using System;

using System.Diagnostics;

using System.Runtime.Serialization;

namespace Python.Runtime

{

/// <summary>

/// Represents a Python (ANSI) string object. See the documentation at

/// PY2: https://docs.python.org/2/c-api/string.html

/// PY3: No Equivalent

/// for details.

/// </summary>

/// <remarks>

/// 2011-01-29: ...Then why does the string constructor call PyUnicode_FromUnicode()???

/// </remarks>

[Serializable]

public class PyString : PySequence, IComparable<string>, IEquatable<string>

{

internal PyString(in StolenReference reference) : base(reference) { }

internal PyString(BorrowedReference reference) : base(reference) { }

protected PyString(SerializationInfo info, StreamingContext context) : base(info, context) { }

private static BorrowedReference FromObject(PyObject o)

{

if (o is null) throw new ArgumentNullException(nameof(o));

if (!IsStringType(o))

{

throw new ArgumentException("object is not a string");

}

return o.Reference;

}

/// <summary>

/// PyString Constructor

/// </summary>

/// <remarks>

/// Copy constructor - obtain a PyString from a generic PyObject.

/// An ArgumentException will be thrown if the given object is not

/// a Python string object.

/// </remarks>

public PyString(PyObject o) : base(FromObject(o))

{

}

/// <summary>

/// PyString Constructor

/// </summary>

/// <remarks>

/// Creates a Python string from a managed string.

/// </remarks>

public PyString(string s) : base(Runtime.PyString_FromString(s).StealOrThrow())

{

}

/// <summary>

/// Returns true if the given object is a Python string.

/// </summary>

public static bool IsStringType(PyObject value)

{

return Runtime.PyString_Check(value.obj);

}

public override TypeCode GetTypeCode() => TypeCode.String;

internal string ToStringUnderGIL()

{

string? result = Runtime.GetManagedString(this.Reference);

Debug.Assert(result is not null);

return result!;

}

public bool Equals(string? other)

=> this.ToStringUnderGIL().Equals(other, StringComparison.CurrentCulture);

public int CompareTo(string? other)

=> string.Compare(this.ToStringUnderGIL(), other, StringComparison.CurrentCulture);

public override string ToString()

{

using var _ = Py.GIL();

return this.ToStringUnderGIL();

}

}

}