package main

import (
	"encoding/json"
	"fmt"
	"io"
)

// UserList stores a collection of users.
type UserList []User

// Find tries to return username from UserList
func (ul UserList) Find(username string) *User {
	for i, u := range ul {
		if u.Username == username {
			return &ul[i]
		}
	}
	return nil
}

// NewUserList creates a UserList from JSON
func NewUserList(rdr io.Reader) (UserList, error) {
	var userList []User
	err := json.NewDecoder(rdr).Decode(&userList)

	if err != nil {
		err = fmt.Errorf("problem parsing userlist, %v", err)
	}
	return userList, err
}