diff --git a/README.md b/README.md index 7ce6b0e..b280553 100644 --- a/README.md +++ b/README.md @@ -1,7 +1,20 @@ # Go - + Some of my projects developed with Golang - -### Colours - - Prende in input da linea di comando un'immagine png/jpeg e, dopo un'analisi pixel per pixel ritorna gli n colori piĆ¹ usati \ No newline at end of file + I use this repository to track my growth + +### **colours** Colours +#### Necessary setup + No additional packages required +#### Short Workflow Description + Accepts an image as parameter (png or jpeg), and gives back the most frequent colours +#### Short Algorithm Description + Executes a pixel by pixel scan of the image, uses a hash function to speed up the process + +### **mailsender** GMail Api Integration with Mail Sending Example +#### Necessary setup + Follow [this](https://developers.google.com/gmail/api/quickstart/go "GMail Api") Google quickstart to setup your mail +#### Short Workflow Description + Uses the specified (sender) account to send a mail to the specified (receiver) account. Needs to be authorized! +#### Short Algorithm Description + Search for client_secret.json file, request a token to the google mail api and then send the mail \ No newline at end of file diff --git a/mailsender.go b/mailsender.go new file mode 100644 index 0000000..b000e25 --- /dev/null +++ b/mailsender.go @@ -0,0 +1,140 @@ +package main + +import ( + "encoding/json" + "fmt" + "io/ioutil" + "log" + "net/http" + "net/url" + "os" + "os/user" + "path/filepath" + "golang.org/x/net/context" + "golang.org/x/oauth2" + "golang.org/x/oauth2/google" + "google.golang.org/api/gmail/v1" + "encoding/base64" +) + +// getClient uses a Context and Config to retrieve a Token +// then generate a Client. It returns the generated Client. +func getClient(ctx context.Context, config *oauth2.Config) *http.Client { + cacheFile, err := tokenCacheFile() + if err != nil { + log.Fatalf("Unable to get path to cached credential file. %v", err) + } + tok, err := tokenFromFile(cacheFile) + if err != nil { + tok = getTokenFromWeb(config) + saveToken(cacheFile, tok) + } + return config.Client(ctx, tok) +} + +// getTokenFromWeb uses Config to request a Token. +// It returns the retrieved Token. +func getTokenFromWeb(config *oauth2.Config) *oauth2.Token { + authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline) + fmt.Printf("Go to the following link in your browser then type the " + + "authorization code: \n%v\n", authURL) + + var code string + if _, err := fmt.Scan(&code); err != nil { + log.Fatalf("Unable to read authorization code %v", err) + } + + tok, err := config.Exchange(oauth2.NoContext, code) + if err != nil { + log.Fatalf("Unable to retrieve token from web %v", err) + } + return tok +} + +// tokenCacheFile generates credential file path/filename. +// It returns the generated credential path/filename. +func tokenCacheFile() (string, error) { + usr, err := user.Current() + if err != nil { + return "", err + } + tokenCacheDir := filepath.Join(usr.HomeDir, ".credentials") + os.MkdirAll(tokenCacheDir, 0700) + return filepath.Join(tokenCacheDir, + url.QueryEscape("gmail-go-quickstart.json")), err +} + +// tokenFromFile retrieves a Token from a given file path. +// It returns the retrieved Token and any read error encountered. +func tokenFromFile(file string) (*oauth2.Token, error) { + f, err := os.Open(file) + if err != nil { + return nil, err + } + t := &oauth2.Token{} + err = json.NewDecoder(f).Decode(t) + defer f.Close() + return t, err +} + +// saveToken uses a file path to create a file and store the +// token in it. +func saveToken(file string, token *oauth2.Token) { + fmt.Printf("Saving credential file to: %s\n", file) + f, err := os.OpenFile(file, os.O_RDWR | os.O_CREATE | os.O_TRUNC, 0600) + if err != nil { + log.Fatalf("Unable to cache oauth token: %v", err) + } + defer f.Close() + json.NewEncoder(f).Encode(token) +} + +// --- MAIN --- + +func main() { + ctx := context.Background() + + b, err := ioutil.ReadFile("client_secret.json") + if err != nil { + log.Fatalf("Unable to read client secret file: %v", err) + } + + // If modifying these scopes, delete your previously saved credentials + // at ~/.credentials/gmail-go-quickstart.json + config, err := google.ConfigFromJSON(b, gmail.GmailSendScope) + if err != nil { + log.Fatalf("Unable to parse client secret file to config: %v", err) + } + client := getClient(ctx, config) + + srv, err := gmail.New(client) + if err != nil { + log.Fatalf("Unable to retrieve gmail Client %v", err) + } + + // New message for our gmail service to send + var message gmail.Message + + sender := "sender@gmail.com" + reciever := "receiver@gmail.com" + subject := "Sample Subject" + msg := "Sample Message" + + // Compose the message + messageStr := []byte( + "From: " + sender + "\r\n" + + "To: " + reciever + "\r\n" + + "Subject: " + subject + "\r\n\r\n" + + msg) + + // Place messageStr into message.Raw in base64 encoded format + message.Raw = base64.URLEncoding.EncodeToString(messageStr) + + // Send the message + _, err = srv.Users.Messages.Send("me", &message).Do() + if err != nil { + log.Printf("Error: %v", err) + } else { + fmt.Println("Message sent!") + } +} \ No newline at end of file