Move all backends into backend directory

backend/yandex/api/client.go

@@ -0,0 +1,135 @@
+package src
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+//Client struct
+type Client struct {
+	token      string
+	basePath   string
+	HTTPClient *http.Client
+}
+
+//NewClient creates new client
+func NewClient(token string, client ...*http.Client) *Client {
+	return newClientInternal(
+		token,
+		"https://cloud-api.yandex.com/v1/disk", //also "https://cloud-api.yandex.net/v1/disk" "https://cloud-api.yandex.ru/v1/disk"
+		client...)
+}
+
+func newClientInternal(token string, basePath string, client ...*http.Client) *Client {
+	c := &Client{
+		token:    token,
+		basePath: basePath,
+	}
+	if len(client) != 0 {
+		c.HTTPClient = client[0]
+	} else {
+		c.HTTPClient = http.DefaultClient
+	}
+	return c
+}
+
+//ErrorHandler type
+type ErrorHandler func(*http.Response) error
+
+var defaultErrorHandler ErrorHandler = func(resp *http.Response) error {
+	if resp.StatusCode/100 == 5 {
+		return errors.New("server error")
+	}
+
+	if resp.StatusCode/100 == 4 {
+		var response DiskClientError
+		contents, _ := ioutil.ReadAll(resp.Body)
+		err := json.Unmarshal(contents, &response)
+		if err != nil {
+			return err
+		}
+		return response
+	}
+
+	if resp.StatusCode/100 == 3 {
+		return errors.New("redirect error")
+	}
+	return nil
+}
+
+func (HTTPRequest *HTTPRequest) run(client *Client) ([]byte, error) {
+	var err error
+	values := make(url.Values)
+	if HTTPRequest.Parameters != nil {
+		for k, v := range HTTPRequest.Parameters {
+			values.Set(k, fmt.Sprintf("%v", v))
+		}
+	}
+
+	var req *http.Request
+	if HTTPRequest.Method == "POST" {
+		// TODO json serialize
+		req, err = http.NewRequest(
+			"POST",
+			client.basePath+HTTPRequest.Path,
+			strings.NewReader(values.Encode()))
+		if err != nil {
+			return nil, err
+		}
+		// TODO
+		// req.Header.Set("Content-Type", "application/json")
+	} else {
+		req, err = http.NewRequest(
+			HTTPRequest.Method,
+			client.basePath+HTTPRequest.Path+"?"+values.Encode(),
+			nil)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	for headerName := range HTTPRequest.Headers {
+		var headerValues = HTTPRequest.Headers[headerName]
+		for _, headerValue := range headerValues {
+			req.Header.Set(headerName, headerValue)
+		}
+	}
+	return runRequest(client, req)
+}
+
+func runRequest(client *Client, req *http.Request) ([]byte, error) {
+	return runRequestWithErrorHandler(client, req, defaultErrorHandler)
+}
+
+func runRequestWithErrorHandler(client *Client, req *http.Request, errorHandler ErrorHandler) (out []byte, err error) {
+	resp, err := client.HTTPClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer CheckClose(resp.Body, &err)
+
+	return checkResponseForErrorsWithErrorHandler(resp, errorHandler)
+}
+
+func checkResponseForErrorsWithErrorHandler(resp *http.Response, errorHandler ErrorHandler) ([]byte, error) {
+	if resp.StatusCode/100 > 2 {
+		return nil, errorHandler(resp)
+	}
+	return ioutil.ReadAll(resp.Body)
+}
+
+// CheckClose is a utility function used to check the return from
+// Close in a defer statement.
+func CheckClose(c io.Closer, err *error) {
+	cerr := c.Close()
+	if *err == nil {
+		*err = cerr
+	}
+}