Casbin/Model/PolicyValues.cs

using System;
using System.Collections;
using System.Collections.Generic;

namespace Casbin.Model;

public record PolicyValues : IPolicyValues
{
    private string _text;

    public static PolicyValues Empty { get; } = new();
    public virtual int Count => 0;
    public virtual string this[int index] => throw new ArgumentOutOfRangeException(nameof(index));
    public virtual IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues>(this);
    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    public string ToText() => _text ??= ToText(this);
    public bool Equals(IPolicyValues other) => Equals(this, other);

    internal static string ToText<T>(T values) where T : IPolicyValues
        => string.Join(PermConstants.PolicySeparatorString, values);

    internal static bool Equals<T>(T values, T other) where T : IPolicyValues
        => values.Count == other.Count && values.ToText().Equals(other.ToText());

    internal static string ToStringValue<T>(T value) =>
        value is not null
            ? value as string ?? value.ToString()
            : string.Empty;
}

public record PolicyValues<T1>(T1 Value1) : PolicyValues
{
    private string _stringValue1;
    public override int Count => 1;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues<T1>>(this);
}

public record PolicyValues<T1, T2>(T1 Value1, T2 Value2) : PolicyValues
{
    private string _stringValue1, _stringValue2;
    public override int Count => 2;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues<T1, T2>>(this);
}

public record PolicyValues<T1, T2, T3>(T1 Value1, T2 Value2, T3 Value3) : PolicyValues
{
    private string _stringValue1, _stringValue2, _stringValue3;
    public override int Count => 3;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        2 => _stringValue3 ??= ToStringValue(Value3),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues<T1, T2, T3>>(this);
}

public record PolicyValues<T1, T2, T3, T4>(T1 Value1, T2 Value2, T3 Value3, T4 Value4) : PolicyValues
{
    private string _stringValue1, _stringValue2, _stringValue3, _stringValue4;
    public override int Count => 4;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        2 => _stringValue3 ??= ToStringValue(Value3),
        3 => _stringValue4 ??= ToStringValue(Value4),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues<T1, T2, T3, T4>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5>(T1 Value1, T2 Value2, T3 Value3, T4 Value4, T5 Value5) : PolicyValues
{
    private string _stringValue1, _stringValue2, _stringValue3, _stringValue4, _stringValue5;
    public override int Count => 5;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        2 => _stringValue3 ??= ToStringValue(Value3),
        3 => _stringValue4 ??= ToStringValue(Value4),
        4 => _stringValue5 ??= ToStringValue(Value5),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() => new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6>
    (T1 Value1, T2 Value2, T3 Value3, T4 Value4, T5 Value5, T6 Value6) : PolicyValues
{
    private string _stringValue1, _stringValue2, _stringValue3, _stringValue4, _stringValue5, _stringValue6;
    public override int Count => 6;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        2 => _stringValue3 ??= ToStringValue(Value3),
        3 => _stringValue4 ??= ToStringValue(Value4),
        4 => _stringValue5 ??= ToStringValue(Value5),
        5 => _stringValue6 ??= ToStringValue(Value6),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7>(T1 Value1, T2 Value2, T3 Value3, T4 Value4, T5 Value5, T6 Value6,
    T7 Value7) : PolicyValues
{
    private string _stringValue1,
        _stringValue2,
        _stringValue3,
        _stringValue4,
        _stringValue5,
        _stringValue6,
        _stringValue7;

    public override int Count => 7;

