refund_service.go

package gocardless

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

	"github.com/google/go-querystring/query"
)

var _ = query.Values
var _ = bytes.NewBuffer
var _ = json.NewDecoder
var _ = errors.New

// RefundService manages refunds
type RefundServiceImpl struct {
	config Config
}

type RefundFx struct {
	EstimatedExchangeRate string `url:"estimated_exchange_rate,omitempty" json:"estimated_exchange_rate,omitempty"`
	ExchangeRate          string `url:"exchange_rate,omitempty" json:"exchange_rate,omitempty"`
	FxAmount              int    `url:"fx_amount,omitempty" json:"fx_amount,omitempty"`
	FxCurrency            string `url:"fx_currency,omitempty" json:"fx_currency,omitempty"`
}

type RefundLinks struct {
	Mandate string `url:"mandate,omitempty" json:"mandate,omitempty"`
	Payment string `url:"payment,omitempty" json:"payment,omitempty"`
}

// Refund model
type Refund struct {
	Amount    int                    `url:"amount,omitempty" json:"amount,omitempty"`
	CreatedAt string                 `url:"created_at,omitempty" json:"created_at,omitempty"`
	Currency  string                 `url:"currency,omitempty" json:"currency,omitempty"`
	Fx        *RefundFx              `url:"fx,omitempty" json:"fx,omitempty"`
	Id        string                 `url:"id,omitempty" json:"id,omitempty"`
	Links     *RefundLinks           `url:"links,omitempty" json:"links,omitempty"`
	Metadata  map[string]interface{} `url:"metadata,omitempty" json:"metadata,omitempty"`
	Reference string                 `url:"reference,omitempty" json:"reference,omitempty"`
	Status    string                 `url:"status,omitempty" json:"status,omitempty"`
}

type RefundService interface {
	Create(ctx context.Context, p RefundCreateParams, opts ...RequestOption) (*Refund, error)
	List(ctx context.Context, p RefundListParams, opts ...RequestOption) (*RefundListResult, error)
	All(ctx context.Context, p RefundListParams, opts ...RequestOption) *RefundListPagingIterator
	Get(ctx context.Context, identity string, opts ...RequestOption) (*Refund, error)
	Update(ctx context.Context, identity string, p RefundUpdateParams, opts ...RequestOption) (*Refund, error)
}

type RefundCreateParamsLinks struct {
	Mandate string `url:"mandate,omitempty" json:"mandate,omitempty"`
	Payment string `url:"payment,omitempty" json:"payment,omitempty"`
}

// RefundCreateParams parameters
type RefundCreateParams struct {
	Amount                  int                     `url:"amount,omitempty" json:"amount,omitempty"`
	Links                   RefundCreateParamsLinks `url:"links,omitempty" json:"links,omitempty"`
	Metadata                map[string]interface{}  `url:"metadata,omitempty" json:"metadata,omitempty"`
	Reference               string                  `url:"reference,omitempty" json:"reference,omitempty"`
	TotalAmountConfirmation int                     `url:"total_amount_confirmation,omitempty" json:"total_amount_confirmation,omitempty"`
}

// Create
// Creates a new refund object.
//
// This fails with:<a name="total_amount_confirmation_invalid"></a><a
// name="number_of_refunds_exceeded"></a><a
// name="available_refund_amount_insufficient"></a>
//
// - `total_amount_confirmation_invalid` if the confirmation amount doesn't
// match the total amount refunded for the payment. This safeguard is there to
// prevent two processes from creating refunds without awareness of each other.
//
// - `number_of_refunds_exceeded` if five or more refunds have already been
// created against the payment.
//
// - `available_refund_amount_insufficient` if the creditor does not have
// sufficient balance for refunds available to cover the cost of the requested
// refund.
func (s *RefundServiceImpl) Create(ctx context.Context, p RefundCreateParams, opts ...RequestOption) (*Refund, error) {
	uri, err := url.Parse(fmt.Sprintf(s.config.Endpoint() + "/refunds"))
	if err != nil {
		return nil, err
	}

