package service

import (
	"context"
	"fmt"

	"github.com/gin-gonic/gin"
	domain "github.com/haydenhargreaves/Potion/internal/domain/user"
	"github.com/haydenhargreaves/Potion/internal/infrastructure/auth"
	"golang.org/x/oauth2"
)

// NOTE: HOW THIS WORKS
//
// I need to store the refresh token along side the user in the DB.
// Create a "session token" (cookie) with an expiration and store that in the DB and the session.
// Send this session token along with all the requests (stored in the session) and when
// authorization is needed, use it.
// Once the expiration of MY token expires, prompt the user to log back in.
//
// So what is the point of the Google refresh token? Well, its not really useful right now, but if
// we need to perform Google actions, we can use it to get more access tokens, which are needed for
// the Google actions. Currently, I have no need for it, but it will be stored anyway.
//
// ------------------------------------------------------------------------------------------------

// GoogleLogin generates a URL which is used to redirect the user to the Google sign in page. This
// URL is in the Google domain and is not coupled with this application. The data from this URL will
// be passed into a callback and work to complete the Google OAuth workflow.
func GoogleLogin(ctx *gin.Context) string {
	url := auth.GoogleAuthConfig.AuthCodeURL(
		"randomstate",
		oauth2.AccessTypeOffline,
		oauth2.ApprovalForce,
	)

	return url
}

// GoogleCallback accepts the data from the Google login endpoint and uses it to fetch the users
// data. The data is then used to log the user in or create an account.
//
// TODO: The repository implementation is not yet done.
func GoogleCallback(ctx *gin.Context) (domain.GoogleUserInfo, error) {
	var (
		state string = ctx.Query("state")
		code  string = ctx.Query("code")
	)

	// Ensure the state matches, prevents M.I.T.M. attacks
	if state != "randomstate" {
		return domain.GoogleUserInfo{}, fmt.Errorf("States don't match, received %s", state)
	}

	// Get access token from Google
	token, err := auth.GoogleAuthConfig.Exchange(context.Background(), code)
	if err != nil {
		return domain.GoogleUserInfo{}, fmt.Errorf("Code exchange failed: %s", err.Error())
	}

	googleUserInfo, err := auth.GetUserData(token.AccessToken)
	if err != nil {
		return domain.GoogleUserInfo{}, err
	}

	// TODO: Need to hit the repository to store the required data in the user table

	// temporary
	return googleUserInfo, nil
}