    public override string this[int index] => index switch
    {
        0 => _stringValue1 ??= ToStringValue(Value1),
        1 => _stringValue2 ??= ToStringValue(Value2),
        2 => _stringValue3 ??= ToStringValue(Value3),
        3 => _stringValue4 ??= ToStringValue(Value4),
        4 => _stringValue5 ??= ToStringValue(Value5),
        5 => _stringValue6 ??= ToStringValue(Value6),
        6 => _stringValue7 ??= ToStringValue(Value7),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8>(T1 Value1, T2 Value2, T3 Value3, T4 Value4, T5 Value5,
    T6 Value6,
    T7 Value7, T8 Value8) : PolicyValues
{
    public override int Count => 8;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9>(T1 Value1, T2 Value2, T3 Value3, T4 Value4, T5 Value5,
    T6 Value6, T7 Value7, T8 Value8, T9 Value9) : PolicyValues
{
    public override int Count => 9;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(T1 Value1, T2 Value2, T3 Value3, T4 Value4,
    T5 Value5,
    T6 Value6, T7 Value7, T8 Value8, T9 Value9, T10 Value10) : PolicyValues
{
    public override int Count => 10;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        9 => ToStringValue(Value10),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>(T1 Value1, T2 Value2, T3 Value3, T4 Value4,
    T5 Value5, T6 Value6, T7 Value7, T8 Value8, T9 Value9, T10 Value10, T11 Value11) : PolicyValues
{
    public override int Count => 11;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        9 => ToStringValue(Value10),
        10 => ToStringValue(Value11),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(T1 Value1, T2 Value2, T3 Value3,
    T4 Value4,
    T5 Value5, T6 Value6, T7 Value7, T8 Value8, T9 Value9, T10 Value10, T11 Value11, T12 Value12) : PolicyValues
{
    public override int Count => 12;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        9 => ToStringValue(Value10),
        10 => ToStringValue(Value11),
        11 => ToStringValue(Value12),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>(T1 Value1, T2 Value2, T3 Value3,
    T4 Value4,
    T5 Value5, T6 Value6, T7 Value7, T8 Value8, T9 Value9, T10 Value10, T11 Value11, T12 Value12, T13 Value13) : PolicyValues
{
    public override int Count => 13;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        9 => ToStringValue(Value10),
        10 => ToStringValue(Value11),
        11 => ToStringValue(Value12),
        12 => ToStringValue(Value13),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>>(this);
}

public record PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>(T1 Value1, T2 Value2, T3 Value3,
    T4 Value4,
    T5 Value5, T6 Value6, T7 Value7, T8 Value8, T9 Value9, T10 Value10, T11 Value11, T12 Value12, T13 Value13, T14 Value14) : PolicyValues
{
    public override int Count => 14;

    public override string this[int index] => index switch
    {
        0 => ToStringValue(Value1),
        1 => ToStringValue(Value2),
        2 => ToStringValue(Value3),
        3 => ToStringValue(Value4),
        4 => ToStringValue(Value5),
        5 => ToStringValue(Value6),
        6 => ToStringValue(Value7),
        7 => ToStringValue(Value8),
        8 => ToStringValue(Value9),
        9 => ToStringValue(Value10),
        10 => ToStringValue(Value11),
        11 => ToStringValue(Value12),
        12 => ToStringValue(Value13),
        13 => ToStringValue(Value14),
        _ => throw new ArgumentOutOfRangeException(nameof(index))
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<PolicyValues<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>>(this);
}

internal record DummyPolicyValues(string Value1 = "", string Value2 = "", string Value3 = "",
    string Value4 = "", string Value5 = "", string Value6 = "",
    string Value7 = "", string Value8 = "", string Value9 = "",
    string Value10 = "", string Value11 = "", string Value12 = "",
    string Value13 = "", string Value14 = "") : PolicyValues
{
    public static new readonly DummyPolicyValues Empty = new();
    public override int Count => 14;

    public override string this[int index] => index switch
    {
        0 => Value1,
        1 => Value2,
        2 => Value3,
        3 => Value4,
        4 => Value5,
        5 => Value6,
        6 => Value7,
        7 => Value8,
        8 => Value9,
        9 => Value10,
        10 => Value11,
        11 => Value12,
        12 => Value13,
        13 => Value14,
        _ => ""
    };

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<DummyPolicyValues>(this);
}

internal record StringListPolicyValues : PolicyValues
{
    private readonly IReadOnlyList<string> _values;

    public StringListPolicyValues(IReadOnlyList<string> values)
    {
        _values = values;
        Count = values.Count;
    }

    public StringListPolicyValues(IReadOnlyList<string> values, int requiredCount)
    {
        _values = values;
        Count = requiredCount;
    }

    public override int Count { get; }

    public override string this[int index] => _values.GetValueOrDefault(index);

    public override IEnumerator<string> GetEnumerator() =>
        new PolicyEnumerator<StringListPolicyValues>(this);
}

internal struct PolicyEnumerator<T> : IEnumerator<string> where T : IPolicyValues
{
    public PolicyEnumerator(T value)
    {
        _value = value;
        _index = -1;
    }

    private int _index;
    private readonly T _value;

    public object Current => _value[_index];
    string IEnumerator<string>.Current => _value[_index];

    public void Dispose()
    {
    }

    public bool MoveNext() => ++_index < _value.Count;
    public void Reset() => _index = -1;
}