From 5257bfa98a7e8f91e601c2bf5d476bfe285ea643 Mon Sep 17 00:00:00 2001
From: Kiryl Andruski <kandruski@lyft.com>
Date: Fri, 22 May 2020 12:55:11 +0300
Subject: [PATCH] post mode

---
 client.go | 38 +++++++++++++++++++++++++++++---------
 osrm.go   |  4 +++-
 types.go  | 13 ++++++-------
 3 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/client.go b/client.go
index de1d54d..aee6246 100644
--- a/client.go
+++ b/client.go
@@ -1,6 +1,7 @@
 package osrm
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -21,28 +22,29 @@ type (
 	client struct {
 		httpClient HTTPClient
 		serverURL  string
+		usePOST    bool
 	}
 )
 
 // newClient creates a client with server url and specific getter
-func newClient(serverURL string, c HTTPClient) client {
-	return client{c, serverURL}
+func newClient(httpClient HTTPClient, serverURL string, usePOST bool) client {
+	return client{httpClient: httpClient, serverURL: serverURL, usePOST: usePOST}
 }
 
 // doRequest makes GET request to OSRM server and decodes the given JSON
 func (c client) doRequest(ctx context.Context, in *request, out interface{}) error {
-	url, err := in.URL(c.serverURL)
+	path, err := in.URLPath()
 	if err != nil {
 		return err
 	}
 
-	resp, err := c.get(ctx, url)
+	resp, err := c.httpRequest(ctx, path)
 	if err != nil {
 		return err
 	}
 	defer closeSilently(resp.Body)
 
-	bytes, err := ioutil.ReadAll(resp.Body)
+	body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
 		return fmt.Errorf("failed to read body: %v", err)
 	}
@@ -51,17 +53,25 @@ func (c client) doRequest(ctx context.Context, in *request, out interface{}) err
 	// In other cases, it returns an unexpected error without a body.
 	// http://project-osrm.org/docs/v5.5.1/api/#responses
 	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusBadRequest {
-		return fmt.Errorf("unexpected http status code %d with body %q", resp.StatusCode, bytes)
+		return fmt.Errorf("unexpected http status code %d with body %q", resp.StatusCode, body)
 	}
 
-	if err := json.Unmarshal(bytes, out); err != nil {
-		return fmt.Errorf("failed to unmarshal body %q: %v", bytes, err)
+	if err := json.Unmarshal(body, out); err != nil {
+		return fmt.Errorf("failed to unmarshal body %q: %v", body, err)
 	}
 
 	return nil
 }
 
-func (c client) get(ctx context.Context, url string) (*http.Response, error) {
+func (c client) httpRequest(ctx context.Context, path string) (*http.Response, error) {
+	if c.usePOST {
+		return c.post(ctx, path)
+	}
+	return c.get(ctx, path)
+}
+
+func (c client) get(ctx context.Context, path string) (*http.Response, error) {
+	url := c.serverURL + "/" + path
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {
 		return nil, err
@@ -70,6 +80,16 @@ func (c client) get(ctx context.Context, url string) (*http.Response, error) {
 	return c.httpClient.Do(req.WithContext(ctx))
 }
 
+func (c client) post(ctx context.Context, path string) (*http.Response, error) {
+	req, err := http.NewRequest("POST", c.serverURL, bytes.NewReader([]byte(path)))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Add("Content-Type", "application/x-uri")
+	return c.httpClient.Do(req.WithContext(ctx))
+}
+
 func closeSilently(c io.Closer) {
 	// #nosec - make github.com/GoASTScanner/gas linter ignore this
 	_ = c.Close() // nothing meaningful to do with this error - so ignore and suppress linter warnings
diff --git a/osrm.go b/osrm.go
index 8a7ebeb..21c6e31 100644
--- a/osrm.go
+++ b/osrm.go
@@ -28,6 +28,8 @@ type Config struct {
 	// Client is custom pre-configured http client to be used for queries.
 	// New http.Client instance with default settings and one second timeout will be used if not set.
 	Client HTTPClient
+	// Use POST method to request OSRM API
+	UsePOST bool
 }
 
 // ResponseStatus represent OSRM API response
@@ -84,7 +86,7 @@ func NewWithConfig(cfg Config) *OSRM {
 		cfg.Client = &http.Client{Timeout: defaultTimeout}
 	}
 
-	return &OSRM{client: newClient(cfg.ServerURL, cfg.Client)}
+	return &OSRM{client: newClient(cfg.Client, cfg.ServerURL, cfg.UsePOST)}
 }
 
 func (o OSRM) query(ctx context.Context, in *request, out response) error {
diff --git a/types.go b/types.go
index 8f5a559..44c6fea 100644
--- a/types.go
+++ b/types.go
@@ -182,8 +182,8 @@ type request struct {
 	options options
 }
 
-// URL generates a url for OSRM request
-func (r *request) URL(serverURL string) (string, error) {
+// URLPath generates a url path for OSRM request
+func (r *request) URLPath() (string, error) {
 	if r.service == "" {
 		return "", ErrEmptyServiceName
 	}
@@ -193,18 +193,17 @@ func (r *request) URL(serverURL string) (string, error) {
 	if r.coords.Length() == 0 {
 		return "", ErrNoCoordinates
 	}
-	// http://{server}/{service}/{version}/{profile}/{coordinates}[.{format}]?option=value&option=value
-	url := strings.Join([]string{
-		serverURL, // server
+	// {service}/{version}/{profile}/{coordinates}[.{format}]?option=value&option=value
+	u := strings.Join([]string{
 		r.service, // service
 		version,   // version
 		r.profile, // profile
 		"polyline(" + url.PathEscape(r.coords.Polyline(polyline5Factor)) + ")", // coordinates
 	}, "/")
 	if len(r.options) > 0 {
-		url += "?" + r.options.encode() // options
+		u += "?" + r.options.encode() // options
 	}
-	return url, nil
+	return u, nil
 }
 
 // Bearing limits the search to segments with given bearing in degrees towards true north in clockwise direction.