<?php

/** FONCTIONS D'ASSEMBLAGE DE REQUETE 
* 
* @package eflore-projets
* @author Mathilde SALTHUN-LASSALLE <mathilde@tela-botanica.org>
* @author Delphine CAUQUIL <delphine@tela-botanica.org>
* @author Jean-Pascal MILCENT <jpm@tela-botanica.org>
* @license GPL v3 <http://www.gnu.org/licenses/gpl.txt>
* @license CECILL v2 <http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt>
* @version 1.0
* @copyright 1999-2011 Tela Botanica (accueil@tela-botanica.org)
 */

class RequetesAssemblage {
	
	private $table;
	private $total_resultat;
	private $Bdd;
	private $condition;
	
	public function __construct(BDD $bdd) {
		$this->Bdd = $bdd;
	}

	public function getTotal_resultat() {
		return $this->total_resultat;
	}
	
	public  function retournerRequeteJointure($requete_jointure) {
		$jointure = '';
		if ($requete_jointure !== "") {
			foreach ($requete_jointure as $req_j) {
				$jointure .= ' '.$req_j['type'].' '.$req_j['table'].' ON '
				.implode(' AND', $req_j['on']);
			}
		}
		return $jointure;
	}

	public function assemblerLaRequete(Requete $requete_param) {
		$this->table = $requete_param->table;
		$requete_jointure = $this->retournerRequeteJointure($requete_param->requete_jointure);
		$this->condition = $this->retournerRequeteCondition($requete_param->requete_condition);
		$limites = $this->delimiterResultatsRequete($requete_param->limite_besoin, $requete_param->limite_requete);
		$requete = 	' SELECT '.$requete_param->champs_recherches.' FROM '.$requete_param->table.' '
		.$requete_jointure .' '.$this->condition.' '.$limites;
		return $requete;
	}

	public function retournerRequeteCondition($requete_condition) {
		$condition = '';
		if ($requete_condition !== "") {
			$condition = ' WHERE '.implode(' AND ', $requete_condition);
		}
		return $condition;
	}

	public function calculerTotalResultat() {
		$requete = 'SELECT count(*) as nombre FROM '.$this->table.' '.$this->condition;
		$res = $this->Bdd->recuperer($requete);
		if ($res) {
			$this->total_resultat = $res['nombre'];
		} else {
			$this->total_resultat = 0;
			$e = 'Données introuvables dans la base';
			throw new Exception($e, RestServeur::HTTP_CODE_RESSOURCE_INTROUVABLE);
		}
	}

	public function delimiterResultatsRequete($limite_besoin, $limite_requete) {
		$this->calculerTotalResultat();
		$requete_limite = '';
		if ($limite_besoin)  {
			if (($limite_requete['depart'] <=  $this->total_resultat) ){
				if (($limite_requete['limite'] + $limite_requete['depart'] )
				< $this->total_resultat  ){
				$requete_limite = 'LIMIT '.$limite_requete['depart'].', '
				.$limite_requete['limite'];
				}
			} else {
				$e = "Erreur : la valeur pour le paramètre navigation.départ est supérieure".
				" au nombre total de résultats.";
				throw new Exception($e, RestServeur::HTTP_CODE_RESSOURCE_INTROUVABLE);
			}
		}
		return $requete_limite;
	}
}
?>