package graphsync

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

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

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

func (f *fakeStore) dump() string {
	f.mu.Lock()
	defer f.mu.Unlock()
	return fmt.Sprintf("%+v %+v", f.upserts, f.replaces)
}

// hyperguild#157 slice 4: IndexDoc and BackfillFromBrainDir read notes with
// os.ReadFile, so a symlinked note put the target's title and wikilinks into
// the graph, and a FIFO hung the read.
func TestIndexDocRefusesSymlinksAndSurvivesSwapRaces(t *testing.T) {
	brain := t.TempDir()
	facts := filepath.Join(brain, "wiki", "w", "facts")
	require.NoError(t, os.MkdirAll(facts, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: zqinside\n---\nbody [[other]]\n"), 0o644))
	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))

	store := newFakeStore()
	require.NoError(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/ok.md"))
	assert.Contains(t, store.dump(), "zqinside", "positive control: a regular note is indexed")
	assert.Error(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/leak.md"))
	// A link to a file elsewhere in the brain: os.Root allows it, only the
	// regular-file check refuses it.
	inBrain := brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "s.md"))
	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "s.md"), filepath.Join(facts, "inlink.md")))
	assert.Error(t, IndexDoc(context.Background(), store, brain, "wiki/w/facts/inlink.md"))
	assert.NotContains(t, store.dump(), brainfstest.Sentinel)

	p := filepath.Join(facts, "r.md")
	read := func() string {
		s := newFakeStore()
		_ = IndexDoc(context.Background(), s, brain, "wiki/w/facts/r.md")
		return s.dump()
	}
	brainfstest.AssertNoLeak(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, read)
	brainfstest.AssertNoLeakFrom(t, p, "---\ntitle: zqinside\n---\n", inBrain, 1500*time.Millisecond, read)
	brainfstest.AssertNoHang(t, p, "---\ntitle: zqinside\n---\n", 1500*time.Millisecond, 6*time.Second, func() { _ = read() })
}

func TestBackfillSkipsSymlinkedNotesAndAbortsOnASymlinkedRoot(t *testing.T) {
	brain := t.TempDir()
	facts := filepath.Join(brain, "wiki", "w", "facts")
	require.NoError(t, os.MkdirAll(facts, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(facts, "ok.md"), []byte("---\ntitle: zqinside\n---\n"), 0o644))
	require.NoError(t, os.Symlink(brainfstest.Outside(t), filepath.Join(facts, "leak.md")))
	require.NoError(t, os.MkdirAll(filepath.Join(brain, "raw"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(brain, "raw", "r.md"), []byte("---\ntitle: zqrawonly\n---\n"), 0o644))
	require.NoError(t, os.Symlink(filepath.Join("..", "..", "..", "raw", "r.md"), filepath.Join(facts, "inlink.md")))
	require.NoError(t, os.Symlink(".", filepath.Join(brain, "knowledge")))

	store := newFakeStore()
	_, err := BackfillFromBrainDir(context.Background(), store, brain)
	assert.Error(t, err, "a symlinked root aborts the backfill")
	assert.NotContains(t, store.dump(), brainfstest.Sentinel)
	assert.NotContains(t, store.dump(), "zqrawonly")

	require.NoError(t, os.Remove(filepath.Join(brain, "knowledge")))
	store = newFakeStore()
	n, err := BackfillFromBrainDir(context.Background(), store, brain)
	require.NoError(t, err)
	assert.Equal(t, 1, n, "only the regular note is indexed")
	assert.Contains(t, store.dump(), "zqinside")
	assert.NotContains(t, store.dump(), brainfstest.Sentinel)
}

// IndexDoc gets caller-supplied paths (brain_tunnel, brain_update): only a
// clean path under wiki/ or knowledge/ is indexed.
func TestIndexDocRefusesPathsOutsideWikiAndKnowledgeAndUncleanPaths(t *testing.T) {
	brain := t.TempDir()
	brainfstest.WriteSentinelAt(t, filepath.Join(brain, "raw", "secret.md"))
	require.NoError(t, os.MkdirAll(filepath.Join(brain, "wiki", "w"), 0o755))
	for _, p := range []string{"raw/secret.md", "wiki/w/../../raw/secret.md", "./raw/secret.md", "/raw/secret.md"} {
		store := newFakeStore()
		assert.Error(t, IndexDoc(context.Background(), store, brain, p), p)
		assert.NotContains(t, store.dump(), brainfstest.Sentinel, p)
	}
}