using System.IO;
using System.Text.Json;

namespace AxCopilot.Services.Agent;

/// <summary>파일 패턴 검색 도구. glob 패턴으로 파일 목록을 반환합니다.</summary>
public class GlobTool : IAgentTool
{
    public string Name => "glob";
    public string Description => "Find files matching a glob pattern (e.g. '**/*.cs', 'src/**/*.json'). Returns matching file paths.";

    public ToolParameterSchema Parameters => new()
    {
        Properties = new()
        {
            ["pattern"] = new() { Type = "string", Description = "Glob pattern to match files (e.g. '**/*.cs', '*.txt')" },
            ["path"] = new() { Type = "string", Description = "Directory to search in. Optional, defaults to work folder." },
        },
        Required = ["pattern"]
    };

    public Task<ToolResult> ExecuteAsync(JsonElement args, AgentContext context, CancellationToken ct)
    {
        var pattern = args.GetProperty("pattern").GetString() ?? "";
        var searchPath = args.TryGetProperty("path", out var p) ? p.GetString() ?? "" : "";

        var baseDir = string.IsNullOrEmpty(searchPath)
            ? context.WorkFolder
            : FileReadTool.ResolvePath(searchPath, context.WorkFolder);

        if (string.IsNullOrEmpty(baseDir) || !Directory.Exists(baseDir))
            return Task.FromResult(ToolResult.Fail($"디렉토리가 존재하지 않습니다: {baseDir}"));

        if (!context.IsPathAllowed(baseDir))
            return Task.FromResult(ToolResult.Fail($"경로 접근 차단: {baseDir}"));

        try
        {
            // glob 패턴을 Directory.EnumerateFiles용으로 변환
            var searchPattern = ExtractSearchPattern(pattern);
            var recursive = pattern.Contains("**") || pattern.Contains('/') || pattern.Contains('\\');
            var option = recursive ? SearchOption.AllDirectories : SearchOption.TopDirectoryOnly;

            var files = Directory.EnumerateFiles(baseDir, searchPattern, option)
                .Where(f => context.IsPathAllowed(f))
                .OrderBy(f => f)
                .Take(200)
                .ToList();

            if (files.Count == 0)
                return Task.FromResult(ToolResult.Ok($"패턴 '{pattern}'에 일치하는 파일이 없습니다."));

            var result = string.Join("\n", files.Select(f => Path.GetRelativePath(baseDir, f)));
            return Task.FromResult(ToolResult.Ok($"{files.Count}개 파일 발견:\n{result}"));
        }
        catch (Exception ex)
        {
            return Task.FromResult(ToolResult.Fail($"검색 실패: {ex.Message}"));
        }
    }

    private static string ExtractSearchPattern(string globPattern)
    {
        // **/*.cs → *.cs, src/**/*.json → *.json
        var parts = globPattern.Replace('/', '\\').Split('\\');
        var last = parts[^1];
        return string.IsNullOrEmpty(last) || last == "**" ? "*" : last;
    }
}