<?php

namespace NF_FU_VENDOR\Aws\EndpointDiscovery;

use NF_FU_VENDOR\Aws\CacheInterface;
use NF_FU_VENDOR\Aws\EndpointDiscovery\Exception\ConfigurationException;
use NF_FU_VENDOR\GuzzleHttp\Promise;
use NF_FU_VENDOR\GuzzleHttp\Promise\PromiseInterface;
/**
 * A configuration provider is a function that returns a promise that is
 * fulfilled with a {@see \Aws\EndpointDiscovery\ConfigurationInterface}
 * or rejected with an {@see \Aws\EndpointDiscovery\Exception\ConfigurationException}.
 *
 * <code>
 * use Aws\EndpointDiscovery\ConfigurationProvider;
 * $provider = ConfigurationProvider::defaultProvider();
 * // Returns a ConfigurationInterface or throws.
 * $config = $provider()->wait();
 * </code>
 *
 * Configuration providers can be composed to create configuration using
 * conditional logic that can create different configurations in different
 * environments. You can compose multiple providers into a single provider using
 * {@see Aws\EndpointDiscovery\ConfigurationProvider::chain}. This function
 * accepts providers as variadic arguments and returns a new function that will
 * invoke each provider until a successful configuration is returned.
 *
 * <code>
 * // First try an INI file at this location.
 * $a = ConfigurationProvider::ini(null, '/path/to/file.ini');
 * // Then try an INI file at this location.
 * $b = ConfigurationProvider::ini(null, '/path/to/other-file.ini');
 * // Then try loading from environment variables.
 * $c = ConfigurationProvider::env();
 * // Combine the three providers together.
 * $composed = ConfigurationProvider::chain($a, $b, $c);
 * // Returns a promise that is fulfilled with a configuration or throws.
 * $promise = $composed();
 * // Wait on the configuration to resolve.
 * $config = $promise->wait();
 * </code>
 */
class ConfigurationProvider
{
    const CACHE_KEY = 'aws_cached_endpoint_discovery_config';
    const DEFAULT_ENABLED = \false;
    const DEFAULT_CACHE_LIMIT = 1000;
    const ENV_ENABLED = 'AWS_ENDPOINT_DISCOVERY_ENABLED';
    const ENV_ENABLED_ALT = 'AWS_ENABLE_ENDPOINT_DISCOVERY';
    const ENV_PROFILE = 'AWS_PROFILE';
    /**
     * Wraps a config provider and saves provided configuration in an
     * instance of Aws\CacheInterface. Forwards calls when no config found
     * in cache and updates cache with the results.
     *
     * @param callable $provider Configuration provider function to wrap
     * @param CacheInterface $cache Cache to store credentials
     * @param string|null $cacheKey (optional) Cache key to use
     *
     * @return callable
     */
    public static function cache(callable $provider, \NF_FU_VENDOR\Aws\CacheInterface $cache, $cacheKey = null)
    {
        $cacheKey = $cacheKey ?: self::CACHE_KEY;
        return function () use($provider, $cache, $cacheKey) {
            $found = $cache->get($cacheKey);
            if ($found instanceof \NF_FU_VENDOR\Aws\EndpointDiscovery\ConfigurationInterface) {
                return \NF_FU_VENDOR\GuzzleHttp\Promise\promise_for($found);
            }
            return $provider()->then(function (\NF_FU_VENDOR\Aws\EndpointDiscovery\ConfigurationInterface $config) use($cache, $cacheKey) {
                $cache->set($cacheKey, $config);
                return $config;
            });
        };
    }
    /**
     * Creates an aggregate credentials provider that invokes the provided
     * variadic providers one after the other until a provider returns
     * credentials.
     *
     * @return callable
     */
    public static function chain()
    {
        $links = \func_get_args();
        if (empty($links)) {
            throw new \InvalidArgumentException('No providers in chain');
        }
        return function () use($links) {
            /** @var callable $parent */
            $parent = \array_shift($links);
            $promise = $parent();
            while ($next = \array_shift($links)) {
                $promise = $promise->otherwise($next);
            }
            return $promise;
        };
    }
    /**
     * Create a default config provider that first checks for environment
     * variables, then checks for a specified profile in ~/.aws/config, then
     * checks for the "default" profile in ~/.aws/config, and failing those uses
     * a default fallback set of configuration options.
     *
     * This provider is automatically wrapped in a memoize function that caches
     * previously provided config options.
     *
     * @param array $config Optional array of ecs/instance profile credentials
     *                      provider options.
     *
     * @return callable
     */
    public static function defaultProvider(array $config = [])
    {
        $configProviders = [self::env(), self::ini(), self::fallback()];
        $memo = self::memoize(\call_user_func_array('self::chain', $configProviders));
        if (isset($config['endpoint_discovery']) && $config['endpoint_discovery'] instanceof \NF_FU_VENDOR\Aws\CacheInterface) {
            return self::cache($memo, $config['endpoint_discovery'], self::CACHE_KEY);
        }
        return $memo;
    }
    /**
     * Provider that creates config from environment variables.
