using System;
using System.Diagnostics.CodeAnalysis;
using CsvHelper.Configuration;
using CsvHelper;
using System.Globalization;
using Splat;

namespace StarsAssistant.CSV;

public class PlanetLoader
{
    /// <summary>
    /// Reference to the game metadata, retrieved by DI
    /// </summary>
    protected Services.Game Game = Locator.Current.GetService<Services.Game>()!;

    /// <summary>
    /// CSV Configuration to use for importing Planet files.
    /// </summary>
    protected CsvConfiguration CsvConfig;

    /// <summary>
    /// Construction
    /// </summary>
    public PlanetLoader()
    {
        CreateConfig();
    }

    /// <summary>
    /// Creates the CSV configuration for planets.
    /// </summary>
    [MemberNotNull(nameof(CsvConfig))]
    protected void CreateConfig() 
    {
        CsvConfig = CsvConfiguration.FromAttributes<Planet>(CultureInfo.InvariantCulture);
        CsvConfig.Delimiter = "\t";
        CsvConfig.Escape = '\0';
        CsvConfig.MissingFieldFound = null;
    }

    /// <summary>
    /// Import the planet file for the given Race.
    /// </summary>
    /// <param name="race">Import File</param>
    public void ImportForRace(Model.Race race)
    {
        using (var db = Locator.Current.GetService<Model.StarsDatabase>()!)
        using (var reader = new StreamReader(Game.PlanetFileForRace(race), System.Text.Encoding.Latin1))
        using (var csv = new CsvReader(reader, CsvConfig))
        {
            List<CSV.Planet> records = csv.GetRecords<Planet>().ToList();
            var planetByPlayer = from csvp in records
                group csvp by csvp.Owner into byOwners
                select byOwners;

            foreach (var owner in planetByPlayer)
            {
                Model.Race? r;
                if (owner.Key == race.Name)
                {
                    r = race;
                }
                else
                {
                    r = db.Race.Find(owner.Key);
                    if (r == null)
                    {
                        r = new() { Name = owner.Key };
                        db.Add(r);
                    }
                }

                foreach (Planet csvp in owner)
                {
                    Model.Planet? p = db.Planet.Find(csvp.Name);
                    if (p == null)
                    {
                        p = new() { Name = csvp.Name };
                        csvp.UpdateDbPlanet(p);
                        db.Add(p);
                    } 
                    else 
                    {
                        csvp.UpdateDbPlanet(p);
                        db.Update(p);
                    }
                }
                db.SaveChanges();
            }
        }
    }
}