//
//  MapAnnotationView.swift
//  Runner
//
//  Created by Groot on 2025/5/9.
//

import UIKit
import MapKit

class MapAnnotationView: MKAnnotationView {
    
    static let identifier: String = "MapAnnotationView"

    var marker: ATMapMarker? {
        didSet {
            updateView()
        }
    }
    var markerImageView: MapAnnotationMarkerImageView?
    var textView: MapAnnotationMarkerTextView?
    
    // spacing between text and image
    let spacing: CGFloat = 6
    
    var annotationSelected: Bool {
        return (marker?.isSelected ?? false) || self.isSelected
    }
    
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        self.marker = annotation as? ATMapMarker
        self.isEnabled = marker?.markerType.supportSelected ?? false
        self.isHidden = false
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - 视图更新与重用
    
    override func prepareForReuse() {
        super.prepareForReuse()
        // 清除当前所有子视图
        for subview in subviews {
            subview.removeFromSuperview()
        }
        markerImageView = nil
        textView = nil
    }
    
    private func updateView() {
        // 确保在更新视图前移除所有子视图
        for subview in subviews {
            subview.removeFromSuperview()
        }
        
        guard let marker = marker else { return }
        
        // 创建并添加图像视图
        markerImageView = MapAnnotationMarkerImageView(markerType: marker.markerType)
        if let markerImageView = markerImageView {
            markerImageView.isSelected = annotationSelected
            addSubview(markerImageView)
        }
        
        // 如果有标题，添加文本视图
        if let markerName = marker.markerName, !markerName.isEmpty {
            textView = MapAnnotationMarkerTextView(text: markerName)
            if let textView = textView {
                addSubview(textView)
            }
        }
        
        // 设置AutoLayout
        setupConstraints()
    }
    
    // MARK: - 布局
    
    private func setupConstraints() {
        // 禁用自动约束转换
        translatesAutoresizingMaskIntoConstraints = false
        
        guard let markerImageView = markerImageView else { return }
        markerImageView.translatesAutoresizingMaskIntoConstraints = false
        
        let markerSize = marker?.markerType.size ?? CGSize(width: 30, height: 30)
        
        // 设置图像视图约束 - 居中显示在标记视图中
        NSLayoutConstraint.activate([
            markerImageView.centerXAnchor.constraint(equalTo: centerXAnchor),
            markerImageView.centerYAnchor.constraint(equalTo: centerYAnchor),
            markerImageView.widthAnchor.constraint(equalToConstant: markerSize.width),
            markerImageView.heightAnchor.constraint(equalToConstant: markerSize.height)
        ])
        
        // 设置文本视图约束 - 位于图像上方，居中对齐
        if let textView = textView {
            textView.translatesAutoresizingMaskIntoConstraints = false
            NSLayoutConstraint.activate([
                textView.centerXAnchor.constraint(equalTo: centerXAnchor),
                textView.bottomAnchor.constraint(equalTo: markerImageView.topAnchor, constant: -spacing)
            ])
        }
        
        // 设置标记视图整体尺寸
        let textHeight = textView?.intrinsicContentSize.height ?? 0
        let totalHeight = textView != nil ? 
            markerSize.height + textHeight + spacing : 
            markerSize.height
        
        // 宽度至少和markerImageView一样宽，高度根据是否有文本决定
        NSLayoutConstraint.activate([
            widthAnchor.constraint(greaterThanOrEqualTo: markerImageView.widthAnchor),
            heightAnchor.constraint(equalToConstant: totalHeight)
        ])
        
        // 更新偏移量
        updateCenterOffset()
    }
    
    // MARK: - 更新视图
    
    override func layoutSubviews() {
        super.layoutSubviews()
        updateCenterOffset()
    }
    
    private func updateCenterOffset() {
        let markerSize = marker?.markerType.size ?? CGSize(width: 30, height: 30)
        
        if let textView = textView {
            let textHeight = textView.frame.height
            let totalHeight = markerSize.height + textHeight + spacing
            
            // 有文本时，调整偏移让图片底部对准坐标点
            centerOffset = CGPoint(x: 0, y: -(totalHeight - markerSize.height)/2)
        } else {
            // 没有文本时，仅需要将图片底部对准坐标点
            centerOffset = CGPoint(x: 0, y: -markerSize.height/2)
        }
    }
    
    override func prepareForDisplay() {
        super.prepareForDisplay()
        // 确保视图已经设置好
        if markerImageView == nil {
            updateView()
        }
        // 更新选中状态
        markerImageView?.isSelected = annotationSelected
    }

    override func setSelected(_ selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)
        marker?.isSelected = selected
        markerImageView?.isSelected = annotationSelected
    }
}