package brain_test

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

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

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

// hyperguild#178: StripUnresolvedLinks runs before every brain_write and
// brain_update. An unreadable directory under knowledge/ or wiki/ made it
// error, the write was refused and the learning lost. When the link index
// cannot be built, the content is now returned unchanged (no link is
// unwrapped, none is invented) and no error stops the write.
func TestStripUnresolvedLinksKeepsContentWhenTheIndexCannotBeBuilt(t *testing.T) {
	if os.Geteuid() == 0 {
		t.Skip("root ignores directory permissions")
	}
	b := t.TempDir()
	require.NoError(t, os.MkdirAll(filepath.Join(b, "wiki", "w", "facts"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(b, "wiki", "w", "facts", "real.md"), []byte("x"), 0o644))
	locked := filepath.Join(b, "wiki", "other", "locked")
	require.NoError(t, os.MkdirAll(locked, 0o755))
	require.NoError(t, os.Chmod(locked, 0o000))
	t.Cleanup(func() { _ = os.Chmod(locked, 0o755) })

	in := "learning [[real]] and [[gone]]"
	out, unlinked, err := brain.StripUnresolvedLinks(b, in)
	require.NoError(t, err)
	assert.Equal(t, in, out, "content unchanged: no link unwrapped on a partial index")
	assert.Empty(t, unlinked)

	require.NoError(t, os.Chmod(locked, 0o755))
	out, _, err = brain.StripUnresolvedLinks(b, in)
	require.NoError(t, err)
	assert.NotContains(t, out, "[[gone]]", "positive control: with a readable tree the strip runs")
}