Tusker/Tusker/Views/Profile Header/ProfileFieldsView.swift

//
//  ProfileFieldsView.swift
//  Tusker
//
//  Created by Shadowfacts on 11/4/22.
//  Copyright © 2022 Shadowfacts. All rights reserved.
//

import UIKit

class ProfileFieldsView: UIView {
    
    weak var delegate: ProfileHeaderViewDelegate?
    
    private let stack = UIStackView()
    private var fieldViews: [(EmojiLabel, ContentTextView)] = []
    private var fieldConstraints: [NSLayoutConstraint] = []
    
    private var isUsingSingleColumn: Bool = false
    private var needsSingleColumn: Bool {
        traitCollection.preferredContentSizeCategory > .large
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }
    
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        commonInit()
    }
    
    private func commonInit() {
        stack.axis = .vertical
        stack.alignment = .fill
        stack.translatesAutoresizingMaskIntoConstraints = false
        addSubview(stack)
        NSLayoutConstraint.activate([
            stack.leadingAnchor.constraint(equalTo: leadingAnchor),
            stack.trailingAnchor.constraint(equalTo: trailingAnchor),
            stack.topAnchor.constraint(equalTo: topAnchor),
            stack.bottomAnchor.constraint(equalTo: bottomAnchor),
        ])
    }
    
    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)
        if isUsingSingleColumn != needsSingleColumn {
            configureFields()
        }
    }
    
    func updateUI(account: AccountMO) {
        isHidden = account.fields.isEmpty
        guard !account.fields.isEmpty else {
            return
        }
        
        for (name, value) in fieldViews {
            name.removeFromSuperview()
            value.removeFromSuperview()
        }
        fieldViews = []
        
        for field in account.fields {
            let nameLabel = EmojiLabel()
            nameLabel.text = field.name
            nameLabel.font = .preferredFont(forTextStyle: .body).withTraits(.traitBold)!
            nameLabel.adjustsFontForContentSizeCategory = true
            nameLabel.numberOfLines = 0
            nameLabel.lineBreakMode = .byWordWrapping
            nameLabel.setEmojis(account.emojis, identifier: account.id)
            nameLabel.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
            
            let valueTextView = ContentTextView()
            valueTextView.isSelectable = false
            valueTextView.defaultFont = .preferredFont(forTextStyle: .body)
            valueTextView.adjustsFontForContentSizeCategory = true
            valueTextView.setTextFromHtml(field.value)
            valueTextView.setEmojis(account.emojis, identifier: account.id)
            valueTextView.navigationDelegate = delegate
            valueTextView.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
            
            fieldViews.append((nameLabel, valueTextView))
        }
        
        configureFields()
    }
    
    @objc private func configureFields() {
        guard !isHidden else {
            return
        }
        
        isUsingSingleColumn = needsSingleColumn
        
        NSLayoutConstraint.deactivate(fieldConstraints)
        fieldConstraints = []
        
        stack.arrangedSubviews.forEach { $0.removeFromSuperview() }
        
        if needsSingleColumn {
            stack.spacing = 4
            var isFirst = true
            for (name, value) in fieldViews {
                if isFirst {
                    isFirst = false
                } else {
                    let spacer = UIView()
                    // don't need any height, since there's 4pts of padding on either side
                    spacer.heightAnchor.constraint(equalToConstant: 0).isActive = true
                    stack.addArrangedSubview(spacer)
                }
                name.textAlignment = .natural
                stack.addArrangedSubview(name)
                value.textAlignment = .natural
                stack.addArrangedSubview(value)
            }
        } else {
            stack.spacing = 8
            
            let dividerLayoutGuide = UILayoutGuide()
            addLayoutGuide(dividerLayoutGuide)
            fieldConstraints.append(contentsOf: [
                dividerLayoutGuide.widthAnchor.constraint(equalToConstant: 8),
            ])
            
            for (name, value) in fieldViews {
                name.textAlignment = .right
                name.translatesAutoresizingMaskIntoConstraints = false
                
                value.textAlignment = .left
                value.translatesAutoresizingMaskIntoConstraints = false
                
                let fieldContainer = UIView()
                fieldContainer.addSubview(name)
                fieldContainer.addSubview(value)
                stack.addArrangedSubview(fieldContainer)
                fieldConstraints.append(contentsOf: [
                    name.leadingAnchor.constraint(equalTo: fieldContainer.leadingAnchor),
                    name.trailingAnchor.constraint(equalTo: dividerLayoutGuide.leadingAnchor),
                    name.topAnchor.constraint(equalTo: fieldContainer.topAnchor),
                    name.bottomAnchor.constraint(equalTo: fieldContainer.bottomAnchor),
                    
                    value.leadingAnchor.constraint(equalTo: dividerLayoutGuide.trailingAnchor),
                    value.trailingAnchor.constraint(equalTo: fieldContainer.trailingAnchor),
                    value.topAnchor.constraint(equalTo: fieldContainer.topAnchor),
                    value.bottomAnchor.constraint(equalTo: fieldContainer.bottomAnchor),
                    
                    name.widthAnchor.constraint(greaterThanOrEqualTo: value.widthAnchor, multiplier: 0.5),
                    name.widthAnchor.constraint(lessThanOrEqualTo: value.widthAnchor, multiplier: 2),
                ])
            }
        }
        
        NSLayoutConstraint.activate(fieldConstraints)
    }
    
}