	o := &requestOptions{
		retries: 3,
	}
	for _, opt := range opts {
		err := opt(o)
		if err != nil {
			return nil, err
		}
	}
	if o.idempotencyKey == "" {
		o.idempotencyKey = NewIdempotencyKey()
	}

	var body io.Reader

	var buf bytes.Buffer
	err = json.NewEncoder(&buf).Encode(map[string]interface{}{
		"refunds": p,
	})
	if err != nil {
		return nil, err
	}
	body = &buf

	req, err := http.NewRequest("POST", uri.String(), body)
	if err != nil {
		return nil, err
	}
	req = req.WithContext(ctx)
	req.Header.Set("Authorization", "Bearer "+s.config.Token())
	req.Header.Set("GoCardless-Version", "2015-07-06")
	req.Header.Set("GoCardless-Client-Library", "gocardless-pro-go")
	req.Header.Set("GoCardless-Client-Version", "4.0.0")
	req.Header.Set("User-Agent", userAgent)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Idempotency-Key", o.idempotencyKey)

	for key, value := range o.headers {
		req.Header.Set(key, value)
	}

	client := s.config.Client()
	if client == nil {
		client = http.DefaultClient
	}

	var result struct {
		Err    *APIError `json:"error"`
		Refund *Refund   `json:"refunds"`
	}

	err = try(o.retries, func() error {
		res, err := client.Do(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		err = responseErr(res)
		if err != nil {
			return err
		}

		err = json.NewDecoder(res.Body).Decode(&result)
		if err != nil {
			return err
		}

		if result.Err != nil {
			return result.Err
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	if result.Refund == nil {
		return nil, errors.New("missing result")
	}

	return result.Refund, nil
}

type RefundListParamsCreatedAt struct {
	Gt  string `url:"gt,omitempty" json:"gt,omitempty"`
	Gte string `url:"gte,omitempty" json:"gte,omitempty"`
	Lt  string `url:"lt,omitempty" json:"lt,omitempty"`
	Lte string `url:"lte,omitempty" json:"lte,omitempty"`
}

// RefundListParams parameters
type RefundListParams struct {
	After      string                     `url:"after,omitempty" json:"after,omitempty"`
	Before     string                     `url:"before,omitempty" json:"before,omitempty"`
	CreatedAt  *RefundListParamsCreatedAt `url:"created_at,omitempty" json:"created_at,omitempty"`
	Limit      int                        `url:"limit,omitempty" json:"limit,omitempty"`
	Mandate    string                     `url:"mandate,omitempty" json:"mandate,omitempty"`
	Payment    string                     `url:"payment,omitempty" json:"payment,omitempty"`
	RefundType string                     `url:"refund_type,omitempty" json:"refund_type,omitempty"`
}

type RefundListResultMetaCursors struct {
	After  string `url:"after,omitempty" json:"after,omitempty"`
	Before string `url:"before,omitempty" json:"before,omitempty"`
}

type RefundListResultMeta struct {
	Cursors *RefundListResultMetaCursors `url:"cursors,omitempty" json:"cursors,omitempty"`
	Limit   int                          `url:"limit,omitempty" json:"limit,omitempty"`
}

type RefundListResult struct {
	Refunds []Refund             `json:"refunds"`
	Meta    RefundListResultMeta `url:"meta,omitempty" json:"meta,omitempty"`
}

