//
//  LocationSectionHeaderView.swift
//  MullvadVPN
//
//  Created by Mojgan on 2024-01-25.
//  Copyright © 2025 Mullvad VPN AB. All rights reserved.
//

import Foundation
import UIKit

class LocationSectionHeaderFooterView: UIView, UIContentView {
    var configuration: UIContentConfiguration {
        get {
            actualConfiguration
        } set {
            guard let newConfiguration = newValue as? Configuration,
                  actualConfiguration != newConfiguration else { return }
            actualConfiguration = newConfiguration
            apply(configuration: newConfiguration)
        }
    }

    private var actualConfiguration: Configuration

    private let containerView: UIStackView = {
        let containerView = UIStackView()
        containerView.axis = .horizontal
        containerView.spacing = 8
        containerView.isLayoutMarginsRelativeArrangement = true
        return containerView
    }()

    private let nameLabel: UILabel = {
        let label = UILabel()
        label.numberOfLines = 0
        label.lineBreakMode = .byWordWrapping
        label.textColor = .primaryTextColor
        label.font = .systemFont(ofSize: 16, weight: .semibold)
        return label
    }()

    private let actionButton: UIButton = {
        let button = UIButton(type: .system)
        button.setImage(UIImage(systemName: "ellipsis"), for: .normal)
        button.tintColor = UIColor(white: 1, alpha: 0.6)
        return button
    }()

    init(configuration: Configuration) {
        self.actualConfiguration = configuration
        super.init(frame: .zero)
        apply(configuration: configuration)
        addSubviews()
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    private func addSubviews() {
        containerView.addArrangedSubview(nameLabel)
        containerView.addArrangedSubview(actionButton)
        addConstrainedSubviews([containerView]) {
            containerView.pinEdgesToSuperviewMargins()
            actionButton.widthAnchor.constraint(equalTo: actionButton.heightAnchor)
        }
    }

    private func apply(configuration: Configuration) {
        let isActionHidden = configuration.primaryAction == nil
        backgroundColor = configuration.style.backgroundColor
        nameLabel.textColor = configuration.style.textColor
        nameLabel.text = configuration.name
        nameLabel.font = configuration.style.font
        nameLabel.textAlignment = configuration.style.textAlignment
        actionButton.isHidden = isActionHidden
        actionButton.accessibilityIdentifier = nil
        actualConfiguration.primaryAction.flatMap { action in
            actionButton.setAccessibilityIdentifier(.openCustomListsMenuButton)
            actionButton.addAction(action, for: .touchUpInside)
        }
        directionalLayoutMargins = actualConfiguration.directionalEdgeInsets
    }
}

extension LocationSectionHeaderFooterView {
    struct Style: Equatable {
        let font: UIFont
        let textColor: UIColor
        let textAlignment: NSTextAlignment
        let backgroundColor: UIColor

        static let header = Style(
            font: .preferredFont(forTextStyle: .body, weight: .semibold),
            textColor: .primaryTextColor,
            textAlignment: .natural,
            backgroundColor: .primaryColor
        )

        static let footer = Style(
            font: .preferredFont(forTextStyle: .body, weight: .regular),
            textColor: .secondaryTextColor,
            textAlignment: .center,
            backgroundColor: .clear
        )
    }

    struct Configuration: UIContentConfiguration, Equatable {
        let name: String
        let style: Style
        var directionalEdgeInsets = NSDirectionalEdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16)
        var primaryAction: UIAction?

        func makeContentView() -> UIView & UIContentView {
            LocationSectionHeaderFooterView(configuration: self)
        }

        func updated(for state: UIConfigurationState) -> Configuration {
            self
        }
    }
}