Improve friend add queries. Merge #55

### Added

- Optionally allow JSON encoding in user login/register operations and responses.

### Changed

- Improve user email storage and comparison.

- Allow group batch fetch by both ID and name.

### Fixed

- Fix Facebook unlink operation.

## [0.12.0] - 2017-03-19

### Added

- Dynamic leaderboards feature.

message TGroupsSelfList {}

message TGroupsFetch {

  message GroupIds {

    repeated bytes group_ids = 1;

  }

  message Names {

    repeated string names = 1;

  }

  oneof set {

    GroupIds group_ids = 1;

    Names names = 2;

  }

}

message TGroupsList {

  int64 page_limit = 1;

  bool order_by_asc = 2;

	logger := l.With(zap.String("friend_id", friendID.String()))

	friendIDBytes := friendID.Bytes()

	if friendID.String() == session.userID.String() {

	if friendID == session.userID {

		logger.Warn("Cannot add self", zap.Error(err))

		session.Send(ErrorMessageBadInput(envelope.CollationId, "Cannot add self"))

		return

	}()

	updatedAt := nowMs()

	res, err := tx.Exec("UPDATE user_edge SET state = 0, updated_at = $3 WHERE source_id = $1 AND destination_id = $2 AND state = 2", friendIDBytes, session.userID.Bytes(), updatedAt)

	// Mark an invite as accepted, if one was in place.

	res, err := tx.Exec(`

UPDATE user_edge SET state = 0, updated_at = $3

WHERE (source_id = $1 AND destination_id = $2 AND state = 2)

OR (source_id = $2 AND destination_id = $1 AND state = 1)

  `, friendIDBytes, session.userID.Bytes(), updatedAt)

	if err != nil {

		return

	}

	state := 2

	rowsAffected, _ := res.RowsAffected()

	if rowsAffected == 1 {

		state = 0

	// If both edges were updated, it was accepting an invite was successful.

	if rowsAffected, _ := res.RowsAffected(); rowsAffected == 2 {

		return

	}

	// If no edge updates took place, it's a new invite being set up.

	res, err = tx.Exec(`

INSERT INTO user_edge (source_id, destination_id, state, position, updated_at)

SELECT $1, $2, $3, $4, $4

WHERE EXISTS (SELECT id FROM users WHERE id=$2)

	`, session.userID.Bytes(), friendIDBytes, state, updatedAt)

SELECT source_id, destination_id, state, position, updated_at

FROM (VALUES

  ($1::BYTEA, $2::BYTEA, 2, $3::BIGINT, $3::BIGINT),

  ($2::BYTEA, $1::BYTEA, 1, $3::BIGINT, $3::BIGINT)

) AS ue(source_id, destination_id, state, position, updated_at)

WHERE EXISTS (SELECT id FROM users WHERE id = $2::BYTEA)

	`, session.userID.Bytes(), friendIDBytes, updatedAt)

	if err != nil {

		return

	}

	rowsAffected, _ = res.RowsAffected()

	if rowsAffected == 0 {

		err = errors.New("did not find friend ID in users table")

	// An invite was successfully added if both components were inserted.

	if rowsAffected, _ := res.RowsAffected(); rowsAffected != 2 {

		err = errors.New("user ID not found or unavailable")

		return

	}

	if state == 2 {

		_, err = tx.Exec("INSERT INTO user_edge (source_id, destination_id, state, position, updated_at) VALUES ($1, $2, $3, $4, $4)",

			friendIDBytes, session.userID.Bytes(), 1, updatedAt)

	// Update the user edge metadata counts.

	res, err = tx.Exec(`

UPDATE user_edge_metadata

SET count = count + 1, updated_at = $1

WHERE source_id = $2

OR source_id = $3`,

		updatedAt, session.userID.Bytes(), friendIDBytes)

	if err != nil {

		return

	}

		_, err = tx.Exec("UPDATE user_edge_metadata SET count = count + 1, updated_at = $1 WHERE source_id = $2", updatedAt, friendIDBytes)

		if err != nil {

	if rowsAffected, _ := res.RowsAffected(); rowsAffected != 2 {

		err = errors.New("could not update user friend counts")

		return

	}

}

	_, err = tx.Exec("UPDATE user_edge_metadata SET count = count + 1, updated_at = $1 WHERE source_id = $2", updatedAt, session.userID.Bytes())

