NdoleStudio / ynote-go

package ynote

import (

	"bytes"

	"context"

	"encoding/json"

	"fmt"

	"io"

	"net/http"

	"net/url"

	"strconv"

	"strings"

	"sync"

	"time"

)

type service struct {

	client *Client

}

// Client is the Y-Note API client.

// Do not instantiate this client with Client{}. Use the New method instead.

type Client struct {

	httpClient *http.Client

	common     service

	customerKey    string

	customerSecret string

	clientID       string

	clientSecret   string

	tokenURL       string

	apiURL         string

	accessToken         string

	tokenExpirationTime int64

	mutex               sync.Mutex

	Refund *RefundService

}

// New creates and returns a new ynote.Client from a slice of ynote.Option.

func New(options ...Option) *Client {

	config := defaultClientConfig()

	for _, option := range options {

		option.apply(config)

	}

	client := &Client{

		httpClient:     config.httpClient,

		tokenURL:       config.tokenURL,

		apiURL:         config.apiURL,

		clientID:       config.clientID,

		clientSecret:   config.clientSecret,

		customerKey:    config.customerKey,

		customerSecret: config.customerSecret,

		mutex:          sync.Mutex{},

	}

	client.common.client = client

	client.Refund = (*RefundService)(&client.common)

	return client

}

// AccessToken fetches the access token used to authenticate api requests.

func (client *Client) AccessToken(ctx context.Context) (*AccessTokenResponse, *Response, error) {

	data := url.Values{}

	data.Set("grant_type", "client_credentials")

	request, err := http.NewRequestWithContext(ctx, http.MethodPost, client.tokenURL+"/oauth2/token", strings.NewReader(data.Encode()))

	if err != nil {

		return nil, nil, err

	}

	request.SetBasicAuth(client.clientID, client.clientSecret)

	request.Header.Add("Content-Type", "application/x-www-form-urlencoded")

	request.Header.Add("Content-Length", strconv.Itoa(len(data.Encode())))

	resp, err := client.do(request)

	if err != nil {

		return nil, resp, err

	}

	var token AccessTokenResponse

	if err = json.Unmarshal(*resp.Body, &token); err != nil {

		return nil, resp, err

	}

	return &token, resp, nil

}

// refreshToken refreshes the authentication AccessTokenResponse

func (client *Client) refreshToken(ctx context.Context) error {

	client.mutex.Lock()

	defer client.mutex.Unlock()

	if client.tokenExpirationTime > time.Now().UTC().Unix() {

		return nil

	}

	client.accessToken = ""

	token, _, err := client.AccessToken(ctx)

	if err != nil {

		return err

	}

	client.accessToken = token.AccessToken

	client.tokenExpirationTime = time.Now().UTC().Unix() + token.ExpiresIn - 100 // Give extra 100 second buffer

	return nil

}

// newRequest creates an API request. A relative URL can be provided in uri,

// in which case it is resolved relative to the BaseURL of the Client.

// URI's should always be specified without a preceding slash.

func (client *Client) newRequest(ctx context.Context, method, uri string, body any) (*http.Request, error) {

	var buf io.ReadWriter

	if body != nil {

		buf = &bytes.Buffer{}

		enc := json.NewEncoder(buf)

		enc.SetEscapeHTML(false)

		err := enc.Encode(body)

		if err != nil {

			return nil, err

		}

	}

	req, err := http.NewRequestWithContext(ctx, method, client.apiURL+uri, buf)

	if err != nil {

		return nil, err

	}

	req.Header.Set("Authorization", "Bearer "+client.accessToken)

	req.Header.Set("Content-Type", "application/json")

	req.Header.Set("Accept", "application/json")

	return req, nil

}

// do carries out an HTTP request and returns a Response

func (client *Client) do(req *http.Request) (*Response, error) {

	if req == nil {

		return nil, fmt.Errorf("%T cannot be nil", req)

	}

	httpResponse, err := client.httpClient.Do(req)

	if err != nil {

		return nil, err

	}

	defer func() { _ = httpResponse.Body.Close() }()

	resp, err := client.newResponse(httpResponse)

	if err != nil {

		return resp, err

	}

	_, err = io.Copy(io.Discard, httpResponse.Body)

	if err != nil {

		return resp, err

	}

	return resp, nil

}

// newResponse converts an *http.Response to *Response

func (client *Client) newResponse(httpResponse *http.Response) (*Response, error) {

	if httpResponse == nil {

		return nil, fmt.Errorf("%T cannot be nil", httpResponse)

	}

	resp := new(Response)

	resp.HTTPResponse = httpResponse

	buf, err := io.ReadAll(resp.HTTPResponse.Body)

	if err != nil {

		return nil, err

	}

	resp.Body = &buf

	return resp, resp.Error()

}