<?php


// 0 - none
define( 'GEDEBUG_NONE', 0 );

// 1 - call logging only
define( 'GEDEBUG_CALL', 1 );

// 2 - calls, and responses
define( 'GEDEBUG_RESP', 2 );

// Selected debug level
define( 'GITHUB_API_LEVEL', GEDEBUG_NONE );


/**
 * This class contains all the functions that actually retrieve information from the GitHub API
 */
class github_api {


	private $client_id = null;
	private $client_secret = null;


	/**
	 * Allow the client ID / secret to be set, and used for subsequent calls
	 */
	function __construct() {

		add_action( 'plugins_loaded', array( $this, 'set_credentials' ) );
		add_filter( 'http_request_timeout', array( $this, 'http_request_timeout' ) );

	}


	/**
	 * Extend the timeout since API calls can easily exceed 5 seconds
	 * @param  int $seconds The current timeout setting
	 * @return int          The revised timeout setting
	 */
	function http_request_timeout( $seconds ) {
		return $seconds < 25 ? 25 : $seconds;
	}


	/**
	 * If you find yourself hitting rate limits, then you can register an application
	 * with GitHub(http://developer.github.com/v3/oauth/) use the filters here to
	 * provide the credentials.
	 */
	public function set_credentials() {

		$this->client_id = apply_filters( 'github-embed-client-id', $this->client_id );
		$this->client_secret = apply_filters( 'github-embed-client-secret', $this->client_secret );

	}


	private function call_api( $url ) {

		// Allow users to supply auth details to enable a higher rate limit
		if ( ! empty( $this->client_id ) && ! empty( $this->client_secret ) ) {
			$url = add_query_arg(
			                     array(
			                           'client_id' => $this->client_id,
			                     	   'client_secret' => $this->client_secret ),
								$url
								);
		}

		$args = array( 'user-agent' => 'WordPress Github oEmbed plugin - https://github.com/leewillis77/wp-github-oembed');

		$this->log( __FUNCTION__." : $url", GEDEBUG_CALL );

		$results = wp_remote_get( $url, $args );

		$this->log( __FUNCTION__ . " : " . print_r( $results,1 ), GEDEBUG_RESP );

		if( is_wp_error( $results ) ||
		    ! isset( $results['response']['code'] ) ||
		    $results['response']['code'] != '200' ) {
			header( 'HTTP/1.0 404 Not Found' );
			die( 'Octocat is lost, and afraid' );
		}

		return $results;

	}


	/**
	 * Get a repository from the GitHub API
	 * @param  string $owner      The repository's owner
	 * @param  string $repository The respository name
	 * @return object             The response from the GitHub API
	 */
	public function get_repo( $owner, $repository ) {

		$this->log( "get_repo( $owner, $repository )", GEDEBUG_CALL );

		$owner = trim( $owner, '/' );
		$repository = trim( $repository, '/' );

		$results = $this->call_api( "https://api.github.com/repos/$owner/$repository" );

		return json_decode( $results['body'] );

	}


	/**
	 * Get commit information for a repository from the GitHub API
	 * @param  string $owner      The repository's owner
	 * @param  string $repository The respository name
	 * @return object             The response from the GitHub API
	 */
	public function get_repo_commits( $owner, $repository ) {

		$this->log( "get_repo_commits( $owner, $repository )", GEDEBUG_CALL );

		$owner = trim( $owner, '/' );
		$repository = trim( $repository, '/' );

		$results = $this->call_api( "https://api.github.com/repos/$owner/$repository/commits" );

		return json_decode( $results['body'] );

	}


	/**
	 * Get a milestone summary from the GitHub API
	 * @param  string $owner      The repository's owner
	 * @param  string $repository The respository name
	 * @param  string $milestone  The milestone ID
	 * @return object             The response from the GitHub API
	 */
	public function get_repo_milestone_summary( $owner, $repository, $milestone ) {

		$this->log( "get_repo_milestone_summary( $owner, $repository, $milestone )", GEDEBUG_CALL );

		$owner = trim( $owner, '/' );
		$repo = trim( $repo, '/' );

		$results = $this->call_api( "https://api.github.com/repos/$owner/$repository/milestones/$milestone" );

		return json_decode( $results['body'] );

	}


	public function get_repo_contributors( $owner, $repository ) {

		$this->log( "get_repo_contributors( $owner, $repository )", GEDEBUG_CALL );

		$owner = trim( $owner, '/' );
		$repo = trim( $repository, '/' );

		$results = $this->call_api( "https://api.github.com/repos/$owner/$repository/stats/contributors" );

		return json_decode( $results['body'] );

	}


	/**
	 * Get a user from the GitHub API
	 * @param  string $user       The username
	 * @return object             The response from the GitHub API
	 */
	public function get_user( $user ) {

		$this->log( "get_user( $user )", GEDEBUG_CALL );

		$user = trim( $user, '/' );

		$results = $this->call_api( "https://api.github.com/users/$user" );

		return json_decode( $results['body'] );

	}


	private function log( $msg, $level ) {
		if ( GITHUB_API_LEVEL >= $level ) {
			error_log( "[GE$level]: ".$msg );
		}
	}


}