<?php
require_once __DIR__ . '/_helpers.php';
api_require_login();
api_require_role(['admin','dinas']);

function haversine_meter(float $lat1, float $lng1, float $lat2, float $lng2): float
{
    $earth = 6371000;
    $dLat = deg2rad($lat2 - $lat1);
    $dLng = deg2rad($lng2 - $lng1);
    $a = sin($dLat / 2) * sin($dLat / 2) +
        cos(deg2rad($lat1)) * cos(deg2rad($lat2)) *
        sin($dLng / 2) * sin($dLng / 2);
    $c = 2 * atan2(sqrt($a), sqrt(1 - $a));
    return $earth * $c;
}

$pdo->beginTransaction();
try {
    $rumahStmt = $pdo->query('SELECT * FROM rumah_ibadah WHERE status = "Aktif" ORDER BY nama ASC');
    $rumahIbadah = $rumahStmt->fetchAll();

    $kelStmt = $pdo->query('SELECT * FROM keluarga ORDER BY FIELD(kerentanan, "Miskin Ekstrem", "Sangat Miskin", "Miskin", "Rentan Miskin"), created_at ASC');
    $keluarga = $kelStmt->fetchAll();

    $terpakai = [];
    foreach ($rumahIbadah as $ri) {
        $terpakai[(int)$ri['id']] = 0;
    }

    $update = $pdo->prepare('UPDATE keluarga SET status_bantuan = ?, rumah_ibadah_id = ? WHERE id = ?');
    $jumlahDitanggung = 0;
    $jumlahBlankSpot = 0;
    $jumlahMenunggu = 0;
    $jumlahTidakValid = 0;

    foreach ($keluarga as $kel) {
        $kelId = (int)$kel['id'];

        if ($kel['status_verifikasi'] === 'Tidak Valid') {
            $update->execute(['Tidak Valid', null, $kelId]);
            $jumlahTidakValid++;
            continue;
        }

        if ($kel['status_verifikasi'] !== 'Valid') {
            $update->execute(['Menunggu Verifikasi', null, $kelId]);
            $jumlahMenunggu++;
            continue;
        }

        $kandidat = [];
        foreach ($rumahIbadah as $ri) {
            $riId = (int)$ri['id'];
            $kuota = (int)$ri['kuota'];
            $radius = (int)$ri['radius'];

            if ($kuota <= 0 || ($terpakai[$riId] ?? 0) >= $kuota) {
                continue;
            }

            $jarak = haversine_meter((float)$kel['lat'], (float)$kel['lng'], (float)$ri['lat'], (float)$ri['lng']);
            if ($jarak <= $radius) {
                $kandidat[] = [
                    'id' => $riId,
                    'jarak' => $jarak,
                    'sisa_kuota' => $kuota - ($terpakai[$riId] ?? 0),
                ];
            }
        }

        if (!empty($kandidat)) {
            usort($kandidat, function ($a, $b) {
                if ($a['jarak'] == $b['jarak']) return $b['sisa_kuota'] <=> $a['sisa_kuota'];
                return $a['jarak'] <=> $b['jarak'];
            });

            $riId = $kandidat[0]['id'];
            $terpakai[$riId]++;
            $update->execute(['Ditanggung', $riId, $kelId]);
            $jumlahDitanggung++;
        } else {
            $update->execute(['Blank Spot', null, $kelId]);
            $jumlahBlankSpot++;
        }
    }

    $pdo->commit();
    json_response([
        'success' => true,
        'message' => 'Analisis tanggungan selesai.',
        'summary' => [
            'ditanggung' => $jumlahDitanggung,
            'blank_spot' => $jumlahBlankSpot,
            'menunggu_verifikasi' => $jumlahMenunggu,
            'tidak_valid' => $jumlahTidakValid,
        ]
    ]);
} catch (Throwable $e) {
    $pdo->rollBack();
    json_response(['success' => false, 'message' => 'Analisis gagal: ' . $e->getMessage()], 500);
}