LNXcodeSupport.mm

//
//  LNXcodeSupport.m
//  LNProvider
//
//  Created by John Holdsworth on 31/03/2017.
//  Copyright © 2017 John Holdsworth. All rights reserved.
//
//  Repo: https://github.com/johnno1962/GitDiff
//
//  $Id: //depot/GitDiff/LNXcodeSupport/LNXcodeSupport.mm#11 $
//

#import "LNXcodeSupport.h"
#import "LNXcodeSupport-Swift.h"
#import "LNExtensionClientDO.h"
#import "LNHighlightGutter.h"

#import "XcodePrivate.h"
#import <objc/runtime.h>

#define REFRESH_INTERVAL 60.
#define REVERT_DELAY 1.5

static LNXcodeSupport *lineNumberPlugin;
static NSString *lastSaved;

@interface LNXcodeSupport () <LNRegistration, LNConnectionDelegate>

@property NSMutableArray<LNExtensionClient *> *extensions;
@property NSMutableDictionary<NSString *, void (^)()> *onupdate;

@property Class sourceDocClass, scrollerClass;
@property NSTextView *popover;
@property NSButton *undoButton;

@end

@implementation LNXcodeSupport

+ (void)pluginDidLoad:(NSBundle *)pluginBundle {
    NSString *currentApplicationName = [NSBundle mainBundle].infoDictionary[@"CFBundleName"];
    static dispatch_once_t onceToken;

    if ([currentApplicationName isEqualToString:@"Xcode"]) {
        dispatch_once(&onceToken, ^{
            LNXcodeSupport *plugin = lineNumberPlugin = [[self alloc] init];
            plugin.extensions = [NSMutableArray new];
            plugin.onupdate = [NSMutableDictionary new];

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
            [self swizzleClass:[NSDocument class]
                      exchange:@selector(_finishSavingToURL:ofType:forSaveOperation:changeCount:)
                          with:@selector(ln_finishSavingToURL:ofType:forSaveOperation:changeCount:)];

            [self swizzleClass:objc_getClass("IDEEditorDocument")
                      exchange:@selector(closeToRevert)
                          with:@selector(ln_closeToRevert)];

            [self swizzleClass:objc_getClass("DVTMarkedScroller")
                      exchange:@selector(drawKnobSlotInRect:highlight:)
                          with:@selector(ln_drawKnobSlotInRect:highlight:)];
#pragma clang diagnostic pop

            dispatch_async(dispatch_get_main_queue(), ^{
                plugin.sourceDocClass = objc_getClass("IDEEditorDocument"); //IDESourceCodeDocument");
                plugin.scrollerClass = objc_getClass("SourceEditorScrollView");

                plugin.undoButton = [[NSButton alloc] initWithFrame:NSZeroRect];
                plugin.undoButton.bordered = FALSE;

                NSBundle *pluginBundle = [NSBundle bundleForClass:self];
                NSString *path = [pluginBundle pathForResource:@"undo" ofType:@"png"];
                plugin.undoButton.image = [[NSImage alloc] initWithContentsOfFile:path];
                plugin.undoButton.imageScaling = NSImageScaleProportionallyDown;

                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
                    NSConnection *registrationDO = [[NSConnection alloc] init];
                    [registrationDO setRootObject:plugin];
                    [registrationDO registerName:XCODE_LINE_NUMBER_REGISTRATION];

                    NSURL *appURL = [pluginBundle URLForResource:@"LNProvider" withExtension:@"app"];
                    [[NSWorkspace sharedWorkspace] openURL:appURL];

                    [[NSRunLoop currentRunLoop] run];
                });
            });
        });
    }
}

+ (void)swizzleClass:(Class)aClass exchange:(SEL)origMethod with:(SEL)altMethod {
    method_exchangeImplementations(class_getInstanceMethod(aClass, origMethod),
                                   class_getInstanceMethod(aClass, altMethod));
}

