
      drawerBankMicr: raw.drawerBankMicr || undefined,
      drawerIfsc: raw.drawerIfsc || undefined,
      depositedDate: this.toApiDate(raw.depositedDate),
      stopPaymentFlag: !!raw.stopPaymentFlag,
      iqaStatus: raw.iqaStatus || undefined,
      iqaDetail: raw.iqaDetail || undefined,
      drawerAccountNumber: raw.drawerAccountNumber || undefined,
      dateFormat: 'yyyy-MM-dd',
      locale: 'en'
    };
    this.ctsService.createOutwardPresentment(payload).subscribe({
      next: (res: any) => {
        const newId = res?.resourceId;
        const front = this.selectedFrontFile;
        const back = this.selectedBackFile;
        if (!newId || (!front && !back)) {
          this.finishCapture('Cheque captured');
          return;
        }
        // upload whichever image(s) were picked, in the same Submit action, before closing the form.
        // Sequential (concat), NOT parallel (forkJoin): two concurrent updates to the same row would race
        // against its @Version optimistic lock and throw OptimisticLockException on the second write.
        const uploads: Observable<any>[] = [];
        if (front) {
          uploads.push(this.ctsService.uploadOutwardPresentmentImage(newId, 'front', front));
        }
        if (back) {
          uploads.push(this.ctsService.uploadOutwardPresentmentImage(newId, 'back', back));
        }
        concat(...uploads).subscribe({
          complete: () => this.finishCapture('Cheque captured with image(s)'),
          error: (err: any) => {
            this.busy = false;
            this.notify(
              clearingError(err, 'Cheque captured, but image upload failed — upload it from the table row'),
              true
            );
            this.showCaptureForm = false;
            this.resetCaptureFiles();
            this.captureForm.reset({ depositingAccountType: 'SAVINGS', stopPaymentFlag: false, iqaStatus: 'PASS' });
            this.loadPresentments();
          }
        });
      },
      error: (err: any) => {
        this.busy = false;
        this.notify(clearingError(err, 'Could not capture the cheque'), true);
      }
    });
  }

  cancelCapture(): void {
    this.showCaptureForm = false;
    this.resetCaptureFiles();
  }

  private finishCapture(message: string): void {
    this.busy = false;
    this.showCaptureForm = false;
    this.resetCaptureFiles();
    this.captureForm.reset({ depositingAccountType: 'SAVINGS', stopPaymentFlag: false, iqaStatus: 'PASS' });
    this.notify(message);
    this.loadPresentments();
  }

  /** Fills the capture form with realistic sample data in one click, for quick demo/testing. */
  fillDummyData(): void {
    const stamp = Date.now().toString().slice(-6);
    const banks = [
      { name: 'IDFC First Bank', micr: '400229015', ifsc: 'IDFC0000045' },
      { name: 'HDFC Bank', micr: '400240012', ifsc: 'HDFC0000078' },
      { name: 'ICICI Bank', micr: '400229033', ifsc: 'ICIC0000112' }
    ];
    const bank = banks[Math.floor(Math.random() * banks.length)];
    const today = new Date();

    this.captureForm.patchValue({
      depositingAccountType: 'SAVINGS',
      depositingAccountId: 1,
      chequeNumber: stamp,
      amount: (Math.floor(Math.random() * 900) + 100) * 100,
      payeeName: 'Test Payee ' + stamp,
      drawerBankName: bank.name,
      drawerBankMicr: bank.micr,
      drawerIfsc: bank.ifsc,
      drawerAccountNumber: 'XXXXXXXX' + stamp,
      depositedDate: today,
      stopPaymentFlag: false,
      iqaStatus: 'PASS',
      iqaDetail: 'Auto-filled sample data'
    });
    this.notify('Dummy values filled — review and Submit');
  }

  /**
   * Manual stand-in for the clearing-session scheduler (currently disabled): bundles every CAPTURED cheque
   * into one CTS batch file and sends it to the clearing house in a single go.
   */
  sendPendingBatch(): void {
    if (this.busy) {
      return;
    }
    this.busy = true;
    this.ctsService.sendPendingOutwardBatch().subscribe({
      next: (res: any) => {
        this.busy = false;
        const count = res?.resourceId ?? '';
        this.notify(count ? `Batch sent to the clearing house — ${count} cheque(s)` : 'No pending cheques to send');
        this.loadPresentments();
        this.loadBatches();
      },
      error: (err: any) => {
        this.busy = false;
        this.notify(clearingError(err, 'Could not send the pending batch'), true);
      }
    });
  }
}