//
//  KMTocOutlineView.swift
//  PDF Reader Pro
//
//  Created by tangchao on 2023/11/17.
//

import Cocoa

@objc protocol KMTocOutlineViewDelegate: KMCustomOutlineViewDelegate {
    @objc optional func outlineView(_ anOutlineView: NSOutlineView, highlightLevelForRow row: Int) -> Int
    @objc optional func outlineView(_ anOutlineView: NSOutlineView, imageContextForItem item: Any?) -> AnyObject?
}

class KMTocOutlineView: KMCustomOutlineView {
    weak var tocDelegate: KMTocOutlineViewDelegate? {
        didSet {
            self._rebuildTrackingAreas()
        }
    }
    
    var hasImageToolTips: Bool {
        get {
            return self._kmTrackingAreas != nil
        }
        set {
            if (newValue && self._kmTrackingAreas == nil) {
                self._kmTrackingAreas = []
                if (self.window != nil) {
                    self._rebuildTrackingAreas()
                }
            } else if (newValue == false && self._kmTrackingAreas != nil) {
                if self.window != nil {
                    self._removeTrackingAreas()
                }
            }
        }
    }
    
    private var _kmTrackingAreas: [NSTrackingArea]?
    
    private let MAX_HIGHLIGHTS = 5
    
    deinit {
        KMPrint("KMTocOutlineView deinit.")
        
        NotificationCenter.default.removeObserver(self)
    }

    override func draw(_ dirtyRect: NSRect) {
        super.draw(dirtyRect)
    }
    
    override func drawRow(_ row: Int, clipRect: NSRect) {
//        if (RUNNING_BEFORE(10_10) && [[self delegate] respondsToSelector:@selector(outlineView:highlightLevelForRow:)] &&
//            [self isRowSelected:row] == NO) {
        if let level = self.tocDelegate?.outlineView?(self, highlightLevelForRow: row), self.isRowSelected(row) == false {
            if (level < MAX_HIGHLIGHTS) {
                var color = NSColor(red: 0.556, green: 0.615, blue: 0.748, alpha: 1.0)
                
                let rect = self.rect(ofRow: row)
                if (NSIntersectsRect(rect, clipRect)) {
                    NSGraphicsContext.saveGraphicsState()
                    color.withAlphaComponent(0.1 * (CGFloat(MAX_HIGHLIGHTS) - level.cgFloat)).setFill()
                    NSBezierPath.fill(rect)
                    NSGraphicsContext.restoreGraphicsState()
                }
            }
        }
        
        super.drawRow(row, clipRect: clipRect)
    }
    
    override func highlightSelection(inClipRect clipRect: NSRect) {
        if self.selectionHighlightStyle == .regular {
            NSGraphicsContext.saveGraphicsState()
            NSColor(red: 0.556, green: 0.615, blue: 0.748, alpha: 1.0).setFill()
            for i in self.selectedRowIndexes {
                __NSRectFill(self.rect(ofRow: i))
            }
            NSGraphicsContext.restoreGraphicsState()
        } else {
            super.highlightSelection(inClipRect: clipRect)
        }
    }
    
    override func preparedCell(atColumn column: Int, row: Int) -> NSCell? {
        let cell = super.preparedCell(atColumn: column, row: row)
        if self.selectionHighlightStyle == .regular && self.isRowSelected(row) && cell?.type == .textCellType {
            if var attrString = cell?.attributedStringValue.mutableCopy() as? NSMutableAttributedString {
                let font = NSFontManager.shared.convert(cell?.font ?? .systemFont(ofSize: 12), toHaveTrait: .boldFontMask)
                attrString.addAttributes([.font : font], range: NSMakeRange(0, attrString.length))
                cell?.attributedStringValue = attrString
            }
        }
        return cell
    }
    
    override func selectRowIndexes(_ indexes: IndexSet, byExtendingSelection extend: Bool) {
        super.selectRowIndexes(indexes, byExtendingSelection: extend)
        
        self._handleHighlightsChanged()
    }
    
    override func deselectRow(_ row: Int) {
        super.deselectRow(row)
        
        self._handleHighlightsChanged()
    }
    
    override func becomeFirstResponder() -> Bool {
        if super.becomeFirstResponder() {
            self._handleHighlightsChanged()
            return true
        }
        return false
    }
    
    override func resignFirstResponder() -> Bool {
        if super.resignFirstResponder() {
            self._handleHighlightsChanged()
            return true
        }
        return false
    }
     
    
    override func updateTrackingAreas() {
        super.updateTrackingAreas()
        
