package brain_test

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

	"github.com/mathiasbq/hyperguild/ingestion/internal/brain"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestBuildWingIndex(t *testing.T) {
	dir := t.TempDir()
	for _, p := range []struct{ rel, body string }{
		{"wiki/jepa-fx/decisions/val-vol.md", "---\ntitle: Val Vol R2\ncreated_at: 2026-05-06T10:00:00Z\n---\nbody\n"},
		{"wiki/jepa-fx/facts/architecture.md", "---\ntitle: Architecture\ncreated_at: 2026-05-04T10:00:00Z\n---\nbody\n"},
		{"wiki/jepa-fx/sources/paper.md", "---\n---\nbody\n"},
	} {
		full := filepath.Join(dir, p.rel)
		require.NoError(t, os.MkdirAll(filepath.Dir(full), 0o755))
		require.NoError(t, os.WriteFile(full, []byte(p.body), 0o644))
	}

	require.NoError(t, brain.BuildWingIndex(dir, "jepa-fx"))

	got, err := os.ReadFile(filepath.Join(dir, "wiki", "jepa-fx", "_index.md"))
	require.NoError(t, err)
	s := string(got)
	assert.Contains(t, s, "# jepa-fx")
	assert.Contains(t, s, "| Hall | Note | Created |")
	assert.Contains(t, s, "| decisions | [Val Vol R2](decisions/val-vol.md) | 2026-05-06 |")
	assert.Contains(t, s, "| facts | [Architecture](facts/architecture.md) | 2026-05-04 |")
	assert.Contains(t, s, "| sources | [paper](sources/paper.md) |")
	// Halls sorted alphabetically.
	assert.Less(t, indexOf(s, "decisions"), indexOf(s, "facts"))
	assert.Less(t, indexOf(s, "facts"), indexOf(s, "sources"))
}

func TestBuildWingIndex_SkipsInvalidHalls(t *testing.T) {
	dir := t.TempDir()
	wingDir := filepath.Join(dir, "wiki", "jepa-fx")
	require.NoError(t, os.MkdirAll(filepath.Join(wingDir, "garbage"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(wingDir, "garbage", "x.md"), []byte("x"), 0o644))
	require.NoError(t, os.MkdirAll(filepath.Join(wingDir, "facts"), 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(wingDir, "facts", "y.md"), []byte("y"), 0o644))

	require.NoError(t, brain.BuildWingIndex(dir, "jepa-fx"))
	got, err := os.ReadFile(filepath.Join(wingDir, "_index.md"))
	require.NoError(t, err)
	s := string(got)
	assert.Contains(t, s, "facts")
	assert.NotContains(t, s, "garbage")
}

func TestBuildAllWingIndexes(t *testing.T) {
	dir := t.TempDir()
	for _, p := range []struct{ rel, body string }{
		{"wiki/a/facts/x.md", "x"},
		{"wiki/b/facts/y.md", "y"},
	} {
		full := filepath.Join(dir, p.rel)
		require.NoError(t, os.MkdirAll(filepath.Dir(full), 0o755))
		require.NoError(t, os.WriteFile(full, []byte(p.body), 0o644))
	}
	require.NoError(t, brain.BuildAllWingIndexes(dir))
	_, err := os.Stat(filepath.Join(dir, "wiki", "a", "_index.md"))
	require.NoError(t, err)
	_, err = os.Stat(filepath.Join(dir, "wiki", "b", "_index.md"))
	require.NoError(t, err)
}

func TestBuildWingIndex_NoWingDir(t *testing.T) {
	dir := t.TempDir()
	require.NoError(t, brain.BuildWingIndex(dir, "ghost"))
}

func indexOf(s, sub string) int {
	for i := 0; i+len(sub) <= len(s); i++ {
		if s[i:i+len(sub)] == sub {
			return i
		}
	}
	return -1
}