<?php
session_start();
require_once __DIR__ . '/db/config.php';

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    header('Location: index.php');
    exit();
}

// Basic validation
$activity_id = $_POST['activity_id'] ?? null;
$activity_type = trim($_POST['activity_type'] ?? '');
$status = trim($_POST['status'] ?? '');
$due_date = $_POST['due_date'] ?? null;
$notes = trim($_POST['notes'] ?? '');

if (empty($activity_id) || empty($activity_type) || empty($status)) {
    $_SESSION['error_message'] = 'Required fields are missing.';
    header('Location: index.php');
    exit();
}

try {
    $pdo = db();
    $stmt = $pdo->prepare(
        'UPDATE activities SET ActivityType = ?, Status = ?, DueDate = ?, Notes = ? WHERE ActivityID = ?'
    );
    $stmt->execute([
        $activity_type,
        $status,
        $due_date,
        $notes,
        $activity_id
    ]);

    $_SESSION['success_message'] = 'Activity updated successfully!';

} catch (PDOException $e) {
    // In a real app, log this error.
    $_SESSION['error_message'] = 'Failed to update activity. Please try again.';
}

header('Location: index.php');
exit();