- (oneway void)registerLineNumberService:(NSString *)serviceName {
    [self deregisterService:serviceName];
    NSLog(@"Registering %@ ...", serviceName);
    [self.extensions addObject:[[LNExtensionClientDO alloc] initServiceName:serviceName delegate:self]];
}

- (oneway void)ping {
}

- (oneway void)deregisterService:(NSString *_Nonnull)serviceName {
    for (LNExtensionClient *extension in self.extensions) {
        if ([extension.serviceName isEqualToString:serviceName]) {
            [self.extensions removeObject:extension];
            break;
        }
    }
}

- (void)updateHighlights:(NSData *)json error:(NSError *)error forFile:(NSString *)filepath {
    dispatch_async(dispatch_get_main_queue(), ^{
        if (error)
            [[NSAlert alertWithError:error] runModal];
        else if (auto update = self.onupdate[filepath])
            update();
    });
}

- (void)updateGutter:(NSString *)filepath {
    self.onupdate[filepath]();
}

- (void)updateLinenumberHighlightsForFile:(NSString *)filepath {
    for (LNExtensionClient *extension in self.extensions)
        [extension requestHighlightsForFile:filepath];
}

- (void)updateConfig:(LNConfig)config forService:(NSString *_Nonnull)serviceName {
    NSLog(@"%@ updateConfig: %@", serviceName, config);
}

- (void)initialOrOccaisionalLineNumberUpdate:(NSString *)filepath {
    // update if not already in memory or 60 seconds has passed
    NSTimeInterval stale = [NSDate timeIntervalSinceReferenceDate] - REFRESH_INTERVAL;
    for (LNExtensionClient *extension in self.extensions) {
        if (filepath && extension[filepath].updated < stale) {
            if (!extension[filepath])
                extension.highightsByFile[filepath] = [[LNFileHighlights alloc] initWithData:nil
                                                                                     service:extension.serviceName];
            [extension requestHighlightsForFile:filepath];
        }
    }
}

@end

@implementation NSDocument (IDESourceCodeDocument)

- (void)forceLineNumberUpdate {
    if ([self isKindOfClass:lineNumberPlugin.sourceDocClass])
        [lineNumberPlugin updateLinenumberHighlightsForFile:lastSaved = [[self fileURL] path]];
}

// source file is being saved
- (void)ln_finishSavingToURL:(id)a0 ofType:(id)a1 forSaveOperation:(NSUInteger)a2 changeCount:(id)a3 {
    [self ln_finishSavingToURL:a0 ofType:a1 forSaveOperation:a2 changeCount:a3];
    [self forceLineNumberUpdate];
}

// revert on change on disk
- (void)ln_closeToRevert {
    [self ln_closeToRevert];
    [self forceLineNumberUpdate];
}

@end

@implementation NSString (LineNumber)

// https://stackoverflow.com/questions/1085524/how-to-count-the-number-of-lines-in-an-objective-c-string-nsstring

- (NSUInteger)numberOfLines {
    NSUInteger numberOfLines, index, stringLength = [self length];

    for (index = 0, numberOfLines = 0; index < stringLength; numberOfLines++)
        index = NSMaxRange([self lineRangeForRange:NSMakeRange(index, 0)]);

    return numberOfLines;
}

- (NSUInteger)indexForLine:(NSUInteger)lineNumber {
    NSUInteger numberOfLines, index, stringLength = [self length];

    for (index = 0, numberOfLines = 0; index < stringLength && numberOfLines < lineNumber; numberOfLines++)
        index = NSMaxRange([self lineRangeForRange:NSMakeRange(index, 0)]);

    return index;
}

@end

@implementation NSScroller (LineNumber)

- (NSString *)editedDocPath {
    return lastSaved ?: @"";
    id name = [KeyPath objectFor:@"hostingEditor.dataSource.name" from:self.superview.superview];
    return [name isKindOfClass:[NSString class]] ? name : @"";
}

