package auth

import (
	"github.com/julienschmidt/httprouter"
	"net/http"
	"net/url"
	"strings"
)

type UserHandler func(rw http.ResponseWriter, req *http.Request, params httprouter.Params, auth UserAuth)

type UserAuth struct {
	Subject  string
	Factor   Factor
	UserInfo UserInfoFields
}

func (u UserAuth) IsGuest() bool { return u.Subject == "" }

func (u UserAuth) NextFlowUrl(origin *url.URL) *url.URL {
	// prevent redirect loops
	if origin.Path == "/login" || origin.Path == "/callback" {
		return nil
	}
	if u.Factor < FactorAuthorized {
		return PrepareRedirectUrl("/login", origin)
	}
	return nil
}

func PrepareRedirectUrl(targetPath string, origin *url.URL) *url.URL {
	// find start of query parameters in target path
	n := strings.IndexByte(targetPath, '?')
	v := url.Values{}

	// parse existing query parameters
	if n != -1 {
		q, err := url.ParseQuery(targetPath[n+1:])
		if err != nil {
			panic("PrepareRedirectUrl: invalid hardcoded target path query parameters")
		}
		v = q
		targetPath = targetPath[:n]
	}

	// add path of origin as a new query parameter
	orig := origin.Path
	if origin.RawQuery != "" || origin.ForceQuery {
		orig += "?" + origin.RawQuery
	}
	if orig != "" {
		v.Set("redirect", orig)
	}
	return &url.URL{Path: targetPath, RawQuery: v.Encode()}
}