// Package middleware to deal with sessions
package middleware

import (
	"context"
	"crypto/rand"
	"fmt"
	"net/http"
)

type Session struct {
	User string
}

type SessionStore struct {
	sessions map[string]Session
}

type ContextKey string

func NewSessionStore() SessionStore {
	return SessionStore{sessions: make(map[string]Session, 10)}
}

func (s *SessionStore) Login(user string, w http.ResponseWriter) {
	sessionID := rand.Text()
	s.sessions[sessionID] = Session{User: user}

	cookie := http.Cookie{
		Name: "id", Value: sessionID, MaxAge: 3600,
		Secure: true, HttpOnly: true, Path: "/",
	}

	http.SetCookie(w, &cookie)
}

func (s *SessionStore) Logout(w http.ResponseWriter, r *http.Request) {
	session := r.Context().Value(ContextKey("session")).(string)

	delete(s.sessions, session)
	cookie := http.Cookie{
		Name: "id", Value: "", MaxAge: -1,
		Secure: true, HttpOnly: true, Path: "/",
	}

	http.SetCookie(w, &cookie)
}

func (s *SessionStore) AsMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		sessionCookie, err := r.Cookie("id")

		for name, values := range r.Header {
			for _, value := range values {
				fmt.Println(name, value)
			}
		}

		// No session yet
		if err != nil {
			http.Redirect(w, r, "/login/", http.StatusFound)
			return
		}

		session, ok := s.sessions[sessionCookie.Value]

		// Session expired
		if !ok {
			http.Redirect(w, r, "/login/", http.StatusFound)
			return
		}

		ctx := r.Context()
		ctx = context.WithValue(
			context.WithValue(
				ctx,
				ContextKey("user"),
				session.User,
			),
			ContextKey("session"),
			sessionCookie.Value,
		)

		next.ServeHTTP(w, r.WithContext(ctx))
	})
}