client.go

package healthcrm

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"time"

	"github.com/savannahghi/authutils"
	"github.com/savannahghi/serverutils"
)

// IAuthUtilsLib holds the method defined in authutils library
type authUtilsLib interface {
	Authenticate() (*authutils.OAUTHResponse, error)
}

// client is the library's client used to make requests
type client struct {
	authClient authUtilsLib
	httpClient *http.Client
}

// newClient is the constructor which initializes health crm's authentication mechanism
func newClient() (*client, error) {
	config := authutils.Config{
		AuthServerEndpoint: serverutils.MustGetEnvVar("HEALTH_CRM_AUTH_SERVER_ENDPOINT"),
		ClientID:           serverutils.MustGetEnvVar("HEALTH_CRM_CLIENT_ID"),
		ClientSecret:       serverutils.MustGetEnvVar("HEALTH_CRM_CLIENT_SECRET"),
		GrantType:          serverutils.MustGetEnvVar("HEALTH_CRM_GRANT_TYPE"),
		Username:           serverutils.MustGetEnvVar("HEALTH_CRM_USERNAME"),
		Password:           serverutils.MustGetEnvVar("HEALTH_CRM_PASSWORD"),
	}
	slade360AuthClient, err := authutils.NewClient(config)
	if err != nil {
		return nil, err
	}

	return &client{
		authClient: slade360AuthClient,
		httpClient: &http.Client{
			Timeout: time.Second * 10,
		},
	}, nil
}

// MakeRequest performs a HTTP request to the provided path and parameters
func (cl *client) MakeRequest(ctx context.Context, method, path string, queryParams url.Values, body interface{}) (*http.Response, error) {
	oauthResponse, err := cl.authClient.Authenticate()
	if err != nil {
		return nil, err
	}

	urlPath := fmt.Sprintf("%s%s", BaseURL, path)

	var request *http.Request
	switch method {
	case http.MethodGet:
		req, err := http.NewRequestWithContext(ctx, method, urlPath, nil)
		if err != nil {
			return nil, err
		}
		request = req

	case http.MethodPost, http.MethodPatch:
		encoded, err := json.Marshal(body)
		if err != nil {
			return nil, err
		}

		payload := bytes.NewBuffer(encoded)

		req, err := http.NewRequestWithContext(ctx, method, urlPath, payload)
		if err != nil {
			return nil, err
		}

		request = req

	default:
		return nil, fmt.Errorf("s.MakeRequest() unsupported http method: %s", method)
	}

	request.Header.Set("Accept", "application/json")
	request.Header.Set("Content-Type", "application/json")
	request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", oauthResponse.AccessToken))

	if queryParams != nil {
		request.URL.RawQuery = queryParams.Encode()
	}

	return cl.httpClient.Do(request)
}