delete_contribution.php

<?php
include 'db_connect.php';

if (isset($_POST['id'], $_POST['amount'], $_POST['salary_account_number'])) {
    $contribution_id = $_POST['id'];
    $amount = $_POST['amount'];
    $salary_account_number = $_POST['salary_account_number'];

    // Start transaction
    $conn->begin_transaction();
    try {
        // Delete the contribution
        $delete_sql = "DELETE FROM contributions WHERE id = ?";
        $stmt = $conn->prepare($delete_sql);
        $stmt->bind_param("i", $contribution_id);
        $stmt->execute();
        if ($stmt->affected_rows == 0) {
            throw new Exception("Failed to delete contribution.");
        }

        // Check if the balance exists in member_balances
        $balance_check_sql = "SELECT balance FROM member_balances WHERE salary_account_number = ?";
        $stmt = $conn->prepare($balance_check_sql);
        $stmt->bind_param("s", $salary_account_number);
        $stmt->execute();
        $balance_result = $stmt->get_result();

        if ($balance_result->num_rows > 0) {
            // Deduct the contribution amount from balance
            $row = $balance_result->fetch_assoc();
            $new_balance = max(0, $row['balance'] - $amount); // Ensure balance doesn't go negative

            $update_balance_sql = "UPDATE member_balances SET balance = ?, date_updated = NOW() WHERE salary_account_number = ?";
            $stmt = $conn->prepare($update_balance_sql);
            $stmt->bind_param("ds", $new_balance, $salary_account_number);
            $stmt->execute();
        }

        // Commit transaction
        $conn->commit();
        echo 1;
    } catch (Exception $e) {
        $conn->rollback();
        echo 0;
    }
}
?>