nexus/backend/Controllers/MemoryController.cs

using Microsoft.AspNetCore.Mvc;
using Nexus.Api.Helpers;

namespace Nexus.Api.Controllers;

[ApiController]
[Route("api/v1/memory")]
public class MemoryController : ControllerBase
{
    [HttpGet]
    public IResult GetAll()
    {
        var basePath = "/mnt/workspace-iris/memory";
        if (!Directory.Exists(basePath))
            return Results.Ok(Array.Empty<object>());

        var files = Directory.GetFiles(basePath, "*.md")
            .Select(f => new FileInfo(f))
            .OrderByDescending(f => f.Name)
            .Select(f => new
            {
                name = f.Name,
                path = f.FullName.Replace(basePath, "").TrimStart('/'),
                size = f.Length,
                modifiedAt = f.LastWriteTimeUtc
            })
            .ToList();

        var longTermPath = "/mnt/workspace-iris/MEMORY.md";
        if (System.IO.File.Exists(longTermPath))
        {
            var fi = new FileInfo(longTermPath);
            files.Insert(0, new { name = "MEMORY.md", path = "MEMORY.md", size = fi.Length, modifiedAt = fi.LastWriteTimeUtc });
        }

        return Results.Ok(files);
    }

    [HttpGet("search")]
    public async Task<IResult> Search([FromQuery] string q)
    {
        if (string.IsNullOrWhiteSpace(q) || q.Length < 2)
            return Results.BadRequest("Query must be at least 2 characters.");

        var basePath = "/mnt/workspace-iris/memory";
        var results = new List<object>();

        const int maxFiles = 50;
        const int maxFileSize = 1_000_000;

        async Task SearchDir(string dir)
        {
            if (!Directory.Exists(dir)) return;
            var files = Directory.GetFiles(dir, "*.md").Take(maxFiles);
            foreach (var file in files)
            {
                var fi = new FileInfo(file);
                if (fi.Length > maxFileSize) continue;
                string content;
                using (var reader = new StreamReader(file))
                    content = await reader.ReadToEndAsync();
                if (content.Contains(q, StringComparison.OrdinalIgnoreCase))
                {
                    var idx = content.IndexOf(q, StringComparison.OrdinalIgnoreCase);
                    var start = Math.Max(0, idx - 60);
                    var excerpt = (start > 0 ? "\u2026" : "") + content.Substring(start, Math.Min(200, content.Length - start)) + "\u2026";
                    results.Add(new { name = Path.GetFileName(file), path = file.Replace(basePath, "").TrimStart('/'), excerpt, size = fi.Length });
                }
            }
        }

        await SearchDir(basePath);

        var longTermPath = "/mnt/workspace-iris/MEMORY.md";
        if (System.IO.File.Exists(longTermPath))
        {
            string content;
            using (var reader = new StreamReader(longTermPath))
                content = await reader.ReadToEndAsync();
            if (content.Contains(q, StringComparison.OrdinalIgnoreCase))
            {
                var idx = content.IndexOf(q, StringComparison.OrdinalIgnoreCase);
                var start = Math.Max(0, idx - 60);
                var excerpt = (start > 0 ? "\u2026" : "") + content.Substring(start, Math.Min(200, content.Length - start)) + "\u2026";
                results.Insert(0, new { name = "MEMORY.md", path = "MEMORY.md", excerpt, size = content.Length });
            }
        }

        return Results.Ok(results);
    }

    [HttpGet("{name}")]
    public async Task<IResult> GetFile(string name)
    {
        if (!PathSecurityHelper.TryResolveSafePath("/mnt/workspace-iris/memory", name, out var filePath))
            return Results.BadRequest("Invalid filename.");

        var longTermPath = "/mnt/workspace-iris/MEMORY.md";
        if (name.Equals("MEMORY.md", StringComparison.OrdinalIgnoreCase))
            filePath = longTermPath;

        if (!System.IO.File.Exists(filePath!))
            return Results.NotFound();

        var content = await System.IO.File.ReadAllTextAsync(filePath!);
        return Results.Ok(new { name, path = name, content, size = content.Length, modifiedAt = System.IO.File.GetLastWriteTimeUtc(filePath!) });
    }
}