using CodePlay.Core.Interfaces;
using CodePlay.Core.Common;

namespace CodePlay.Core.Parsers;

/// <summary>
/// Python 解析器
/// </summary>
public class PythonParser : BaseParser
{
    public override LanguageType SupportedLanguage => LanguageType.None; // Python 暂不加入枚举
    
    public override Task<SyntaxTree> ParseAsync(string sourceCode, CancellationToken cancellationToken = default)
    {
        var tree = CreateSyntaxTree();
        tree.SourceCode = sourceCode;
        tree.Root = ParseRoot(sourceCode);
        tree.Comments = ExtractComments(sourceCode);
        
        return Task.FromResult(tree);
    }
    
    private SyntaxNode ParseRoot(string sourceCode)
    {
        var root = new SyntaxNode { Type = SyntaxNodeType.CompilationUnit, Text = sourceCode };
        
        ExtractClasses(sourceCode, root);
        ExtractFunctions(sourceCode, root);
        ExtractImports(sourceCode, root);
        
        return root;
    }
    
    private void ExtractClasses(string code, SyntaxNode root)
    {
        var pattern = @"class\s+(\w+)\s*(?:\(([^)]*)\))?";
        var matches = System.Text.RegularExpressions.Regex.Matches(code, pattern);
        
        foreach (System.Text.RegularExpressions.Match match in matches)
        {
            var classNode = new SyntaxNode
            {
                Type = SyntaxNodeType.Class,
                Text = match.Value,
                Metadata = new Dictionary<string, object?>
                {
                    ["Name"] = match.Groups[1].Value,
                    ["BaseClasses"] = match.Groups[2].Success ? match.Groups[2].Value : null
                }
            };
            root.Children.Add(classNode);
        }
    }
    
    private void ExtractFunctions(string code, SyntaxNode root)
    {
        var pattern = @"def\s+(\w+)\s*\(([^)]*)\)";
        var matches = System.Text.RegularExpressions.Regex.Matches(code, pattern);
        
        foreach (System.Text.RegularExpressions.Match match in matches)
        {
            var funcNode = new SyntaxNode
            {
                Type = SyntaxNodeType.Method,
                Text = match.Value,
                Metadata = new Dictionary<string, object?>
                {
                    ["Name"] = match.Groups[1].Value,
                    ["Parameters"] = match.Groups[2].Value
                }
            };
            root.Children.Add(funcNode);
        }
    }
    
    private void ExtractImports(string code, SyntaxNode root)
    {
        var lines = code.Split('\n');
        foreach (var line in lines)
        {
            var trimmed = line.Trim();
            if (trimmed.StartsWith("import ") || trimmed.StartsWith("from "))
            {
                root.Children.Add(new SyntaxNode
                {
                    Type = SyntaxNodeType.Type,
                    Text = trimmed,
                    Metadata = { ["Kind"] = "import" }
                });
            }
        }
    }
    
    private List<SyntaxComment> ExtractComments(string sourceCode)
    {
        var comments = new List<SyntaxComment>();
        var lines = sourceCode.Split('\n');
        
        for (int i = 0; i < lines.Length; i++)
        {
            var line = lines[i].Trim();
            if (line.StartsWith("#"))
            {
                comments.Add(new SyntaxComment
                {
                    Type = CommentType.SingleLine,
                    Text = line.TrimStart('#').Trim(),
                    LineNumber = i + 1
                });
            }
        }
        
        return comments;
    }
}