using System.Reflection.PortableExecutable;
using Splat;

namespace StarsAssistant.Services;

public class Game
{
    /// <summary>
    /// Default constructor, initialize required fields manually, targeted
    /// for Initial DB creation.
    /// </summary>
    public Game() {}

    /// <summary>
    /// Init game state from database, targeted for CLI arg.
    /// </summary>
    /// <param name="dbGame">Record loaded from DB</param>
    public Game(Model.Game dbGame)
    {
        GamePath = dbGame.GamePath;
        BaseName = dbGame.BaseName;
    }

    /// <summary>
    /// Save this record in the database. Uses the service locator to access the 
    /// database unless you specify an instance. This is needed during initial
    /// game creation, where the services are not yet established.
    /// </summary>
    /// <param name="db">Optional DB instance if services are yet unavailable.</param>
    public void SaveToDatabase(Model.StarsDatabase? db = null) 
    {
        db ??= Locator.Current.GetService<Model.StarsDatabase>()!;
        
        Model.Game? dbGame = db.Game.FirstOrDefault();
        if (dbGame == null)
        {
            dbGame = new Model.Game();
            db.Add(dbGame);
            db.SaveChanges();
        }
        dbGame.GamePath = GamePath;
        dbGame.BaseName = BaseName; 
        db.Update(dbGame);
        db.SaveChanges();
    }

    /// <summary>
    /// The base path in which all game files reside.
    /// </summary>
    public string GamePath { get; set; } = String.Empty;

    /// <summary>
    /// The base name without extensions of your game, inside the GamePath folder.
    /// All dependant files are resolved using this name.
    /// </summary>
    public string BaseName { get; set; } = String.Empty;

    /// <summary>
    /// Combine into the DatabaseName
    /// </summary>
    public string DatabaseFileName => Path.Combine(GamePath, $"{BaseName}.sqlite");

    /// <summary>
    /// Search for Planet files using this pattern, will give you all pxx files.
    /// </summary>
    public string PlanetFileSearchPattern => $"{BaseName}.p*";
    
    /// <summary>
    /// Internal helper to lazily load the current player from the DB.
    /// </summary>
    private readonly static Lazy<Model.Race>LazyPlayer = new ( () => {
        using var db = Locator.Current.GetService<Model.StarsDatabase>()!;
        Model.Race result = db.Race
            .Where(r => r.PlayerRace == true)
            .First();
        return result;
    });

    /// <summary>
    /// Get the Race object for the current player, lazy initialized.
    /// </summary>
    public static Model.Race Player => LazyPlayer.Value;

    /// <summary>
    /// Get the name of a planet file for a given race.
    /// </summary>
    /// <param name="r">The race to load.</param>
    /// <returns>Fully qualified file path.</returns>
    public string PlanetFileForRace (Model.Race r) => Path.Combine(GamePath, $"{BaseName}.p{r.PlayerFileId}");

}