using System;
using System.IO;

namespace NHSE.Core;

/// <summary>
/// Logic for loading decrypted game files.
/// </summary>
/// <seealso cref="GameFileDumper"/>
public static class GameFileLoader
{
    /// <summary>
    /// Loads a copy of the <see cref="sav"/>'s files in their decrypted state from the requested <see cref="path"/>.
    /// </summary>
    /// <param name="sav">Save Data to load</param>
    /// <param name="path">Path to load from</param>
    public static void Load(this HorizonSave sav, string path)
    {
        sav.Main.Load(path);
        foreach (var p in sav.Players)
        {
            var dir = Path.Combine(path, p.DirectoryName);
            p.Load(dir);
        }
    }

    /// <summary>
    /// Loads a copy of the <see cref="player"/>'s files in their decrypted state from the requested <see cref="path"/>.
    /// </summary>
    /// <param name="player">Save Data to load</param>
    /// <param name="path">Path to load from</param>
    public static void Load(this Player player, string path)
    {
        foreach (var pair in player)
            pair.Load(path);
    }

    /// <summary>
    /// Loads the <see cref="pair"/>'s files in their decrypted state from the requested <see cref="path"/>.
    /// </summary>
    /// <param name="pair">Save Data to load</param>
    /// <param name="path">Path to load from</param>
    public static void Load(this EncryptedFilePair pair, string path)
    {
        Load(path, pair.Data, pair.NameData);
    }

    private static void Load(string path, Span<byte> data, string name)
    {
        if (!Directory.Exists(path))
            return;

        var file = Path.Combine(path, name);
        if (!File.Exists(file))
            return;

        var import = File.ReadAllBytes(file);
        if (data.Length != import.Length)
            return;

        import.CopyTo(data);
    }
}