<?php
header('Content-Type: application/json');
include 'db_config.php';

function distanceMeters($lat1, $lng1, $lat2, $lng2) {
    $earthRadius = 6371000;
    $toRadians = function ($value) {
        return $value * M_PI / 180;
    };

    $deltaLat = $toRadians($lat2 - $lat1);
    $deltaLng = $toRadians($lng2 - $lng1);
    $a = sin($deltaLat / 2) * sin($deltaLat / 2) + cos($toRadians($lat1)) * cos($toRadians($lat2)) * sin($deltaLng / 2) * sin($deltaLng / 2);

    return 2 * $earthRadius * atan2(sqrt($a), sqrt(1 - $a));
}

function findNearestRumahIbadah($conn, $lat, $lng) {
    $result = $conn->query("SELECT id, nama, latitude, longitude FROM rumah_ibadah ORDER BY created_at DESC");
    if (!$result || $result->num_rows === 0) {
        return null;
    }

    $nearest = null;
    while ($row = $result->fetch_assoc()) {
        $distance = distanceMeters($lat, $lng, (float)$row['latitude'], (float)$row['longitude']);
        if ($nearest === null || $distance < $nearest['distance']) {
            $nearest = [
                'id' => (int)$row['id'],
                'nama' => $row['nama'],
                'distance' => $distance
            ];
        }
    }

    return $nearest;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $id = (int)($_POST['id'] ?? 0);
    $namaKetuaKk = trim($_POST['nama_ketua_kk'] ?? '');
    $jumlahAnggota = (int)($_POST['jumlah_anggota'] ?? 0);
    $lat = $_POST['latitude'] ?? null;
    $lng = $_POST['longitude'] ?? null;
    $rumahIbadahId = $_POST['rumah_ibadah_id'] ?? null;
    $rumahIbadahNama = trim($_POST['rumah_ibadah_nama'] ?? '');
    $jarak = $_POST['jarak_ke_rumah_ibadah_m'] ?? null;

    if ($id <= 0 || $namaKetuaKk === '' || $jumlahAnggota <= 0 || $lat === null || $lng === null) {
        echo json_encode(['status' => 'error', 'message' => 'Data penduduk miskin tidak lengkap']);
        $conn->close();
        exit;
    }

    $lat = (float)$lat;
    $lng = (float)$lng;
    $nearest = findNearestRumahIbadah($conn, $lat, $lng);

    if (!$nearest) {
        echo json_encode(['status' => 'error', 'message' => 'Tambahkan rumah ibadah terlebih dahulu']);
        $conn->close();
        exit;
    }

    $jarak = $nearest['distance'];
    $rumahIbadahId = $nearest['id'];
    $rumahIbadahNama = $nearest['nama'];

    $stmt = $conn->prepare("UPDATE penduduk_miskin SET nama_ketua_kk = ?, jumlah_anggota = ?, latitude = ?, longitude = ?, rumah_ibadah_id = ?, rumah_ibadah_nama = ?, jarak_ke_rumah_ibadah_m = ? WHERE id = ?");
    $stmt->bind_param("siddisdi", $namaKetuaKk, $jumlahAnggota, $lat, $lng, $rumahIbadahId, $rumahIbadahNama, $jarak, $id);

    if ($stmt->execute()) {
        echo json_encode(['status' => 'success', 'message' => 'Data penduduk miskin berhasil diperbarui']);
    } else {
        echo json_encode(['status' => 'error', 'message' => $stmt->error]);
    }

    $stmt->close();
}

$conn->close();
?>