// scroll bar overview
- (void)ln_drawKnobSlotInRect:(CGRect)rect highlight:(BOOL)highlight {
    [self ln_drawKnobSlotInRect:rect highlight:highlight];
    if (![self.superview isKindOfClass:lineNumberPlugin.scrollerClass])
        return;

    NSString *filepath = [self editedDocPath];
    [lineNumberPlugin initialOrOccaisionalLineNumberUpdate:filepath];
    NSLog(@"ln_drawKnobSlotInRect: %@ %@", self, filepath);

    __weak NSScroller *weakSelf = self;
    lineNumberPlugin.onupdate[filepath] = ^{
        [weakSelf updateLineNumberFlecksFor:filepath];
        [weakSelf updateScrollbarMarkersFor:filepath in:rect];
    };

    [NSObject cancelPreviousPerformRequestsWithTarget:lineNumberPlugin];
    [lineNumberPlugin performSelector:@selector(updateGutter:) withObject:filepath afterDelay:.1];
}

static CGFloat gutterWidth;

- (void)updateLineNumberFlecksFor:(NSString *)filepath {
    NSView *floatingContainer = self.superview.subviews[1];
    NSArray *floating = floatingContainer.subviews;
    LNHighlightGutter *highlightGutter = floating.lastObject;
    SourceEditorGutterMarginContentView *lineNumberGutter;

    if (![highlightGutter isKindOfClass:[LNHighlightGutter class]]) {
        lineNumberGutter = floating.lastObject;
        highlightGutter = [[LNHighlightGutter alloc] initWithFrame:NSZeroRect];
        [floatingContainer addSubview:highlightGutter];
    } else
        lineNumberGutter = floating.firstObject;

    NSLog(@"updateLineNumberFlecksFor: %@ %@ %@ %@", filepath, highlightGutter,
          NSStringFromRect(highlightGutter.frame), lineNumberGutter);

    static Class gutterContentClasss;
    if (!gutterContentClasss)
        gutterContentClasss = objc_getClass("SourceEditor.SourceEditorGutterMarginContentView");
    if (![lineNumberGutter isKindOfClass:gutterContentClasss] &&
        !(floating.count > 1 &&
          [lineNumberGutter = floating[1] isKindOfClass:gutterContentClasss]))
            return;

    NSRect rect = lineNumberGutter.frame;
    gutterWidth = rect.size.width;

    rect.origin.y = 0.;
    rect.origin.x += gutterWidth - 3.;
    rect.size.width = 8.;
    rect.size.height += 5000.;
    if (!NSEqualRects(highlightGutter.frame, rect))
        highlightGutter.frame = rect;

    NSDictionary *lineNumberLayers = [KeyPath objectFor:@"lineNumberLayers" from:lineNumberGutter];
    NSMutableArray<LNHighlightFleck *> *next = [NSMutableArray new];
    SourceEditorContentView *sourceTextView = self.superview.subviews[0].subviews[0];
    CGFloat lineHeight = [sourceTextView defaultLineHeight];

    for (NSNumber *line in lineNumberLayers) {
        SourceEditorFontSmoothingTextLayer *layer = lineNumberLayers[line];
        NSRect rect = layer.frame;
        rect.size.width = LNFLECK_WIDTH;
        rect.size.height = lineHeight;
        rect.origin.x = NSWidth(highlightGutter.frame) - NSWidth(rect);
        rect.origin.y = NSHeight(highlightGutter.frame) -
                        lineNumberGutter.frame.origin.y - rect.origin.y - lineHeight + 4.;
        for (LNExtensionClient *extension in lineNumberPlugin.extensions.reverseObjectEnumerator) {
            if (LNFileHighlights *diffs = extension[filepath]) {
                if (LNHighlightElement *element = diffs[line.integerValue + 1]) {
                    LNHighlightFleck *fleck = [LNHighlightFleck fleck];
                    fleck.frame = rect;
                    fleck.element = element;
                    fleck.extension = extension;
                    fleck.yoffset = [lineNumberLayers[@(element.start - 1)] frame].origin.y;
                    [next addObject:fleck];
                    rect.origin.x -= LNFLECK_VISIBLE;
                }
            }
        }
    }

