using Newtonsoft.Json;
using System.Collections.Generic;

namespace Pilz.Cryptography;

[JsonConverter(typeof(Json.Converters.SecureStringJsonConverter))]
public class SecureString
{
    public static ICrypter DefaultCrypter { get; set; }
    public ICrypter Crypter { get; set; }
    public string EncryptedValue { get; set; }
    public string Value
    {
        get => GetCrypter()?.Decrypt(EncryptedValue);
        set => EncryptedValue = GetCrypter().Encrypt(value);
    }

    [JsonConstructor]
    private SecureString(JsonConstructorAttribute dummyAttribute)
    {
    }

    public SecureString() :
        this(string.Empty, true)
    {
    }

    public SecureString(string value, bool isEncrypted) :
        this(value, isEncrypted, null)
    {
    }

    public SecureString(string value, bool isEncrypted, ICrypter crypter)
    {
        Crypter = crypter;

        if (isEncrypted)
            EncryptedValue = value;
        else
            Value = value;
    }

    private ICrypter GetCrypter()
    {
        if (Crypter == null)
        {
            if (DefaultCrypter == null)
                DefaultCrypter = new SimpleStringCrypter(string.Empty);
            Crypter = DefaultCrypter;
        }
        return Crypter;
    }

    public override string ToString() => Value;

    public override bool Equals(object obj)
    {
        var @string = obj as SecureString;
        return @string != null &&
               EncryptedValue == @string.EncryptedValue;
    }

    public override int GetHashCode()
    {
        return -2303024 + EqualityComparer<string>.Default.GetHashCode(EncryptedValue);
    }

    public static implicit operator string(SecureString value) => value?.Value;
    public static implicit operator SecureString(string value) => new SecureString(value, false);

    public static bool operator ==(SecureString left, SecureString right) => left?.EncryptedValue == right?.EncryptedValue;
    public static bool operator !=(SecureString left, SecureString right) => left?.EncryptedValue != right?.EncryptedValue;
}