package mcp

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

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

	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs/brainfstest"
)

// hyperguild#157 slice 2: readExcerpt (brain_context) read by path, so a
// symlink in the Syncthing-shared brain put an outside file in context, and
// a FIFO hung it. It now reads through brainfs.
func TestReadExcerptRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
	brain := t.TempDir()
	facts := filepath.Join(brain, "wiki", "w", "facts")
	require.NoError(t, os.MkdirAll(facts, 0o755))
	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
	assert.NotContains(t, readExcerpt(brain, "wiki/w/facts/leak.md", 500), brainfstest.Sentinel)

	p := filepath.Join(facts, "r.md")
	require.NoError(t, os.WriteFile(p, []byte("---\nx: y\n---\ninside"), 0o644))
	assert.Equal(t, "inside", readExcerpt(brain, "wiki/w/facts/r.md", 500))
	brainfstest.AssertNoLeak(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, func() string {
		return readExcerpt(brain, "wiki/w/facts/r.md", 500)
	})
	brainfstest.AssertNoHang(t, p, "---\nx: y\n---\ninside", 1500*time.Millisecond, 6*time.Second, func() {
		_ = readExcerpt(brain, "wiki/w/facts/r.md", 500)
	})
}