package middleware

import (
	"net/http"
	"strings"

	"spend-sparrow/internal/log"
	"spend-sparrow/internal/service"
	"spend-sparrow/internal/types"
	"spend-sparrow/internal/utils"
)

type csrfResponseWriter struct {
	http.ResponseWriter
	auth    service.Auth
	session *types.Session
}

func newCsrfResponseWriter(w http.ResponseWriter, auth service.Auth, session *types.Session) *csrfResponseWriter {
	return &csrfResponseWriter{
		ResponseWriter: w,
		auth:           auth,
		session:        session,
	}
}

func (rr *csrfResponseWriter) Write(data []byte) (int, error) {
	dataStr := string(data)
	csrfToken, err := rr.auth.GetCsrfToken(rr.session)
	if err == nil {
		dataStr = strings.ReplaceAll(dataStr, "CSRF_TOKEN", csrfToken)
	}

	return rr.ResponseWriter.Write([]byte(dataStr))
}

func CrossSiteRequestForgery(auth service.Auth) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			session := GetSession(r)

			if r.Method == http.MethodPost ||
				r.Method == http.MethodPut ||
				r.Method == http.MethodDelete ||
				r.Method == http.MethodPatch {
				csrfToken := r.Header.Get("Csrf-Token")

				if session == nil || csrfToken == "" || !auth.IsCsrfTokenValid(csrfToken, session.Id) {
					log.Info("CSRF-Token \"%s\" not correct", csrfToken)
					if r.Header.Get("Hx-Request") == "true" {
						utils.TriggerToastWithStatus(w, r, "error", "CSRF-Token not correct", http.StatusBadRequest)
					} else {
						http.Error(w, "CSRF-Token not correct", http.StatusBadRequest)
					}
					return
				}
			}

			responseWriter := newCsrfResponseWriter(w, auth, session)
			next.ServeHTTP(responseWriter, r)
		})
	}
}