hanayo/vendor/gopkg.in/mailgun/mailgun-go.v1/events.go
2019-02-23 13:29:15 +00:00

419 lines
12 KiB
Go

package mailgun
import (
"fmt"
"time"
"github.com/pkg/errors"
)
// Events are open-ended, loosely-defined JSON documents.
// They will always have an event and a timestamp field, however.
type Event map[string]interface{}
// Parse the timestamp field for this event into a Time object
func (e Event) ParseTimeStamp() (time.Time, error) {
obj, ok := e["timestamp"]
if !ok {
return time.Time{}, errors.New("'timestamp' field not found in event")
}
timestamp, ok := obj.(float64)
if !ok {
return time.Time{}, errors.New("'timestamp' field not a float64")
}
microseconds := int64(timestamp * 1000000)
return time.Unix(0, microseconds*int64(time.Microsecond/time.Nanosecond)).UTC(), nil
}
func (e Event) ParseMessageId() (string, error) {
message, err := toMapInterface("message", e)
if err != nil {
return "", err
}
headers, err := toMapInterface("headers", message)
if err != nil {
return "", err
}
return headers["message-id"].(string), nil
}
// noTime always equals an uninitialized Time structure.
// It's used to detect when a time parameter is provided.
var noTime time.Time
// GetEventsOptions lets the caller of GetEvents() specify how the results are to be returned.
// Begin and End time-box the results returned.
// ForceAscending and ForceDescending are used to force Mailgun to use a given traversal order of the events.
// If both ForceAscending and ForceDescending are true, an error will result.
// If none, the default will be inferred from the Begin and End parameters.
// Limit caps the number of results returned. If left unspecified, Mailgun assumes 100.
// Compact, if true, compacts the returned JSON to minimize transmission bandwidth.
// Otherwise, the JSON is spaced appropriately for human consumption.
// Filter allows the caller to provide more specialized filters on the query.
// Consult the Mailgun documentation for more details.
type EventsOptions struct {
Begin, End time.Time
ForceAscending, ForceDescending, Compact bool
Limit int
Filter map[string]string
ThresholdAge time.Duration
PollInterval time.Duration
}
// Depreciated See `ListEvents()`
type GetEventsOptions struct {
Begin, End time.Time
ForceAscending, ForceDescending, Compact bool
Limit int
Filter map[string]string
}
// EventIterator maintains the state necessary for paging though small parcels of a larger set of events.
type EventIterator struct {
events []Event
NextURL, PrevURL, FirstURL, LastURL string
mg Mailgun
err error
}
// NewEventIterator creates a new iterator for events.
// Use GetFirstPage to retrieve the first batch of events.
// Use GetNext and GetPrevious thereafter as appropriate to iterate through sets of data.
//
// *This call is Deprecated, use ListEvents() instead*
func (mg *MailgunImpl) NewEventIterator() *EventIterator {
return &EventIterator{mg: mg}
}
// Create an new iterator to fetch a page of events from the events api
// it := mg.ListEvents(EventsOptions{})
// var events []Event
// for it.Next(&events) {
// for _, event := range events {
// // Do things with events
// }
// }
// if it.Err() != nil {
// log.Fatal(it.Err())
// }
func (mg *MailgunImpl) ListEvents(opts *EventsOptions) *EventIterator {
req := newHTTPRequest(generateApiUrl(mg, eventsEndpoint))
if opts != nil {
if opts.Limit != 0 {
req.addParameter("limit", fmt.Sprintf("%d", opts.Limit))
}
if opts.Compact {
req.addParameter("pretty", "no")
}
if opts.ForceAscending {
req.addParameter("ascending", "yes")
}
if opts.ForceDescending {
req.addParameter("ascending", "no")
}
if opts.Begin != noTime {
req.addParameter("begin", formatMailgunTime(&opts.Begin))
}
if opts.End != noTime {
req.addParameter("end", formatMailgunTime(&opts.End))
}
if opts.Filter != nil {
for k, v := range opts.Filter {
req.addParameter(k, v)
}
}
}
url, err := req.generateUrlWithParameters()
return &EventIterator{
mg: mg,
NextURL: url,
FirstURL: url,
PrevURL: "",
err: err,
}
}
// If an error occurred during iteration `Err()` will return non nil
func (ei *EventIterator) Err() error {
return ei.err
}
// Events returns the most recently retrieved batch of events.