}

func (p *pipeline) friendRemove(l zap.Logger, session *session, envelope *Envelope) {

	removeFriendRequest := envelope.GetFriendRemove()

	if len(removeFriendRequest.UserId) == 0 {

	logger := l.With(zap.String("friend_id", friendID.String()))

	friendIDBytes := friendID.Bytes()

	if friendID.String() == session.userID.String() {

	if friendID == session.userID {

		logger.Warn("Cannot remove self", zap.Error(err))

		session.Send(ErrorMessageBadInput(envelope.CollationId, "Cannot remove self"))

		return

	logger := l.With(zap.String("user_id", userID.String()))

	userIDBytes := userID.Bytes()

	if userID.String() == session.userID.String() {

	if userID == session.userID {

		logger.Warn("Cannot block self", zap.Error(err))

		session.Send(ErrorMessageBadInput(envelope.CollationId, "Cannot block self"))

		return

func (p *pipeline) groupsFetch(logger zap.Logger, session *session, envelope *Envelope) {

	g := envelope.GetGroupsFetch()

	validGroupIds := make([]interface{}, 0)

	statements := make([]string, 0)

	statements := []string{}

	params := []interface{}{}

	for _, gid := range g.GroupIds {

	switch g.Set.(type) {

	case *TGroupsFetch_GroupIds_:

		for _, gid := range g.GetGroupIds().GroupIds {

			groupID, err := uuid.FromBytes(gid)

			if err != nil {

			logger.Warn("Could not get group")

		} else {

			validGroupIds = append(validGroupIds, groupID.Bytes())

			statements = append(statements, "id = $"+strconv.Itoa(len(validGroupIds)))

				params = append(params, groupID.Bytes())

				statements = append(statements, "id = $"+strconv.Itoa(len(params)))

			}

		}

	case *TGroupsFetch_Names_:

		for _, name := range g.GetNames().Names {

			params = append(params, name)

			statements = append(statements, "name = $"+strconv.Itoa(len(params)))

		}

	case nil:

		session.Send(ErrorMessageBadInput(envelope.CollationId, "A fetch set is required"))

		return

	default:

		session.Send(ErrorMessageBadInput(envelope.CollationId, "Unknown fetch set"))

		return

	}

	if len(statements) == 0 {

		session.Send(ErrorMessageBadInput(envelope.CollationId, "One or more fetch set values are required"))

		return

	}

	rows, err := p.db.Query(

		`SELECT id, creator_id, name, description, avatar_url, lang, utc_offset_ms, metadata, state, count, created_at, updated_at

FROM groups WHERE disabled_at = 0 AND ( `+strings.Join(statements, " OR ")+" )",

		validGroupIds...)

		params...)

	if err != nil {

		logger.Error("Could not get groups", zap.Error(err))

		session.Send(ErrorMessageRuntimeException(envelope.CollationId, "Could not get groups"))

		return

	}

	if userID.String() == session.userID.String() {

	if userID == session.userID {

		session.Send(ErrorMessageBadInput(envelope.CollationId, "You can't kick yourself from the group"))

		return

	}

		return

	}

	if userID.String() == session.userID.String() {

	if userID == session.userID {

		session.Send(ErrorMessageBadInput(envelope.CollationId, "You can't promote yourself"))

		return

	}

	"github.com/uber-go/zap"

	"golang.org/x/crypto/bcrypt"

	"strings"

)

func (p *pipeline) linkID(logger zap.Logger, session *session, envelope *Envelope) {

     FROM users

     WHERE email = $2)`,

		session.userID.Bytes(),

		email.Email,

		strings.ToLower(email.Email),

		hashedPassword,

		nowMs())

	case *TUnlink_Facebook:

		query = `UPDATE users SET facebook_id = NULL, updated_at = $3

WHERE id = $1

AND custom_id = $2

AND facebook_id = $2

AND ((google_id IS NOT NULL

      OR gamecenter_id IS NOT NULL

      OR steam_id IS NOT NULL

	case *TUnlink_Google:

		query = `UPDATE users SET google_id = NULL, updated_at = $3

WHERE id = $1

AND custom_id = $2

AND google_id = $2

AND ((facebook_id IS NOT NULL

      OR gamecenter_id IS NOT NULL

      OR steam_id IS NOT NULL

	case *TUnlink_GameCenter:

		query = `UPDATE users SET gamecenter_id = NULL, updated_at = $3

WHERE id = $1

AND custom_id = $2

AND gamecenter_id = $2

AND ((facebook_id IS NOT NULL

      OR google_id IS NOT NULL

      OR steam_id IS NOT NULL

	case *TUnlink_Steam:

		query = `UPDATE users SET steam_id = NULL, updated_at = $3

WHERE id = $1

AND custom_id = $2

AND steam_id = $2

AND ((facebook_id IS NOT NULL

      OR google_id IS NOT NULL

      OR gamecenter_id IS NOT NULL

	case *TUnlink_Email:

		query = `UPDATE users SET email = NULL, password = NULL, updated_at = $3

WHERE id = $1

AND custom_id = $2

AND email = $2

AND ((facebook_id IS NOT NULL

      OR google_id IS NOT NULL

      OR gamecenter_id IS NOT NULL

      OR custom_id IS NOT NULL)

     OR

     EXISTS (SELECT id FROM user_device WHERE user_id = $1 LIMIT 1))`

		param = envelope.GetUnlink().GetEmail()

		param = strings.ToLower(envelope.GetUnlink().GetEmail())

	case *TUnlink_Custom:

		query = `UPDATE users SET custom_id = NULL, updated_at = $3

WHERE id = $1