//
//  TCPageIndicator.m
//  MyMacDevDemo
//
//  Created by tangchao on 2021/12/11.
//

#import "TCPageIndicator.h"

@interface TCPageIndicator () {}

@property (nonatomic, strong) NSMutableArray *indicatorRects;

@end

@implementation TCPageIndicator

- (instancetype)initWithFrame:(NSRect)frameRect {
    if (self = [super initWithFrame:frameRect]) {
        self.selectedColor = [NSColor grayColor];
        self.normalColor = [[NSColor grayColor] colorWithAlphaComponent:0.5];
        
        self.indicatorMargin = 8.f;
        self.currentPage = 0;
        
        self.numberOfPages = 0;
        self.pageIndicatorSize = CGSizeMake(6, 6);
        self.enabled = YES;
        
        self.indicatorRects = [NSMutableArray arrayWithCapacity:4];
    }
    return self;
}

- (void)setIndicatorMargin:(CGFloat)indicatorMargin {
    _indicatorMargin = indicatorMargin;
    
    [self setNeedsDisplay:YES];
}

- (void)setCurrentPage:(NSUInteger)currentPage {
    _currentPage = currentPage;
    
    [self setNeedsDisplay:YES];
}

- (void)setNumberOfPages:(NSUInteger)numberOfPages {
    _numberOfPages = numberOfPages;
    
    [self setNeedsDisplay:YES];
}

- (void)setPageIndicatorSize:(NSSize)pageIndicatorSize {
    _pageIndicatorSize = pageIndicatorSize;
    
    [self setNeedsDisplay:YES];
}

- (void)drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];
    
    CGFloat indicatorAreaWidth = self.pageIndicatorSize.width * self.numberOfPages + self.indicatorMargin * (self.numberOfPages-1);
    CGFloat leftPosition = (self.bounds.size.width - indicatorAreaWidth) * 0.5;
    CGFloat topPadding = (self.bounds.size.height - self.pageIndicatorSize.height) * 0.5;
    
    [self.indicatorRects removeAllObjects];
    
    for (int i = 0; i < self.numberOfPages; i++) {
        NSPoint position = NSMakePoint(leftPosition, topPadding);
        CGRect rect = CGRectMake(position.x, position.y, self.pageIndicatorSize.width, self.pageIndicatorSize.height);
        [self.indicatorRects addObject:[NSValue valueWithRect:rect]];
        
        NSBezierPath *path = [NSBezierPath bezierPathWithOvalInRect:rect];
        if (self.currentPage == i) {
            [self.selectedColor setFill];
        } else {
            [self.normalColor setFill];
        }
        [path fill];
        leftPosition += (self.pageIndicatorSize.width + self.indicatorMargin);
    }
}

- (void)mouseDown:(NSEvent *)event {
    [super mouseDown:event];
    
    if (self.enabled == NO) {
        return;
    }
    
    NSPoint eventLocation = event.locationInWindow;
    /// 转换成视图的本地坐标
    NSPoint pointInView = [self convertPoint:eventLocation fromView:nil];
    for (int i = 0; i < self.numberOfPages; i++) {
        NSRect rect = CGRectInset([self.indicatorRects[i] CGRectValue], -2, -2);
        if (NSPointInRect(pointInView, rect)) {
            self.currentPage = i;
        }
    }
}

@end