<?php

namespace App\Libraries;

use App\Models\InvoiceModel;

class FinancialCorrectionReportService
{
    private InvoiceModel $invoiceModel;
    private FinancialReportProjectionService $projectionService;

    public function __construct(?FinancialReportProjectionService $projectionService = null)
    {
        $this->invoiceModel = new InvoiceModel();
        $this->projectionService = $projectionService ?? new FinancialReportProjectionService();
    }

    public function invoiceReport(?string $schoolYear = null): array
    {
        $query = $this->invoiceModel->orderBy('id', 'ASC');
        if ($schoolYear !== null && $schoolYear !== '') {
            $query->where('school_year', $schoolYear);
        }

        $rows = [];
        foreach ($query->findAll() as $invoice) {
            $projection = $this->projectionService->invoiceProjection((int) $invoice['id']);
            $storedTotalCents = $this->toCents((float) ($invoice['total_amount'] ?? 0));
            $storedBalanceCents = $this->toCents((float) ($invoice['balance'] ?? 0));
            $flags = [];

            if ($storedTotalCents !== $projection['invoice_gross_charges_cents']) {
                $flags[] = 'stored_total_mismatch';
            }
            if ($storedBalanceCents !== $projection['amount_due_cents']) {
                $flags[] = 'stored_balance_mismatch';
            }
            if ($projection['completed_cash_refunds_cents'] < 0) {
                $flags[] = 'wrong_refund_sign';
            }
            if ($projection['applied_discounts_cents'] > $projection['invoice_gross_charges_cents']) {
                $flags[] = 'discount_above_eligible_base';
            }

            $rows[] = [
                'invoice_id' => (int) $invoice['id'],
                'invoice_number' => $invoice['invoice_number'] ?? null,
                'stored_total_cents' => $storedTotalCents,
                'canonical_frozen_charge_total_cents' => $projection['invoice_gross_charges_cents'],
                'valid_payment_total_cents' => $projection['valid_payments_cents'],
                'completed_refund_payout_total_cents' => $projection['completed_cash_refunds_cents'],
                'applied_discount_total_cents' => $projection['applied_discounts_cents'],
                'expected_balance_due_cents' => $projection['amount_due_cents'],
                'expected_customer_credit_cents' => $projection['customer_credit_cents'],
                'flags' => $flags,
            ];
        }

        return $rows;
    }

    private function toCents(float $amount): int
    {
        return (int) round($amount * 100);
    }
}