// The length is guaranteed to fall between 0 and the limit set in the GetEventsOptions structure passed to GetFirstPage.
func (ei *EventIterator) Events() []Event {
return ei.events
}
// GetFirstPage retrieves the first batch of events, according to your criteria.
// See the GetEventsOptions structure for more details on how the fields affect the data returned.
func (ei *EventIterator) GetFirstPage(opts GetEventsOptions) error {
if opts.ForceAscending && opts.ForceDescending {
return fmt.Errorf("collation cannot at once be both ascending and descending")
}
payload := newUrlEncodedPayload()
if opts.Limit != 0 {
payload.addValue("limit", fmt.Sprintf("%d", opts.Limit))
}
if opts.Compact {
payload.addValue("pretty", "no")
}
if opts.ForceAscending {
payload.addValue("ascending", "yes")
}
if opts.ForceDescending {
payload.addValue("ascending", "no")
}
if opts.Begin != noTime {
payload.addValue("begin", formatMailgunTime(&opts.Begin))
}
if opts.End != noTime {
payload.addValue("end", formatMailgunTime(&opts.End))
}
if opts.Filter != nil {
for k, v := range opts.Filter {
payload.addValue(k, v)
}
}
url, err := generateParameterizedUrl(ei.mg, eventsEndpoint, payload)
if err != nil {
return err
}
return ei.fetch(url)
}
// Retrieves the chronologically previous batch of events, if any exist.
// You know you're at the end of the list when len(Events())==0.
func (ei *EventIterator) GetPrevious() error {
return ei.fetch(ei.PrevURL)
}
// Retrieves the chronologically next batch of events, if any exist.
// You know you're at the end of the list when len(Events())==0.
func (ei *EventIterator) GetNext() error {
return ei.fetch(ei.NextURL)
}
// Retrieves the next page of events from the api. Returns false when there
// no more pages to retrieve or if there was an error. Use `.Err()` to retrieve
// the error
func (ei *EventIterator) Next(events *[]Event) bool {
if ei.err != nil {
return false
}
ei.err = ei.fetch(ei.NextURL)
if ei.err != nil {
return false
}
*events = ei.events
if len(ei.events) == 0 {
return false
}
return true
}
// Retrieves the first page of events from the api. Returns false if there
// was an error. It also sets the iterator object to the first page.
// Use `.Err()` to retrieve the error.
func (ei *EventIterator) First(events *[]Event) bool {
if ei.err != nil {
return false
}
ei.err = ei.fetch(ei.FirstURL)
if ei.err != nil {
return false
}
*events = ei.events
return true
}
// Retrieves the last page of events from the api.
// Calling Last() is invalid unless you first call First() or Next()
// Returns false if there was an error. It also sets the iterator object
// to the last page. Use `.Err()` to retrieve the error.
