/**
 * 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, inject } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule } from '@angular/forms';
import { catchError } from 'rxjs/operators';
import { of } from 'rxjs';

import { DividendDashboardService } from '../dividend-dashboard.service';
import { DividendClaimRequestService } from '../dividend-claim-request.service';

/**
 * Bank Manager's Dividend Dashboard: summary stats, every dividend ever declared, full 3-year
 * lock history, members whose unclaimed dividend sits alongside an overdue loan EMI (with a
 * proactive "Apply to Loan" action), and the maker-checker claim workflow for members who come to
 * claim their dividend directly (split across loan, savings, or cash).
 */
@Component({
  selector: 'mifosx-dividend-dashboard',
  templateUrl: './dividend-dashboard.component.html',
  styleUrls: [
    '../../cashier/cashier-shared.scss',
    '../clerk-shared.scss',
    './dividend-dashboard.component.scss'
  ],
  standalone: true,
  imports: [
    CommonModule,
    FormsModule
  ]
})
export class DividendDashboardComponent implements OnInit {
  private service = inject(DividendDashboardService);
  private claimRequestService = inject(DividendClaimRequestService);

  rows: any[] = [];
  loading = false;
  loaded = false;

  expandedLockId: number | null = null;
  selectedLoanId: Record<number, number | null> = {};
  applyAmount: Record<number, number | null> = {};
  applying = false;
  applyError: string | null = null;

  summary: any = null;
  summaryLoading = false;

  declarations: any[] = [];
  declarationsLoading = false;
  declarationsLoaded = false;

  /** Every lock the status filter returned, before the year filter narrows it. */
  locks: any[] = [];
  locksLoading = false;
  locksLoaded = false;
  lockStatusFilter = 'ALL';

  /**
   * Financial years that actually have locks, newest first — derived from the data rather than
   * listed anywhere, so a new declaration adds its year on its own and a year whose locks are all
   * gone stops being offered. No maintenance as years roll over.
   */
  lockYears: string[] = [];
  lockYearFilter = 'ALL';

  expandedClaimLockId: number | null = null;
  /**
   * A dividend is collected as a Demand Draft and nothing else — the savings-credit, cash and
   * loan-set-off routes are retired, so the panel only gathers what a draft needs: how much, drawn
   * in whose favour, and payable where.
   */
  claimDdAmount: Record<number, number | null> = {};
  claimDdBeneficiary: Record<number, string> = {};
  claimDdPayableAtBranch: Record<number, string> = {};
  claimDdPayableAtCity: Record<number, string> = {};
  claimSubmitting = false;
  claimError: string | null = null;

  claimRequests: any[] = [];
  claimRequestsLoading = false;
  claimRequestsLoaded = false;
  claimActioningId: number | null = null;
  claimActionError: Record<number, string> = {};

  /**
   * The Demand Draft just drawn by approving a claim. Held so the clerk can read off the number
   * after the row it came from has left the pending list — it is what goes on the counterfoil and
   * into the member's hand, and there is nowhere else on this screen to find it.
   */
  lastIssuedDd: { ddNumber: string; clientName: string; amount: number } | null = null;
  expandedRejectClaimId: number | null = null;
  rejectReason: Record<number, string> = {};

  ngOnInit(): void {
    this.loadSummary();
    this.loadDeclarations();
    this.load();
    this.loadLocks();
    this.loadClaimRequests();
  }

  toggleClaim(lock: any): void {
    if (this.expandedClaimLockId === lock.lockId) {
      this.expandedClaimLockId = null;
      return;
    }
    this.expandedClaimLockId = lock.lockId;
    this.claimError = null;
    // Defaults to the whole unclaimed balance and the member's own name, which is what a member
    // asks for almost every time; the clerk overrides only when the member wants otherwise.
    this.claimDdAmount[lock.lockId] = Number(lock.amount);
    this.claimDdBeneficiary[lock.lockId] = lock.clientName ?? '';
    this.claimDdPayableAtBranch[lock.lockId] = '';
    this.claimDdPayableAtCity[lock.lockId] = '';
  }

  submitClaim(lock: any): void {
    const ddAmount = Number(this.claimDdAmount[lock.lockId] || 0);
    const beneficiary = this.claimDdBeneficiary[lock.lockId]?.trim();
    const payableAtBranch = this.claimDdPayableAtBranch[lock.lockId]?.trim();
    const payableAtCity = this.claimDdPayableAtCity[lock.lockId]?.trim();

