Move remaining Go-NEB code into gomatrix

client.go

@@ -4,26 +4,46 @@
 package gomatrix
 
 import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
 	"net/http"
 	"net/url"
 	"path"
+	"strconv"
 	"sync"
+	"time"
 )
 
 // Client represents a Matrix client.
 type Client struct {
-	HomeserverURL   *url.URL        // The base homeserver URL
-	Prefix          string          // The API prefix eg '/_matrix/client/r0'
-	UserID          string          // The user ID of the client. Used for forming HTTP paths which use the client's user ID.
-	AccessToken     string          // The access_token for the client.
-	syncingMutex    sync.Mutex      // protects syncingID
-	syncingID       uint32          // Identifies the current Sync. Only one Sync can be active at any given time.
-	Client          *http.Client    // The underlying HTTP client which will be used to make HTTP requests.
-	FilterStorer    FilterStorer    // Interface for saving and loading the filter ID for sync.
-	NextBatchStorer NextBatchStorer // Interface for saving and loading the "next_batch" sync token.
+	HomeserverURL *url.URL     // The base homeserver URL
+	Prefix        string       // The API prefix eg '/_matrix/client/r0'
+	UserID        string       // The user ID of the client. Used for forming HTTP paths which use the client's user ID.
+	AccessToken   string       // The access_token for the client.
+	syncingMutex  sync.Mutex   // protects syncingID
+	syncingID     uint32       // Identifies the current Sync. Only one Sync can be active at any given time.
+	Client        *http.Client // The underlying HTTP client which will be used to make HTTP requests.
+	Syncer        Syncer       // The thing which can process /sync responses
 	// TODO: Worker and Rooms
 }
 
+// HTTPError An HTTP Error response, which may wrap an underlying native Go Error.
+type HTTPError struct {
+	WrappedError error
+	Message      string
+	Code         int
+}
+
+func (e HTTPError) Error() string {
+	var wrappedErrMsg string
+	if e.WrappedError != nil {
+		wrappedErrMsg = e.WrappedError.Error()
+	}
+	return fmt.Sprintf("%s: %d: %s", e.Message, e.Code, wrappedErrMsg)
+}
+
 // BuildURL builds a URL with the Client's homserver/prefix/access_token set already.
 func (cli *Client) BuildURL(urlPath ...string) string {
 	ps := []string{cli.Prefix}
@@ -58,6 +78,154 @@ func (cli *Client) BuildURLWithQuery(urlPath []string, urlQuery map[string]strin
 	return u.String()
 }
 
