namespace OnekoOnline;

class ConfigFile
{
    public readonly string Path;
    readonly Dictionary<string, string> ConfigOptions = [];
    bool OptionChanged = false;
    const string TopLine = "# OnekoOnline Config File";

    public ConfigFile(string path)
    {
        Path = path;

        if (!File.Exists(Path)) {
            Console.WriteLine("Config file does not exist, creating one.");
            File.WriteAllText(Path, TopLine);
            OptionChanged = true;
            SaveFileDelayed(3000);
            return;
        }

        string[] fileContents = File.ReadAllLines(Path);

        foreach (string line in fileContents) {
            if (line[0] == '#' || !line.Contains('=') || line.Length < 3) continue;

            string key = line[0..line.IndexOf('=')];
            string value = line[(line.IndexOf('=')+1)..];
            ConfigOptions.Add(key, value);
        }
    }

    public async void SaveFileDelayed(int delayInMilliseconds)
    {
        await Task.Delay(delayInMilliseconds);
        SaveFile();
    }

    public void SaveFile()
    {
        if (!OptionChanged) return;

        List<string> linesToWrite = [TopLine];
        foreach (KeyValuePair<string, string> pair in ConfigOptions.OrderBy(k => k.Key)) linesToWrite.Add(pair.Key + "=" + pair.Value);
        File.WriteAllLines(Path, linesToWrite);

        OptionChanged = false;
    }

    public T GetValue<T>(string Key, T defaultValue) where T : IConvertible
    {
        if (ConfigOptions.TryGetValue(Key, out string? value)) {
            try {
                return (T)Convert.ChangeType(value, typeof(T));
            } catch {
                Console.WriteLine($"Config option {Key} is invalid, setting to default.");
            }
        }

        SetValue(Key, defaultValue);
        return defaultValue;
    }

    public string GetValue(string Key, string defaultValue)
    {
        if (ConfigOptions.TryGetValue(Key, out string? value)) {
            return value;
        }

        SetValue(Key, defaultValue);
        return defaultValue;
    }

    public void SetValue<T>(string Key, T Value) where T : IConvertible
    {
        string? ValueString = Value.ToString();
        if (ValueString is null) return;

        SetValue(Key, ValueString);
    }

    public void SetValue(string Key, string Value)
    {
        if (ConfigOptions.TryAdd(Key, Value)) {
            OptionChanged = true;
        } else if (ConfigOptions[Key] != Value) {
            ConfigOptions[Key] = Value;
            OptionChanged = true;
        }
    }
}