// <copyright file="Settings.cs" company="MUnique">
// Licensed under the MIT License. See LICENSE file in the project root for full license information.
// </copyright>

namespace MUnique.OpenMU.ChatServer.ExDbConnector;

using System.Globalization;
using System.IO;

/// <summary>
/// A class which reads settings from a file.
/// Line Format:
/// [Key]=[Value]
/// Line comments can be added by starting with "#".
/// </summary>
internal class Settings
{
    private readonly IDictionary<string, string> _settingsDictionary = new Dictionary<string, string>();

    /// <summary>
    /// Initializes a new instance of the <see cref="Settings"/> class.
    /// Reads the file contents in, if the file is available.
    /// </summary>
    /// <param name="file">The file.</param>
    public Settings(string file)
    {
        if (!File.Exists(file))
        {
            return;
        }

        foreach (var line in File.ReadAllLines(file))
        {
            var elements = line.Split('=');
            if (elements.Length > 1
                && !elements[0].StartsWith("#", StringComparison.InvariantCulture)
                && !this._settingsDictionary.ContainsKey(elements[0]))
            {
                this._settingsDictionary.Add(elements[0], elements[1]);
            }
        }
    }

    /// <summary>
    /// Gets the configured chat server listener port.
    /// </summary>
    public int? ChatServerListenerPort
    {
        get
        {
            if (this["ChatServerListenerPort"] != null && int.TryParse(this["ChatServerListenerPort"], out var result))
            {
                return result;
            }

            return default;
        }
    }

    /// <summary>
    /// Gets the configured exDb server port.
    /// </summary>
    public int? ExDbPort
    {
        get
        {
            if (this["ExDbPort"] != null)
            {
                if (int.TryParse(this["ExDbPort"], out int result))
                {
                    return result;
                }

                return default;
            }

            return null;
        }
    }

    /// <summary>
    /// Gets the configured exDb server host.
    /// </summary>
    public string? ExDbHost => this["ExDbHost"];

    /// <summary>
    /// Gets the configured xor32 key.
    /// </summary>
    public byte[]? Xor32Key
    {
        get
        {
            if (this["Xor32Key"] != null)
            {
                var customXor32KeyList = new List<byte>();
                var keyAsString = this["Xor32Key"];
                if (keyAsString is not null)
                {
                    var bytesAsString = keyAsString.Split(' ');
                    foreach (var byteString in bytesAsString)
                    {
                        customXor32KeyList.Add(byte.Parse(byteString, NumberStyles.HexNumber, CultureInfo.InvariantCulture));
                    }
                }

                return customXor32KeyList.ToArray();
            }

            return null;
        }
    }

    private string? this[string key]
    {
        get
        {
            this._settingsDictionary.TryGetValue(key, out var value);
            return value;
        }
    }
}