package mcp_test

import (
	"os"
	"path/filepath"
	"syscall"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/mathiasbq/hyperguild/ingestion/internal/mcp"
)

// hyperguild#192: brain_edit snapshotted the note with os.ReadFile by path,
// which blocks on a FIFO held open by a writer, and hung the call.
func TestBrainEditReturnsPromptlyOnAFIFONoteWithAWriter(t *testing.T) {
	dir := newBrainRepo(t)
	fifo := filepath.Join(dir, "wiki", "homelab", "facts", "f.md")
	require.NoError(t, syscall.Mkfifo(fifo, 0o644))
	w, err := os.OpenFile(fifo, os.O_RDWR, 0)
	require.NoError(t, err)
	t.Cleanup(func() { _ = w.Close() })
	srv := mcp.NewServer(dir, nil, nil, nil)

	done := make(chan map[string]any, 1)
	go func() {
		done <- call(t, srv, "brain_edit", map[string]any{"path": "wiki/homelab/facts/f.md", "old_str": "a", "new_str": "b"})
	}()
	select {
	case resp := <-done:
		assert.Contains(t, resp, "error", "a FIFO note is refused")
	case <-time.After(3 * time.Second):
		t.Fatal("brain_edit hung on a FIFO note")
	}

	resp := call(t, srv, "brain_edit", map[string]any{"path": "wiki/homelab/facts/n.md", "old_str": "beta", "new_str": "BETA"})
	require.NotContains(t, resp, "error", "positive control: a regular note is edited: %v", resp["error"])
}

// hyperguild#192: the edit lock "<note>.lock" was opened by path with
// O_CREATE, so a planted dangling .lock symlink made a successful edit create
// a file at the link's target, outside the brain or elsewhere in it.
func TestBrainEditDoesNotCreateAFileThroughADanglingLockSymlink(t *testing.T) {
	for name, target := range map[string]func(t *testing.T, dir string) string{
		"outside":  func(t *testing.T, _ string) string { return filepath.Join(t.TempDir(), "created") },
		"in-brain": func(t *testing.T, dir string) string { return filepath.Join(dir, "raw", "created") },
	} {
		t.Run(name, func(t *testing.T) {
			dir := newBrainRepo(t)
			require.NoError(t, os.MkdirAll(filepath.Join(dir, "raw"), 0o755))
			tgt := target(t, dir)
			require.NoError(t, os.Symlink(tgt, filepath.Join(dir, "wiki", "homelab", "facts", "n.md.lock")))
			srv := mcp.NewServer(dir, nil, nil, nil)
			_ = call(t, srv, "brain_edit", map[string]any{"path": "wiki/homelab/facts/n.md", "old_str": "beta", "new_str": "BETA"})
			_, err := os.Lstat(tgt)
			assert.True(t, os.IsNotExist(err), "a file was created at the lock symlink's target")
		})
	}
}