// List
// Returns a [cursor-paginated](#api-usage-cursor-pagination) list of your
// refunds.
func (s *RefundServiceImpl) List(ctx context.Context, p RefundListParams, opts ...RequestOption) (*RefundListResult, error) {
	uri, err := url.Parse(fmt.Sprintf(s.config.Endpoint() + "/refunds"))
	if err != nil {
		return nil, err
	}

	o := &requestOptions{
		retries: 3,
	}
	for _, opt := range opts {
		err := opt(o)
		if err != nil {
			return nil, err
		}
	}

	var body io.Reader

	v, err := query.Values(p)
	if err != nil {
		return nil, err
	}
	uri.RawQuery = v.Encode()

	req, err := http.NewRequest("GET", uri.String(), body)
	if err != nil {
		return nil, err
	}
	req = req.WithContext(ctx)
	req.Header.Set("Authorization", "Bearer "+s.config.Token())
	req.Header.Set("GoCardless-Version", "2015-07-06")
	req.Header.Set("GoCardless-Client-Library", "gocardless-pro-go")
	req.Header.Set("GoCardless-Client-Version", "4.0.0")
	req.Header.Set("User-Agent", userAgent)

	for key, value := range o.headers {
		req.Header.Set(key, value)
	}

	client := s.config.Client()
	if client == nil {
		client = http.DefaultClient
	}

	var result struct {
		Err *APIError `json:"error"`
		*RefundListResult
	}

	err = try(o.retries, func() error {
		res, err := client.Do(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		err = responseErr(res)
		if err != nil {
			return err
		}

		err = json.NewDecoder(res.Body).Decode(&result)
		if err != nil {
			return err
		}

		if result.Err != nil {
			return result.Err
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	if result.RefundListResult == nil {
		return nil, errors.New("missing result")
	}

	return result.RefundListResult, nil
}

type RefundListPagingIterator struct {
	cursor         string
	response       *RefundListResult
	params         RefundListParams
	service        *RefundServiceImpl
	requestOptions []RequestOption
}

func (c *RefundListPagingIterator) Next() bool {
	if c.cursor == "" && c.response != nil {
		return false
	}

	return true
}

func (c *RefundListPagingIterator) Value(ctx context.Context) (*RefundListResult, error) {
	if !c.Next() {
		return c.response, nil
	}

	s := c.service
	p := c.params
	p.After = c.cursor

	uri, err := url.Parse(fmt.Sprintf(s.config.Endpoint() + "/refunds"))

	if err != nil {
		return nil, err
	}

	o := &requestOptions{
		retries: 3,
	}
	for _, opt := range c.requestOptions {
		err := opt(o)
		if err != nil {
			return nil, err
		}
	}

	var body io.Reader

	v, err := query.Values(p)
	if err != nil {
		return nil, err
	}
	uri.RawQuery = v.Encode()

	req, err := http.NewRequest("GET", uri.String(), body)
	if err != nil {
		return nil, err
	}

	req = req.WithContext(ctx)
	req.Header.Set("Authorization", "Bearer "+s.config.Token())
	req.Header.Set("GoCardless-Version", "2015-07-06")
	req.Header.Set("GoCardless-Client-Library", "gocardless-pro-go")
	req.Header.Set("GoCardless-Client-Version", "4.0.0")
	req.Header.Set("User-Agent", userAgent)

	for key, value := range o.headers {
		req.Header.Set(key, value)
	}
	client := s.config.Client()
	if client == nil {
		client = http.DefaultClient
	}

	var result struct {
		Err *APIError `json:"error"`
		*RefundListResult
	}

	err = try(o.retries, func() error {
		res, err := client.Do(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		err = responseErr(res)

		if err != nil {
			return err
		}

		err = json.NewDecoder(res.Body).Decode(&result)
		if err != nil {
			return err
		}

		if result.Err != nil {
			return result.Err
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	if result.RefundListResult == nil {
		return nil, errors.New("missing result")
	}

	c.response = result.RefundListResult
	c.cursor = c.response.Meta.Cursors.After
	return c.response, nil
}

func (s *RefundServiceImpl) All(ctx context.Context,
	p RefundListParams,
	opts ...RequestOption) *RefundListPagingIterator {
	return &RefundListPagingIterator{
		params:         p,
		service:        s,
		requestOptions: opts,
	}
}

