From e284861539cec6f3a0ad30d2295cd76d33c2d265 Mon Sep 17 00:00:00 2001
From: Alexander Zhuravlev <a.zhuravlev@ekomobile.ru>
Date: Tue, 14 May 2024 23:23:03 +0300
Subject: [PATCH] Raw encoder.

---
 README.md                      | 25 ++++++++++++++++
 client/client.go               |  2 +-
 client/client_test.go          | 25 ++++++++++++++++
 client/transport/encoder/rw.go | 54 ++++++++++++++++++++++++++++++++++
 dadata_test.go                 | 25 ++++++++++++++++
 5 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 client/transport/encoder/rw.go

diff --git a/README.md b/README.md
index c39f695..4be0ef7 100644
--- a/README.md
+++ b/README.md
@@ -75,6 +75,31 @@ httpClient := &http.Client{}
 api := NewSuggestApi(WithHttpClient(httpClient))
 ```
 
+### Low level client usage
+
+Pass and consume raw bytes/strings:
+
+```go
+    endpointUrl, err := url.Parse("https://suggestions.dadata.ru/suggestions/api/4_1/rs/")
+    if err != nil {
+        return
+    }
+
+    cli := client.NewClient(endpointUrl,
+        client.WithEncoderFactory(encoder.RawEncoderFactory()),
+        client.WithDecoderFactory(encoder.RawDecoderFactory()),     
+    )
+
+    request := bytes.NewBufferString("{ \"query\": \"москва хабар\" }")
+    response := &bytes.Buffer{}
+
+    err = cli.Post(context.Background(), "suggest/address", request, response)
+    if err != nil {
+        return
+    }
+
+    fmt.Print(response.String()) // Output: `{"suggestions":[{"value":"г Москва, ул Хабаровская",...`
+```
 
 ## Licence
 MIT see [LICENSE](LICENSE)
diff --git a/client/client.go b/client/client.go
index 26d34c0..4765163 100644
--- a/client/client.go
+++ b/client/client.go
@@ -94,7 +94,7 @@ func (c *Client) doRequest(ctx context.Context, method string, url *url.URL, bod
 		)
 	}
 
-	if err = c.options.decoderFactory(response.Body)(&result); err != nil {
+	if err = c.options.decoderFactory(response.Body)(result); err != nil {
 		return fmt.Errorf("doRequest: response body decode err: %w", err)
 	}
 
diff --git a/client/client_test.go b/client/client_test.go
index 22595c2..b0757c9 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -1,6 +1,7 @@
 package client
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -9,6 +10,7 @@ import (
 
 	"github.com/ekomobile/dadata/v2/api/suggest"
 	"github.com/ekomobile/dadata/v2/client/transport"
+	"github.com/ekomobile/dadata/v2/client/transport/encoder"
 )
 
 func ExampleNewClient() {
@@ -108,3 +110,26 @@ func ExampleWithEncoderFactory() {
 		fmt.Printf("%s", s.Value)
 	}
 }
+
+func ExampleClient_low_level() {
+	var err error
+	endpointUrl, err := url.Parse("https://suggestions.dadata.ru/suggestions/api/4_1/rs/")
+	if err != nil {
+		return
+	}
+
+	cli := NewClient(endpointUrl,
+		WithEncoderFactory(encoder.RawEncoderFactory()),
+		WithDecoderFactory(encoder.RawDecoderFactory()),
+	)
+
+	request := bytes.NewBufferString("{ \"query\": \"москва хабар\" }")
+	response := &bytes.Buffer{}
+
+	err = cli.Post(context.Background(), "suggest/address", request, response)
+	if err != nil {
+		return
+	}
+
+	fmt.Print(response.String())
+}
diff --git a/client/transport/encoder/rw.go b/client/transport/encoder/rw.go
new file mode 100644
index 0000000..4fe9669
--- /dev/null
+++ b/client/transport/encoder/rw.go
@@ -0,0 +1,54 @@
+package encoder
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/ekomobile/dadata/v2/client/transport"
+)
+
+// RawEncoderFactory is a factory for noop-encoder that just writes to transport io.Writer.
+func RawEncoderFactory() transport.EncoderFactory {
+	return func(w io.Writer) transport.Encoder {
+		return func(v interface{}) (err error) {
+			switch value := v.(type) {
+			case *string:
+				_, err = w.Write([]byte(*value))
+			case string:
+				_, err = w.Write([]byte(value))
+			case *[]byte:
+				_, err = w.Write(*value)
+			case []byte:
+				_, err = w.Write(value)
+			case io.Reader:
+				_, err = io.Copy(w, value)
+			case io.WriterTo:
+				_, err = value.WriteTo(w)
+			default:
+				err = fmt.Errorf("can not encode from value: %#v", v)
+			}
+			return err
+		}
+	}
+}
+
+// RawDecoderFactory is a factory for noop-decoder that just reads from transport io.Reader.
+func RawDecoderFactory() transport.DecoderFactory {
+	return func(r io.Reader) transport.Decoder {
+		return func(v interface{}) (err error) {
+			switch value := v.(type) {
+			case *[]byte:
+				_, err = r.Read(*value)
+			case []byte:
+				_, err = r.Read(value)
+			case io.Writer:
+				_, err = io.Copy(value, r)
+			case io.ReaderFrom:
+				_, err = value.ReadFrom(r)
+			default:
+				err = fmt.Errorf("can not decode into value: %#v", v)
+			}
+			return err
+		}
+	}
+}
diff --git a/dadata_test.go b/dadata_test.go
index 5c08a94..e76d937 100644
--- a/dadata_test.go
+++ b/dadata_test.go
@@ -3,11 +3,15 @@
 package dadata
 
 import (
+	"bytes"
 	"context"
 	"fmt"
+	"net/url"
 	"os"
 	"testing"
 
+	"github.com/ekomobile/dadata/v2/client"
+	"github.com/ekomobile/dadata/v2/client/transport/encoder"
 	"github.com/stretchr/testify/suite"
 
 	"github.com/ekomobile/dadata/v2/api/suggest"
@@ -53,6 +57,27 @@ func (s *ApiSuggestIntegrationTest) TestAddress() {
 	s.NotEmpty(res)
 }
 
+func (s *ApiSuggestIntegrationTest) TestAddress_low_level() {
+	var err error
+	endpointUrl, err := url.Parse(EndpointURLSuggest)
+	if err != nil {
+		return
+	}
+
+	cli := client.NewClient(endpointUrl,
+		client.WithEncoderFactory(encoder.RawEncoderFactory()),
+		client.WithDecoderFactory(encoder.RawDecoderFactory()),
+	)
+
+	request := bytes.NewBufferString("{ \"query\": \"москва хабар\" }")
+	response := &bytes.Buffer{}
+
+	err = cli.Post(context.Background(), "suggest/address", request, response)
+
+	s.NoError(err)
+	s.NotEmpty(response.String())
+}
+
 func (s *ApiSuggestIntegrationTest) TestAddressWithLanguageParamRU() {
 	api := NewSuggestApi()