<?php
// api/notifikasi.php v2.0
// ============================================================
// API Sistem Notifikasi + Generate Otomatis
// ============================================================
require_once __DIR__ . '/../includes/config.php';

header('Content-Type: application/json; charset=utf-8');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, PUT, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') exit;

$method = $_SERVER['REQUEST_METHOD'];
$db     = getDB();

switch ($method) {

    // ════════════════════════════════════════════════════════
    // GET – Ambil notifikasi (dengan auto-generate)
    // ════════════════════════════════════════════════════════
    case 'GET':
        $userId    = $_GET['user_id'] ?? null;
        $generate  = isset($_GET['generate']); // ?generate → trigger auto-create

        if ($generate) generateNotifikasi($db);

        $sql    = "SELECT n.*, pm.nama_kk FROM notifikasi n LEFT JOIN penduduk_miskin pm ON pm.id = n.penduduk_id WHERE 1=1";
        $params = [];

        if ($userId) {
            $sql   .= " AND (n.user_id = ? OR n.user_id IS NULL)";
            $params[] = $userId;
        }

        // Filter belum dibaca
        if (isset($_GET['unread'])) {
            $sql .= " AND n.sudah_dibaca = 0";
        }

        $sql .= " ORDER BY n.created_at DESC LIMIT 50";
        $stmt = $db->prepare($sql);
        $stmt->execute($params);
        $rows = $stmt->fetchAll();

        // Hitung unread
        $unreadStmt = $db->prepare("SELECT COUNT(*) FROM notifikasi WHERE sudah_dibaca = 0 AND (user_id = ? OR user_id IS NULL)");
        $unreadStmt->execute([$userId ?? 0]);
        $unreadCount = (int)$unreadStmt->fetchColumn();

        jsonResponse(['success' => true, 'data' => $rows, 'unread_count' => $unreadCount]);
        break;

    // ════════════════════════════════════════════════════════
    // PUT – Tandai sudah dibaca
    // ════════════════════════════════════════════════════════
    case 'PUT':
        $in = getInput();
        $id = $in['id'] ?? 'all';

        if ($id === 'all') {
            $userId = (int)($in['user_id'] ?? 0);
            $db->prepare("UPDATE notifikasi SET sudah_dibaca = 1 WHERE user_id = ? OR user_id IS NULL")
               ->execute([$userId]);
            jsonResponse(['success' => true, 'message' => 'Semua notifikasi ditandai dibaca']);
        } else {
            $db->prepare("UPDATE notifikasi SET sudah_dibaca = 1 WHERE id = ?")
               ->execute([(int)$id]);
            jsonResponse(['success' => true, 'message' => 'Notifikasi ditandai dibaca']);
        }
        break;

    // ════════════════════════════════════════════════════════
    // POST – Buat notifikasi manual
    // ════════════════════════════════════════════════════════
    case 'POST':
        $in = getInput();
        if (empty($in['judul']) || empty($in['pesan'])) {
            jsonResponse(['success' => false, 'error' => 'Judul dan pesan wajib diisi'], 400);
        }
        $db->prepare("
            INSERT INTO notifikasi (user_id, jenis, judul, pesan, penduduk_id)
            VALUES (?,?,?,?,?)
        ")->execute([
            $in['user_id']     ?? null,
            $in['jenis']       ?? 'info',
            $in['judul'],
            $in['pesan'],
            $in['penduduk_id'] ?? null,
        ]);
        jsonResponse(['success' => true, 'id' => $db->lastInsertId(), 'message' => 'Notifikasi dibuat']);
        break;

    default:
        jsonResponse(['success' => false, 'error' => 'Method tidak diizinkan'], 405);
}

// ============================================================
// FUNGSI: Generate notifikasi otomatis
// ============================================================
function generateNotifikasi(PDO $db): void {

    // 1. KK belum terverifikasi
    $belumVerif = $db->query("
        SELECT id, nama_kk FROM penduduk_miskin
        WHERE status_verifikasi = 'belum_diverifikasi'
        AND id NOT IN (
            SELECT DISTINCT penduduk_id FROM notifikasi
            WHERE jenis = 'belum_verifikasi' AND sudah_dibaca = 0
        )
        LIMIT 20
    ")->fetchAll();

    foreach ($belumVerif as $p) {
        $db->prepare("
            INSERT INTO notifikasi (jenis, judul, pesan, penduduk_id)
            VALUES ('belum_verifikasi','Data Menunggu Verifikasi',?,?)
        ")->execute(["KK {$p['nama_kk']} belum diverifikasi.", $p['id']]);
    }

    // 2. KK belum menerima bantuan apapun (sangat miskin)
    $belumBantuan = $db->query("
        SELECT id, nama_kk FROM penduduk_miskin
        WHERE kategori_kemiskinan = 'sangat_miskin'
        AND id NOT IN (
            SELECT penduduk_id FROM bantuan_penduduk WHERE status = 'aktif'
        )
        AND id NOT IN (
            SELECT DISTINCT penduduk_id FROM notifikasi
            WHERE jenis = 'belum_bantuan' AND sudah_dibaca = 0
        )
        LIMIT 20
    ")->fetchAll();

    foreach ($belumBantuan as $p) {
        $db->prepare("
            INSERT INTO notifikasi (jenis, judul, pesan, penduduk_id)
            VALUES ('belum_bantuan','KK Sangat Miskin Tanpa Bantuan',?,?)
        ")->execute(["KK {$p['nama_kk']} berkategori sangat miskin namun belum menerima bantuan apapun.", $p['id']]);
    }

    // 3. Data usang (tidak diupdate > DATA_USANG_HARI hari)
    $usang = $db->prepare("
        SELECT id, nama_kk, DATEDIFF(NOW(), updated_at) AS hari_usang
        FROM penduduk_miskin
        WHERE updated_at < DATE_SUB(NOW(), INTERVAL ? DAY)
        AND id NOT IN (
            SELECT DISTINCT penduduk_id FROM notifikasi
            WHERE jenis = 'data_usang' AND sudah_dibaca = 0
        )
        LIMIT 10
    ");
    $usang->execute([DATA_USANG_HARI]);

    foreach ($usang->fetchAll() as $p) {
        $db->prepare("
            INSERT INTO notifikasi (jenis, judul, pesan, penduduk_id)
            VALUES ('data_usang','Data Tidak Diperbarui',?,?)
        ")->execute(["Data KK {$p['nama_kk']} belum diperbarui selama {$p['hari_usang']} hari.", $p['id']]);
    }
}