using BuildingDirectory.Model;

namespace BuildingDirectory;

/// <summary>
///     Represents a simple building information system
/// </summary>
public sealed class BuildingInformation
{
    private readonly MyDictionary<Floor, MyDictionary<string, Company>> _companiesPerFloor;

    /// <summary>
    ///     Creates a new instance with the supplied building information
    /// </summary>
    /// <param name="companiesPerFloor"></param>
    public BuildingInformation(MyDictionary<Floor, MyDictionary<string, Company>> companiesPerFloor)
    {
        _companiesPerFloor = companiesPerFloor;
    }

    /// <summary>
    ///     Returns all floors in the building
    /// </summary>
    /// <returns>A list of available floors</returns>
    public List<Floor> GetFloorSelection() => _companiesPerFloor.GetKeys();

    /// <summary>
    ///     Returns all companies residing on a specific floor.
    ///     If floor is not available null is returned.
    /// </summary>
    /// <param name="floor">The floor to check</param>
    /// <returns>A list of names of companies residing on the provided floor</returns>
    public List<string>? GetCompaniesOnFloor(Floor floor)
    {
         _companiesPerFloor.TryGetValue(floor, out MyDictionary<string, Company>? companies);
        return companies?.GetKeys();
    }

    /// <summary>
    ///     Returns the company identified by floor and company name.
    ///     If the specified company is not found null is returned.
    /// </summary>
    /// <param name="floor">Floor to look at</param>
    /// <param name="companyName">Name of the requested company</param>
    /// <returns>Company information if found; null otherwise</returns>
    public Company? GetCompany(Floor floor, string companyName)
    {
        //Needed to declare here, else you get an initialization error
        Company? company = null;
        
        _companiesPerFloor.TryGetValue(floor, out MyDictionary<string, Company>? companies);
        companies?.TryGetValue(companyName, out company);
        return company;
    }
}