<?php

/**
 * Class CouldNotConnectDatabaseException
 * @author Dennis Thompson
 * @license MIT
 * @version 1.0
 */
class CouldNotConnectDatabaseException extends Exception {

	public function __construct($message, $code = 0, Exception $previous = null) {
		parent::__construct($message, $code, $previous);
	}

}

/**
 * Class FileNotFoundException
 * @author Dennis Thompson
 * @license MIT
 * @version 1.0
 */
class FileNotFoundException extends Exception {

	public function __construct($message, $code = 0, Exception $previous = null) {
		parent::__construct($message, $code, $previous);
	}

}

/**
 * A really simple logging class.
 * @author Dennis Thompsoin
 * @license MIT
 */
class Log {

	private $handle;

	public function __construct($file, $mode = "a") {
		$this->handle = fopen($file, $mode);
	}

	/**
	 * Writes info to the log
	 * @param mixed $entries and string or an array to write to log
	 * @access public
	 */
	public function log($entries) {
		if(is_string($entries)) {
			fwrite($this->handle, "Error: [" . date("d/M/Y H:i:s") . "] " . $entries . "\n");
		} else {
			foreach($entries as $value) {
				fwrite($this->handle, "Error: [" . date("d/M/Y H:i:s") . "] " . $value . "\n");
			}
		}
	}

}

/**
 * A simple database class that uses an active record approach to writing information to the database
 * @author Dennis Thompson
 * @license MIT
 * @since 1.0
 */
class Database {

	private $db, $log;

	public function __construct($host, $user, $pass, $db, $log) {
		try {
			if(!is_object($log)) {
				throw new InvalidArgumentException('$log expected to be an object. Got ' . gettype($log), 2);
			}
			$this->log = &$log;
		} catch(InvalidArgumentException $e) {
			$this->log = new Log(Import::LOG_NAME); // create a new instance
			$this->log->log($e->message);
		}
		$this->db = new mysqli($host, $user, $pass, $db);
	}

	/**
	 * Inserts information into the database using an active record approach and prepared statements
	 * @param string $table the name of the table to write
	 * @param array $data the array of data to write to the table
	 * @access public
	 * @throws InvalidArgumentException
	 */
	public function insert($table, $data) {
		if(!is_array($data)) {
			$msg = '$data expects to be an array or an object. Got ' . gettype($data);
			$this->log->log($msg);
			throw new InvalidArgumentException($msg, 1);
		}

		$handle = $this->db->prepare("INSERT INTO `" . $table . "` (room, mon, tue, wed, thu, fri, sat, sun) VALUES(?, ?, ?, ?, ?, ?, ?, ?)"); // prepared statements are a safer way to send data to a database
		$handle->bind_param('ssssssss', $room, $mon, $tue, $wed, $thu, $fri, $sat, $sun);
		list($room, $mon, $tue, $wed, $thu, $fri, $sat, $sun) = $data;
		$handle->execute();
	}

	/**
	 * Inserts information into the database using active record approach
	 * @param string $table
	 * @param array $data a 2D array
	 * @access public
	 * @uses Database::insert()
	 * @throws InvalidArgumentException
	 */
	public function insert_batch($table, $data) {
		if(!is_array($data)) {
			$msg = '$data expects to be an array or an object. Got ' . gettype($data);
			$this->log->log($msg);
			throw new InvalidArgumentException($msg, 1);
		}

		foreach($data as $value) {
			$this->insert($table, $value);
		}
	}

}

class Import {

	const LOG_NAME = "csv_import_error.log";
	const REMOTE_URL = "http://example.com/";
	const REMOTE_FILE = "file.csv";
	const LOCAL_CSV_FILENAME = "local_csv.csv";

	private $errors, $mail_on_failure, $to, $subject, $headers, $db, $log;

	public function __construct($mail_on_failure = true) {
		$this->log = new Log(self::LOG_NAME);
		$this->db = new Database("127.0.0.1", "root", "", "my_database", $this->log); // create a new database object
		$this->errors = array(); // initialize errors to an empty array
		$this->mail_on_failure = $mail_on_failure;
		if($this->mail_on_failure) {
			$this->to = "user@foo.com";
			$this->subject  = count($this->errors) . " Errors during import";
			$this->headers  = "From: " . $_SERVER["SERVER_NAME"] . "<noreply@example.com>\r\n";
			$this->headers .= "X-Mailer: PHP/" . phpversion();
		}
	}

