// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Composition;
using System.IO;
using System.Text;
using System.Threading;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.CodeAnalysis.Shared.Utilities;
using Microsoft.CodeAnalysis.Text;

namespace Microsoft.CodeAnalysis.Host;

[ExportWorkspaceService(typeof(ITextFactoryService), ServiceLayer.Default), Shared]
internal sealed class TextFactoryService : ITextFactoryService
{
    [ImportingConstructor]
    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
    public TextFactoryService()
    {
    }

    public SourceText CreateText(Stream stream, Encoding? defaultEncoding, SourceHashAlgorithm checksumAlgorithm, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();
        return EncodedStringText.Create(stream, defaultEncoding, checksumAlgorithm);
    }

    public SourceText CreateText(TextReader reader, Encoding? encoding, SourceHashAlgorithm checksumAlgorithm, CancellationToken cancellationToken)
    {
        cancellationToken.ThrowIfCancellationRequested();

        return (reader is TextReaderWithLength textReaderWithLength)
            ? SourceText.From(textReaderWithLength, textReaderWithLength.Length, encoding, checksumAlgorithm)
            : SourceText.From(reader.ReadToEnd(), encoding, checksumAlgorithm);
    }
}