+// Sync starts syncing with the provided Homeserver. This function will block until a fatal /sync error occurs, so should
+// almost always be started as a new goroutine. If Sync() is called twice then the first sync will be stopped.
+func (cli *Client) Sync() error {
+	// Mark the client as syncing.
+	// We will keep syncing until the syncing state changes. Either because
+	// Sync is called or StopSync is called.
+	syncingID := cli.incrementSyncingID()
+	nextBatch := cli.Syncer.NextBatchStorer().LoadNextBatch(cli.UserID)
+	filterID := cli.Syncer.FilterStorer().LoadFilter(cli.UserID)
+	if filterID == "" {
+		filterJSON := cli.Syncer.FilterStorer().GetFilterJSON(cli.UserID)
+		resFilter, err := cli.CreateFilter(filterJSON)
+		if err != nil {
+			return err
+		}
+		filterID = resFilter.FilterID
+		cli.Syncer.FilterStorer().SaveFilter(cli.UserID, filterID)
+	}
+
+	for {
+		resSync, err := cli.SyncRequest(30000, nextBatch, filterID, false, "")
+		if err != nil {
+			duration, err2 := cli.Syncer.OnFailedSync(resSync, err)
+			if err2 != nil {
+				return err2
+			}
+			time.Sleep(duration)
+			continue
+		}
+
+		// Check that the syncing state hasn't changed
+		// Either because we've stopped syncing or another sync has been started.
+		// We discard the response from our sync.
+		if cli.getSyncingID() != syncingID {
+			return nil
+		}
+
+		// Save the token now *before* processing it. This means it's possible
+		// to not process some events, but it means that we won't get constantly stuck processing
+		// a malformed/buggy event which keeps making us panic.
+		cli.Syncer.NextBatchStorer().SaveNextBatch(cli.UserID, resSync.NextBatch)
+		if err = cli.Syncer.ProcessResponse(resSync, nextBatch); err != nil {
+			return err
+		}
+
+		nextBatch = resSync.NextBatch
+	}
+}
+
+func (cli *Client) incrementSyncingID() uint32 {
+	cli.syncingMutex.Lock()
+	defer cli.syncingMutex.Unlock()
+	cli.syncingID++
+	return cli.syncingID
+}
+
+func (cli *Client) getSyncingID() uint32 {
+	cli.syncingMutex.Lock()
+	defer cli.syncingMutex.Unlock()
+	return cli.syncingID
+}
+
+// StopSync stops the ongoing sync started by Sync.
+func (cli *Client) StopSync() {
+	// Advance the syncing state so that any running Syncs will terminate.
+	cli.incrementSyncingID()
+}
+
+// SendJSON sends JSON to the given URL. Returns an error if the response is not 2xx.
+func (cli *Client) SendJSON(method string, httpURL string, contentJSON interface{}) ([]byte, error) {
+	jsonStr, err := json.Marshal(contentJSON)
+	if err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequest(method, httpURL, bytes.NewBuffer(jsonStr))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	res, err := cli.Client.Do(req)
+	if res != nil {
+		defer res.Body.Close()
+	}
+	if err != nil {
+		return nil, err
+	}
+	contents, err := ioutil.ReadAll(res.Body)
+	if res.StatusCode >= 300 || res.StatusCode < 200 {
+		return nil, HTTPError{
+			Code:    res.StatusCode,
+			Message: "Failed to " + method + " JSON: HTTP " + strconv.Itoa(res.StatusCode),
+		}
+	}
+	if err != nil {
+		return nil, err
+	}
+	return contents, nil
+}
+
+// CreateFilter makes an HTTP request according to http://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-client-r0-user-userid-filter
+func (cli *Client) CreateFilter(filter json.RawMessage) (*RespCreateFilter, error) {
+	urlPath := cli.BuildURL("user", cli.UserID, "filter")
+	resBytes, err := cli.SendJSON("POST", urlPath, &filter)
+	if err != nil {
+		return nil, err
+	}
+	var filterResponse RespCreateFilter
+	if err = json.Unmarshal(resBytes, &filterResponse); err != nil {
+		return nil, err
+	}
+	return &filterResponse, nil
+}
+
+// SyncRequest makes an HTTP request according to http://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-sync
+func (cli *Client) SyncRequest(timeout int, since, filterID string, fullState bool, setPresence string) (*RespSync, error) {
+	query := map[string]string{
+		"timeout": strconv.Itoa(timeout),
+	}
+	if since != "" {
+		query["since"] = since
+	}
+	if filterID != "" {
+		query["filter"] = filterID
+	}
+	if setPresence != "" {
+		query["set_presence"] = setPresence
+	}
+	if fullState {
+		query["full_state"] = "true"
+	}
+	urlPath := cli.BuildURLWithQuery([]string{"sync"}, query)
+	req, err := http.NewRequest("GET", urlPath, nil)
+	if err != nil {
+		return nil, err
+	}
+	res, err := cli.Client.Do(req)
+	if res != nil {
+		defer res.Body.Close()
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	var syncResponse RespSync
+	err = json.NewDecoder(res.Body).Decode(&syncResponse)
+	return &syncResponse, err
+}
+
 // NewClient creates a new Matrix Client ready for syncing
 func NewClient(homeserverURL, userID, accessToken string) (*Client, error) {
 	hsURL, err := url.Parse(homeserverURL)
@@ -69,15 +237,21 @@ func NewClient(homeserverURL, userID, accessToken string) (*Client, error) {
 		HomeserverURL: hsURL,
 		UserID:        userID,
 		Prefix:        "/_matrix/client/r0",
+		Syncer: NewDefaultSyncer(
+			userID,
+			// By default, use an in-memory next_batch storer which will never save tokens to disk.
+			// The client will work with this storer: it just won't
+			// remember the token across restarts. In practice, a database backend should be used.
+			&InMemoryNextBatchStore{make(map[string]string)},
+			// By default, use an in-memory filter storer which will never save the filter ID to disk.
+			// The client will work with this storer: it just won't remember the filter
+			// ID across restarts and hence request a new one. In practice, a database backend should be used.
+			&InMemoryFilterStore{
+				Filter:       json.RawMessage(`{"room":{"timeline":{"limit":50}}}`),
+				UserToFilter: make(map[string]string),
+			},
+		),
 	}
-	// By default, use a no-op next_batch storer which will never save tokens and always
-	// "load" the empty string as a token. The client will work with this storer: it just won't
-	// remember the token across restarts. In practice, a database backend should be used.
-	cli.NextBatchStorer = NopNextBatchStore{}
-	// By default, use a no-op filter storer which will never save the filter ID and always
-	// "load" nothing. The client will work with this storer: it just won't remember the filter
-	// ID across restarts and hence request a new one. In practice, a database backend should be used.
-	cli.FilterStorer = NopFilterStore{}
 	// By default, use the default HTTP client.
 	cli.Client = http.DefaultClient