/*

File: Grid.m

Abstract: Abstract superclass of regular geometric grids of GridCells that Bits can be placed on.

Version: 1.0

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*/

#import "Grid.h"

#import "Bit.h"

#import "Game.h"

#import "QuartzUtils.h"

/**  WARNING: THIS CODE REQUIRES GARBAGE COLLECTION!

 **  This sample application uses Objective-C 2.0 garbage collection.

 **  Therefore, the source code in this file does NOT perform manual object memory management.

 **  If you reuse any of this code in a process that isn't garbage collected, you will need to

 **  add all necessary retain/release/autorelease calls, and implement -dealloc methods,

 **  otherwise unpleasant leakage will occur!

 **/

@implementation Grid

- (id) initWithRows: (unsigned)nRows columns: (unsigned)nColumns

            spacing: (CGSize)spacing

           position: (CGPoint)pos

{

    NSParameterAssert(nRows>0 && nColumns>0);

    self = [super init];

    if( self ) {

        _nRows = nRows;

        _nColumns = nColumns;

        _spacing = spacing;

        _cellClass = [GridCell class];

        _lineColor = kBlackColor;

        _allowsMoves = YES;

        _usesDiagonals = YES;

        self.bounds = CGRectMake(-1, -1, nColumns*spacing.width+2, nRows*spacing.height+2);

        self.position = pos;

        self.anchorPoint = CGPointMake(0,0);

        self.zPosition = kBoardZ;

        self.needsDisplayOnBoundsChange = YES;

        unsigned n = nRows*nColumns;

        _cells = [NSMutableArray arrayWithCapacity: n];

        id null = [NSNull null];

        while( n-- > 0 )

            [_cells addObject: null];

        [self setNeedsDisplay];

    }

    return self;

}

- (id) initWithRows: (unsigned)nRows columns: (unsigned)nColumns

              frame: (CGRect)frame

{

    CGFloat spacing = floor(MIN( (frame.size.width -2)/(CGFloat)nColumns,

                               (frame.size.height-2)/(CGFloat)nRows) );

    return [self initWithRows: nRows columns: nColumns

                      spacing: CGSizeMake(spacing,spacing)

                     position: frame.origin];

}

static void setcolor( CGColorRef *var, CGColorRef color )

{

    if( color != *var ) {

        // Garbage collection does not apply to CF objects like CGColors!

        CGColorRelease(*var);

        *var = CGColorRetain(color);

    }

}

- (CGColorRef) cellColor                        {return _cellColor;}

- (void) setCellColor: (CGColorRef)cellColor    {setcolor(&_cellColor,cellColor);}

- (CGColorRef) lineColor                        {return _lineColor;}

- (void) setLineColor: (CGColorRef)lineColor    {setcolor(&_lineColor,lineColor);}

@synthesize cellClass=_cellClass, rows=_nRows, columns=_nColumns, spacing=_spacing,

            usesDiagonals=_usesDiagonals, allowsMoves=_allowsMoves, allowsCaptures=_allowsCaptures;

#pragma mark -

#pragma mark GEOMETRY:

- (GridCell*) cellAtRow: (unsigned)row column: (unsigned)col

{

    if( row < _nRows && col < _nColumns ) {

        id cell = [_cells objectAtIndex: row*_nColumns+col];

        if( cell != [NSNull null] )

            return cell;

    }

    return nil;

}

/** Subclasses can override this, to change the cell's class or frame. */

- (GridCell*) createCellAtRow: (unsigned)row column: (unsigned)col 

               suggestedFrame: (CGRect)frame

{

    return [[_cellClass alloc] initWithGrid: self 

                                        row: row column: col

                                      frame: frame];

}

- (GridCell*) addCellAtRow: (unsigned)row column: (unsigned)col

{

    NSParameterAssert(row<_nRows);

    NSParameterAssert(col<_nColumns);

    unsigned index = row*_nColumns+col;

    GridCell *cell = [_cells objectAtIndex: index];

    if( (id)cell == [NSNull null] ) {

        CGRect frame = CGRectMake(col*_spacing.width, row*_spacing.height,

                                  _spacing.width,_spacing.height);

        cell = [self createCellAtRow: row column: col suggestedFrame: frame];

        if( cell ) {

            [_cells replaceObjectAtIndex: index withObject: cell];

            [self addSublayer: cell];

            [self setNeedsDisplay];

        }

    }

    return cell;

}

- (void) addAllCells

{

    for( int row=_nRows-1; row>=0; row-- )                // makes 'upper' cells be in 'back'

        for( int col=0; col<_nColumns; col++ ) 

            [self addCellAtRow: row column: col];

}

- (void) removeCellAtRow: (unsigned)row column: (unsigned)col

{

    NSParameterAssert(row<_nRows);

    NSParameterAssert(col<_nColumns);

    unsigned index = row*_nColumns+col;

    id cell = [_cells objectAtIndex: index];

    if( cell != [NSNull null] )

