user.go

package sofa

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

// UserDocument contains all of the fields used by CouchDB to represent a
// user on the server.
type UserDocument struct {
	DocumentMetadata

	Name    string   `json:"name"`
	Roles   []string `json:"roles"`
	TheType string   `json:"type"`

	// This field is never sent back from CouchDB (for obvious reasons)
	Password string `json:"password,omitempty"`

	// These fields are generated by CouchDB from the password provided on creation
	DerivedKey     string `json:"derived_key,omitempty"`
	Iterations     int    `json:"iterations,omitempty"`
	PasswordScheme string `json:"password_scheme,omitempty"`
	Salt           string `json:"salt,omitempty"`
}

// Users gets a list of all users currently active on this CouchDB server
func (con *Connection) Users() ([]UserDocument, error) {
	db := con.Database("_users")

	table, err := db.AllDocuments()
	if err != nil {
		return nil, err
	}

	users := []UserDocument{}
	for _, rawUser := range table.RawDocuments() {
		user := UserDocument{}
		if err := json.Unmarshal(rawUser, &user); err != nil {
			return nil, err
		}
		users = append(users, user)
	}
	return users, nil
}

// User gets a particular UserDocument from the server by name. A revision can
// also be specified to retrieve a particular revision of the document (or an
// empty string supplied to fetch the current version).
// This makes the assumption that the user exists in the 'org.couchdb.user' namespace
// but I am unaware of any situation where that is not true. If the user doesn't
// exist in this namespace it should be possible to retrieve them with UserByID.
func (con *Connection) User(name string, rev string) (UserDocument, error) {
	id := fmt.Sprintf("org.couchdb.user:%s", name)
	return con.UserByID(id, rev)
}

// UserByID gets a CouchDB user by the ID of ther user document rather than their
// name.
func (con *Connection) UserByID(id string, rev string) (UserDocument, error) {
	db := con.Database("_users")

	user := UserDocument{}
	_, err := db.Get(&user, id, rev)
	if err != nil {
		return user, err
	}

	return user, nil
}

// CreateUser creates a new document in the _users database.
func (con *Connection) CreateUser(user *UserDocument) (string, error) {
	db := con.Database("_users")

	id := fmt.Sprintf("org.couchdb.user:%s", user.Name)

	// For convenience fill in the ID if it was left blank
	if user.DocumentMetadata.ID == "" {
		user.DocumentMetadata.ID = id
	}

	rev, err := db.Put(user)
	if err != nil {
		return "", err
	}

	user.DocumentMetadata.Rev = rev

	return rev, err
}

// DeleteUser deletes an existing user from the _users database.
func (con *Connection) DeleteUser(user *UserDocument) (string, error) {
	db := con.Database("_users")

	if user.DocumentMetadata.ID == "" {
		return "", errors.New("cannot delete a user with an unknown id")
	}

	if user.DocumentMetadata.Rev == "" {
		return "", errors.New("cannot delete a user with no current rev")
	}

	rev, err := db.Delete(user)
	if err != nil {
		return "", err
	}

	user.DocumentMetadata.Rev = rev

	return rev, err
}

// UpdateUser modifies details of a user document.
func (con *Connection) UpdateUser(user *UserDocument) (string, error) {
	db := con.Database("_users")

	if user.DocumentMetadata.ID == "" {
		return "", errors.New("cannot update a user with an unknown id")
	}

	if user.DocumentMetadata.Rev == "" {
		return "", errors.New("cannot update a user with no current rev")
	}

	rev, err := db.Put(user)
	if err != nil {
		return "", err
	}

	user.DocumentMetadata.Rev = rev

	return rev, err
}