    #define NSOrderedCompare(a, b) a<b ? NSOrderedAscending : a>b ? NSOrderedDescending : NSOrderedSame
    [next sortUsingComparator:^NSComparisonResult(LNHighlightFleck *obj1, LNHighlightFleck *obj2) {
        return NSOrderedCompare(obj1.yoffset, obj2.yoffset);
    }];

    if (![[highlightGutter subviews] isEqualToArray:next]) {
        [[[highlightGutter subviews] copy] makeObjectsPerformSelector:@selector(removeFromSuperview)];
        for (LNHighlightFleck *fleck in next)
            [highlightGutter addSubview:fleck];
    } else
        [LNHighlightFleck recycle:next];
}

- (void)updateScrollbarMarkersFor:(NSString *)filepath in:(NSRect)rect {
    static NSMutableDictionary<NSString *, NSNumber *> *lineCountCache;
    if (!lineCountCache)
        lineCountCache = [NSMutableDictionary new];

    SourceEditorContentView *sourceTextView = self.superview.subviews[0].subviews[0];
    NSInteger lines = lineCountCache[filepath].intValue;
    if (!lines)
        lineCountCache[filepath] = @(lines = [sourceTextView.accessibilityValue numberOfLines] ?: 1);

    CGFloat lineHeight = [sourceTextView defaultLineHeight];
    CGFloat scale = lines * lineHeight < NSHeight(self.frame) ? lineHeight : NSHeight(self.frame) / lines;
    NSMutableArray *marks = [NSMutableArray new], *markRects = [NSMutableArray new];

    static Class markerListClass9_2;
    if (!markerListClass9_2 && (markerListClass9_2 = objc_getClass("_DVTMarkerList"))) {
        markerListClass9_2 = objc_allocateClassPair(markerListClass9_2, "ln_DVTMarkerList", 0);
        class_addMethod(markerListClass9_2, @selector(_recomputeMarkRects),
                        imp_implementationWithBlock(^{}), "v16@0:8");
        objc_registerClassPair(markerListClass9_2);
    }

    if (!markerListClass9_2)
        [self clearDiffMarks];

    for (LNExtensionClient *extension in lineNumberPlugin.extensions) {
        if (LNFileHighlights *diffs = extension[filepath]) {
            [diffs foreachHighlightRange:^(NSRange range, LNHighlightElement *element) {
                if (markerListClass9_2) {
                    NSRect rect = NSMakeRect(4., (range.location - 1) * scale, 2., MAX(range.length * scale, 2.));
                    [marks addObject:@((range.location - 1.) / lines)];
                    [markRects addObject:[NSValue valueWithRect:rect]];
                } else
                    [self addMark:(range.location - 1.) / lines onLine:range.location ofType:2];
            }];
        }
    }

    if (markerListClass9_2) {
        _DVTMarkerList *markers = [[markerListClass9_2 alloc] initWithSlotRect:rect];
        [markers setValue:marks forKey:@"_marks"];
        [markers setValue:markRects forKey:@"_markRects"];
        [self setValue:markers forKey:@"_diffMarks"];
    }
}

@end

@implementation LNHighlightFleck (LNXcodeSupport)

- (SourceEditorContentView *)editorContentView {
    return self.superview.superview.superview.subviews[0].subviews[0];
}

- (void)mouseEntered:(NSEvent *)theEvent {
    if (!self.element.text)
        return;
    NSLog(@"mouseEntered: %@", self);
//    NSUInteger start = self.element.start;
    NSMutableAttributedString *attString = [[self.element attributedText] mutableCopy];

    // https://panupan.com/2012/06/04/trim-leading-and-trailing-whitespaces-from-nsmutableattributedstring/