        [cell removeFromSuperlayer];

    [_cells replaceObjectAtIndex: index withObject: [NSNull null]];

    [self setNeedsDisplay];

}

#pragma mark -

#pragma mark DRAWING:

- (void) drawCellsInContext: (CGContextRef)ctx fill: (BOOL)fill

{

    // Subroutine of -drawInContext:. Draws all the cells, with or without a fill.

    for( unsigned row=0; row<_nRows; row++ )

        for( unsigned col=0; col<_nColumns; col++ ) {

            GridCell *cell = [self cellAtRow: row column: col];

            if( cell )

                [cell drawInParentContext: ctx fill: fill];

        }

}

- (void)drawInContext:(CGContextRef)ctx

{

    // Custom CALayer drawing implementation. Delegates to the cells to draw themselves

    // in me; this is more efficient than having each cell have its own drawing.

    if( _cellColor ) {

        CGContextSetFillColorWithColor(ctx, _cellColor);

        [self drawCellsInContext: ctx fill: YES];

    }

    if( _lineColor ) {

        CGContextSetStrokeColorWithColor(ctx,_lineColor);

        [self drawCellsInContext:ctx fill: NO];

    }

}

@end

#pragma mark -

@implementation GridCell

- (id) initWithGrid: (Grid*)grid 

                row: (unsigned)row column: (unsigned)col

              frame: (CGRect)frame

{

    self = [super init];

    if (self != nil) {

        _grid = grid;

        _row = row;

        _column = col;

        self.position = frame.origin;

        CGRect bounds = frame;

        bounds.origin.x -= floor(bounds.origin.x);  // make sure my coords fall on pixel boundaries

        bounds.origin.y -= floor(bounds.origin.y);

        self.bounds = bounds;

        self.anchorPoint = CGPointMake(0,0);

        self.borderColor = kHighlightColor;         // Used when highlighting (see -setHighlighted:)

    }

    return self;

}

- (NSString*) description

{

    return [NSString stringWithFormat: @"%@(%u,%u)", [self class],_column,_row];

}

@synthesize grid=_grid, row=_row, column=_column;

- (void) drawInParentContext: (CGContextRef)ctx fill: (BOOL)fill

{

    // Default implementation just fills or outlines the cell.

    CGRect frame = self.frame;

    if( fill )

        CGContextFillRect(ctx,frame);

    else

        CGContextStrokeRect(ctx, frame);

}

- (void) setBit: (Bit*)bit

{

    if( bit != self.bit ) {

        [super setBit: bit];

        if( bit ) {

            // Center it:

            CGSize size = self.bounds.size;

            bit.position = CGPointMake(floor(size.width/2.0),

                                       floor(size.height/2.0));

        }

    }

}

- (Bit*) canDragBit: (Bit*)bit

{

    if( _grid.allowsMoves && bit==self.bit )

        return [super canDragBit: bit];

    else

        return nil;

}

- (BOOL) canDropBit: (Bit*)bit atPoint: (CGPoint)point

{

    return self.bit == nil || _grid.allowsCaptures;

}

- (BOOL) fwdIsN 

{

    return self.game.currentPlayer.index == 0;

}

- (NSArray*) neighbors

{

    BOOL orthogonal = ! _grid.usesDiagonals;

    NSMutableArray *neighbors = [NSMutableArray arrayWithCapacity: 8];

    for( int dy=-1; dy<=1; dy++ )

        for( int dx=-1; dx<=1; dx++ )

            if( (dx || dy) && !(orthogonal && dx && dy) ) {

                GridCell *cell = [_grid cellAtRow: _row+dy column: _column+dx];

                if( cell )

                    [neighbors addObject: cell];

            }

    return neighbors;

}

// Recursive subroutine used by getGroup:.

- (void) x_addToGroup: (NSMutableSet*)group liberties: (NSMutableSet*)liberties owner: (Player*)owner

{

    Bit *bit = self.bit;

    if( bit == nil ) {

        if( [liberties containsObject: self] )

            return; // already traversed

        [liberties addObject: self];

    } else if( bit.owner==owner ) {

        if( [group containsObject: self] )

            return; // already traversed

        [group addObject: self];

        for( GridCell *c in self.neighbors )

            [c x_addToGroup: group liberties: liberties owner: owner];

    }

}

- (NSSet*) getGroup: (int*)outLiberties

{

    NSMutableSet *group=[NSMutableSet set], *liberties=nil;

    if( outLiberties )

        liberties = [NSMutableSet set];

    [self x_addToGroup: group liberties: liberties owner: self.bit.owner];

    if( outLiberties )

        *outLiberties = liberties.count;

    return group;

}

#pragma mark -

#pragma mark DRAG-AND-DROP:

// An image from another app can be dragged onto a Dispenser to change the Piece's appearance.

- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender

{

    NSPasteboard *pb = [sender draggingPasteboard];

    if( [NSImage canInitWithPasteboard: pb] )

        return NSDragOperationCopy;

    else

        return NSDragOperationNone;

}

- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender

{

    CGImageRef image = GetCGImageFromPasteboard([sender draggingPasteboard]);

    if( image ) {

        _grid.cellColor = CreatePatternColor(image);

        [_grid setNeedsDisplay];

        return YES;

    } else

        return NO;

}

@end

#pragma mark -

@implementation RectGrid

- (id) initWithRows: (unsigned)nRows columns: (unsigned)nColumns

            spacing: (CGSize)spacing

           position: (CGPoint)pos

{

    self = [super initWithRows: nRows columns: nColumns spacing: spacing position: pos];

    if( self ) {

        _cellClass = [Square class];

    }

    return self;

}

- (CGColorRef) altCellColor                         {return _altCellColor;}

- (void) setAltCellColor: (CGColorRef)altCellColor  {setcolor(&_altCellColor,altCellColor);}

@end

#pragma mark -

@implementation Square

- (void) drawInParentContext: (CGContextRef)ctx fill: (BOOL)fill

{

    if( fill ) {

        CGColorRef c = ((RectGrid*)_grid).altCellColor;

        if( c ) {

            if( ! ((_row+_column) & 1) )

                c = _grid.cellColor;

            CGContextSetFillColorWithColor(ctx, c);

        }

    }

    [super drawInParentContext: ctx fill: fill];

}

- (void) setHighlighted: (BOOL)highlighted

{

    [super setHighlighted: highlighted];

    self.borderWidth = (highlighted ?6 :0);

}

- (Square*) nw     {return (Square*)[_grid cellAtRow: _row+1 column: _column-1];}

- (Square*) n      {return (Square*)[_grid cellAtRow: _row+1 column: _column  ];}

- (Square*) ne     {return (Square*)[_grid cellAtRow: _row+1 column: _column+1];}

- (Square*) e      {return (Square*)[_grid cellAtRow: _row   column: _column+1];}

- (Square*) se     {return (Square*)[_grid cellAtRow: _row-1 column: _column+1];}

- (Square*) s      {return (Square*)[_grid cellAtRow: _row-1 column: _column  ];}

- (Square*) sw     {return (Square*)[_grid cellAtRow: _row-1 column: _column-1];}

- (Square*) w      {return (Square*)[_grid cellAtRow: _row   column: _column-1];}

// Directions relative to the current player:

- (Square*) fl     {return self.fwdIsN ?self.nw :self.se;}

- (Square*) f      {return self.fwdIsN ?self.n  :self.s;}

- (Square*) fr     {return self.fwdIsN ?self.ne :self.sw;}

- (Square*) r      {return self.fwdIsN ?self.e  :self.w;}

- (Square*) br     {return self.fwdIsN ?self.se :self.nw;}

- (Square*) b      {return self.fwdIsN ?self.s  :self.n;}

- (Square*) bl     {return self.fwdIsN ?self.sw :self.ne;}

- (Square*) l      {return self.fwdIsN ?self.w  :self.e;}

- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender

{

    CGImageRef image = GetCGImageFromPasteboard([sender draggingPasteboard]);

    if( image ) {

        CGColorRef color = CreatePatternColor(image);

        RectGrid *rectGrid = (RectGrid*)_grid;

        if( rectGrid.altCellColor && ((_row+_column) & 1) )

            rectGrid.altCellColor = color;

        else

            rectGrid.cellColor = color;

        [rectGrid setNeedsDisplay];

        return YES;

    } else

        return NO;

}

@end

#pragma mark -

@implementation GoSquare

@synthesize dotted=_dotted;

- (void) drawInParentContext: (CGContextRef)ctx fill: (BOOL)fill

{

    if( fill )

        [super drawInParentContext: ctx fill: fill];

    else {

        CGRect frame = self.frame;

        const CGFloat midx=floor(CGRectGetMidX(frame))+0.5, 

                    midy=floor(CGRectGetMidY(frame))+0.5;

        CGPoint p[4] = {{CGRectGetMinX(frame),midy},

                        {CGRectGetMaxX(frame),midy},

                        {midx,CGRectGetMinY(frame)},

                        {midx,CGRectGetMaxY(frame)}};

        if( ! self.s )  p[2].y = midy;

        if( ! self.n )  p[3].y = midy;

        if( ! self.w )  p[0].x = midx;

        if( ! self.e )  p[1].x = midx;

        CGContextStrokeLineSegments(ctx, p, 4);

        if( _dotted ) {

            CGContextSetFillColorWithColor(ctx,_grid.lineColor);

            CGRect dot = CGRectMake(midx-2.5, midy-2.5, 5, 5);

            CGContextFillEllipseInRect(ctx, dot);

        }

    }

}

@end