    if (ddAmount <= 0) {
      this.claimError = 'Enter a DD amount greater than zero.';
      return;
    }
    if (ddAmount > Number(lock.amount)) {
      this.claimError = `DD amount (${ddAmount}) cannot exceed the unclaimed amount of ${lock.amount}.`;
      return;
    }
    if (!beneficiary) {
      this.claimError = 'Enter the beneficiary name — a Demand Draft cannot be drawn without a payee.';
      return;
    }
    if (!payableAtBranch || !payableAtCity) {
      this.claimError = 'Enter both the branch and city the Demand Draft is payable at.';
      return;
    }

    this.claimSubmitting = true;
    this.claimError = null;
    this.claimRequestService
      .submit(lock.lockId, {
        ddApplyAmount: ddAmount,
        ddBeneficiaryName: beneficiary,
        ddPayableAtBranch: payableAtBranch,
        ddPayableAtCity: payableAtCity
      })
      .subscribe({
        next: () => {
          this.claimSubmitting = false;
          this.expandedClaimLockId = null;
          this.loadClaimRequests();
        },
        error: (err: any) => {
          this.claimSubmitting = false;
          this.claimError = err?.error?.message || 'Failed to submit claim request.';
        }
      });
  }

  loadClaimRequests(): void {
    this.claimRequestsLoading = true;
    this.claimRequestService
      .list('PENDING')
      .pipe(catchError(() => of([])))
      .subscribe((res: any[]) => {
        this.claimRequests = res ?? [];
        this.claimRequestsLoading = false;
        this.claimRequestsLoaded = true;
      });
  }

  approveClaim(req: any): void {
    this.claimActioningId = req.id;
    delete this.claimActionError[req.id];
    this.claimRequestService.approve(req.id).subscribe({
      next: (res: any) => {
        this.claimActioningId = null;
        // The draft number is the one thing the clerk needs off this action — it is what they write
        // on the counterfoil and hand to the member. Approving refreshes the list, so the row this
        // came from disappears; without surfacing it here the number would be lost.
        if (res?.ddNumber) {
          this.lastIssuedDd = {
            ddNumber: res.ddNumber,
            clientName: req.client_name,
            amount: Number(res.totalDisbursed) || Number(req.dd_apply_amount) || 0
          };
        }
        this.loadClaimRequests();
        this.loadLocks();
        this.loadSummary();
      },
      error: (err: any) => {
        this.claimActioningId = null;
        this.claimActionError[req.id] = err?.error?.message || 'Failed to approve claim.';
      }
    });
  }

  toggleRejectClaim(req: any): void {
    this.expandedRejectClaimId = this.expandedRejectClaimId === req.id ? null : req.id;
  }

  rejectClaim(req: any): void {
    const reason = this.rejectReason[req.id];
    if (!reason || !reason.trim()) {
      this.claimActionError[req.id] = 'Rejection reason is required.';
      return;
    }
    this.claimActioningId = req.id;
    delete this.claimActionError[req.id];
    this.claimRequestService.reject(req.id, reason).subscribe({
      next: () => {
        this.claimActioningId = null;
        this.expandedRejectClaimId = null;
        this.loadClaimRequests();
      },
      error: (err: any) => {
        this.claimActioningId = null;
        this.claimActionError[req.id] = err?.error?.message || 'Failed to reject claim.';
      }
    });
  }

  loadSummary(): void {
    this.summaryLoading = true;
    this.service
      .getSummary()
      .pipe(catchError(() => of(null)))
      .subscribe((res: any) => {
        this.summary = res;
        this.summaryLoading = false;
      });
  }

  loadDeclarations(): void {
    this.declarationsLoading = true;
    this.service
      .getDeclarations()
      .pipe(catchError(() => of([])))
      .subscribe((res: any[]) => {
        this.declarations = res ?? [];
        this.declarationsLoading = false;
        this.declarationsLoaded = true;
      });
  }

  declarationStatusLabel(status: string): string {
    return status === 'PENDING_APPROVAL' ? 'Pending Approval' : 'Approved';
  }

  declarationStatusClass(status: string): string {
    return status === 'PENDING_APPROVAL' ? 'dd-badge--pending' : 'dd-badge--posted';
  }

  loadLocks(): void {
    this.locksLoading = true;
    this.service
      .getLocks(this.lockStatusFilter)
      .pipe(catchError(() => of([])))
      .subscribe((res: any[]) => {
        this.locks = res ?? [];
        this.rebuildLockYears();
        this.locksLoading = false;
        this.locksLoaded = true;
      });
  }

