package brain_test

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

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

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

// hyperguild#174 / #157 slice 5b: DetectTunnels walked wiki/ and opened
// every note with a blocking os.Open, so a FIFO named *.md anywhere under
// wiki/ hung every brain_write and brain_update (wikiUpkeep -> AutoTunnel),
// and a symlinked note's title became a tunnel candidate.
func TestDetectTunnelsReturnsPromptlyWithAFIFOUnderWiki(t *testing.T) {
	b := t.TempDir()
	facts := filepath.Join(b, "wiki", "w", "facts")
	require.NoError(t, os.MkdirAll(facts, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: Zqinside Phrase\n---\n"), 0o644))
	require.NoError(t, syscall.Mkfifo(filepath.Join(facts, "f.md"), 0o644))
	done := make(chan []brain.TunnelCandidate, 1)
	go func() {
		cs, _ := brain.DetectTunnels(b, "text mentioning zqinside phrase here")
		done <- cs
	}()
	select {
	case cs := <-done:
		assert.Contains(t, fmt.Sprintf("%+v", cs), "Zqinside Phrase", "positive control")
	case <-time.After(3 * time.Second):
		if r, err := os.OpenFile(filepath.Join(facts, "f.md"), os.O_WRONLY|syscall.O_NONBLOCK, 0); err == nil {
			_ = r.Close()
		}
		t.Fatal("DetectTunnels blocked on a FIFO")
	}
}

func TestDetectTunnelsRefusesSymlinkedNotesAndSurvivesSwapRaces(t *testing.T) {
	b := t.TempDir()
	facts := filepath.Join(b, "wiki", "w", "facts")
	require.NoError(t, os.MkdirAll(facts, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: Zqinside Phrase\n---\n"), 0o644))
	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "out.md")))
	inBrain := brainfstest.WriteSentinelAt(t, filepath.Join(b, "raw", "s.md"))
	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "s.md"), filepath.Join(facts, "in.md")))
	content := "zqinside phrase and " + brainfstest.Sentinel

	cs, err := brain.DetectTunnels(b, content)
	require.NoError(t, err)
	got := fmt.Sprintf("%+v", cs)
	assert.Contains(t, got, "Zqinside Phrase", "positive control")
	assert.NotContains(t, got, brainfstest.Sentinel)

	p := filepath.Join(facts, "r.md")
	read := func() string {
		cs, _ := brain.DetectTunnels(b, content)
		return fmt.Sprintf("%+v", cs)
	}
	brainfstest.AssertNoLeak(t, p, "---\ntitle: Zqinside Phrase\n---\n", 1500*time.Millisecond, read)
	brainfstest.AssertNoLeakFrom(t, p, "---\ntitle: Zqinside Phrase\n---\n", inBrain, 1500*time.Millisecond, read)
}

// A wiki/ that is not a real directory yields no candidates and no error:
// AutoTunnel runs inside brain_write.
func TestDetectTunnelsSkipsAWikiThatIsNotARealDirectory(t *testing.T) {
	b := t.TempDir()
	require.NoError(t, os.MkdirAll(filepath.Join(b, "raw", "w", "facts"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(b, "raw", "w", "facts", "r.md"), []byte("---\ntitle: Zqrawonly Phrase\n---\n"), 0o644))
	require.NoError(t, os.Symlink("raw", filepath.Join(b, "wiki")))
	cs, err := brain.DetectTunnels(b, "zqrawonly phrase")
	require.NoError(t, err)
	assert.Empty(t, cs)
}