/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2018 CERN
 * @author Jon Evans <jon@craftyjon.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _SCH_CONNECTION_H
#define _SCH_CONNECTION_H

#include <memory>
#include <unordered_set>

#include <boost/optional.hpp>
#include <wx/regex.h>

#include <bus_alias.h>
#include <msgpanel.h>
#include <sch_sheet_path.h>


class SCH_ITEM;
class SCH_SHEET_PATH;


enum CONNECTION_TYPE
{
    CONNECTION_NONE,    ///< No connection to this item
    CONNECTION_NET,     ///< This item represents a net
    CONNECTION_BUS,     ///< This item represents a bus vector
    CONNECTION_BUS_GROUP,   ///< This item represents a bus group
};

/**
 * Each graphical item can have a SCH_CONNECTION describing its logical
 * connection (to a bus or net).  These are generated when netlisting, or when
 * editing operations that can change the netlist are performed.
 *
 * In hierarchical schematics, a single SCH_ITEM object can refer to multiple
 * distinct parts of a design (in the case of a sub-sheet that is instanced
 * more than once in a higher level sheet).  Because of this, a single item may
 * contain more than one SCH_CONNECTION -- each is specific to a sheet.
 *
 * Components contain connections for each of their pins (and for each sheet
 * they exist on) but don't use their own connection object.
 */
class SCH_CONNECTION
{
public:
    SCH_CONNECTION( SCH_ITEM* aParent = nullptr, SCH_SHEET_PATH aPath = SCH_SHEET_PATH() );

    ~SCH_CONNECTION()
    {}

    /**
     * Note: the equality operator for SCH_CONNECTION only tests the net
     * properties, not the ownership / sheet location!
     */
    bool operator==( const SCH_CONNECTION& aOther ) const;

    bool operator!=( const SCH_CONNECTION& aOther ) const;

    /**
     * Configures the connection given a label.
     * For CONNECTION_NET, this just sets the name.
     * For CONNECTION_BUS, this will deduce the correct BUS_TYPE and also
     * generate a correct list of members.
     */
    void ConfigureFromLabel( wxString aLabel );

    /**
     * Clears connectivity information
     */
    void Reset();

    /**
     * Copies connectivity information (but not parent) from another connection
     *
     * @param aOther is the connection to clone
     */
    void Clone( SCH_CONNECTION& aOther );

    SCH_ITEM* Parent() const
    {
        return m_parent;
    }

    SCH_ITEM* Driver() const
    {
        return m_driver;
    }

    SCH_SHEET_PATH Sheet() const
    {
        return m_sheet;
    }

    void SetDriver( SCH_ITEM* aItem );

    void SetSheet( SCH_SHEET_PATH aSheet );

    /**
     * Checks if the SCH_ITEM this connection is attached to can drive connections
     * Drivers can be labels, sheet pins, or component pins.
     *
     * @return true if the attached items is a driver
     */
    bool IsDriver() const;

    bool IsBus() const
    {
        return ( m_type == CONNECTION_BUS || m_type == CONNECTION_BUS_GROUP );
    }

    bool IsNet() const
    {
        return ( m_type == CONNECTION_NET );
    }

    bool IsDirty() const
    {
        return m_dirty;
    }

    void SetDirty()
    {
        m_dirty = true;
    }

    void ClearDirty()
    {
        m_dirty = false;
    }

    wxString Name( bool aIgnoreSheet = false ) const;

    wxString RawName() const
    {
        return m_name;
    }

    wxString LocalName() const { return m_local_name; }

    void SetName( const wxString& aName )
    {
        m_name = aName;
    }

    wxString Prefix() const
    {
        return m_prefix;
    }

    wxString Suffix() const
    {
        return m_suffix;
    }

    void SetPrefix( const wxString& aPrefix );

    void SetSuffix( const wxString& aSuffix );

    CONNECTION_TYPE Type() const
    {
        return m_type;
    }

    void SetType( CONNECTION_TYPE aType )
    {
        m_type = aType;
    }

    int NetCode() const
    {
        return m_net_code;
    }

    void SetNetCode( int aCode )
    {
        m_net_code = aCode;
    }

    int BusCode() const
    {
        return m_bus_code;
    }

    void SetBusCode( int aCode )
    {
        m_bus_code = aCode;
    }

    int SubgraphCode() const
    {
        return m_subgraph_code;
    }

    void SetSubgraphCode( int aCode )
    {
        m_subgraph_code = aCode;
    }

    long VectorStart() const
    {
        return m_vector_start;
    }

    long VectorEnd() const
    {
        return m_vector_end;
    }

    long VectorIndex() const
    {
        return m_vector_index;
    }

    wxString VectorPrefix() const
    {
        return m_vector_prefix;
    }

    std::vector< std::shared_ptr< SCH_CONNECTION > >& Members()
    {
        return m_members;
    }

    const std::vector< std::shared_ptr< SCH_CONNECTION > >& Members() const
    {
        return m_members;
    }

