-- Auteur: 
-- Gérer un stock de matériel informatique.

package Stocks_Materiel is


    CAPACITE : constant Integer := 10;      -- nombre maximum de matériels dans un stock

    type T_Nature is (UNITE_CENTRALE, DISQUE, ECRAN, CLAVIER, IMPRIMANTE);
    type t_Materiel is limited private;
    type T_Array is array (1..CAPACITE) of T_Materiel;
    type T_Stock is limited private;
    
    procedure Creer (Stock : out T_Stock) with
        Post => Nb_Materiels (Stock) = 0;
    
    
    function Nb_Materiels (Stock: in T_Stock) return Integer with
        Post => Nb_Materiels'Result >= 0 and Nb_Materiels'Result <= CAPACITE;

    
    procedure Enregistrer (
            Stock        : in out T_Stock;
            Numero_Serie : in     Integer;
            Nature       : in     T_Nature;
            Annee_Achat  : in     Integer
        ) with
            Pre => Nb_Materiels (Stock) < CAPACITE,
            Post => Nb_Materiels (Stock) = Nb_Materiels (Stock)'Old + 1;
    
    
    function Nb_Materiels_DEAD (Stock: in T_Stock) return Integer with
    	Post => Nb_Materiels_DEAD'Result >= 0 and Nb_Materiels_DEAD'Result <= CAPACITE;

    
    procedure change_state (Stock: in out T_Stock; state: in Boolean; identifiant: in Integer);
    
    
    procedure supprimer_materiel (stock: in out T_Stock; identifiant: in Integer);
  
    
    procedure supprimer_all_dead (stock: in out T_Stock);

    
private

    type T_Materiel is
        record
            ID: Integer := -1;
            Nature: T_Nature;
            Annee: Integer;
            Etat: Boolean;
        end record;    
    
    type T_Stock is
       record
           Elements: T_Array;
           Taille: Integer := 0;
       end record;
    
end Stocks_Materiel;