        self._rebuildTrackingAreas()
    }
    
    override func noteNumberOfRowsChanged() {
        super.noteNumberOfRowsChanged()
        
        self._rebuildTrackingAreas()
    }
    
    override func viewDidMoveToWindow() {
        super.viewDidMoveToWindow()
        
        if self.window != nil {
            self._handleKeyOrMainStateChanged(nil)
        }
    }
    
    override func viewWillMove(toWindow newWindow: NSWindow?) {
        let oldWindow = self.window
        let names = [NSWindow.didBecomeMainNotification, NSWindow.didResignMainNotification, NSWindow.didBecomeKeyNotification, NSWindow.didResignKeyNotification]
        if oldWindow != nil {
            for name in names {
                NotificationCenter.default.removeObserver(self, name: name, object: oldWindow)
            }
        }
        if newWindow != nil {
            for name in names {
                NotificationCenter.default.addObserver(self, selector: #selector(_handleKeyOrMainStateChanged), name: name, object: newWindow)
            }
        }
        super.viewWillMove(toWindow: newWindow)
    }
    
    override func keyDown(with event: NSEvent) {
        let eventChar = event.firstCharacter()
        let modifiers = event.standardPDFListViewModifierFlags()
        
        if (eventChar == NSLeftArrowFunctionKey && modifiers == (NSEvent.ModifierFlags.command.rawValue + NSEvent.ModifierFlags.option.rawValue)) {
            self.collapseItem(nil, collapseChildren: true)
        } else if (eventChar == NSRightArrowFunctionKey && modifiers == (NSEvent.ModifierFlags.command.rawValue + NSEvent.ModifierFlags.option.rawValue)) {
            self.expandItem(nil, expandChildren: true)
        } else {
            super.keyDown(with: event)
        }
    }
    
    override func mouseEntered(with event: NSEvent) {
        if (self._kmTrackingAreas == nil) {
            return
        }
        
        let userInfo = event.trackingArea?.userInfo
        if let rowNumber = userInfo?["row"] as? Int {
            var item = self.item(atRow: rowNumber)
            if let context = self.tocDelegate?.outlineView?(self, imageContextForItem: item) as? KMImageToolTipContext {
                KMImageToolTipWindow.shared.showForImageContext(context, at: .zero)
            }
        }
    }
    
    override func mouseExited(with event: NSEvent) {
        let userInfo = event.trackingArea?.userInfo
        if let row = userInfo?["row"] {
            KMImageToolTipWindow.shared.fadeOut()
        }
    }
    
}

// MARK: - Private Methods

extension KMTocOutlineView {
    private func _handleHighlightsChanged() {
//        if (RUNNING_BEFORE(10_10) && [[self delegate] respondsToSelector:@selector(outlineView:highlightLevelForRow:)])
        if let _ = self.tocDelegate?.outlineView?(self, highlightLevelForRow: -1) {
            self.needsDisplay = true
        }
    }
    
    @objc private func _handleKeyOrMainStateChanged(_ note: NSNotification?) {
        if self.selectionHighlightStyle == .sourceList {
            self._handleHighlightsChanged()
        } else {
            if let win = self.window, win.isMainWindow || win.isKeyWindow {
//                self.backgroundColor = NSColor(calibratedRed: 0.839216, green: 0.866667, blue: 0.898039, alpha: 1)
            } else {
//                self.backgroundColor = .controlColor
            }
            self.needsDisplay = true
        }
    }
    
    private func _rebuildTrackingAreas() {
        if self._kmTrackingAreas == nil || self.tocDelegate?.outlineView?(self, imageContextForItem: nil) == nil {
            return
        }
        
        self._removeTrackingAreas()
        
        if (self.window != nil) {
            let visibleRect = self.visibleRect
            let rowRange = self.rows(in: visibleRect)
//            NSUInteger row;
            
            for row in rowRange.location ..< NSMaxRange(rowRange) {
                self._addTrackingAreaForRow(row)
            }
        }
    }
    
    private func _removeTrackingAreas() {
        if (self._kmTrackingAreas == nil) {
            return
        }
        
        for area in self._kmTrackingAreas! {
            self.removeTrackingArea(area)
        }
        self._kmTrackingAreas?.removeAll()
    }
    
    private func _addTrackingAreaForRow(_ row: Int) {
        if (self._kmTrackingAreas == nil) {
            return
        }
        
        let userInfo = ["row" : row]
        let area = NSTrackingArea(rect: self.rect(ofRow: row), options: [.mouseEnteredAndExited, .activeInActiveApp], owner: self, userInfo: userInfo)
        self.addTrackingArea(area)
        self._kmTrackingAreas?.append(area)
    }
}