// 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.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Indentation;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Text;

namespace Microsoft.CodeAnalysis.Wrapping;

/// <summary>
/// Common implementation of all <see cref="ISyntaxWrapper"/>.  This type takes care of a lot of common logic for
/// all of them, including:
/// 
/// 1. Keeping track of code action invocations, allowing code actions to then be prioritized on
///    subsequent invocations.
///    
/// 2. Checking nodes and tokens to make sure they are safe to be wrapped.
/// 
/// Individual subclasses may be targeted at specific syntactic forms.  For example, wrapping
/// lists, or wrapping logical expressions.
/// </summary>
internal abstract partial class AbstractSyntaxWrapper : ISyntaxWrapper
{
    protected IIndentationService IndentationService { get; }

    protected AbstractSyntaxWrapper(IIndentationService indentationService)
        => IndentationService = indentationService;

    public abstract Task<ICodeActionComputer?> TryCreateComputerAsync(
        Document document, int position, SyntaxNode node, SyntaxWrappingOptions options, bool containsSyntaxError, CancellationToken cancellationToken);

    protected static async Task<bool> ContainsUnformattableContentAsync(
        Document document, IEnumerable<SyntaxNodeOrToken> nodesAndTokens, CancellationToken cancellationToken)
    {
        // For now, don't offer if any item spans multiple lines.  We'll very likely screw up
        // formatting badly.  If this is really important to support, we can put in the effort
        // to properly move multi-line items around (which would involve properly fixing up the
        // indentation of lines within them.
        //
        // https://github.com/dotnet/roslyn/issues/31575
        var sourceText = await document.GetValueTextAsync(cancellationToken).ConfigureAwait(false);
        foreach (var item in nodesAndTokens)
        {
            if (item == null || item.Span.IsEmpty || item.IsMissing)
                return true;

            var firstToken = item.IsToken ? item.AsToken() : item.AsNode()!.GetFirstToken();
            var lastToken = item.IsToken ? item.AsToken() : item.AsNode()!.GetLastToken();

            // Note: we check if things are on the same line, even in the case of a single token.
            // This is so that we don't try to wrap multiline tokens either (like a multi-line 
            // string).
            if (!sourceText.AreOnSameLine(firstToken, lastToken))
                return true;
        }

        return false;
    }

    protected static bool ContainsOverlappingSyntaxError(SyntaxNode declaration, TextSpan headerSpan)
        => declaration.GetDiagnostics().Any(d => d.Severity == DiagnosticSeverity.Error && d.Location.SourceSpan.OverlapsWith(headerSpan));
}