1. 開始之前我們調整一下之前在adapter\google\oauth.go的OAuthLoginURL()，把原本寫死的第一個參數”state-token”改成外部代入的lineID，這個lineID可以在驗證完成後被帶到api/v1/ouath-login，也就是在處理Redirect URL時跟OAuth token一起取出。

   // internal\adapter\google\oauth.go
   func (oa *GoogleOAuth) OAuthLoginURL(lineID string) (oauthURL string) {
   	oauthURL = oa.Config.AuthCodeURL(lineID, oauth2.AccessTypeOffline, oauth2.ApprovalForce) // oauth2.ApprovalForce
   	return oauthURL
   }
   

2. adapter的interface也要記得更新

   // internal\adapter\google\interface.go
   type GoogleOAuthI interface {
   	OAuthLoginURL(lineID string) (oauthURL string)
   	UserOAuthToken(authCode string) (*oauth2.Token, error)
   	NewGoogleDrive(ctx context.Context, tok *oauth2.Token) (*GoogleDrive, error)
   }
   

3. 接著到Service的interface.go，把OAuthLoginURL的地方換一下之後，為了要將OAuth Token存到Dynamodb中，我們得在drive Service中能調用Dynamodb，所以這邊做一個DriveServiceDynamodbI，放入要使用的方法。

   // internal\app\service\drive\interface.go
   package drive
   
   import (
   	"context"
   
   	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
   	"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
   	dynamodbAdapter "github.com/onepiece010938/Line2GoogleDriveBot/internal/adapter/dynamodb"
   	"github.com/onepiece010938/Line2GoogleDriveBot/internal/adapter/google"
   	"golang.org/x/oauth2"
   )
   
   type DriveServiceGoogleOAuthI interface {
   	OAuthLoginURL(lineID string) (oauthURL string)
   	UserOAuthToken(authCode string) (*oauth2.Token, error)
   	NewGoogleDrive(ctx context.Context, tok *oauth2.Token) (*google.GoogleDrive, error)
   }
   type DriveServiceDynamodbI interface {
   	GetGoogleOAuthToken(line_userid string) (dynamodbAdapter.GoogleOAuthToken, error)
   	CreateGoogleOAuthTable() (*types.TableDescription, error)
   	AddGoogleOAuthToken(tok dynamodbAdapter.GoogleOAuthToken) error
   	TxUpdateGoogleOAuthToken(tok dynamodbAdapter.GoogleOAuthToken) (*dynamodb.TransactWriteItemsOutput, error)
   }
   

4. 接著更新service.go，讓NewGoogleDriveService的時候能把Dynamodb放進GoogleDriveService中，讓GoogleDriveService能直接調用到Dynamodb

   // internal\app\service\drive\service.go
   package drive
   
   import "context"
   
   type GoogleDriveService struct {
   	driveServiceGoogleOA DriveServiceGoogleOAuthI
   	driveServiceDynamodb DriveServiceDynamodbI
   }
   
   type GoogleDriveServiceParam struct {
   	DriveServiceGoogleOA DriveServiceGoogleOAuthI
   	DriveServiceDynamodb DriveServiceDynamodbI
   }
   
   func NewGoogleDriveService(_ context.Context, param GoogleDriveServiceParam) *GoogleDriveService {
   	return &GoogleDriveService{
   		driveServiceGoogleOA: param.DriveServiceGoogleOA,
   		driveServiceDynamodb: param.DriveServiceDynamodb,
   	}
   }
   

5. 最後到application.go，新增DriveServiceDynamodb: dynamodb，注入到DriveService裡面

   // internal\app\application.go
   func NewApplication(ctx context.Context, dynamodb dynamodb.DynamodbI, oauth google.GoogleOAuthI, lineBotClient *linebot.Client) *Application {
   
   	app := &Application{
   		LineBotClient: lineBotClient,
   		SampleService: serviceSample.NewSampleService(ctx, serviceSample.SampleServiceParam{
   			SampleServiceDynamodb: dynamodb,
   		}),
   		DriveService: serviceDrive.NewGoogleDriveService(ctx, serviceDrive.GoogleDriveServiceParam{
   			DriveServiceGoogleOA: oauth,
   			DriveServiceDynamodb: dynamodb,
   		}),
   	}
   	return app
   }
   

6. 接著我們在drive service下面，建立一個login_service.go專門處理登入相關的操作。LoginURL將傳入的lineID代入state，生成對應的Redirect URL；Login會把從Redirect URL中解出的authCode和lineID，拿去取得OAuthToken後製作成dynamodb定義的格式，最後調用AddGoogleOAuthToken把製作好的token存進去。

   // internal\app\service\drive\login_service.go
   package drive
   
   import (
   	"context"
   
   	"github.com/onepiece010938/Line2GoogleDriveBot/internal/adapter/dynamodb"
   )
   
   func (dr *GoogleDriveService) Login(ctx context.Context, lineID string, authCode string) error {
   	tok, err := dr.driveServiceGoogleOA.UserOAuthToken(authCode)
   	if err != nil {
   		return err
   	}
   
   	dToken := dynamodb.GoogleOAuthToken{
   		PK:           lineID,
   		AccessToken:  tok.AccessToken,
   		TokenType:    tok.TokenType,
   		RefreshToken: tok.RefreshToken,
   		Expiry:       tok.Expiry.String(),
   	}
   
   	err = dr.driveServiceDynamodb.AddGoogleOAuthToken(dToken)
   	if err != nil {
   		return err
   	}
   
   	return nil
   }
   
   func (dr *GoogleDriveService) LoginURL(ctx context.Context, lineID string) string {
   	oauthURL := dr.driveServiceGoogleOA.OAuthLoginURL(lineID)
   	return oauthURL
   }
   
   

7. 最後我們回到router層把callback和OAuthLogin改成調用app中對應的service

   // internal\router\api\v1\callback.go
   for _, event := range events {
   			if event.Type == linebot.EventTypeMessage {
   				switch message := event.Message.(type) {
   				case *linebot.TextMessage:
   					if message.Text == "login" {
   						lineID := event.Source.UserID
   						authURL := app.DriveService.LoginURL(ctx, lineID)
   						if _, err = app.LineBotClient.ReplyMessage(event.ReplyToken, linebot.NewTextMessage(authURL)).Do(); err != nil {
   							log.Println(err)
   						}
   						return
   					}
   ...
   

   // internal\router\api\v1\oauth.go
   func OAuthLogin(app *app.Application) gin.HandlerFunc {
   	return func(c *gin.Context) {
   		authCode := c.Query("code")
   		lineID := c.Query("state") //get lineid
   		err := app.DriveService.Login(c.Request.Context(), lineID, authCode)
   		if err != nil {
   			log.Printf("Unable to retrieve DriveService.Login %v", err)
   			c.String(http.StatusInternalServerError, "Unable to retrieve DriveService.Login")
   			return
   		}
   		_, err = c.Writer.Write([]byte("<html><title>Login</title> <body> Authorized successfully, please close this window</body></html>"))
   		if err != nil {
   			log.Printf("Unable to write HTML: %v", err)
   		}
   	}
   }
   

8. 登入後打開Dynamodb admin，就可以看到成功存進去囉~

   
   

那今天我們就先寫到這邊，明天再見囉~