initial commit

vendor/github.com/sendgrid/sendgrid-go/sendgrid.go

@@ -0,0 +1,127 @@
+// Package sendgrid provides a simple interface to interact with the SendGrid API
+package sendgrid
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/sendgrid/rest" // depends on version 2.2.0
+	"github.com/sendgrid/sendgrid-go/helpers/mail"
+)
+
+// Version is this client library's current version
+const (
+	Version        = "3.1.0"
+	rateLimitRetry = 5
+	rateLimitSleep = 1100
+)
+
+// Client is the SendGrid Go client
+type Client struct {
+	// rest.Request
+	rest.Request
+}
+
+// GetRequest returns a default request object.
+func GetRequest(key string, endpoint string, host string) rest.Request {
+	if host == "" {
+		host = "https://api.sendgrid.com"
+	}
+	baseURL := host + endpoint
+	requestHeaders := map[string]string{
+		"Authorization": "Bearer " + key,
+		"User-Agent": "sendgrid/" + Version + ";go",
+		"Accept": "application/json",
+	}
+	request := rest.Request{
+		BaseURL: baseURL,
+		Headers: requestHeaders,
+	}
+	return request
+}
+
+// Send sends an email through SendGrid
+func (cl *Client) Send(email *mail.SGMailV3) (*rest.Response, error) {
+	cl.Body = mail.GetRequestBody(email)
+	return API(cl.Request)
+}
+
+// NewSendClient constructs a new SendGrid client given an API key
+func NewSendClient(key string) *Client {
+	request := GetRequest(key, "/v3/mail/send", "")
+	request.Method = "POST"
+	return &Client{request}
+}
+
+// DefaultClient is used if no custom HTTP client is defined
+var DefaultClient = rest.DefaultClient
+
+// API sets up the request to the SendGrid API, this is main interface.
+// This function is deprecated. Please use the MakeRequest or
+// MakeRequestAsync functions.
+func API(request rest.Request) (*rest.Response, error) {
+	return DefaultClient.API(request)
+}
+
+// MakeRequest attemps a SendGrid request synchronously.
+func MakeRequest(request rest.Request) (*rest.Response, error) {
+	return DefaultClient.API(request)
+}
+
+// MakeRequestRetry a synchronous request, but retry in the event of a rate
+// limited response.
+func MakeRequestRetry(request rest.Request) (*rest.Response, error) {
+	retry := 0
+	var response *rest.Response
+	var err error
+
+	for {
+		response, err = DefaultClient.API(request)
+		if err != nil {
+			return nil, err
+		}
+
+		if response.StatusCode != http.StatusTooManyRequests {
+			return response, nil
+		}
+
+		if retry > rateLimitRetry {
+			return nil, errors.New("Rate limit retry exceeded")
+		}
+		retry++
+
+		resetTime := time.Now().Add(rateLimitSleep * time.Millisecond)
+
+		reset, ok := response.Headers["X-RateLimit-Reset"]
+		if ok && len(reset) > 0 {
+			t, err := strconv.Atoi(reset[0])
+			if err == nil {
+				resetTime = time.Unix(int64(t), 0)
+			}
+		}
+		time.Sleep(resetTime.Sub(time.Now()))
+	}
+}
+
+// MakeRequestAsync attempts a request asynchronously in a new go
+// routine. This function returns two channels: responses
+// and errors. This function will retry in the case of a
+// rate limit.
+func MakeRequestAsync(request rest.Request) (chan *rest.Response, chan error) {
+	r := make(chan *rest.Response)
+	e := make(chan error)
+
+	go func() {
+		response, err := MakeRequestRetry(request)
+		if err != nil {
+			e <- err
+		}
+		if response != nil {
+			r <- response
+		}
+	}()
+
+	return r, e
+}