From 54034e1d72ffc39da45c1ce25eeca20cb250fa07 Mon Sep 17 00:00:00 2001
From: Alexander Plutov <pliutau.aliaksandr@lazada.com>
Date: Thu, 15 Oct 2015 12:43:50 +0700
Subject: [PATCH] GetAccessToken

---
 README.md        |  1 +
 client.go        | 86 ++++++++++++++++++++++++++++++++++++++++++++++++
 examples/main.go | 10 +++++-
 paypal.go        | 16 ---------
 types.go         | 22 +++++++++++++
 5 files changed, 118 insertions(+), 17 deletions(-)
 create mode 100644 README.md
 create mode 100644 client.go
 delete mode 100644 paypal.go

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..35974fb
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+PayPal REST API
diff --git a/client.go b/client.go
new file mode 100644
index 0000000..b523f06
--- /dev/null
+++ b/client.go
@@ -0,0 +1,86 @@
+package paypalsdk
+
+import (
+    "encoding/json"
+    "io/ioutil"
+    "net/http"
+    "bytes"
+    "time"
+    "fmt"
+    "io"
+)
+
+// NewClient returns new Client struct
+func NewClient(clientID string, secret string, APIBase string) (*Client, error) {
+    return &Client{
+        &http.Client{},
+        clientID,
+        secret,
+        APIBase,
+        nil,
+    }, nil
+}
+
+// GetAcessToken request a new access token from Paypal
+func (c *Client) GetAccessToken() (*TokenResponse, error) {
+    buf := bytes.NewBuffer([]byte("grant_type=client_credentials"))
+    req, err := http.NewRequest("POST", fmt.Sprintf("%s%s", c.APIBase, "/oauth2/token"), buf)
+    if err != nil {
+        return nil, err
+    }
+
+    req.SetBasicAuth(c.ClientID, c.Secret)
+    req.Header.Set("Content-type", "application/x-www-form-urlencoded")
+
+    t := TokenResponse{}
+    err = c.Send(req, &t)
+    if err == nil {
+        t.ExpiresAt = time.Now().Add(time.Duration(t.ExpiresIn/2) * time.Second)
+    }
+
+    return &t, err
+}
+
+// Send makes a request to the API, the response body will be
+// unmarshaled into v, or if v is an io.Writer, the response will
+// be written to it without decoding
+func (c *Client) Send(req *http.Request, v interface{}) error {
+    // Set default headers
+    req.Header.Set("Accept", "application/json")
+    req.Header.Set("Accept-Language", "en_US")
+
+    // Default values for headers
+    if req.Header.Get("Content-type") == "" {
+        req.Header.Set("Content-type", "application/json")
+    }
+
+    resp, err := c.client.Do(req)
+    if err != nil {
+        return err
+    }
+    defer resp.Body.Close()
+
+    if resp.StatusCode < 200 || resp.StatusCode > 299 {
+        errResp := &ErrorResponse{Response: resp}
+        data, err := ioutil.ReadAll(resp.Body)
+
+        if err == nil && len(data) > 0 {
+            json.Unmarshal(data, errResp)
+        }
+
+        return errResp
+    }
+
+    if v != nil {
+        if w, ok := v.(io.Writer); ok {
+            io.Copy(w, resp.Body)
+        } else {
+            err = json.NewDecoder(resp.Body).Decode(v)
+            if err != nil {
+                return err
+            }
+        }
+    }
+
+    return nil
+}
diff --git a/examples/main.go b/examples/main.go
index 1749a4b..932e754 100644
--- a/examples/main.go
+++ b/examples/main.go
@@ -8,11 +8,19 @@ import (
 )
 
 func main() {
-    client, err := paypalsdk.NewClient("123", "123", paypalsdk.APIBaseSandBox)
+    client, err := paypalsdk.NewClient("AZgwu4yt5Ba0gyTu1dGBH3txHCJbMuFNvrmQxBaQbfDncDiCs6W_rwJD8Ir-0pZrN-_eq7n9zVd8Y-5f", "EBzA1wRl5t73OMugOieDj_tI3vihfJmGl47ukQT-cpctooIzDu0K7IPESNC0cKodlLSOXzwI8qXSM0rd", paypalsdk.APIBaseSandBox)
     if err == nil {
         fmt.Println("DEBUG: ClientID=" + client.ClientID + " APIBase=" + client.APIBase)
     } else {
         fmt.Println("ERROR: " + err.Error())
         os.Exit(1)
     }
+
+    token, err := client.GetAccessToken()
+    if err == nil {
+        fmt.Println("DEBUG: Access token=" + token.Token)
+    } else {
+        fmt.Println("ERROR: " + err.Error())
+        os.Exit(1)
+    }
 }
diff --git a/paypal.go b/paypal.go
deleted file mode 100644
index f36ecec..0000000
--- a/paypal.go
+++ /dev/null
@@ -1,16 +0,0 @@
-package paypalsdk
-
-import (
-    "net/http"
-)
-
-// NewClient returns new Client struct
-func NewClient(clientID string, secret string, APIBase string) (*Client, error) {
-    return &Client{
-        &http.Client{},
-        clientID,
-        secret,
-        APIBase,
-        nil,
-    }, nil
-}
diff --git a/types.go b/types.go
index b67d3d0..e0d04d8 100644
--- a/types.go
+++ b/types.go
@@ -3,6 +3,7 @@ package paypalsdk
 import (
     "net/http"
     "time"
+    "fmt"
 )
 
 const (
@@ -32,4 +33,25 @@ type (
         ExpiresIn int       `json:"expires_in"`   // 28800
         ExpiresAt time.Time `json:"expires_at"`
     }
+
+    // ErrorResponse is used when a response has errors
+    ErrorResponse struct {
+        Response        *http.Response `json:"-"`
+        Name            string        `json:"name"`
+        DebugID         string        `json:"debug_id"`
+        Message         string        `json:"message"`
+        InformationLink string        `json:"information_link"`
+        Details         []ErrorDetail `json:"details"`
+    }
+
+    // ErrorDetails map to error_details object
+    ErrorDetail struct {
+        Field string `json:"field"`
+        Issue string `json:"issue"`
+    }
 )
+
+// Error method implementation for ErrorResponse struct
+func (r *ErrorResponse) Error() string {
+    return fmt.Sprintf("%v %v: %d %v\nDetails: %v", r.Response.Request.Method, r.Response.Request.URL, r.Response.StatusCode, r.Message, r.Details)
+}