Gemini/Gemini-iOS/NavigationBarView.swift

//
//  NavigationBarView.swift
//  Gemini-iOS
//
//  Created by Shadowfacts on 12/19/20.
//

import UIKit
import BrowserCore
import Combine

class NavigationBarView: UIView {

    let navigator: NavigationManager
    
    private var border: UIView!
    private(set) var textField: UITextField!
    
    private var cancellables = [AnyCancellable]()
    
    init(navigator: NavigationManager) {
        self.navigator = navigator
        
        super.init(frame: .zero)
        
        backgroundColor = .systemBackground
        
        border = UIView()
        border.backgroundColor = UIColor(white: traitCollection.userInterfaceStyle == .dark ? 0.25 : 0.75, alpha: 1)
        border.translatesAutoresizingMaskIntoConstraints = false
        addSubview(border)
        NSLayoutConstraint.activate([
            border.leadingAnchor.constraint(equalTo: leadingAnchor),
            border.trailingAnchor.constraint(equalTo: trailingAnchor),
            border.bottomAnchor.constraint(equalTo: bottomAnchor),
            border.heightAnchor.constraint(equalToConstant: 1),
        ])
        
        textField = UITextField()
        textField.text = navigator.displayURL
        textField.borderStyle = .roundedRect
        textField.keyboardType = .URL
        textField.returnKeyType = .go
        textField.autocapitalizationType = .none
        textField.autocorrectionType = .no
        textField.addTarget(self, action: #selector(commitURL), for: .primaryActionTriggered)
        textField.translatesAutoresizingMaskIntoConstraints = false
        addSubview(textField)
        NSLayoutConstraint.activate([
            textField.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 8),
            textField.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -8),
            textField.topAnchor.constraint(equalTo: safeAreaLayoutGuide.topAnchor),
            textField.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -9),
        ])
        
        navigator.$currentURL
            .sink { (newURL) in
                // can't use navigator.displayURL because the publisher fires before the underlying value is updated, so the displayURL getter returns the old value
                var components = URLComponents(url: newURL, resolvingAgainstBaseURL: false)!
                if components.port == 1965 {
                    components.port = nil
                }
                self.textField.text = components.string!
            }
            .store(in: &cancellables)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)
        
        border.backgroundColor = UIColor(white: traitCollection.userInterfaceStyle == .dark ? 0.25 : 0.75, alpha: 1)
    }
    
    @objc private func commitURL() {
        textField.resignFirstResponder()
        if let text = textField.text, var components = URLComponents(string: text) {
            if components.scheme == nil {
                components.scheme = "gemini"
            }
            navigator.changeURL(components.url!)
        } else {
            textField.text = navigator.displayURL
        }
    }

}