<?php

namespace SparkPost;

use Ivory\HttpAdapter\Configuration;
use Ivory\HttpAdapter\HttpAdapterInterface;

class SparkPost
{
    public $transmission;
    public $messageEvents;

    /**
     * Library version, used for setting User-Agent.
     */
    private $version = '1.2.0';

    /**
     * Connection config for making requests.
     */
    private $config;

    /**
     * @var \Ivory\HttpAdapter\HttpAdapterInterface to make requests through.
     */
    public $httpAdapter;

    /**
     * Default config values. Passed in values will override these.
     */
    private static $apiDefaults = [
        'host' => 'api.sparkpost.com',
        'protocol' => 'https',
        'port' => 443,
        'strictSSL' => true,
        'key' => '',
        'version' => 'v1',
    ];

    /**
     * Sets up httpAdapter and config.
     *
     * Sets up instances of sub libraries.
     *
     * @param \Ivory\HttpAdapter\HttpAdapterInterface $httpAdapter    - An adapter for making http requests
     * @param string | array                          $settingsConfig - Hashmap that contains config values
     *                                                                for the SDK to connect to SparkPost. If its a string we assume that
     *                                                                its just they API Key.
     */
    public function __construct($httpAdapter, $settingsConfig)
    {
        //config needs to be setup before adapter because of default adapter settings
        $this->setConfig($settingsConfig);
        $this->setHttpAdapter($httpAdapter);

        $this->transmission = new Transmission($this);
        $this->messageEvents = new MessageEvents($this);
    }

    /**
     * Creates an unwrapped api interface for endpoints that aren't yet supported.
     * The new resource is attached to this object as well as returned.
     *
     * @param string $endpoint
     *
     * @return APIResource - the unwrapped resource
     */
    public function setupUnwrapped($endpoint)
    {
        $this->{$endpoint} = new APIResource($this);
        $this->{$endpoint}->endpoint = $endpoint;

        return $this->{$endpoint};
    }

    /**
     * Merges passed in headers with default headers for http requests.
     */
    public function getHttpHeaders()
    {
        $defaultOptions = [
            'Authorization' => $this->config['key'],
            'Content-Type' => 'application/json',
        ];

        return $defaultOptions;
    }

    /**
     * Helper function for getting the configuration for http requests.
     *
     * @param array $config
     *
     * @return Configuration
     */
    private function getHttpConfig($config)
    {
        // create Configuration for http adapter
        $httpConfig = new Configuration();
        $baseUrl = $config['protocol'].'://'.$config['host'].($config['port'] ? ':'.$config['port'] : '').'/api/'.$config['version'];
        $httpConfig->setBaseUri($baseUrl);
        $httpConfig->setUserAgent('php-sparkpost/'.$this->version);

        return $httpConfig;
    }

    /**
     * Validates and sets up the httpAdapter.
     *
     * @param $httpAdapter \Ivory\HttpAdapter\HttpAdapterInterface to make requests through.
     *
     * @throws \Exception
     */
    public function setHttpAdapter(HttpAdapterInterface $httpAdapter)
    {
        $this->httpAdapter = $httpAdapter;
        $this->httpAdapter->setConfiguration($this->getHttpConfig($this->config));
    }

    /**
     * Allows the user to pass in values to override the defaults and set their API key.
     *
     * @param string | array $settingsConfig - Hashmap that contains config values
     *                                       for the SDK to connect to SparkPost. If its a string we assume that
     *                                       its just they API Key.
     *
     * @throws \Exception
     */
    public function setConfig($settingsConfig)
    {
        // if the config map is a string we should assume that its an api key
        if (is_string($settingsConfig)) {
            $settingsConfig = ['key' => $settingsConfig];
        }

        // Validate API key because its required
        if (!isset($settingsConfig['key']) || !preg_match('/\S/', $settingsConfig['key'])) {
            throw new \Exception('You must provide an API key');
        }

        $this->config = self::$apiDefaults;

        // set config, overriding defaults
        foreach ($settingsConfig as $configOption => $configValue) {
            if (key_exists($configOption, $this->config)) {
                $this->config[$configOption] = $configValue;
            }
        }
    }
}