// Get
// Retrieves all details for a single refund
func (s *RefundServiceImpl) Get(ctx context.Context, identity string, opts ...RequestOption) (*Refund, error) {
	uri, err := url.Parse(fmt.Sprintf(s.config.Endpoint()+"/refunds/%v",
		identity))
	if err != nil {
		return nil, err
	}

	o := &requestOptions{
		retries: 3,
	}
	for _, opt := range opts {
		err := opt(o)
		if err != nil {
			return nil, err
		}
	}

	var body io.Reader

	req, err := http.NewRequest("GET", uri.String(), body)
	if err != nil {
		return nil, err
	}
	req = req.WithContext(ctx)
	req.Header.Set("Authorization", "Bearer "+s.config.Token())
	req.Header.Set("GoCardless-Version", "2015-07-06")
	req.Header.Set("GoCardless-Client-Library", "gocardless-pro-go")
	req.Header.Set("GoCardless-Client-Version", "4.0.0")
	req.Header.Set("User-Agent", userAgent)

	for key, value := range o.headers {
		req.Header.Set(key, value)
	}

	client := s.config.Client()
	if client == nil {
		client = http.DefaultClient
	}

	var result struct {
		Err    *APIError `json:"error"`
		Refund *Refund   `json:"refunds"`
	}

	err = try(o.retries, func() error {
		res, err := client.Do(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		err = responseErr(res)
		if err != nil {
			return err
		}

		err = json.NewDecoder(res.Body).Decode(&result)
		if err != nil {
			return err
		}

		if result.Err != nil {
			return result.Err
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	if result.Refund == nil {
		return nil, errors.New("missing result")
	}

	return result.Refund, nil
}

// RefundUpdateParams parameters
type RefundUpdateParams struct {
	Metadata map[string]interface{} `url:"metadata,omitempty" json:"metadata,omitempty"`
}

// Update
// Updates a refund object.
func (s *RefundServiceImpl) Update(ctx context.Context, identity string, p RefundUpdateParams, opts ...RequestOption) (*Refund, error) {
	uri, err := url.Parse(fmt.Sprintf(s.config.Endpoint()+"/refunds/%v",
		identity))
	if err != nil {
		return nil, err
	}

	o := &requestOptions{
		retries: 3,
	}
	for _, opt := range opts {
		err := opt(o)
		if err != nil {
			return nil, err
		}
	}
	if o.idempotencyKey == "" {
		o.idempotencyKey = NewIdempotencyKey()
	}

	var body io.Reader

	var buf bytes.Buffer
	err = json.NewEncoder(&buf).Encode(map[string]interface{}{
		"refunds": p,
	})
	if err != nil {
		return nil, err
	}
	body = &buf

	req, err := http.NewRequest("PUT", uri.String(), body)
	if err != nil {
		return nil, err
	}
	req = req.WithContext(ctx)
	req.Header.Set("Authorization", "Bearer "+s.config.Token())
	req.Header.Set("GoCardless-Version", "2015-07-06")
	req.Header.Set("GoCardless-Client-Library", "gocardless-pro-go")
	req.Header.Set("GoCardless-Client-Version", "4.0.0")
	req.Header.Set("User-Agent", userAgent)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Idempotency-Key", o.idempotencyKey)

	for key, value := range o.headers {
		req.Header.Set(key, value)
	}

	client := s.config.Client()
	if client == nil {
		client = http.DefaultClient
	}

	var result struct {
		Err    *APIError `json:"error"`
		Refund *Refund   `json:"refunds"`
	}

	err = try(o.retries, func() error {
		res, err := client.Do(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		err = responseErr(res)
		if err != nil {
			return err
		}

		err = json.NewDecoder(res.Body).Decode(&result)
		if err != nil {
			return err
		}

		if result.Err != nil {
			return result.Err
		}

		return nil
	})
	if err != nil {
		return nil, err
	}

	if result.Refund == nil {
		return nil, errors.New("missing result")
	}

	return result.Refund, nil
}