Feature/preapproval (#32)

* implementation, unit test, integration test and example

* refactoring to adapt to merge

* refactor type at integration test

* edit comment

* remove blank line

* add omitempy to FreeTrialRequest

* refactor field name

* remove omitempty

* rename variable name

* rename variable name

* rename variable name

* refactor comment

* refactor preapproval search IT

* refactor searchResponse

examples/apis/preapproval/create/main.go

@@ -0,0 +1,38 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/mercadopago/sdk-go/pkg/config"
+	"github.com/mercadopago/sdk-go/pkg/preapproval"
+)
+
+func main() {
+	cfg, err := config.New("{{ACCESS_TOKEN}}")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	req := preapproval.Request{
+		AutoRecurring: &preapproval.AutoRecurringRequest{
+			Frequency:         1,
+			FrequencyType:     "months",
+			TransactionAmount: 100,
+			CurrencyID:        "BRL",
+		},
+		BackURL:           "https://www.yoursite.com",
+		ExternalReference: "Ref-123",
+		PayerEmail:        "[email protected]",
+		Reason:            "Yoga Class",
+	}
+
+	client := preapproval.NewClient(cfg)
+	result, err := client.Create(context.Background(), req)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(result)
+}

examples/apis/preapproval/get/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/mercadopago/sdk-go/pkg/config"
+	"github.com/mercadopago/sdk-go/pkg/preapproval"
+)
+
+func main() {
+	cfg, err := config.New("{{ACCESS_TOKEN}}")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	client := preapproval.NewClient(cfg)
+
+	preApprovalID := "123"
+
+	result, err := client.Get(context.Background(), preApprovalID)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(result)
+}

examples/apis/preapproval/search/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/mercadopago/sdk-go/pkg/config"
+	"github.com/mercadopago/sdk-go/pkg/preapproval"
+)
+
+func main() {
+	cfg, err := config.New("{{ACCESS_TOKEN}}")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	client := preapproval.NewClient(cfg)
+
+	filters := preapproval.SearchRequest{
+		Limit:  "10",
+		Offset: "10",
+		Filters: map[string]string{
+			"payer_id": "123123123",
+		},
+	}
+
+	result, err := client.Search(context.Background(), filters)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	for _, plan := range result.Results {
+		fmt.Println(plan)
+	}
+}

examples/apis/preapproval/update/main.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"github.com/mercadopago/sdk-go/pkg/config"
+	"github.com/mercadopago/sdk-go/pkg/preapproval"
+)
+
+func main() {
+	cfg, err := config.New("{{ACCESS_TOKEN}}")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	req := preapproval.Request{
+		AutoRecurring: &preapproval.AutoRecurringRequest{
+			Frequency:         1,
+			FrequencyType:     "months",
+			TransactionAmount: 100,
+			CurrencyID:        "BRL",
+		},
+		BackURL:           "https://www.yoursite.com",
+		ExternalReference: "Ref-123",
+		PayerEmail:        "[email protected]",
+		Reason:            "Yoga Class",
+	}
+
+	client := preapproval.NewClient(cfg)
+	result, err := client.Create(context.Background(), req)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	update := preapproval.UpdateRequest{
+		AutoRecurring: &preapproval.AutoRecurringRequest{
+			Frequency:         1,
+			FrequencyType:     "months",
+			TransactionAmount: 100,
+			CurrencyID:        "BRL",
+		},
+		BackURL:           "https://www.yoursite.com",
+		ExternalReference: "Ref-123",
+		Reason:            "Yoga Class",
+	}
+
+	result, err = client.Update(context.Background(), update, result.ID)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+
+	fmt.Println(result)
+}

pkg/preapproval/client.go

@@ -0,0 +1,116 @@
+package preapproval
+
+import (
+	"context"
+	"github.com/mercadopago/sdk-go/pkg/config"
+	"github.com/mercadopago/sdk-go/pkg/internal/httpclient"
+	"net/http"
+)
+
+const (
+	urlBase   = "https://api.mercadopago.com/preapproval"
+	urlWithID = urlBase + "/{id}"
+	urlSearch = urlBase + "/search"
+)
+
+// Client contains the methods to interact with the Pre Approval API.
+type Client interface {
+	// Create creates a new pre-approval.
+	// It is a post request to the endpoint: https://api.mercadopago.com/preapproval
+	// Reference: https://www.mercadopago.com/developers/en/reference/subscriptions/_preapproval/post
+	Create(ctx context.Context, request Request) (*Response, error)
+
+	// Get finds a pre-approval by ID.
+	// It is a get request to the endpoint: https://api.mercadopago.com/preapproval/{id}
+	// Reference: https://www.mercadopago.com/developers/en/reference/subscriptions/_preapproval_id/get
+	Get(ctx context.Context, id string) (*Response, error)
+
+	// Update updates details a pre-approval by ID.
+	// It is a put request to the endpoint: https://api.mercadopago.com/preapproval/{id}
+	// Reference: https://www.mercadopago.com/developers/en/reference/subscriptions/_preapproval_id/put
+	Update(ctx context.Context, request UpdateRequest, id string) (*Response, error)
+
+	// Search finds all pre-approval information generated through specific filters.
+	// It is a get request to the endpoint: https://api.mercadopago.com/preapproval/search
+	// Reference: https://www.mercadopago.com/developers/en/reference/subscriptions/_preapproval_search/get
+	Search(ctx context.Context, request SearchRequest) (*SearchResponse, error)
+}
+
+// client is the implementation of Client.
+type client struct {
+	cfg *config.Config
+}
+
+// NewClient returns a new Pre Approval API Client.
+func NewClient(c *config.Config) Client {
+	return &client{
+		cfg: c,
+	}
+}
+
+func (c *client) Create(ctx context.Context, request Request) (*Response, error) {
+	requestData := httpclient.RequestData{
+		Body:   request,
+		Method: http.MethodPost,
+		URL:    urlBase,
+	}
+	result, err := httpclient.DoRequest[*Response](ctx, c.cfg, requestData)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+func (c *client) Get(ctx context.Context, id string) (*Response, error) {
+	pathParams := map[string]string{
+		"id": id,
+	}
+
+	requestData := httpclient.RequestData{
+		PathParams: pathParams,
+		Method:     http.MethodGet,
+		URL:        urlWithID,
+	}
+	result, err := httpclient.DoRequest[*Response](ctx, c.cfg, requestData)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+func (c *client) Update(ctx context.Context, request UpdateRequest, id string) (*Response, error) {
+	pathParams := map[string]string{
+		"id": id,
+	}
+
+	requestData := httpclient.RequestData{
+		Body:       request,
+		PathParams: pathParams,
+		Method:     http.MethodPut,
+		URL:        urlWithID,
+	}
+	result, err := httpclient.DoRequest[*Response](ctx, c.cfg, requestData)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+func (c *client) Search(ctx context.Context, request SearchRequest) (*SearchResponse, error) {
+	queryParams := request.GetParams()
+
+	requestData := httpclient.RequestData{
+		QueryParams: queryParams,
+		Method:      http.MethodGet,
+		URL:         urlSearch,
+	}
+	result, err := httpclient.DoRequest[*SearchResponse](ctx, c.cfg, requestData)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}