/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2017 Chris Pavlina <pavlina.chris@gmail.com>
 * Copyright (C) 2014 Henner Zeller <h.zeller@acm.org>
 * Copyright (C) 2014-2017 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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 3 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/>.
 */

#include <cmp_tree_model.h>

#include <class_library.h>
#include <eda_pattern_match.h>
#include <make_unique.h>
#include <utility>


// Each node gets this lowest score initially, without any matches applied.
// Matches will then increase this score depending on match quality.  This way,
// an empty search string will result in all components being displayed as they
// have the minimum score. However, in that case, we avoid expanding all the
// nodes asd the result is very unspecific.
static const unsigned kLowestDefaultScore = 1;


// Creates a score depending on the position of a string match. If the position
// is 0 (= prefix match), this returns the maximum score. This degrades until
// pos == max, which returns a score of 0; Evertyhing else beyond that is just
// 0. Only values >= 0 allowed for position and max.
//
// @param aPosition is the position a string has been found in a substring.
// @param aMaximum is the maximum score this function returns.
// @return position dependent score.
static int matchPosScore(int aPosition, int aMaximum)
{
    return ( aPosition < aMaximum ) ? aMaximum - aPosition : 0;
}


void CMP_TREE_NODE::ResetScore()
{
    for( auto& child: Children )
        child->ResetScore();

    Score = kLowestDefaultScore;
}


void CMP_TREE_NODE::AssignIntrinsicRanks()
{
    std::vector<CMP_TREE_NODE*> sort_buf;

    for( auto const& node: Children )
        sort_buf.push_back( &*node );

    std::sort( sort_buf.begin(), sort_buf.end(),
            []( CMP_TREE_NODE* a, CMP_TREE_NODE* b ) -> bool
                { return a->MatchName > b->MatchName; } );

    for( int i = 0; i < (int) sort_buf.size(); ++i )
        sort_buf[i]->IntrinsicRank = i;
}


void CMP_TREE_NODE::SortNodes()
{
    std::sort( Children.begin(), Children.end(),
            []( std::unique_ptr<CMP_TREE_NODE> const& a, std::unique_ptr<CMP_TREE_NODE> const& b )
                { return Compare( *a, *b ) > 0; } );

    for( auto& node: Children )
    {
        node->SortNodes();
    }
}


int CMP_TREE_NODE::Compare( CMP_TREE_NODE const& aNode1, CMP_TREE_NODE const& aNode2 )
{
    if( aNode1.Type != aNode2.Type )
        return 0;

    if( aNode1.Score != aNode2.Score )
        return aNode1.Score - aNode2.Score;

    if( aNode1.Parent != aNode2.Parent )
        return 0;

    return aNode1.IntrinsicRank - aNode2.IntrinsicRank;
}


CMP_TREE_NODE::CMP_TREE_NODE()
    : Parent( nullptr ),
        IntrinsicRank( 0 ),
        Score( kLowestDefaultScore ),
        Alias( nullptr ),
        Unit( 0 )
{}


CMP_TREE_NODE_UNIT::CMP_TREE_NODE_UNIT( CMP_TREE_NODE* aParent, int aUnit )
{
    Parent = aParent;
    Type = UNIT;

    Unit = aUnit;
    Alias = aParent->Alias;

    Name = _( "Unit" ) + " " + LIB_PART::SubReference( aUnit, false );
    Desc = wxEmptyString;
    MatchName = wxEmptyString;

    IntrinsicRank = -aUnit;
}


CMP_TREE_NODE_ALIAS::CMP_TREE_NODE_ALIAS( CMP_TREE_NODE* aParent, LIB_ALIAS* aAlias )
{
    Parent      = aParent;
    Type        = ALIAS;
    Name        = aAlias->GetName();
    Desc        = aAlias->GetDescription();
    MatchName   = aAlias->GetName().Lower();
    SearchText  = aAlias->GetKeyWords() + "        " + Desc;
    Alias       = aAlias;

    if( aAlias->GetPart()->IsMulti() )
    {
        for( int u = 1; u <= aAlias->GetPart()->GetUnitCount(); ++u )
        {
            AddUnit( u );
        }
    }
}


CMP_TREE_NODE_UNIT& CMP_TREE_NODE_ALIAS::AddUnit( int aUnit )
{
    CMP_TREE_NODE_UNIT* unit = new CMP_TREE_NODE_UNIT( this, aUnit );
    Children.push_back( std::unique_ptr<CMP_TREE_NODE>( unit ) );
    return *unit;
}


void CMP_TREE_NODE_ALIAS::UpdateScore( EDA_COMBINED_MATCHER& aMatcher )
{
    if( Score <= 0 )
        return; // Leaf nodes without scores are out of the game.

    // Keywords and description we only count if the match string is at
    // least two characters long. That avoids spurious, low quality
    // matches. Most abbreviations are at three characters long.
    int found_pos = EDA_PATTERN_NOT_FOUND;
    int matchers_fired = 0;

    if( aMatcher.GetPattern() == MatchName )
        Score += 1000;  // exact match. High score :)
    else if( aMatcher.Find( MatchName, matchers_fired, found_pos ) )
    {
        // Substring match. The earlier in the string the better.
        Score += matchPosScore( found_pos, 20 ) + 20;
    }
    else if( aMatcher.Find( Parent->MatchName, matchers_fired, found_pos ) )
        Score += 19;   // parent name matches.         score += 19
    else if( aMatcher.Find( SearchText, matchers_fired, found_pos ) )
    {
        // If we have a very short search term (like one or two letters),
        // we don't want to accumulate scores if they just happen to be in
        // keywords or description as almost any one or two-letter
        // combination shows up in there.
        if( aMatcher.GetPattern().length() >= 2 )
        {
            // For longer terms, we add scores 1..18 for positional match
            // (higher in the front, where the keywords are).
            Score += matchPosScore( found_pos, 17 ) + 1;
        }
    }
    else
    {
        // No match. That's it for this item.
        Score = 0;
    }

    // More matchers = better match
    Score += 2 * matchers_fired;
}


CMP_TREE_NODE_LIB::CMP_TREE_NODE_LIB( CMP_TREE_NODE* aParent, wxString const& aName )
{
    Type = LIB;
    Name = aName;
    MatchName = aName.Lower();
    Parent = aParent;
}


CMP_TREE_NODE_ALIAS& CMP_TREE_NODE_LIB::AddAlias( LIB_ALIAS* aAlias )
{
    CMP_TREE_NODE_ALIAS* alias = new CMP_TREE_NODE_ALIAS( this, aAlias );
    Children.push_back( std::unique_ptr<CMP_TREE_NODE>( alias ) );
    return *alias;
}


void CMP_TREE_NODE_LIB::UpdateScore( EDA_COMBINED_MATCHER& aMatcher )
{
    Score = 0;

    for( auto& child: Children )
    {
        child->UpdateScore( aMatcher );
        Score = std::max( Score, child->Score );
    }
}


CMP_TREE_NODE_ROOT::CMP_TREE_NODE_ROOT()
{
    Type = ROOT;
}


CMP_TREE_NODE_LIB& CMP_TREE_NODE_ROOT::AddLib( wxString const& aName )
{
    CMP_TREE_NODE_LIB* lib = new CMP_TREE_NODE_LIB( this, aName );
    Children.push_back( std::unique_ptr<CMP_TREE_NODE>( lib ) );
    return *lib;
}


void CMP_TREE_NODE_ROOT::UpdateScore( EDA_COMBINED_MATCHER& aMatcher )
{
    for( auto& child: Children )
        child->UpdateScore( aMatcher );
}