<?php

namespace bff\currency;

use Site;
use Closure;
use Currency;
use Component;
use Providers;
use bff\traits\Macroable;
use bff\contracts\CurrencyRatesProvider;

/**
 * Currency rates manager
 */
class Rates extends Component
{
    use Macroable;

    /**
     * @return static
     */
    public static function i()
    {
        bff()->singletonIf('currency.rates', function ($c) {
            $i = $c->make(static::class);
            $i->init();
            return $i;
        });

        return bff('currency.rates');
    }

    /**
     * Register currency rates provider
     * @param CurrencyRatesProvider|Closure|string $provider
     * @param int|null $priority
     * @return mixed
     */
    public static function registerProvider($provider, ?int $priority = null)
    {
        return Providers::register('currency.rates.providers', $provider, $priority);
    }

    /**
     * Get registered currency rates providers
     * @param string|null $key provider key
     * @return CurrencyRatesProvider | CurrencyRatesProvider[]
     */
    public function getProvidersList(?string $key = null)
    {
        return Providers::get('currency.rates.providers', CurrencyRatesProvider::class, $key);
    }

    /**
     * Get registered provider
     * @param string $key registered currency rates provider key
     * @return CurrencyRatesProvider | null
     */
    public function getProvider(string $key): ?CurrencyRatesProvider
    {
        return $this->getProvidersList($key) ?? null;
    }

    /**
     * Get update provider
     * @return CurrencyRatesProvider | null
     */
    public function getUpdateProvider(): ?CurrencyRatesProvider
    {
        $providerKey = $this->config('currency.rates.update.provider', '', TYPE_STR);
        if (! empty($providerKey)) {
            return $this->getProvider($providerKey);
        }
        return $this->getProviderByCurrency(Currency::default('keyword'));
    }

    /**
     * Get provider by currency code
     * @param string $currencyCode
     * @return CurrencyRatesProvider | null
     */
    public function getProviderByCurrency($currencyCode): ?CurrencyRatesProvider
    {
        $currencyCode = mb_strtoupper(strval($currencyCode));
        $providers = $this->getProvidersList();
        foreach ($providers as $provider) {
            if ($provider->providerCurrency() === $currencyCode) {
                return $provider;
            }
        }
        return null;
    }

    /**
     * Autoupdate rates
     * @return bool
     */
    public function updateEnabled(): bool
    {
        return $this->config('currency.rates.update', false, TYPE_BOOL);
    }

    /**
     * Update rates
     * @param string|null $providerKey
     * @return bool
     */
    public function update(?string $providerKey = null): ?bool
    {
        $currencies = $this->currencies();
        if (empty($currencies)) {
            return false;
        }

        if ($providerKey) {
            $provider = $this->getProvider($providerKey);
        } else {
            $provider = $this->getUpdateProvider();
        }
        if (! $provider) {
            return false;
        }

        $rates = $provider->getRates();
        if ($rates === false || empty($rates)) {
            $this->log(_t('site', 'Error loading currency exchange rates by provider: [provider]', [
                'provider' => $provider->providerTitle(),
            ]));
            return false;
        }

        foreach ($rates as $code => $data) {
            # Skip currency
            if (! isset($currencies[$code])) {
                continue;
            }
            $currency = $currencies[$code];

            # Rate changed
            if (round($currency['rate'], 8) === round($data['rate'], 8)) {
                continue;
            }

            $this->updateRate($currency['id'], $data['rate']);
        }

        return true;
    }

    /**
     * Update currency rates
     * @param int $id currency ID
     * @param float $rate
     * @return bool
     */
    protected function updateRate(int $id, float $rate): bool
    {
        if (empty($id)) {
            return false;
        }

        $updated = $this->db->update(Site::TABLE_CURRENCIES, [
            'rate' => $rate,
            'modified' => $this->db->now(),
        ], [
            'id' => $id,
        ]);
        if (! $updated) {
            return false;
        }

        $this->app->callModules('onCurrencyRateChange', [
            $id,
            $rate,
            [
                'context' => 'site-currency-rate-autoupdate',
            ],
        ]);

        return true;
    }

    /**
     * Currency settings
     * @return array
     */
    protected function currencies(): array
    {
        $list = Currency::list();
        $default = Currency::id();
        unset($list[$default]);

        $result = [];
        foreach ($list as $v) {
            $code = mb_strtoupper($v['keyword']);
            $result[$code] = [
                'id'   => $v['id'],
                'code' => $code,
                'rate' => floatval($v['rate']),
            ];
        } unset($v);
        return $result;
    }
}