<?php

/*
    Parametri za povezivanje sa bazom podataka
    korisnicko ime: root;
    sifra: prazna niska
    host: localhost
    dbname: sentiments
*/
interface ConnectionData{
    const username='root';
    const password='';
    const host='localhost';
    const dbname='sentiments';
}

class PDO_DB implements ConnectionData{
    static private $db=NULL;

    private $connection;

    private function __construct(){
    }

    private function __clone(){
    }

    private function __wakeup(){
    }

    public static function getInstance(){
        if(self::$db==NULL){
            self::$db=new PDO_DB();
            self::$db->connection=new PDO('mysql:'.ConnectionData::host.';dbname='.ConnectionData::dbname,
                                ConnectionData::username, ConnectionData::password,
                                 array(PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION));
        }

        return self::$db;
    }


    /*
        Implementirati metodu koja dohvata sve reci iz leksikona
    */
    public function getAllWords(){
        $query = "select word, score from sentiments.lexicon";
        $stmt=self::$db->connection->prepare($query);
        $stmt->execute();

        return $stmt->fetch(PDO::FETCH_OBJ);
    }


    /*
        Metoda koja dohvata samo jednu rec iz leksikona
        vraca objekat koji sadrzi rec i njen skor ili false ako se trazena rec ne nalazi u leksikonu
     */
    public function getWord($word){
        $query="select word, score from sentiments.lexicon where word=:word";
        $stmt=self::$db->connection->prepare($query);
        $stmt->bindParam(":word", $word, PDO::PARAM_STR);

        $stmt->execute();

        return $stmt->fetch(PDO::FETCH_OBJ);
    }


    /*
        Implementirati metodu koja upisuje zadatu rec i njenu sentiment ocenu u leksikon
    */
    public function insertWord($word, $score){
        $query="insert into sentiments.lexicon (:word, :score)";
        $stmt = self::$db->connection->prepare($query);
        $stmt->bindParam(":word", $word, PDO::PARAM_STR);
        $stmt->bindParam(":score", strval($score), PDO::PARAM_STR);
        return $stmt->execute();
    }

    /*
        Implementirati metodu koja upisuje dokument opisan naslovom, sadrzajem i sentiment ocenom
        u bazu
    */
    public function insertDocument($title, $content, $sentiment){
        $query="insert into sentiments.documents (:title, :content, :sentiment)";
        $stmt = self::$db->connection->prepare($query);
        $stmt->bindParam(":title", $title, PDO::PARAM_STR);
        $stmt->bindParam(":content", $content, PDO::PARAM_STR);
        $stmt->bindParam(":sentiment", strval($sentiment), PDO::PARAM_STR);
        return $stmt->execute();
    }
}

/*

try{
    $pdo=PDO_DB::getInstance();


//    //allWords test
//    $allWords=$pdo->getAllWords();
//    var_dump($allWords);

//    //getWord test
//    $word="super nice";
//    $wordInfo=$pdo->getWord($word);
//    var_dump($wordInfo);

//    //insertWord test
//    $insertWordFlag=$pdo->insertWord("super word", 1);
//    var_dump($insertWordFlag);

//    //insertDocument test
//    $insertDocumentFlag=$pdo->insertDocument("Test title", "Test content", 0.5);
//    var_dump($insertDocumentFlag);

}catch(PDOException $e){
    echo $e->getMessage();
    unset($pdo);
}
*/

?>