package mfer_test

import (
	"crypto/sha256"
	"encoding/hex"
	"os"
	"strings"
	"testing"

	"github.com/stretchr/testify/require"
	"google.golang.org/protobuf/reflect/protoreflect"
	"sneak.berlin/go/mfer/mfer"
)

// mf.pb.go is generated from mf.proto and committed. `make generate`
// records the hash of the mf.proto it generated from in mf.proto.sha256.
func TestGeneratedCodeMatchesProto(t *testing.T) {
	t.Parallel()

	proto, err := os.ReadFile("mf.proto")
	require.NoError(t, err)

	recorded, err := os.ReadFile("mf.proto.sha256")
	require.NoError(t, err)

	recordedHash, _, _ := strings.Cut(string(recorded), " ")
	sum := sha256.Sum256(proto)
	require.Equal(t, recordedHash, hex.EncodeToString(sum[:]),
		"mfer/mf.proto has changed since mfer/mf.pb.go was generated "+
			"from it: run `make generate` and commit the result")
}

// A file entry has exactly the fields docs/FORMAT.md lists for MFFilePath.
func TestFileEntryFieldsMatchSpec(t *testing.T) {
	t.Parallel()

	want := map[string]protoreflect.FieldNumber{
		"path":     1,
		"size":     2,
		"hashes":   3,
		"mimeType": 301,
		"mtime":    302,
		"ctime":    303,
	}

	got := map[string]protoreflect.FieldNumber{}

	fields := (&mfer.MFFilePath{}).ProtoReflect().Descriptor().Fields()
	for i := range fields.Len() {
		got[string(fields.Get(i).Name())] = fields.Get(i).Number()
	}

	require.Equal(t, want, got)
}