<?php

namespace App\Services;

final class FinancialCategorySummaryService
{
    /**
     * Classify grouped rows from the legacy expenses table by accounting meaning.
     * Donation rows are incoming funds, not school expenses.
     */
    public static function summarize(array $rows): array
    {
        $expenseCategories = [];
        $totalExpenses = 0.0;
        $donationIncome = 0.0;

        foreach ($rows as $row) {
            $category = trim((string) ($row['category'] ?? '')) ?: 'Uncategorized';
            $amount = round((float) ($row['amount'] ?? $row['total_amount'] ?? 0), 2);
            if ($amount <= 0) {
                continue;
            }

            if (strcasecmp($category, 'Donation') === 0) {
                $donationIncome += $amount;
                continue;
            }

            $expenseCategories[$category] = round(($expenseCategories[$category] ?? 0) + $amount, 2);
            $totalExpenses += $amount;
        }

        arsort($expenseCategories, SORT_NUMERIC);

        return [
            'totalExpenses' => round($totalExpenses, 2),
            'donationIncome' => round($donationIncome, 2),
            'expenseCategories' => $expenseCategories,
        ];
    }
}