status-im/status-go

package subscriptions

import (
    "fmt"

    "github.com/status-im/status-go/rpc"
)

type whisperFilter struct {
    id        string
    rpcClient *rpc.Client
}

func installShhFilter(rpcClient *rpc.Client, method string, args []interface{}) (*whisperFilter, error) {

    if err := validateShhMethod(method); err != nil {
        return nil, err
    }

    var result string

    err := rpcClient.Call(&result, rpcClient.UpstreamChainID, method, args...)

    if err != nil {
        return nil, err
    }

    filter := &whisperFilter{
        id:        result,
        rpcClient: rpcClient,
    }

    return filter, nil
}

func (wf *whisperFilter) getChanges() ([]interface{}, error) {
    var result []interface{}

    err := wf.rpcClient.Call(&result, wf.rpcClient.UpstreamChainID, "shh_getFilterMessages", wf.getID())

    return result, err
}

func (wf *whisperFilter) getID() string {
    return wf.id
}

func (wf *whisperFilter) uninstall() error {
    return wf.rpcClient.Call(nil, wf.rpcClient.UpstreamChainID, "shh_deleteMessageFilter", wf.getID())
}

func validateShhMethod(method string) error {
    if method != "shh_newMessageFilter" {
        return fmt.Errorf("unexpected filter method: %s", method)
    }
    return nil
}