feat(ga): upgrade measurement protocol to GA4 from UA

Signed-off-by: Niladri Halder <niladri.halder26@gmail.com>

.gitignore

@@ -1 +1,2 @@
-example/tracker-id.txt
+example/tracker-id.txt
+**/.idea

README.md

@@ -2,58 +2,72 @@
 
 Track and monitor your Go programs for free with Google Analytics
 
-The `ga` package is essentially a Go wrapper around the [Google Analytics - Measurement Protocol](https://developers.google.com/analytics/devguides/collection/protocol/v1/reference)
-
-**Warning** This package is 95% generated from the [Parameter Reference](https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters) so it may contain bugs - please report them. GA allows "10 million hits per month per property" and will reject requests after that.
+The `ga` package is essentially a Go wrapper around the [Google Analytics - Measurement Protocol (Google Analytics 4)](https://developers.google.com/analytics/devguides/collection/protocol/ga4/reference?client_type=gtag)
 
 ### Install
 
 ```
-go get -v github.com/jpillora/go-ogle-analytics
+go get -v github.com/openebs/go-ogle-analytics
 ```
 
 ### API
 
-Create a new `client` and `Send()` a 'pageview', 'screenview', 'event', 'transaction', 'item', 'social', 'exception' or 'timing' event.
-
-#### http://godoc.org/github.com/jpillora/go-ogle-analytics
+Create a new `client` and `Send()` an 'event'.
 
 ### Quick Usage
 
-1. Log into GA and create a new property and note its Tracker ID
+1. Log into GA and create a new property and note its Measurement ID
 
-1. Create a `ga-test.go` file
+2. Create a `ga-test.go` file
 
 	``` go
 	package main
 
-	import "github.com/jpillora/go-ogle-analytics"
+	import (
+            gaClient "github.com/openebs/go-ogle-analytics/client"
+            gaEvent "github.com/openebs/go-ogle-analytics/event"
+	)
 
 	func main() {
-		client, err := ga.NewClient("UA-XXXXXXXX-Y")
-		if err != nil {
-			panic(err)
-		}
-
-		err = client.Send(ga.NewEvent("Foo", "Bar").Label("Bazz"))
-		if err != nil {
-			panic(err)
-		}
-
-		println("Event fired!")
-	}
+	    client, err := gaClient.NewMeasurementClient(
+                gaClient.WithApiSecret("yourApiSecret"),
+                gaClient.WithMeasurementId("G-yourMeasurementClient"),
+                gaClient.WithClientId("uniqueUserId-000000001"),
+	    )
+            if err != nil {
+                panic(err)
+            }
+
+            event, err := gaEvent.NewOpenebsEvent(
+                gaEvent.WithCategory("Foo"),
+                gaEvent.WithAction("Bar"),
+                gaEvent.WithLabel("Baz"),
+                gaEvent.WithValue(19072023),
+            )
+            if err != nil {
+                panic(err)
+            }
+
+            err = client.Send(event)
+            if err != nil {
+                panic(err)
+            }
+
+            println("Event fired!")
+ 	}
+
 	```
 
-1. In GA, go to Real-time > Events
+3. In GA, go to Report > Realtime
 
-1. Run `ga-test.go`
+4. Run `ga-test.go`
 
 	```
 	$ go run ga-test.go
 	Event fired!
 	```
 
-1. Watch as your event appears
+5. Watch as your event appears
 
 	![foo-ga](https://cloud.githubusercontent.com/assets/633843/5979585/023fc580-a8fd-11e4-803a-956610bcc2e2.png)
 

client/build.go

@@ -0,0 +1,87 @@
+package client
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"regexp"
+
+	"github.com/openebs/lib-csi/pkg/common/errors"
+)
+
+var measurementIDMatcher = regexp.MustCompile(`^G-[a-zA-Z0-9]+$`)
+
+type MeasurementClientOption func(*MeasurementClient) error
+
+type MeasurementClient struct {
+	HttpClient    *http.Client
+	apiSecret     string
+	measurementId string
+	clientId      string
+}
+
+func NewMeasurementClient(opts ...MeasurementClientOption) (*MeasurementClient, error) {
+	dialer := &net.Dialer{
+		Resolver: &net.Resolver{
+			PreferGo: true,
+			Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+				dialer := net.Dialer{}
+				return dialer.DialContext(ctx, network, "8.8.8.8:53")
+			},
+		},
+	}
+	c := &MeasurementClient{
+		HttpClient: &http.Client{
+			Transport: &http.Transport{
+				DialContext: dialer.DialContext,
+			},
+		},
+	}
+
+	var err error
+	for _, opt := range opts {
+		err = opt(c)
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to build MeasurementClient")
+		}
+	}
+
+	return c, nil
+}
+
+func WithApiSecret(secret string) MeasurementClientOption {
+	return func(s *MeasurementClient) error {
+		if len(secret) == 0 {
+			return errors.Errorf("failed to set api_secret: secret is an empty string")
+		}
+
+		s.apiSecret = secret
+		return nil
+	}
+}
+
+func WithMeasurementId(measurementId string) MeasurementClientOption {
+	return func(s *MeasurementClient) error {
+		if len(measurementId) == 0 {
+			return errors.Errorf("failed to set measurement_id: id is an empty string")
+		}
+
+		if !measurementIDMatcher.MatchString(measurementId) {
+			return errors.Errorf("Invalid measurement_id: %s", measurementId)
+		}
+
+		s.measurementId = measurementId
+		return nil
+	}
+}
+
+func WithClientId(clientId string) MeasurementClientOption {
+	return func(s *MeasurementClient) error {
+		if len(clientId) == 0 {
+			return errors.Errorf("failed to set client_id: id is an empty string")
+		}
+
+		s.clientId = clientId
+		return nil
+	}
+}

client/client.go

@@ -0,0 +1,61 @@
+package client
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/url"
+
+	"github.com/openebs/lib-csi/pkg/common/errors"
+
+	"github.com/openebs/go-ogle-analytics/event"
+	"github.com/openebs/go-ogle-analytics/payload"
+)
+
+func (c *MeasurementClient) Copy() *MeasurementClient {
+	cpy := *c
+	return &cpy
+}
+
+func (c *MeasurementClient) addFields(v url.Values) {
+	v.Add("api_secret", c.apiSecret)
+	v.Add("measurement_id", c.measurementId)
+}
+
+func (c *MeasurementClient) Send(event *event.OpenebsEvent) error {
+
+	client := c.Copy()
+
+	dataPayload, err := payload.NewPayload(
+		payload.WithClientId(client.clientId),
+		payload.WithOpenebsEvent(event),
+	)
+
+	if err != nil {
+		return err
+	}
+	jsonData, err := json.Marshal(dataPayload)
+	if err != nil {
+		return err
+	}
+
+	gaUrl := "https://www.google-analytics.com/mp/collect"
+
+	req, err := http.NewRequest("POST", gaUrl, bytes.NewReader(jsonData))
+	v := req.URL.Query()
+	client.addFields(v)
+	req.URL.RawQuery = v.Encode()
+
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.HttpClient.Do(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode/100 != 2 {
+		return errors.Errorf("Rejected by Google with code %d", resp.StatusCode)
+	}
+
+	return nil
+}