  /**
   * Rebuilds the year chips from whatever locks came back, newest first.
   *
   * A year the current status filter has no locks for disappears from the chips, so the selected
   * year is reset to ALL when that happens — otherwise the table would show nothing with no
   * indication why.
   */
  private rebuildLockYears(): void {
    this.lockYears = [...new Set(this.locks.map((l) => l.financialYear).filter((y) => !!y))].sort((a, b) =>
      b.localeCompare(a)
    );
    if (this.lockYearFilter !== 'ALL' && !this.lockYears.includes(this.lockYearFilter)) {
      this.lockYearFilter = 'ALL';
    }
  }

  /** Locks the table actually renders — the status filter is applied server-side, the year here. */
  get visibleLocks(): any[] {
    return this.lockYearFilter === 'ALL'
      ? this.locks
      : this.locks.filter((l) => l.financialYear === this.lockYearFilter);
  }

  /** Total of what is on screen, so a year's worth of dividend can be read off directly. */
  get visibleLocksTotal(): number {
    return this.visibleLocks.reduce((sum, l) => sum + (Number(l.amount) || 0), 0);
  }

  setLockStatusFilter(status: string): void {
    this.lockStatusFilter = status;
    this.loadLocks();
  }

  setLockYearFilter(year: string): void {
    this.lockYearFilter = year;
  }

  lockStatusClass(status: string): string {
    switch (status) {
      case 'UNCLAIMED':
        return 'dd-badge--pending';
      case 'CLAIMED':
        return 'dd-badge--posted';
      case 'FORFEITED':
        return 'dd-badge--failed';
      default:
        return 'dd-badge--pending';
    }
  }

  load(): void {
    this.loading = true;
    this.expandedLockId = null;
    this.service
      .getDashboard()
      .pipe(catchError(() => of([])))
      .subscribe((res: any[]) => {
        this.rows = res ?? [];
        this.loading = false;
        this.loaded = true;
      });
  }

  totalOverdue(row: any): number {
    return (row.overdueLoans || []).reduce((sum: number, l: any) => sum + Number(l.overdueAmount || 0), 0);
  }

  toggleApply(row: any): void {
    if (this.expandedLockId === row.lockId) {
      this.expandedLockId = null;
      return;
    }
    this.expandedLockId = row.lockId;
    this.applyError = null;
    const firstLoan = (row.overdueLoans || [])[0];
    this.selectedLoanId[row.lockId] = firstLoan ? firstLoan.loanId : null;
    this.applyAmount[row.lockId] = firstLoan
      ? Math.min(Number(row.lockedAmount), Number(firstLoan.overdueAmount))
      : Number(row.lockedAmount);
  }

  maxAmountFor(row: any): number {
    const loanId = this.selectedLoanId[row.lockId];
    const loan = (row.overdueLoans || []).find((l: any) => l.loanId === loanId);
    const overdue = loan ? Number(loan.overdueAmount) : Number(row.lockedAmount);
    return Math.min(Number(row.lockedAmount), overdue);
  }

  onLoanChange(row: any): void {
    this.applyAmount[row.lockId] = this.maxAmountFor(row);
  }

  submitApply(row: any): void {
    const loanId = this.selectedLoanId[row.lockId];
    const amount = this.applyAmount[row.lockId];
    if (!loanId || !amount || amount <= 0) {
      this.applyError = 'Select a loan and enter a valid amount.';
      return;
    }
    this.applying = true;
    this.applyError = null;
    this.service.applyToLoan(row.lockId, loanId, amount).subscribe({
      next: () => {
        this.applying = false;
        this.load();
        this.loadLocks();
        this.loadSummary();
      },
      error: (err: any) => {
        this.applying = false;
        this.applyError = err?.error?.message || 'Failed to apply dividend to loan.';
      }
    });
  }
}