    // Trim trailing whitespace and newlines.
    NSCharacterSet *charSet = [NSCharacterSet whitespaceAndNewlineCharacterSet];
    NSRange range = [attString.string rangeOfCharacterFromSet:charSet
                                                      options:NSBackwardsSearch];
    while (range.length != 0 && NSMaxRange(range) == attString.length) {
        [attString replaceCharactersInRange:range
                                 withString:@""];
        range = [attString.string rangeOfCharacterFromSet:charSet
                                                  options:NSBackwardsSearch];
    }

    SourceEditorContentView *sourceTextView = [self editorContentView];
    CGFloat lineHeight = [sourceTextView defaultLineHeight];

    NSMutableParagraphStyle *myStyle = [NSMutableParagraphStyle new];
    [myStyle setMinimumLineHeight:lineHeight];
    [attString setAttributes:@{NSParagraphStyleAttributeName : myStyle}
                       range:NSMakeRange(0, attString.length)];

    [lineNumberPlugin.popover removeFromSuperview];
    NSTextView *popover =
        lineNumberPlugin.popover = [[NSTextView alloc] initWithFrame:NSZeroRect];

    [[popover textStorage] setAttributedString:attString];
    popover.font = [KeyPath objectFor:@"layoutManager.fontTheme.plainTextFont" from:sourceTextView];

    CGFloat width = NSWidth(sourceTextView.frame);
    CGFloat height = lineHeight * [popover.string numberOfLines];

    popover.frame = NSMakeRect(gutterWidth + 5., self.yoffset - 4., width, height);

    NSLog(@"%@ %f %f - %@ %@", NSStringFromRect(popover.frame), lineHeight, height, self.element.range, sourceTextView);

    NSString *popoverColor = self.extension.config[LNPopoverColorKey] ?: @"1 0.914 0.662 1";
    popover.backgroundColor = [NSColor colorWithString:popoverColor];
    [sourceTextView addSubview:popover];

    if (self.element.range)
        [self performSelector:@selector(showUndoButton) withObject:nil afterDelay:REVERT_DELAY];
}

- (void)mouseExited:(NSEvent *)theEvent {
    [lineNumberPlugin.popover removeFromSuperview];
    [lineNumberPlugin.undoButton removeFromSuperview];
}

- (void)showUndoButton {
    if (lineNumberPlugin.popover.superview) {
        NSButton *undoButton = lineNumberPlugin.undoButton;
        undoButton.action = @selector(performUndo:);
        undoButton.target = self;

        CGFloat width = NSWidth(self.superview.frame);
        undoButton.frame = NSMakeRect(0, self.frame.origin.y + width, width, width);
        [self.superview addSubview:undoButton];
    }
}

- (void)performUndo:(NSButton *)sender {
    SourceEditorContentView *sourceTextView = [self editorContentView];
    NSRange lineRange, charRange;

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
    LNConfig config = self.extension.config;
    if (sscanf(self.element.range.UTF8String ?: "", "%ld %ld", &lineRange.location, &lineRange.length) != 2 ||
        [[NSAlert alertWithMessageText:config[LNApplyTitleKey] ?: @"Line Number Plugin:"
                         defaultButton:config[LNApplyConfirmKey] ?: @"Modify"
                       alternateButton:@"Cancel"
                           otherButton:nil
             informativeTextWithFormat:config[LNApplyPromptKey] ?: @"Apply suggested changes at line %d-%d?",
          (int)lineRange.location, (int)(lineRange.location + MAX(lineRange.length, 1) - 1)]
         runModal] == NSAlertAlternateReturn)
        return;
#pragma clang diagnostic pop

    lineRange.location--;
    NSString *buffer = sourceTextView.accessibilityValue;
    charRange.location = [buffer indexForLine:lineRange.location];
    charRange.length = [buffer indexForLine:lineRange.location + lineRange.length] - charRange.location;
    NSLog(@"performUndo: %@ %@", sourceTextView, [buffer substringWithRange:charRange]);

    [sourceTextView setAccessibilitySelectedTextRange:charRange];
    [sourceTextView setAccessibilitySelectedText:self.element.attributedText.string];
}

@end