     *
     * @param $cacheLimit
     * @return callable
     */
    public static function env($cacheLimit = self::DEFAULT_CACHE_LIMIT)
    {
        return function () use($cacheLimit) {
            // Use config from environment variables, if available
            $enabled = \getenv(self::ENV_ENABLED);
            if ($enabled === \false || $enabled === '') {
                $enabled = \getenv(self::ENV_ENABLED_ALT);
            }
            if ($enabled !== \false && $enabled !== '') {
                return \NF_FU_VENDOR\GuzzleHttp\Promise\promise_for(new \NF_FU_VENDOR\Aws\EndpointDiscovery\Configuration($enabled, $cacheLimit));
            }
            return self::reject('Could not find environment variable config' . ' in ' . self::ENV_ENABLED);
        };
    }
    /**
     * Fallback config options when other sources are not set.
     *
     * @return callable
     */
    public static function fallback()
    {
        return function () {
            return \NF_FU_VENDOR\GuzzleHttp\Promise\promise_for(new \NF_FU_VENDOR\Aws\EndpointDiscovery\Configuration(self::DEFAULT_ENABLED, self::DEFAULT_CACHE_LIMIT));
        };
    }
    /**
     * Gets the environment's HOME directory if available.
     *
     * @return null|string
     */
    private static function getHomeDir()
    {
        // On Linux/Unix-like systems, use the HOME environment variable
        if ($homeDir = \getenv('HOME')) {
            return $homeDir;
        }
        // Get the HOMEDRIVE and HOMEPATH values for Windows hosts
        $homeDrive = \getenv('HOMEDRIVE');
        $homePath = \getenv('HOMEPATH');
        return $homeDrive && $homePath ? $homeDrive . $homePath : null;
    }
    /**
     * Config provider that creates config using an ini file stored
     * in the current user's home directory.
     *
     * @param string|null $profile  Profile to use. If not specified will use
     *                              the "default" profile in "~/.aws/config".
     * @param string|null $filename If provided, uses a custom filename rather
     *                              than looking in the home directory.
     * @param int $cacheLimit
     *
     * @return callable
     */
    public static function ini($profile = null, $filename = null, $cacheLimit = self::DEFAULT_CACHE_LIMIT)
    {
        $filename = $filename ?: self::getHomeDir() . '/.aws/config';
        $profile = $profile ?: (\getenv(self::ENV_PROFILE) ?: 'default');
        return function () use($profile, $filename, $cacheLimit) {
            if (!\is_readable($filename)) {
                return self::reject("Cannot read configuration from {$filename}");
            }
            $data = \NF_FU_VENDOR\Aws\parse_ini_file($filename, \true);
            if ($data === \false) {
                return self::reject("Invalid config file: {$filename}");
            }
            if (!isset($data[$profile])) {
                return self::reject("'{$profile}' not found in config file");
            }
            if (!isset($data[$profile]['endpoint_discovery_enabled'])) {
                return self::reject("Required endpoint discovery config values \n                    not present in INI profile '{$profile}' ({$filename})");
            }
            return \NF_FU_VENDOR\GuzzleHttp\Promise\promise_for(new \NF_FU_VENDOR\Aws\EndpointDiscovery\Configuration($data[$profile]['endpoint_discovery_enabled'], $cacheLimit));
        };
    }
    /**
     * Wraps a config provider and caches previously provided configuration.
     *
     * Ensures that cached configuration is refreshed when it expires.
     *
     * @param callable $provider Config provider function to wrap.
     *
     * @return callable
     */
    public static function memoize(callable $provider)
    {
        return function () use($provider) {
            static $result;
            static $isConstant;
            // Constant config will be returned constantly.
            if ($isConstant) {
                return $result;
            }
            // Create the initial promise that will be used as the cached value
            // until it expires.
            if (null === $result) {
                $result = $provider();
            }
            // Return config and set flag that provider is already set
            return $result->then(function (\NF_FU_VENDOR\Aws\EndpointDiscovery\ConfigurationInterface $config) use(&$isConstant) {
                $isConstant = \true;
                return $config;
            });
        };
    }
    /**
     * Reject promise with standardized exception.
     *
     * @param $msg
     * @return Promise\RejectedPromise
     */
    private static function reject($msg)
    {
        return new \NF_FU_VENDOR\GuzzleHttp\Promise\RejectedPromise(new \NF_FU_VENDOR\Aws\EndpointDiscovery\Exception\ConfigurationException($msg));
    }
    /**
     * Unwraps a configuration object in whatever valid form it is in,
     * always returning a ConfigurationInterface object.
     *
     * @param  mixed $config
     * @return ConfigurationInterface
     * @throws \InvalidArgumentException
     */
    public static function unwrap($config)
    {
        if (\is_callable($config)) {
            $config = $config();
        }
        if ($config instanceof \NF_FU_VENDOR\GuzzleHttp\Promise\PromiseInterface) {
            $config = $config->wait();
        }
        if ($config instanceof \NF_FU_VENDOR\Aws\EndpointDiscovery\ConfigurationInterface) {
            return $config;
        } elseif (\is_array($config) && isset($config['enabled'])) {
            if (isset($config['cache_limit'])) {
                return new \NF_FU_VENDOR\Aws\EndpointDiscovery\Configuration($config['enabled'], $config['cache_limit']);
            }
            return new \NF_FU_VENDOR\Aws\EndpointDiscovery\Configuration($config['enabled'], self::DEFAULT_CACHE_LIMIT);
        }
        throw new \InvalidArgumentException('Not a valid endpoint_discovery ' . 'configuration argument.');
    }
}
