package controllers

import (
	"bytes"
	"encoding/base32"
	"encoding/base64"
	"fmt"
	"image/png"

	"git.readonly.ch/bouzoure/popvaud-people/helpers"
	"git.readonly.ch/bouzoure/popvaud-people/models"
	"github.com/gofiber/fiber/v2"
	"github.com/pquerna/otp/totp"
)

func TotpEnrollPage(c *fiber.Ctx) error {
	db, err := helpers.GetDatabase()
	if err != nil {
		return err
	}

	userid, err := helpers.GetSessionUserId(c)
	if err != nil {
		return err
	}

	var user models.User
	result := db.First(&user, "id = ?", userid)

	if result.Error != nil {
		return result.Error
	}

	if user.TotpSecret.Valid {
		return fiber.NewError(fiber.StatusForbidden, "Forbidden")
	}

	sess, err := helpers.GetSessionStore(c)
	if err != nil {
		return err
	}

	options := totp.GenerateOpts{
		Issuer:      "POP Vaud",
		AccountName: user.Email,
	}

	existingSecret := sess.Get("totp-enroll-secret")
	if existingSecret != nil {
		var b32NoPadding = base32.StdEncoding.WithPadding(base32.NoPadding)
		options.Secret, err = b32NoPadding.DecodeString(existingSecret.(string))
		if err != nil {
			return err
		}
	}

	key, err := totp.Generate(options)
	if err != nil {
		return err
	}

	img, err := key.Image(200, 200)
	if err != nil {
		return err
	}

	var buf bytes.Buffer
	err = png.Encode(&buf, img)
	if err != nil {
		return err
	}

	imgBase64 := fmt.Sprintf(
		"data:image/png;base64,%s",
		base64.StdEncoding.EncodeToString(buf.Bytes()),
	)

	var mfaError string
	if c.Method() == "POST" {
		otp := c.FormValue("otp")
		if totp.Validate(otp, key.Secret()) {
			err = user.TotpSecret.Scan(key.Secret())
			if err != nil {
				return err
			}

			result = db.Save(&user)
			if result.Error != nil {
				return err
			}

			sess.Set("totp-verified", "yes")

			redirectId := c.Query("redirect")
			redirectUrl := "/"

			if len(redirectId) > 0 {
				redirectKey := fmt.Sprintf("redirect-%s", redirectId)
				redirectVal := sess.Get(redirectKey)

				if redirectVal != nil {
					redirectUrl = redirectVal.(string)
				}
			}

			err = sess.Save()
			if err != nil {
				return err
			}

			return c.Redirect(redirectUrl)
		} else {
			mfaError = "Code temporaire invalide"
		}
	}

	sess.Set("totp-enroll-secret", key.Secret())
	err = sess.Save()
	if err != nil {
		return err
	}

	return c.Render("totp_enroll", fiber.Map{
		"PageTitle": "Enregistrement multifacteur (TOTP)",
		"QrCode":    imgBase64,
		"Secret":    key.Secret(),
		"MfaError":  mfaError,
	})
}

func TotpVerifyPage(c *fiber.Ctx) error {
	db, err := helpers.GetDatabase()
	if err != nil {
		return err
	}

	sess, err := helpers.GetSessionStore(c)
	if err != nil {
		return err
	}

	totpVerified := sess.Get("totp-verified")
	if totpVerified != nil {
		return fiber.NewError(fiber.StatusForbidden, "Forbidden")
	}

	userid, err := helpers.GetSessionUserId(c)
	if err != nil {
		return err
	}

	var user models.User
	result := db.First(&user, "id = ?", userid)

	if result.Error != nil {
		return result.Error
	}

	if !user.TotpSecret.Valid {
		return fiber.NewError(fiber.StatusForbidden, "Forbidden")
	}

	var mfaError string
	if c.Method() == "POST" {
		otp := c.FormValue("otp")
		if totp.Validate(otp, user.TotpSecret.String) {
			redirectId := c.Query("redirect")
			redirectUrl := "/"

			if len(redirectId) > 0 {
				redirectKey := fmt.Sprintf("redirect-%s", redirectId)
				redirectVal := sess.Get(redirectKey)

				if redirectVal != nil {
					redirectUrl = redirectVal.(string)
				}
			}

			sess.Set("totp-verified", "yes")
			sess.Save()

			return c.Redirect(redirectUrl)
		} else {
			mfaError = "Code temporaire invalide"
		}
	}

	return c.Render("totp_verify", fiber.Map{
		"PageTitle": "Vérification multifacteur (TOTP)",
		"MfaError":  mfaError,
	})
}