package data.stdforms.twotableformsheet;

import sale.*;

import data.*;
import data.stdforms.*;

import users.*;

/**
  * MoveStrategy for a Catalog source and a StoringStock destination. <i>Abstract</i> as creating StockItems is
  * application dependant.
  *
  * @see #createStockItem
  *
  * @author Steffen Zschaler
  * @version 2.0 20/08/1999
  * @since v2.0
  */
public abstract class CSSStrategy extends MoveStrategy {

  /**
    * Get the sub-process that will move items from the source to the destination.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param ci the CatalogItem that is selected in the source.
    * @param ttfs the FormSheet that triggers the process.
    *
    * @override Never
    */
  public Transition getMoveToDestProcess (SaleProcess p,
                                          SalesPoint sp,
                                          Catalog cSource,
                                          StoringStock ssDest,
                                          DataBasket db,
                                          CatalogItem ci,
                                          TwoTableFormSheet ttfs) {
    return new GateChangeTransition (getCheckMoveToDestGate (p, sp, cSource, ssDest, db, ci, ttfs));
  }

  /**
    * Get the first gate of the sub-process that will move items from the source to the destination.
    *
    * <p>This Gate will check whether the move is allowable, and if so, will trigger a Transition that
    * performs it.</p>
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param ci the CatalogItem that is selected in the source.
    * @param ttfs the FormSheet that triggers the process.
    *
    * @override Never Instead, override {@link #checkMoveToDest}, {@link #createStockItem} and/or
    * {@link #moveToDest}.
    */
  protected Gate getCheckMoveToDestGate (SaleProcess p,
                                         final SalesPoint sp,
                                         final Catalog cSource,
                                         final StoringStock ssDest,
                                         final DataBasket db,
                                         final CatalogItem ci,
                                         final TwoTableFormSheet ttfs) {
    return new Gate() {
      public Transition getNextTransition (SaleProcess p, User u)
        throws InterruptedException {
        int nCheckReturn = checkMoveToDest (p, sp, cSource, ssDest, db, ci);

        if (nCheckReturn == 0) {
          final StockItem si = createStockItem (p, sp, cSource, ssDest, db, ci);

          if (si != null) {
            return new Transition() {
              public Gate perform (SaleProcess p, User u) {
                moveToDest (p, sp, cSource, ssDest, db, si);

                return ttfs.getGate();
              }
            };
          }
        }
        else {
          error (p, nCheckReturn);
        }

        return new GateChangeTransition (ttfs.getGate());
      }
    };
  }

  /**
    * Check whether the indicated move is allowable. If so, return 0, otherwise return a non-zero error value
    * that can be passed on to {@link sale.stdforms.FormSheetStrategy#error}. You can assume that you are at a {@link Gate}.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param ci the CatalogItem that is selected in the source.
    *
    * @override Sometimes The default implementation returns 0.
    */
  protected int checkMoveToDest (SaleProcess p,
                                 SalesPoint sp,
                                 Catalog cSource,
                                 StoringStock ssDest,
                                 DataBasket db,
                                 CatalogItem ci)
    throws InterruptedException {
    return 0;
  }

  /**
    * Create a fresh StockItem following the specifications given. You can assume that you are at a
    * {@link Gate}.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param ci the CatalogItem that is selected in the source.
    *
    * @override Always This method is application dependant.
    */
  protected abstract StockItem createStockItem (SaleProcess p,
                                                SalesPoint sp,
                                                Catalog cSource,
                                                StoringStock ssDest,
                                                DataBasket db,
                                                CatalogItem ci)
    throws InterruptedException;

  /**
    * Move the item as indicated into the destination Stock. You can assume that you are in a
    * {@link Transition}.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param si the StockItem to be moved into the destination.
    *
    * @override Sometimes
    */
  protected void moveToDest (SaleProcess p,
                             SalesPoint sp,
                             Catalog cSource,
                             StoringStock ssDest,
                             DataBasket db,
                             StockItem si) {
    ssDest.add (si, db);
  }

  /**
    * Get the sub-process that will move items from the destination to the source.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param si the StockItem that is selected in the destination.
    * @param ttfs the FormSheet that triggers the process.
    *
    * @override Never
    */
  public Transition getMoveToSourceProcess (SaleProcess p,
                                            SalesPoint sp,
                                            Catalog cSource,
                                            StoringStock ssDest,
                                            DataBasket db,
                                            StockItem si,
                                            TwoTableFormSheet ttfs) {
    return new GateChangeTransition (getCheckMoveToSourceGate (p, sp, cSource, ssDest, db, si, ttfs));
  }

  /**
    * Get the first gate of the sub-process that will move items from the destination to the source.
    *
    * <p>This Gate will check whether the move is allowable, and if so, will trigger a Transition that
    * performs it.</p>
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param si the StockItem that is selected in the destination.
    * @param ttfs the FormSheet that triggers the process.
    *
    * @override Never Instead, override {@link #checkMoveToSource} and/or {@link #moveToSource}.
    */
  protected Gate getCheckMoveToSourceGate (SaleProcess p,
                                           final SalesPoint sp,
                                           final Catalog cSource,
                                           final StoringStock ssDest,
                                           final DataBasket db,
                                           final StockItem si,
                                           final TwoTableFormSheet ttfs) {
    return new Gate() {
      public Transition getNextTransition (SaleProcess p, User u)
        throws InterruptedException {
        int nCheckReturn = checkMoveToSource (p, sp, cSource, ssDest, db, si);

        if (nCheckReturn == 0) {
          return new Transition() {
            public Gate perform (SaleProcess p, User u) {
              moveToSource (p, sp, cSource, ssDest, db, si);

              return ttfs.getGate();
            }
          };
        }
        else {
          error (p, nCheckReturn);

          return new GateChangeTransition (ttfs.getGate());
        }
      }
    };
  }

  /**
    * Check whether the indicated move is allowable. If so, return 0, otherwise return a non-zero error value
    * that can be passed on to {@link sale.stdforms.FormSheetStrategy#error}. You can assume that you are at a {@link Gate}.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param si the StockItem that is selected in the destination.
    *
    * @override Sometimes The default implementation returns 0.
    */
  protected int checkMoveToSource (SaleProcess p,
                                   SalesPoint sp,
                                   Catalog cSource,
                                   StoringStock ssDest,
                                   DataBasket db,
                                   StockItem si)
    throws InterruptedException {
    return 0;
  }

  /**
    * Move the indicated item as indicated from the destination Stock. You can assume that you are in a
    * {@link Transition}.
    *
    * @param p the process into which the sub-process wil be embedded.
    * @param sp the SalesPoint, if any, at which the FormSheet is being displayed.
    * @param cSource the source Catalog.
    * @param ssDest the destination StoringStock.
    * @param db the DataBasket relative to which to perform the operation.
    * @param si the StockItem that is selected in the destination.
    *
    * @override Sometimes
    */
  protected void moveToSource (SaleProcess p,
                               SalesPoint sp,
                               Catalog cSource,
                               StoringStock ssDest,
                               DataBasket db,
                               StockItem si) {
    try {
      ssDest.remove (si, db);
    }
    catch (data.events.VetoException ve) {
      error (p, REMOVE_VETO_EXCEPTION);
    }
  }
}