//
//  EmployeeTableViewCell.swift
//  EmployeeDirectory
//
//  Created by Matt Bruce on 1/20/25.
//
import UIKit
import Combine

/// This is the Cell used in the EmployeesTableViewController to show
/// the properties of an Employee model.
public class EmployeeTableViewCell: UITableViewCell {
    
    /// Used in the TableView registration
    static let identifier = "EmployeeTableViewCell"

    // MARK: - Properties

    
    /// UI Elements
    private let photoImageView = UIImageView()
    private let nameLabel = UILabel()
    private let emailLabel = UILabel()
    private let teamLabel = UILabel()
    private let employeeTypeLabel = UILabel()
    private let phoneLabel = UILabel()
    private let bioLabel = UILabel()
    private let stackView = UIStackView()
    
    /// Used for grabbing the photo
    private var smallPhotoSubscriber: AnyCancellable?

    // MARK: - Initializer

    public override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
        setupUI()
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    // MARK: - Private Methods
    
    private func setupUI() {
        // Configure photoImageView
        photoImageView.contentMode = .scaleAspectFill
        photoImageView.clipsToBounds = true
        photoImageView.layer.cornerRadius = 25
        photoImageView.translatesAutoresizingMaskIntoConstraints = false
        photoImageView.image = UIImage(systemName: "person.crop.circle")
        
        // Configure labels with text styles
        nameLabel.font = UIFont.preferredFont(forTextStyle: .headline) // Bold, prominent text
        nameLabel.adjustsFontForContentSizeCategory = true // Adapts to Dynamic Type
        
        emailLabel.font = UIFont.preferredFont(forTextStyle: .body)
        emailLabel.textColor = .blue
        emailLabel.adjustsFontForContentSizeCategory = true // Adapts to Dynamic Type

        teamLabel.font = UIFont.preferredFont(forTextStyle: .subheadline) // Secondary, smaller text
        teamLabel.textColor = .gray
        teamLabel.adjustsFontForContentSizeCategory = true // Adapts to Dynamic Type
        
        employeeTypeLabel.font = UIFont.preferredFont(forTextStyle: .subheadline)
        employeeTypeLabel.adjustsFontForContentSizeCategory = true // Adapts to Dynamic Type
        
        phoneLabel.font = UIFont.preferredFont(forTextStyle: .body) // Standard body text
        phoneLabel.textColor = .darkGray
        phoneLabel.adjustsFontForContentSizeCategory = true// Adapts to Dynamic Type
                
        bioLabel.font = UIFont.preferredFont(forTextStyle: .footnote) // Smaller text for additional info
        bioLabel.numberOfLines = 0
        bioLabel.textColor = .lightGray
        bioLabel.adjustsFontForContentSizeCategory = true // Adapts to Dynamic Type

        // Configure stackView
        stackView.axis = .vertical
        stackView.spacing = 5
        stackView.translatesAutoresizingMaskIntoConstraints = false
        
        // Add labels to stackView
        stackView.addArrangedSubview(nameLabel)
        stackView.addArrangedSubview(teamLabel)
        stackView.addArrangedSubview(employeeTypeLabel)
        stackView.addArrangedSubview(phoneLabel)
        stackView.addArrangedSubview(emailLabel)
        stackView.addArrangedSubview(bioLabel)

        // Add subviews
        contentView.addSubview(photoImageView)
        contentView.addSubview(stackView)
        
        // Add constraints
        NSLayoutConstraint.activate([
            photoImageView.leadingAnchor.constraint(equalTo: contentView.leadingAnchor, constant: 10),
            photoImageView.centerYAnchor.constraint(equalTo: contentView.centerYAnchor),
            photoImageView.widthAnchor.constraint(equalToConstant: 50),
            photoImageView.heightAnchor.constraint(equalToConstant: 50),
            
            stackView.leadingAnchor.constraint(equalTo: photoImageView.trailingAnchor, constant: 10),
            stackView.trailingAnchor.constraint(equalTo: contentView.trailingAnchor, constant: -10),
            stackView.topAnchor.constraint(equalTo: contentView.topAnchor, constant: 10),
            stackView.bottomAnchor.constraint(lessThanOrEqualTo: contentView.bottomAnchor, constant: -10)
        ])
    }
    
    // MARK: - Public Methods

    
    /// Override for setting back to a default state
    public override func prepareForReuse() {
        super.prepareForReuse()
        smallPhotoSubscriber = nil
        photoImageView.image = UIImage(systemName: "person.crop.circle")
        nameLabel.text = nil
        emailLabel.text = nil
        teamLabel.text = nil
        employeeTypeLabel.text = nil
        phoneLabel.text = nil
        bioLabel.text = nil
    }

    /// Configures the UI Elements with the properties of the EmployeeCellViewModel.
    /// - Parameter viewModel: Employee Model wrapped for Cell.
    public func configure(with viewModel: EmployeeCellViewModel) {

        // Bind the image to the photoImageView
        smallPhotoSubscriber = viewModel.$smallPhoto
            .receive(on: DispatchQueue.main)
            .sink { [weak self] image in
                self?.photoImageView.image = image
            }

        // Bind data to UI components
        nameLabel.text = viewModel.fullName
        emailLabel.text = viewModel.emailAddress
        teamLabel.text = viewModel.team
        employeeTypeLabel.text = viewModel.employeeType
        phoneLabel.text = viewModel.phoneNumber
        bioLabel.text = viewModel.biography

        // Dynamically show or hide elements based on their content
        phoneLabel.isHidden = viewModel.phoneNumber == nil
        bioLabel.isHidden = viewModel.biography == nil

    }
}