func (ei *EventIterator) Last(events *[]Event) bool {
if ei.err != nil {
return false
}
ei.err = ei.fetch(ei.LastURL)
if ei.err != nil {
return false
}
*events = ei.events
return true
}
// Retrieves the previous page of events from the api. Returns false when there
// no more pages to retrieve or if there was an error. Use `.Err()` to retrieve
// the error if any
func (ei *EventIterator) Previous(events *[]Event) bool {
if ei.err != nil {
return false
}
if ei.PrevURL == "" {
return false
}
ei.err = ei.fetch(ei.PrevURL)
if ei.err != nil {
return false
}
*events = ei.events
if len(ei.events) == 0 {
return false
}
return true
}
// EventPoller maintains the state necessary for polling events
type EventPoller struct {
it *EventIterator
opts EventsOptions
thresholdTime time.Time
sleepUntil time.Time
mg Mailgun
err error
}
// Poll the events api and return new events as they occur
// it = mg.PollEvents(&EventsOptions{
// // Poll() returns after this threshold is met, or events older than this threshold appear
// ThresholdAge: time.Second * 10,
// // Only events with a timestamp after this date/time will be returned
// Begin: time.Now().Add(time.Second * -3),
// // How often we poll the api for new events
// PollInterval: time.Second * 4})
// var events []Event
// // Blocks until new events appear
// for it.Poll(&events) {
// for _, event := range(events) {
// fmt.Printf("Event %+v\n", event)
// }
// }
// if it.Err() != nil {
// log.Fatal(it.Err())
// }
func (mg *MailgunImpl) PollEvents(opts *EventsOptions) *EventPoller {
now := time.Now()
// ForceAscending must be set
opts.ForceAscending = true
// Default begin time is 30 minutes ago
if opts.Begin == noTime {
opts.Begin = now.Add(time.Minute * -30)
}
// Default threshold age is 30 minutes
if opts.ThresholdAge.Nanoseconds() == 0 {
opts.ThresholdAge = time.Duration(time.Minute * 30)
}
// Set a 15 second poll interval if none set
if opts.PollInterval.Nanoseconds() == 0 {
opts.PollInterval = time.Duration(time.Second * 15)
}
return &EventPoller{
it: mg.ListEvents(opts),
opts: *opts,
mg: mg,
}
}
// If an error occurred during polling `Err()` will return non nil
func (ep *EventPoller) Err() error {
return ep.err
}
func (ep *EventPoller) Poll(events *[]Event) bool {
var currentPage string
ep.thresholdTime = time.Now().UTC().Add(ep.opts.ThresholdAge)
for {
if ep.sleepUntil != noTime {
// Sleep the rest of our duration
time.Sleep(ep.sleepUntil.Sub(time.Now()))
}
// Remember our current page url
currentPage = ep.it.NextURL
// Attempt to get a page of events
var page []Event
if ep.it.Next(&page) == false {
if ep.it.Err() == nil && len(page) == 0 {
// No events, sleep for our poll interval
ep.sleepUntil = time.Now().Add(ep.opts.PollInterval)
continue
}
ep.err = ep.it.Err()
return false
}
// Last event on the page
lastEvent := page[len(page)-1]
timeStamp, err := lastEvent.ParseTimeStamp()
if err != nil {
ep.err = errors.Wrap(err, "event timestamp error")
return false
}
// Record the next time we should query for new events
ep.sleepUntil = time.Now().Add(ep.opts.PollInterval)
// If the last event on the page is older than our threshold time
// or we have been polling for longer than our threshold time
if timeStamp.After(ep.thresholdTime) || time.Now().UTC().After(ep.thresholdTime) {
ep.thresholdTime = time.Now().UTC().Add(ep.opts.ThresholdAge)
// Return the page of events to the user
*events = page
return true
}
// Since we didn't find an event older than our
// threshold, fetch this same page again
ep.it.NextURL = currentPage
}
}
// GetFirstPage, GetPrevious, and GetNext all have a common body of code.
// fetch completes the API fetch common to all three of these functions.
func (ei *EventIterator) fetch(url string) error {
r := newHTTPRequest(url)
r.setClient(ei.mg.Client())
r.setBasicAuth(basicAuthUser, ei.mg.ApiKey())
var response map[string]interface{}
err := getResponseFromJSON(r, &response)
if err != nil {
return err
}
items := response["items"].([]interface{})
ei.events = make([]Event, len(items))
for i, item := range items {
ei.events[i] = item.(map[string]interface{})
}
pagings := response["paging"].(map[string]interface{})
links := make(map[string]string, len(pagings))
for key, page := range pagings {
links[key] = page.(string)
}
ei.NextURL = links["next"]
ei.PrevURL = links["previous"]
ei.FirstURL = links["first"]
ei.LastURL = links["last"]
return err
}
func toMapInterface(field string, thingy map[string]interface{}) (map[string]interface{}, error) {
var empty map[string]interface{}
obj, ok := thingy[field]
if !ok {
return empty, errors.Errorf("'%s' field not found in event", field)
}
result, ok := obj.(map[string]interface{})
if !ok {
return empty, errors.Errorf("'%s' field not a map[string]interface{}", field)
}
return result, nil
}