eqn.ios/Sources/Earthquake Network/UI/EQNCustomAnnotationView.swift

//
//  EQNCustomAnnotationView.swift
//  Earthquake Network
//
//  Created by Andrea Busi on 06/03/21.
//  Copyright © 2021 Earthquake Network. All rights reserved.
//

import UIKit
import MapKit


@objc
public class EQNCustomAnnotationView: MKAnnotationView {
    
    @objc static let SmallIdentifier = "EQNCustomAnnotationViewSmall"
    @objc static let SingleLineIdentifier = "EQNCustomAnnotationViewSingleLine"
    @objc static let DoubleLineIdentifier = "EQNCustomAnnotationViewDoubleLine"
    
    @objc static let SmallViewHeight: CGFloat = 12.0
    @objc static let SmallViewImageHeight: CGFloat = SmallViewHeight
    @objc static let SingleLineViewHeight: CGFloat = 40.0
    @objc static let SingleLineLabelHeight: CGFloat = 15.0
    @objc static let SingleLineImageHeight: CGFloat = SingleLineViewHeight - SingleLineLabelHeight
    @objc static let DoubleLineViewHeight: CGFloat = 55.0
    @objc static let DoubleLineLabelHeight: CGFloat = 15.0
    @objc static let DoubleLineImageHeight: CGFloat = DoubleLineViewHeight - 2*DoubleLineLabelHeight
    
    // MARK: - Public
    
    @objc public override var image: UIImage? {
        set { imageView.image = newValue }
        get { imageView.image }
    }
    
    @objc public var title: String? {
        set { labelTop.text = newValue }
        get { labelTop.text }
    }
    
    @objc public var subtitle: String? {
        set { labelBottom.text = newValue }
        get { labelBottom.text }
    }
    
    // MARK: - UI
    
    private lazy var imageView: UIImageView = {
        let imageView = UIImageView()
        imageView.contentMode = .scaleAspectFit
        return imageView
    }()
    
    private lazy var labelTop: UILabel = {
        let label = UILabel()
        label.font = UIFont.systemFont(ofSize: 11, weight: .medium)
        label.textAlignment = .center
        return label
    }()
    
    private lazy var labelBottom: UILabel = {
        let label = UILabel()
        label.font = UIFont.systemFont(ofSize: 11, weight: .medium)
        label.textAlignment = .center
        label.textColor = .red
        return label
    }()
    
    // MARK: - Init
    
    @objc
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        
        backgroundColor = .clear
        
        if reuseIdentifier == Self.SmallIdentifier {
            frame = CGRect(x: 0, y: 0, width: Self.SmallViewHeight, height: Self.SmallViewHeight)
            setupSmallUI()
        } else if reuseIdentifier == Self.SingleLineIdentifier {
            frame = CGRect(x: 0, y: 0, width: Self.SingleLineViewHeight, height: Self.SingleLineViewHeight)
            setupSingleLineUI()
        } else if reuseIdentifier == Self.DoubleLineIdentifier {
            frame = CGRect(x: 0, y: 0, width: 40, height: Self.DoubleLineViewHeight)
            setupDoubleLineUI()
        }
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Private
    
    private func setupSmallUI() {
        imageView.frame = CGRect(x: 0, y: 0, width: frame.width, height: frame.height)
        addSubview(imageView)
    }
    
    private func setupSingleLineUI() {
        let labelFrame =  CGRect(x: 0, y: 0, width: frame.width, height: Self.SingleLineLabelHeight)
        labelTop.frame = labelFrame
        addSubview(labelTop)
        
        let imageViewHeight = frame.height - labelFrame.height
        imageView.frame = CGRect(x: 0, y: labelFrame.height, width: frame.width, height: imageViewHeight)
        addSubview(imageView)
        
        let yOffeset = frame.height / 2.0 - (Self.SingleLineLabelHeight + imageViewHeight / 2.0)
        centerOffset = CGPoint(x: 0, y: yOffeset)
    }
    
    private func setupDoubleLineUI() {
        let labelTopFrame =  CGRect(x: 0, y: 0, width: frame.width, height: Self.DoubleLineLabelHeight)
        labelTop.frame = labelTopFrame
        addSubview(labelTop)
        
        let imageViewHeight = frame.height - labelTopFrame.height * 2.0
        imageView.frame = CGRect(x: 0, y: labelTopFrame.height, width: frame.width, height: imageViewHeight)
        addSubview(imageView)
        
        labelBottom.frame = CGRect(x: 0, y: imageView.frame.maxY, width: frame.width, height: Self.DoubleLineLabelHeight)
        addSubview(labelBottom)
    }
}