//
//  MPParenthesisFunctionLayout.m
//  MathPad
//
//  Created by Kim Wittenburg on 17.09.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import "MPParenthesisFunctionLayout.h"

#define MPParenthesisFunctionOpeningParensOffset 2
#define MPParenthesisFunctionClosingParensOffset 0

@interface MPParenthesisFunctionLayout ()

- (NSBezierPath *)openingParens;
- (NSBezierPath *)closingParens;

- (NSBezierPath *)transformedOpeningParens;
- (NSBezierPath *)transformedClosingParens;

- (NSAffineTransform *)parenthesisTransform;

@end

@implementation MPParenthesisFunctionLayout

- (MPParenthesisFunction *)parenthesisFunction
{
    return (MPParenthesisFunction *)self.function;
}

- (NSBezierPath *)openingParens
{
    NSBezierPath *parens = [self objectForPrivateCacheIndex:0 generator:^id{
        CTLineRef line = [self createLineForString:@"("];
        CFArrayRef glyphRuns = CTLineGetGlyphRuns(line);
        CFRetain(glyphRuns);
        CTRunRef glyphRun = CFArrayGetValueAtIndex(glyphRuns, 0);
        CFRetain(glyphRun);
        
        CGGlyph *glyphs = malloc(1 * sizeof(CGGlyph));
        CTRunGetGlyphs(glyphRun, CFRangeMake(0, 1), glyphs);
        NSGlyph glyph = glyphs[0];
        
        NSBezierPath *path = [[NSBezierPath alloc] init];
        [path moveToPoint:NSZeroPoint];
        [path appendBezierPathWithGlyph:glyph
                                 inFont:self.font];
        
        CFRelease(line);
        CFRelease(glyphRuns);
        CFRelease(glyphRun);
        free(glyphs);
        
        return path;
    }];
    return parens;
}

- (NSBezierPath *)closingParens
{
    NSBezierPath *parens = [self objectForPrivateCacheIndex:1 generator:^id{
        CTLineRef line = [self createLineForString:@")"];
        CFArrayRef glyphRuns = CTLineGetGlyphRuns(line);
        CFRetain(glyphRuns);
        CTRunRef glyphRun = CFArrayGetValueAtIndex(glyphRuns, 0);
        CFRetain(glyphRun);
        
        CGGlyph *glyphs = malloc(1 * sizeof(CGGlyph));
        CTRunGetGlyphs(glyphRun, CFRangeMake(0, 1), glyphs);
        NSGlyph glyph = glyphs[0];
        
        NSBezierPath *path = [[NSBezierPath alloc] init];
        [path moveToPoint:NSZeroPoint];
        [path appendBezierPathWithGlyph:glyph
                                 inFont:self.font];
        
        CFRelease(line);
        CFRelease(glyphRuns);
        CFRelease(glyphRun);
        free(glyphs);
        
        return path;
    }];
    return parens;
}

- (NSBezierPath *)transformedOpeningParens
{
    NSBezierPath *parens = self.openingParens.copy;
    [parens transformUsingAffineTransform:self.parenthesisTransform];
    return parens;
}

- (NSBezierPath *)transformedClosingParens
{
    NSBezierPath *parens = self.closingParens.copy;
    [parens transformUsingAffineTransform:self.parenthesisTransform];
    return parens;
}

- (NSAffineTransform *)parenthesisTransform
{
    NSRect parensBounds = self.openingParens.bounds;
    NSRect expressionBounds = [self childLayoutAtIndex:0].bounds;
    NSAffineTransform *transform = [NSAffineTransform transform];
    if (expressionBounds.size.height >= parensBounds.size.height) {
        return transform;
    }
    CGFloat scaleFactor = expressionBounds.size.height / parensBounds.size.height;
    [transform scaleXBy:1
                    yBy:scaleFactor];
    return transform;
}

- (NSPoint)offsetOfChildLayoutAtIndex:(NSUInteger)index
{
    if (index == 0) {
        return NSMakePoint(self.openingParens.bounds.size.width + MPParenthesisFunctionOpeningParensOffset, 0);
    }
    return NSZeroPoint;
}

- (NSIndexPath *)indexPathForLocalMousePoint:(NSPoint)point
{
#warning Missing Implementation
    return [NSIndexPath indexPathWithIndex:0];
}

- (NSIndexSet *)indexesOfRemainingChildren
{
    return [NSIndexSet indexSetWithIndex:0];
}

- (NSRect)generateBounds
{
    NSRect openingParensBounds = self.transformedOpeningParens.bounds;
    NSRect closingParensBounds = self.transformedClosingParens.bounds;
    NSRect bounds = [self childLayoutAtIndex:0].bounds;
    
    if (openingParensBounds.size.height > bounds.size.height) {
        bounds.size.height = openingParensBounds.size.height;
    }
    if (closingParensBounds.size.height > bounds.size.height) {
        bounds.size.height = closingParensBounds.size.height;
    }
    
    bounds.size.width += MPParenthesisFunctionOpeningParensOffset;
    bounds.size.width += openingParensBounds.size.width;
    bounds.size.width += MPParenthesisFunctionClosingParensOffset;
    bounds.size.width += closingParensBounds.size.width;
    
    return bounds;
}

#warning Let the children be drawn automatically
- (BOOL)drawsChildrenManually
{
    return YES;
}

- (void)draw
{
    NSBezierPath *openingParens = self.transformedOpeningParens;
    MPLayout *expressionLayout = [self childLayoutAtIndex:0];
    NSBezierPath *closingParens = self.transformedClosingParens;
    
    CGFloat x = 0;
    
    [openingParens fill];
    x += openingParens.bounds.size.width;
    x += MPParenthesisFunctionOpeningParensOffset;
    [expressionLayout drawAtPoint:NSMakePoint(x, 0)];
    x += expressionLayout.bounds.size.width;
    x += MPParenthesisFunctionClosingParensOffset;
    
    NSAffineTransform *transform = [NSAffineTransform transform];
    [transform translateXBy:x
                        yBy:0];
    [closingParens transformUsingAffineTransform:transform];
    [closingParens fill];
}

@end