using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using CodePlay.Core.Models;
using CodePlay.Core.Common;
using CodePlay.Core.Interfaces;

namespace CodePlay.Core.Parsers;

/// <summary>
/// C# 语法解析器
/// </summary>
public class CSharpParser : BaseParser
{
    /// <summary>
    /// 支持的语言类型
    /// </summary>
    public override LanguageType SupportedLanguage => LanguageType.CSharp;
    
    /// <summary>
    /// 解析 C# 源代码
    /// </summary>
    public override Task<Interfaces.SyntaxTree> ParseAsync(string sourceCode, CancellationToken cancellationToken = default)
    {
        var tree = CreateSyntaxTree();
        tree.SourceCode = sourceCode;
        
        var compilationUnit = CSharpSyntaxTree.ParseText(sourceCode, cancellationToken: cancellationToken);
        var root = compilationUnit.GetRoot(cancellationToken);
        
        tree.Root = ConvertNode(root);
        ExtractComments(tree, root);
        ExtractDocumentation(tree, root);
        
        return Task.FromResult(tree);
    }
    
    private Interfaces.SyntaxNode ConvertNode(Microsoft.CodeAnalysis.SyntaxNode node)
    {
        var newNode = new Interfaces.SyntaxNode
        {
            Type = MapNodeType(node.Kind()),
            Text = node.ToString(),
            Metadata = new Dictionary<string, object?>()
        };
        
        foreach (var child in node.ChildNodes())
        {
            var childNode = ConvertNode(child);
            childNode.Parent = newNode;
            newNode.Children.Add(childNode);
        }
        
        return newNode;
    }
    
    private SyntaxNodeType MapNodeType(Microsoft.CodeAnalysis.CSharp.SyntaxKind kind)
    {
        return kind switch
        {
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.CompilationUnit => SyntaxNodeType.CompilationUnit,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.NamespaceDeclaration => SyntaxNodeType.Namespace,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ClassDeclaration => SyntaxNodeType.Class,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.InterfaceDeclaration => SyntaxNodeType.Interface,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.MethodDeclaration => SyntaxNodeType.Method,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.PropertyDeclaration => SyntaxNodeType.Property,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.FieldDeclaration => SyntaxNodeType.Field,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ConstructorDeclaration => SyntaxNodeType.Constructor,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.Parameter => SyntaxNodeType.Parameter,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.TypeArgumentList or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.GenericName => SyntaxNodeType.Type,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.Block or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ExpressionStatement or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.IfStatement or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ForStatement or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ForEachStatement or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.WhileStatement or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.ReturnStatement => SyntaxNodeType.Statement,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.InvocationExpression or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.AddExpression or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.SubtractExpression or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.MultiplyExpression or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.DivideExpression or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.SimpleAssignmentExpression => SyntaxNodeType.Expression,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.SingleLineCommentTrivia or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.MultiLineCommentTrivia => SyntaxNodeType.Comment,
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.SingleLineDocumentationCommentTrivia or
            Microsoft.CodeAnalysis.CSharp.SyntaxKind.MultiLineDocumentationCommentTrivia => SyntaxNodeType.DocumentationComment,
            _ => SyntaxNodeType.Unknown
        };
    }
    
    private void ExtractComments(Interfaces.SyntaxTree tree, Microsoft.CodeAnalysis.SyntaxNode root)
    {
        var trivia = root.DescendantTrivia()
            .Where(t => t.IsKind(Microsoft.CodeAnalysis.CSharp.SyntaxKind.SingleLineCommentTrivia) ||
                       t.IsKind(Microsoft.CodeAnalysis.CSharp.SyntaxKind.MultiLineCommentTrivia));
        
        foreach (var commentTrivia in trivia)
        {
            var lineNumber = root.SyntaxTree.GetLineSpan(commentTrivia.Span).StartLinePosition.Line + 1;
            var type = commentTrivia.IsKind(Microsoft.CodeAnalysis.CSharp.SyntaxKind.SingleLineCommentTrivia)
                ? CommentType.SingleLine
                : CommentType.MultiLine;
            
            AddComment(tree, commentTrivia.ToString(), type, lineNumber);
        }
    }
    
    private void ExtractDocumentation(Interfaces.SyntaxTree tree, Microsoft.CodeAnalysis.SyntaxNode root)
    {
        var docComments = root.DescendantTrivia()
            .Where(t => t.IsKind(Microsoft.CodeAnalysis.CSharp.SyntaxKind.SingleLineDocumentationCommentTrivia) ||
                       t.IsKind(Microsoft.CodeAnalysis.CSharp.SyntaxKind.MultiLineDocumentationCommentTrivia));
        
        foreach (var docComment in docComments)
        {
            var node = root.FindNode(docComment.Span);
            var lineNumber = root.SyntaxTree.GetLineSpan(docComment.Span).StartLinePosition.Line + 1;
            
            tree.Documentation.Add(new SyntaxDocumentation
            {
                ElementName = node.Parent?.ToString() ?? "Unknown",
                Content = docComment.ToString(),
                Format = DocFormat.XmlDoc
            });
        }
    }
}