package main

import (
	"fmt"
	"reflect"
	"strings"
)

type MyUrlParams struct {
	UserId string `path:"user",json:"-"`
	OrgId  string `path:"org"`
	Foo    string
}

func main() {
	params := MyUrlParams{
		UserId: "abc123",
		OrgId:  "xyz789",
		Foo:    "bar",
	}

	uri := "/api/v1/users/{user}/orgs/{org}"

	fmt.Println(resolvePath(uri, params))
}

func resolvePath(uri string, params interface{}) string {
	for search, replace := range getPathParams(params) {
		uri = strings.Replace(uri, "{"+search+"}", replace, 1)
	}

	return uri
}

func getPathParams(params interface{}) map[string]string {
	p := map[string]string{}
	v := reflect.ValueOf(params)
	for i := 0; i < v.NumField(); i++ {
		val := v.Field(i).String()
		tag := v.Type().Field(i).Tag.Get("path")
		if tag != "" {
			p[tag] = val
		}
	}

	return p
}