request_builder.go

package requestbuilder

import (
	"errors"
	"fmt"
	"strings"
)

var (
	ErrNoMethodFound     = errors.New("Empty Method")
	ErrNoUrlFound        = errors.New("Empty URL")
	ErrNoSupportedMethod = errors.New("unsupported method")
)

var SupportedValidMethods = map[string]bool{
	"GET":    true,
	"POST":   true,
	"DELETE": true,
	"PATCH":  true,
	"PUT":    true,
}

// keeping the Request struct private and exposing only builder struct
type RequestBuilder struct {
	requestInProgress request
}

func NewRequestBuilder() *RequestBuilder {
	return &RequestBuilder{
		requestInProgress: request{
			headers:          make(map[string]string),
			timeoutInSeconds: 30,
			method:           "GET",
		},
	}
}

func (rb *RequestBuilder) WithUrl(url string) *RequestBuilder {
	rb.requestInProgress.url = url
	return rb
}

func (rb *RequestBuilder) WithTimeout(timeout int) *RequestBuilder {
	rb.requestInProgress.timeoutInSeconds = timeout
	return rb
}

func (rb *RequestBuilder) WithMethod(method string) *RequestBuilder {
	rb.requestInProgress.method = strings.ToUpper(method)
	return rb
}

func (rb *RequestBuilder) WithBody(body string) *RequestBuilder {
	if rb.requestInProgress.method == "GET" {
		fmt.Println("Unusual practice detected adding body with GET method")
	}

	rb.requestInProgress.body = body
	return rb
}

func (rb *RequestBuilder) WithHeader(key, val string) *RequestBuilder {
	rb.requestInProgress.headers[key] = val
	return rb
}

func (rb *RequestBuilder) WithHeaders(mapOfHeader map[string]string) *RequestBuilder {
	if mapOfHeader == nil {
		mapOfHeader = make(map[string]string)
	}

	for key, val := range mapOfHeader {
		rb.requestInProgress.headers[key] = val
	}

	return rb
}

func (rb *RequestBuilder) Build() (Request, error) {
	if rb.requestInProgress.url == "" {
		return nil, ErrNoUrlFound
	}

	if rb.requestInProgress.method == "" {
		return nil, ErrNoMethodFound
	}

	_, ok := SupportedValidMethods[rb.requestInProgress.method]
	if !ok {
		return nil, ErrNoSupportedMethod
	}

	return rb.requestInProgress, nil
}