	/**
	 * Change who the failure email is sent to
	 * @access public
	 * @since 1.0
	 */
	public function to($to) {
		$this->to = $to;
	}

	/**
	 * Change the subject line of the failure email
	 * @access public
	 * @since 1.0
	 */
	public function subject($subject) {
		$this->subject = $subject;
	}

	/**
	 * Change the headers of the failure email
	 * @access public
	 * @since 1.0
	 */
	public function headers($headers) {
		$this->headers = $headers;
	}

	/**
	 * Gets the errors for custom error handling
	 * @return array
	 * @access public
	 * @since 1.0
	 */
	public function getErrors() {
		return $this->errors;
	}

	/**
	 * Parses the CSV file into an array and imports the file into the database
	 * @param string [ $file = self::LOCAL_CSV_FILENAME ]
	 * @param string [ $delimiter = "," ]
	 * @param string [ $enclosure = "'" ]
	 * @param string [ $escape = "\\" ]
	 * @access public
	 * @uses Database
	 * @throws FileNotFoundException
	 */
	public function import($file = self::LOCAL_CSV_FILENAME, $delimiter = ",", $enclosure = "'", $escape = "\\") {
		if(!file_exists($file)) {
			$this->log->log($this->errors[] = "'" . $file . "' does not exist or the path is invalid");
			$this->sendErrorEmail(); // force email before exception is thrown
			throw new FileNotFoundException($this->errors[count($this->errors) - 1]);
		}

		$handle = fopen($file, "r");
		$data = fgetcsv($handle, 0, $delimiter, $enclosure, $escape);
		$this->db->insert_batch("times", array_chunk($data, 8));
	}

	/**
	 * Gets a file from a remote server and downloads it
	 * @access public
	 */
	public function getRemoteFile() {
		if(function_exists("curl_version")) {
			$file = $this->getRemoteFileCurl();
			$handle = fopen(self::LOCAL_CSV_FILENAME, "w");
			fwrite($handle, $file);
			fclose($handle);
		} else {
			$this->getRemoteFileCopy();
		}
	}

	/**
	 * Sends email upon failure to import CSV
	 * @access private
	 */
	private function sendErrorEmail() {
		$message = "Errors:\r\n";
		for($i = 0; $i < count($this->errors); $i++) {
			$message .= "#" . $i . " " . $this->errors[$i] . "\r\n";
		}

		if(mail($this->to, $this->subject, $message, $this->headers)) {
			$this->log->log("Success sending error report to " . $this->to);
		} else {
			$this->log->log($this->errors[] = "Error sending failure email. Issues are described below");
		}
	}

	/**
	 * Gets remote file and returns it's contents using cURL
	 * @access private
	 * @return string
	 */
	private function getRemoteFileCurl() {
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, self::REMOTE_URL . self::REMOTE_FILE);
		curl_setopt($ch, CURLOPT_VERBOSE, 0);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_AUTOREFERER, false);
		curl_setopt($ch, CURLOPT_REFERER, self::REMOTE_URL);
		curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
		curl_setopt($ch, CURLOPT_HEADER, 0);
		$result = curl_exec($ch);
		curl_close($ch);
		return $result;
	}

	/**
	 * Gets remote file and returns it's contents using copy
	 * @throws Exception
	 */
	private function getRemoteFileCopy() {
		if(!copy(self::REMOTE_URL . self::REMOTE_FILE, "./" . self::LOCAL_CSV_FILENAME)) {
			$msg = "Failed to copy " . self::REMOTE_URL . self::REMOTE_FILE . " into " . self::LOCAL_CSV_FILENAME;
			$this->log->log($msg);
			$this->sendErrorEmail();
			throw new Exception($msg, 1);
		}
	}

}

$foo = new Import();
$foo->getRemoteFile();
$foo->import();