// This is called if an error occured in a front hook.
func DErr(uni *context.Uni, err error) {
	if _, isjson := uni.Req.Form["json"]; isjson {
		putJSON(uni)
		return
	}
	uni.Put(err)
}

// Prints errors during query running to http response. (Kinda nonsense now as it is.)
func queryErr(uni *context.Uni) {
	r := recover()
	if r != nil {
		uni.Put("There was an error running the queries: ", r)
		debug.PrintStack()
	}
}

// Prints errors during template file display to http response. (Kinda nonsense now as it is.)
func displErr(uni *context.Uni) {
	r := recover()
	if r != nil {
		uni.Put("There was an error executing the template.")
		fmt.Println("problem with template: ", r)
		debug.PrintStack()
	}
}

// Prints all available data to http response as a JSON.
func putJSON(uni *context.Uni) {
	var v []byte
	if _, format := uni.Req.Form["fmt"]; format {
		v, _ = json.MarshalIndent(uni.Dat, "", "    ")
	} else {
		v, _ = json.Marshal(uni.Dat)
	}
	uni.W.Header().Set("Content-Type", "application/json; charset=utf-8")
	uni.Put(string(v))
}

// Tries to dislay a template file.
func DisplayTemplate(uni *context.Uni, filep string) error {
	_, src := uni.Req.Form["src"]
	file, err := require.R("", filep+".tpl",
		func(root, fi string) ([]byte, error) {
			return GetFileAndConvert(uni.Root, fi, uni.Opt, uni.Req.Host, nil)
		})
	if err != nil {
		return fmt.Errorf("Cant find template file %v.", filep)
	}
	if src {
		uni.Put(string(file))
		return nil
	}
	uni.Dat["_tpl"] = "/templates/" + scut.TemplateType(uni.Opt) + "/" + scut.TemplateName(uni.Opt) + "/"
	prepareAndExec(uni, string(file))
	return nil
}

// Displays a display point.
func D(uni *context.Uni) {
	points, points_exist := uni.Dat["_points"]
	var point string
	if points_exist {
		point = points.([]string)[0]
	} else {
		p := uni.Req.URL.Path
		if p == "/" {
			point = "index"
		} else {
			point = p
		}
	}
	queries, queries_exists := jsonp.Get(uni.Opt, "Display-points."+point+".queries")
	if queries_exists {
		qmap, ok := queries.(map[string]interface{})
		if ok {
			runQueries(uni, qmap)
		}
	}
	BeforeDisplay(uni)
	// While it is not the cheapest solution to convert bson.ObjectIds to strings here, where we have to iterate trough all values,
	// it is still better than remembering (and forgetting) to convert it at every specific place.
	scut.IdsToStrings(uni.Dat)
	langs, _ := jsonp.Get(uni.Dat, "_user.languages") // _user always has language member
	langs_s := toStringSlice(langs)
	loc, _ := display_model.LoadLocStrings(uni.Dat, langs_s, uni.Root, scut.GetTPath(uni.Opt, uni.Req.Host), nil) // TODO: think about errors here.
	if loc != nil {
		uni.Dat["loc"] = loc
	}
	if _, isjson := uni.Req.Form["json"]; isjson {
		putJSON(uni)
		return
	} else {
		err := DisplayFile(uni, point)
		if err != nil {
			uni.Dat["missing_file"] = point
			err_404 := DisplayFile(uni, "404")
			if err_404 != nil {
				uni.Put("Cant find file: ", point)
			}
		}
	}
}

// After running a background operation this either redirects with data in url paramters or prints out the json encoded result.
func actionResponse(uni *context.Uni, err error, action_name string) {
	if DEBUG {
		fmt.Println(uni.Req.Referer())
		fmt.Println("	", err)
	}
	_, is_json := uni.Req.Form["json"]
	redir := uni.Req.Referer()
	if red, ok := uni.Dat["redirect"]; ok {
		redir = red.(string)
	} else if post_red, okr := uni.Req.Form["redirect"]; okr && len(post_red) == 1 {
		redir = post_red[1]
	}
	var cont map[string]interface{}
	cont_i, has := uni.Dat["_cont"]
	if has {
		cont = cont_i.(map[string]interface{})
	} else {
		cont = map[string]interface{}{}
	}
	redir = appendParams(redir, action_name, err, cont)
	if is_json {
		cont["redirect"] = redir
		if err == nil {
			cont["ok"] = true
		} else {
			cont["error"] = err.Error()
		}
		var v []byte
		if _, fmt := uni.Req.Form["fmt"]; fmt {
			v, _ = json.MarshalIndent(cont, "", "    ")
		} else {
			v, _ = json.Marshal(cont)
		}
		uni.Put(string(v))
	} else {
		http.Redirect(uni.W, uni.Req, redir, 303)
	}
}

// Tries to display a module file.
func DisplayFallback(uni *context.Uni, filep string) error {
	_, src := uni.Req.Form["src"]
	if strings.Index(filep, "/") != -1 {
		return fmt.Errorf("Nothing to fall back to.") // No slash in fallback path means no modulename to fall back to.
	}
	if scut.PossibleModPath(filep) {
		return fmt.Errorf("Not a possible fallback path.")
	}
	file, err := require.R("", filep+".tpl", // Tricky, care.
		func(root, fi string) ([]byte, error) {
			return GetFileAndConvert(uni.Root, fi, uni.Opt, uni.Req.Host, nil)
		})
	if err != nil {
		fmt.Errorf("Cant find fallback file %v.", filep)
	}
	if src {
		uni.Put(string(file))
		return nil
	}
	uni.Dat["_tpl"] = "/modules/" + strings.Split(filep, "/")[0] + "/tpl/"
	prepareAndExec(uni, string(file))
	return nil
}

// Helper function to hotregister a guest user, log him in and build his user data into uni.Dat["_user"].
func RegLoginBuild(uni *context.Uni, solved_puzzle bool) error {
	db := uni.Db
	ev := uni.Ev
	guest_rules := guestRules(uni)
	inp := uni.Req.Form
	http_header := uni.Req.Header
	dat := uni.Dat
	w := uni.W
	block_key := []byte(uni.Secret())
	guest_id, err := user_model.RegisterGuest(db, ev, guest_rules, inp, solved_puzzle)
	if err != nil {
		return err
	}
	err = user_model.Login(w, guest_id, block_key)
	if err != nil {
		return err
	}
	user, err := user_model.BuildUser(db, ev, guest_id, http_header)
	if err != nil {
		return err
	}
	dat["_user"] = user
	return nil
}

func showTimer(uni *context.Uni, puzzle_opt map[string]interface{}) (string, error) {
	return user_model.ShowTimer(uni.Secret(), puzzle_opt)
}

func solveTimer(uni *context.Uni, puzzle_opts map[string]interface{}) error {
	return user_model.SolveTimer(uni.Secret(), uni.Req.Form, puzzle_opts)
}

func adErr(uni *context.Uni) {
	if r := recover(); r != nil {
		uni.Put("There was an error running the admin module.\n", r)
		debug.PrintStack()
	}
}