VictorAvelar / mollie-api-go

import (

	"bytes"

	"encoding/json"

	"errors"

	"fmt"

	"io"

	"io/ioutil"

	"net/http"

	"net/url"

	"os"

	"strings"

)

// Mollie  constants holding values to initialize the client and create requests.

const (

	BaseURL            string = "https://api.mollie.com/"

	AuthHeader         string = "Authorization"

	TokenType          string = "Bearer"

	APITokenEnv        string = "MOLLIE_API_TOKEN"

	OrgTokenEnv        string = "MOLLIE_ORG_TOKEN"

	RequestContentType string = "application/json"

)

var (

	errEmptyAPIKey = errors.New("you must provide a non-empty API key")

	errBadBaseURL  = errors.New("malformed base url, it must contain a trailing slash")

)

// Client manages communication with Mollie's API.

type Client struct {

	BaseURL        *url.URL

	authentication string

	client         *http.Client

	common         service // Reuse a single struct instead of allocating one for each service on the heap.

	config         *Config

	// Services

	Payments *PaymentsService

}

type service struct {

	client *Client

}

// WithAuthenticationValue offers a convenient setter for any of the valid authentication

// tokens provided by Mollie.

//

// Ideally your API key will be provided from and environment variable or

// a secret management engine.

// This should only be used when environment variables are "impossible" to be used.

func (c *Client) WithAuthenticationValue(k string) error {

	if k == "" {

		return errEmptyAPIKey

	}

	c.authentication = strings.TrimSpace(k)

	return nil

}

// NewAPIRequest is a wrapper around the http.NewRequest function.

//

// It will setup the authentication headers/parameters according to the client config.

func (c *Client) NewAPIRequest(method string, uri string, body interface{}) (req *http.Request, err error) {

	if !strings.HasSuffix(c.BaseURL.Path, "/") {

		return nil, errBadBaseURL

	}

	u, err := c.BaseURL.Parse(uri)

	if err != nil {

		return nil, err

	}

	if c.config.testing == true {

		u.Query().Add("testmode", "true")

	}

	var buf io.ReadWriter

	if body != nil {

		buf = new(bytes.Buffer)

		enc := json.NewEncoder(buf)

		enc.SetEscapeHTML(false)

		err := enc.Encode(body)

		if err != nil {

			return nil, err

		}

	}

	req, err = http.NewRequest(method, u.String(), buf)

	if err != nil {

		return nil, err

	}

	req.Header.Add(AuthHeader, strings.Join([]string{TokenType, c.authentication}, " "))

	if body != nil {

		req.Header.Set("Content-Type", RequestContentType)

	}

	req.Header.Set("Accept", RequestContentType)

	return

}

// Do sends an API request and returns the API response or returned as an

// error if an API error has occurred.

func (c *Client) Do(req *http.Request) (*Response, error) {

	resp, err := c.client.Do(req)

	if err != nil {

		return nil, err

	}

	defer resp.Body.Close()

	response := newResponse(resp)

	err = CheckResponse(resp)

	if err != nil {

		return nil, err

	}

	return response, nil

}

// NewClient returns a new Mollie HTTP API client.

// You can pass a previously build http client, if none is provided then

// http.DefaultClient will be used.

//

// NewClient will lookup the environment for values to assign to the

// API token (`MOLLIE_API_TOKEN`) and the Organization token (`MOLLIE_ORG_TOKEN`)

// according to the provided Config object.

//

// You can also set the token values programmatically by using the Client

// WithAPIKey and WithOrganizationKey functions.

func NewClient(baseClient *http.Client, c *Config) (mollie *Client, err error) {

	if baseClient == nil {

		baseClient = http.DefaultClient

	}

	u, _ := url.Parse(BaseURL)

	mollie = &Client{

		BaseURL: u,

		client:  baseClient,

		config:  c,

	}

	mollie.common.client = mollie

	// services for resources

	mollie.Payments = (*PaymentsService)(&mollie.common)

	// Parse authorization from environment

	if tkn, ok := os.LookupEnv(APITokenEnv); ok {

		mollie.authentication = tkn

	}

	return

}

/*

Error reports details on a failed API request.

The success or failure of each HTTP request is shown in the status field of the HTTP response header,

which contains standard HTTP status codes:

- a 2xx code for success

- a 4xx or 5xx code for failure

*/

type Error struct {

	Code     int            `json:"code"`

	Message  string         `json:"message"`

	Response *http.Response `json:"response"` // the full response that produced the error

}

// Error functions implement the Error interface on the zuora.Error struct.

func (e *Error) Error() string {

	return fmt.Sprintf("response failed with status %v", e.Message)

}

/*

Constructor for Error

*/

func newError(r *http.Response) *Error {

	var e Error

	e.Response = r

	e.Code = r.StatusCode

	e.Message = r.Status

	return &e

}

// Response is a Mollie API response. This wraps the standard http.Response

// returned from Mollie and provides convenient access to things like

// pagination links.

type Response struct {

	*http.Response

	content []byte

}

// CheckResponse checks the API response for errors, and returns them if

// present. A response is considered an error if it has a status code outside

// the 200 range.

// API error responses are expected to have either no response

// body, or a JSON response body.

func CheckResponse(r *http.Response) error {

	if r.StatusCode >= http.StatusMultipleChoices {

		return newError(r)

	}

	return nil

}