//
//  KMImageToolTipContext.swift
//  PDF Reader Pro
//
//  Created by tangchao on 2023/11/23.
//

import Foundation

protocol KMImageToolTipContext: NSObjectProtocol {
    func toolTipImage() -> NSImage?
}

extension NSAttributedString: KMImageToolTipContext {
    func toolTipImage() -> NSImage? {
        return nil
    }
}

var _km_dest_labelAttributes: [NSAttributedString.Key : Any]?
var _km_dest_labelColor: NSColor?

var _km_text_margin_x: CGFloat = 2
var _km_text_margin_y: CGFloat = 2

extension CPDFDestination: KMImageToolTipContext {
    func toolTipImage() -> NSImage? {
        return self._toolTipImage(offset: NSMakePoint(-50.0, 20.0))
    }

    @objc private func _toolTipImage(offset: NSPoint) -> NSImage? {
        guard let page = self.page() else {
            return nil
        }
        
        if _km_dest_labelAttributes == nil {
            let style = NSMutableParagraphStyle()
            style.lineBreakMode = .byClipping
            _km_dest_labelAttributes = [.font : NSFont.boldSystemFont(ofSize: 11), .foregroundColor : NSColor.white, .paragraphStyle : style]
        }
        let attri = _km_dest_labelAttributes ?? [:]
        
        if _km_dest_labelColor == nil {
            _km_dest_labelColor = NSColor(calibratedWhite: 0.5, alpha: 0.8)
        }
        let labelColor = _km_dest_labelColor ?? NSColor(calibratedWhite: 0.5, alpha: 0.8)
                
        //        NSImage *pageImage = [page thumbnailWithSize:0.0 forBox:kPDFDisplayBoxCropBox shadowBlurRadius:0.0 readingBar:nil];
        let pageImage = page.thumbnail(of: page.bounds(for: .cropBox).size)
        let pageSize = page.bounds(for: .cropBox)
        let pageImageRect = NSMakeRect(0, 0, pageSize.width, pageSize.height)
        let bounds = page.bounds(for: .cropBox)
        var sourceRect: NSRect = .zero
        let selection = page.selection(for: bounds)
        
        let transform = page.km_affineTransform(for: .cropBox)

        //        sourceRect.size.width = [[NSUserDefaults standardUserDefaults] doubleForKey:SKToolTipWidthKey];
        sourceRect.size.width = 260
        //        sourceRect.size.height = [[NSUserDefaults standardUserDefaults] doubleForKey:SKToolTipHeightKey];
        sourceRect.size.height = 120
        sourceRect.origin = KMAddPoints(transform.transform(self.point), offset)
        sourceRect.origin.y -= NSHeight(sourceRect)
                
        if let data = selection?.hasCharacters(), data {
            var selBounds = selection?.bounds(for: page) ?? .zero
            let blPoint = KMBottomLeftPoint(selBounds)
            let trPoint = KMTopRightPoint(selBounds)
            selBounds = KMRectFromPoints(aPoint: blPoint, bPoint: trPoint)
            let top = ceil(fmax(NSMaxY(selBounds), NSMinY(selBounds) + NSHeight(sourceRect)))
            let left = floor(fmin(NSMinX(selBounds), NSMaxX(selBounds) - NSWidth(sourceRect)))
            if (top < NSMaxY(sourceRect)) {
                sourceRect.origin.y = top - NSHeight(sourceRect)
            }
            if (left > NSMinX(sourceRect)) {
                sourceRect.origin.x = left
            }
        }
                
        sourceRect = KMConstrainRect(rect: sourceRect, boundary: pageImageRect)
                
        let labelString = NSAttributedString(string: String(format: KMLocalizedString("Page %@", "Tool tip label format"), page.km_displayLabel), attributes: attri)
        var labelRect = labelString.boundingRect(with: .zero, options: [.usesLineFragmentOrigin])
        labelRect.size.width = floor(NSWidth(labelRect))
        labelRect.size.height = 2.0 * floor(0.5 * NSHeight(labelRect)) // make sure the cap radius is integral
        labelRect.origin.x = NSWidth(sourceRect) - NSWidth(labelRect) - 0.5 * NSHeight(labelRect) - _km_text_margin_x
        labelRect.origin.y = _km_text_margin_y
        labelRect = NSIntegralRect(labelRect)

        let image = NSImage.bitmapImage(with: sourceRect.size) { rect in
            pageImage?.draw(in: rect, from: sourceRect, operation: .copy, fraction: 1)
            let radius = 0.5 * NSHeight(labelRect)
            let path = NSBezierPath()
            path.move(to: KMTopLeftPoint(labelRect))
            path.appendArc(withCenter: NSMakePoint(NSMinX(labelRect), NSMidY(labelRect)), radius: radius, startAngle: 90.0, endAngle: 270.0)
            path.appendArc(withCenter: NSMakePoint(NSMaxX(labelRect), NSMidY(labelRect)), radius: radius, startAngle: -90, endAngle: 90)
            path.close()

            labelColor.setFill()
            path.fill()

            labelString.draw(with: labelRect, options: [.usesLineFragmentOrigin])
        }

        return image
    }
}

extension CPDFAnnotation: KMImageToolTipContext {
    func toolTipImage() -> NSImage? {
        return nil
    }
}

extension CPDFPage: KMImageToolTipContext {
    func toolTipImage() -> NSImage? {
        return nil
    }
}