main.go

package main

import (
	"net/http"
	"fmt"
	"html/template"
	"log"
	"regexp"
	"database/sql"
	"github.com/mattn/go-sqlite3"
	"strings"
)

const DB_NAME  = "testersDB.sqlite"

var DB_DRIVER string

func init() {
	var err error
	sql.Register(DB_DRIVER, &sqlite3.SQLiteDriver{})
	if err = initDB(); err != nil {
		panic(err)
	}
}


func acceptEmail(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		http.Redirect(w, r, "/send", http.StatusMovedPermanently)
		return
	}

	r.ParseForm()
	email := r.Form["email"][0]
	if validateEmail(email) {
		if err := save(email); err != nil {
			http.Redirect(w, r, "/send", http.StatusMovedPermanently)
			panic(err)
		}
	}

	http.Redirect(w, r, "/send", http.StatusMovedPermanently)
}


func main() {
	http.HandleFunc("/", acceptEmail)
	http.HandleFunc("/send", sendEmail)
	if err := http.ListenAndServe(":8089", nil); err != nil {
		panic(err)
	}
}


func initDB() error {
	db, err := sql.Open(DB_DRIVER, DB_NAME)
	if err != nil {
		return err
	}
	defer db.Close()

	if err = db.Ping(); err != nil {
		return err
	}

	if _, err = db.Begin(); err != nil {
		return err
	}

	_, err = db.Exec(
		"create table if not exists Testers " +
		"(id integer primary key autoincrement," +
		"name varchar(255)," +
		"email varchar(255) not null unique)",
	);

	return err
}


func save(email string) error {
	db, err := sql.Open(DB_DRIVER, DB_NAME)
	if err != nil {
		return err
	}
	defer db.Close()

	name := strings.Split(email, "@")[0]
	_, err = db.Exec(
		"insert into Testers (name, email) values (?, ?)",
		name,
		email,
	)

	return err
}


//>>>>>>>>>>>>>>>>>>>>>>>> Tests <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
func sendEmail(w http.ResponseWriter, r *http.Request) {
	render(w, "sendEmail.html")
}


func render(w http.ResponseWriter, tmpl string) {
	w.Header().Set("Content-Type", "text/html")
	tmpl = fmt.Sprintf("static/template/%s", tmpl)

	t, err := template.ParseFiles(tmpl)
	if err != nil {
		log.Println("template parsing error: ", err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

	if err = t.Execute(w, nil); err != nil {
		log.Println("template executing error: ", err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}
}


func validateEmail(email string) bool {
	re := regexp.MustCompile(".+@.+\\..+")
  	return re.Match([]byte(email))
}