<?php
declare(strict_types=1);

require_once __DIR__ . '/db.php';

const SERUBI_PRODUCTS = ['giro' => 'Giro Umum', 'simanja' => 'Tabungan SIMANJA', 'simpeda' => 'Tabungan SIMPEDA'];

const SERUBI_GROUPS = [
    'dana'     => ['Struktur dana', 'Bagaimana dana nasabah dibagi sebelum menghasilkan pendapatan.'],
    'bunga'    => ['Suku bunga pendapatan', 'Rate yang menghasilkan pendapatan bank dari dana kelolaan.'],
    'biaya'    => ['Biaya', 'Biaya yang mengurangi spread sebelum dibagi ke nasabah.'],
    'pajak'    => ['Pajak', 'Tarif pajak atas bunga dan cashback.'],
    'konvensi' => ['Konvensi perhitungan', 'Hari bunga, pinalti, dan batas minimal.'],
];

/** Raw settings rows keyed by skey. */
function settings_rows(): array
{
    $rows = db()->query('SELECT * FROM settings ORDER BY sort')->fetchAll();
    return array_column($rows, null, 'skey');
}

function to_num($v): ?float
{
    return $v === null ? null : (float)$v;
}

const PARAMS_CACHE_TTL = 300;   // seconds; the cache is also cleared whenever an admin saves

function params_cache_file(): string
{
    $dir = (string)(app_config()['app']['cache_dir'] ?? '');
    if ($dir === '') {
        $dir = sys_get_temp_dir() . '/serubi-' . substr(md5(__DIR__), 0, 12);
    }
    return rtrim($dir, '/\\') . '/params.json';
}

/** Parameters in the shape assets/js/engine.js expects (cached to spare the database). */
function load_params(): array
{
    $file = params_cache_file();
    if (is_file($file) && time() - (int)@filemtime($file) < PARAMS_CACHE_TTL) {
        $cached = json_decode((string)@file_get_contents($file), true);
        if (is_array($cached) && isset($cached['settings'])) {
            return $cached;
        }
    }
    $params = load_params_db();
    $dir = dirname($file);
    if (is_dir($dir) || @mkdir($dir, 0700, true)) {
        $tmp = $file . '.' . bin2hex(random_bytes(4));
        if (@file_put_contents($tmp, json_encode($params, JSON_PRESERVE_ZERO_FRACTION)) !== false) {
            @rename($tmp, $file);
        }
        @unlink($tmp);
    }
    return $params;
}

function params_cache_clear(): void
{
    @unlink(params_cache_file());
}

function load_params_db(): array
{
    $pdo = db();
    $settings = [];
    $updated = null;
    foreach (settings_rows() as $key => $row) {
        $settings[$key] = (float)$row['value'];
        $updated = max($updated ?? '', $row['updated_at']);
    }

    $tenors = $pdo->query('SELECT months, cashback FROM tenors ORDER BY months')->fetchAll();

    $productRates = array_fill_keys(array_keys(SERUBI_PRODUCTS), []);
    foreach ($pdo->query('SELECT product, max_nominal, rate FROM product_rates ORDER BY product, sort, id') as $r) {
        $productRates[$r['product']][] = ['max' => to_num($r['max_nominal']), 'rate' => (float)$r['rate']];
    }

    $bands = $pdo->query('SELECT id, max_nominal FROM deposito_bands ORDER BY sort, id')->fetchAll();
    $rates = [];
    foreach ($pdo->query('SELECT band_id, tenor, rate FROM deposito_rates') as $r) {
        $rates[$r['band_id']][$r['tenor']] = (float)$r['rate'];
    }
    $depositoRates = [];
    foreach ($tenors as $t) {
        $m = (int)$t['months'];
        $depositoRates[$m] = array_map(fn($b) => [
            'max' => to_num($b['max_nominal']),
            'rate' => $rates[$b['id']][$m] ?? 0.0,
        ], $bands);
    }

    $tiers = array_map(fn($r) => ['min' => (float)$r['min_nominal'], 'nasabah' => (float)$r['share_nasabah']],
        $pdo->query('SELECT min_nominal, share_nasabah FROM cashback_tiers ORDER BY min_nominal')->fetchAll());

    $last = $pdo->query("SELECT username, created_at FROM audit_log WHERE action LIKE 'param%' ORDER BY id DESC LIMIT 1")->fetch();

    return [
        'settings'       => $settings,
        'tenors'         => array_map(fn($t) => (int)$t['months'], $tenors),
        'cashbackTenors' => array_values(array_map(fn($t) => (int)$t['months'], array_filter($tenors, fn($t) => (int)$t['cashback'] === 1))),
        'productRates'   => $productRates,
        'depositoBands'  => array_map(fn($b) => to_num($b['max_nominal']), $bands),
        'depositoRates'  => $depositoRates,
        'cashbackTiers'  => $tiers,
        'updatedAt'      => $last['created_at'] ?? $updated,
        'updatedBy'      => $last['username'] ?? null,
    ];
}