package sso

import (
	"embed"
	"net/http"

	"github.com/gorilla/sessions"
	"imuslab.com/zoraxy/mod/database"
	"imuslab.com/zoraxy/mod/info/logger"
)

/*
	sso.go

	This file contains the main SSO handler and the SSO configuration
	structure. It also contains the main SSO handler functions.

	SSO web interface are stored in the static folder, which is embedded
	into the binary.
*/

//go:embed static/*
var staticFiles embed.FS //Static files for the SSO portal

type SSOConfig struct {
	SystemUUID       string //System UUID, should be passed in from main scope
	AuthURL          string //Authentication subdomain URL, e.g. auth.example.com
	PortalServerPort int    //SSO portal server port
	Database         *database.Database
	Logger           *logger.Logger
}
type SSOHandler struct {
	cookieStore     *sessions.CookieStore
	ssoPortalServer *http.Server
	ssoPortalMux    *http.ServeMux
	Oauth2Server    *OAuth2Server
	Config          *SSOConfig
}

// Create a new Zoraxy SSO handler
func NewSSOHandler(config *SSOConfig) (*SSOHandler, error) {
	//Create a cookie store for the SSO handler
	cookieStore := sessions.NewCookieStore([]byte(config.SystemUUID))
	cookieStore.Options = &sessions.Options{
		Path:     "",
		Domain:   "",
		MaxAge:   0,
		Secure:   false,
		HttpOnly: false,
		SameSite: 0,
	}
	//Create a table for the new sso user management system
	err := config.Database.NewTable("sso_users")
	if err != nil {
		return nil, err
	}

	//Create the SSO Handler
	thisHandler := SSOHandler{
		cookieStore: cookieStore,
		Config:      config,
	}

	//Create an oauth2 server
	oauth2Server, err := NewOAuth2Server(config, &thisHandler)
	if err != nil {
		return nil, err
	}

	//Register endpoints
	thisHandler.Oauth2Server = oauth2Server
	thisHandler.InitSSOPortal(config.PortalServerPort)

	return &thisHandler, nil
}

// ServeForwardAuth handle the SSO request by forwarding auth to the authelia server
// return false if the request is not authorized and shall not be proceed
// Note that only accounts that have SSO enabled will be handled by this handler
func (h *SSOHandler) ServeForwardAuth(w http.ResponseWriter, r *http.Request) bool {
	//Get the current uri for appending to the auth subdomain
	originalRequestURL := r.RequestURI

	//Check if the user have the cookie "Zoraxy-SSO" set
	session, err := h.cookieStore.Get(r, "Zoraxy-SSO")
	if err != nil {
		//Redirect to auth subdomain
		http.Redirect(w, r, h.Config.AuthURL+"?m=new&t="+originalRequestURL, http.StatusFound)
		return false
	}

	//Check if the user is logged in
	if session.Values["username"] != true {
		//Redirect to auth subdomain
		http.Redirect(w, r, h.Config.AuthURL+"?m=expired&t="+originalRequestURL, http.StatusFound)
		return false
	}

	//Check if the current request subdomain is allowed
	userName := session.Values["username"].(string)
	user, err := h.SSO_GetUser(userName)
	if err != nil {
		//User might have been removed from SSO. Redirect to auth subdomain
		http.Redirect(w, r, h.Config.AuthURL, http.StatusFound)
		return false
	}

	//Check if the user have access to the current subdomain
	if !user.Subdomains[r.Host].AllowAccess {
		//User is not allowed to access the current subdomain. Sent 403
		http.Error(w, "Forbidden", http.StatusForbidden)
		//TODO: Use better looking template if exists
		return false
	}

	//User is logged in, continue to the next handler
	return true
}

// Log a message with the SSO module tag
func (h *SSOHandler) Log(message string, err error) {
	h.Config.Logger.PrintAndLog("SSO", message, err)
}