    /**
     * Returns true if aOther is a subset of this connection or vice versa.
     *
     * For plain nets, this just tests whether or not the connectio names are
     * the same.  For buses, this tests whether the two have any shared members.
     *
     * Will always return false if one connection is a bus and the other a net.
     */
    bool IsSubsetOf( SCH_CONNECTION* aOther ) const;

    /**
     * Returns true if this connection is a member of bus connection aOther
     *
     * Will always return false if aOther is not a bus connection
     */
    bool IsMemberOfBus( SCH_CONNECTION* aOther ) const;

    /**
     * Parses a bus vector (e.g. A[7..0]) into name, begin, and end.
     * Ensures that begin and end are positive and that end > begin.
     *
     * @param aBus is a bus vector label string
     * @param aName out is the bus name, e.g. "A"
     * @param aMemberList is a list of member strings, e.g. "A7", "A6", and so on
     * @return true if aBus was successfully parsed
     */
    bool ParseBusVector( wxString aBus, wxString* aName,
                         std::vector<wxString>& aMemberList ) const;

    /**
     * Parses a bus group label into the name and a list of components
     *
     * @param aGroup is the input label, e.g. "USB{DP DM}"
     * @param name is the output group name, e.g. "USB"
     * @param aMemberList is a list of member strings, e.g. "DP", "DM"
     * @return true if aGroup was successfully parsed
     */
    bool ParseBusGroup( wxString aGroup, wxString* name,
                        std::vector<wxString>& aMemberList ) const;

    /**
     * Adds information about the connection object to aList
     */
    void AppendInfoToMsgPanel( MSG_PANEL_ITEMS& aList ) const;

    /**
     * Adds extended debug information about the connection object to aList
     */
    void AppendDebugInfoToMsgPanel( MSG_PANEL_ITEMS& aList ) const;

    /**
     * Test if \a aLabel has a bus notation.
     *
     * @param aLabel A wxString object containing the label to test.
     * @return true if text is a bus notation format otherwise false is returned.
     */
    static bool IsBusLabel( const wxString& aLabel );

    /**
     * Test if \a aLabel has a bus vector notation (simple bus, e.g. A[7..0])
     *
     * @param aLabel A wxString object containing the label to test.
     * @return true if text is a bus notation format otherwise false is returned.
     */
    static bool IsBusVectorLabel( const wxString& aLabel );

    /**
     * Test if \a aLabel has a bus group notation.
     *
     * @param aLabel A wxString object containing the label to test.
     * @return true if text is a bus group notation format
     */
    static bool IsBusGroupLabel( const wxString& aLabel );

private:

    bool m_dirty;

    SCH_SHEET_PATH m_sheet; ///< The hierarchical sheet this connection is on

    SCH_ITEM* m_parent;     ///< The SCH_ITEM this connection is owned by

    SCH_ITEM* m_driver;     ///< The SCH_ITEM that drives this connection's net

    CONNECTION_TYPE m_type; ///< @see enum CONNECTION_TYPE

    wxString m_name;        ///< Name of the connection.

    /**
     * For bus members, we want to keep track of the "local" name of a member, that is,
     * the name it takes on from its parent bus name.  This is because we always want to use
     * the local name for bus unfolding, matching within buses, etc.  The actual resolved name
     * of this bus member might change, for example if it's connected elsewhere to some other
     * item with higher priority.
     */
    wxString m_local_name;

    ///< Prefix if connection is member of a labeled bus group (or "" if not)
    wxString m_prefix;

    wxString m_suffix;      ///< Name suffix (used only for disambiguation)

    int m_net_code;         // TODO(JE) remove if unused

    int m_bus_code;         // TODO(JE) remove if unused

    int m_subgraph_code;    ///< Groups directly-connected items

    long m_vector_index;    ///< Index of bus vector member nets

    long m_vector_start;    ///< Highest member of a vector bus

    long m_vector_end;      ///< Lowest member of a vector bus

    ///< Prefix name of the vector, if m_type == CONNECTION_BUS (or "" if not)
    wxString m_vector_prefix;

    /**
     * For bus connections, store a list of member connections
     *
     * NOTE: All connections that Clone() others share the list of member
     * pointers.  This seems fine at the moment.
     */
    std::vector< std::shared_ptr< SCH_CONNECTION > > m_members;

};

#endif