package main

import (
	"github.com/gin-gonic/gin"
	"github.com/pquerna/otp/totp"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

var (
	db *gorm.DB
)

type User struct {
	gorm.Model
	Secret   string
	Username string `gorm:"uniqueIndex"`
	Email    string
}

func init() {
	var err error
	db, err = gorm.Open(sqlite.Open("test.db"), &gorm.Config{})
	if err != nil {
		panic("failed to connect database")
	}
	db.AutoMigrate(&User{})
}

func main() {
	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.String(200, "format string, values ...any")
	})
	r.POST("/signup", signup)
	r.POST("/login", login)
	r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")}
}

type Signup struct {
	Username string `form:"username"`
	Email    string `form:"email"`
}

func signup(c *gin.Context) {
	var s Signup
	c.Bind(&s)

	key, err := totp.Generate(totp.GenerateOpts{AccountName: s.Username, Issuer: "me"})
	if err != nil {
		c.Status(502)
		return
	}

	var user User
	user.Email = s.Email
	user.Username = s.Username
	user.Secret = key.Secret()
	db.Create(&user)

	c.String(200, "%s", key.Secret())
}

type Login struct {
	Username string `form:"username"`
	Code     string `form:"code"`
}

func login(c *gin.Context) {
	var login Login
	var user User
	c.Bind(&login)
	if err := db.Where("username = ?", login.Username).First(&user).Error; err != nil {
		c.String(404, "something went wrong")
		return
	}
	correct := totp.Validate(login.Code, user.Secret)
	if correct {
		c.String(200, "success!")
	} else {
		c.String(404, "something went wrong")
	}
}