From 55146a82f6dcf590fb40c56e33c1f49a4e1ce09c Mon Sep 17 00:00:00 2001
From: Dmitry Shihovtsev <soffokulus@gmail.com>
Date: Fri, 5 Nov 2021 11:30:50 +0600
Subject: [PATCH] Autodetect client location if we didn't passed it

---
 cmd/main.go          | 16 ++++++------
 config/options.go    | 13 ++++++++++
 location/location.go | 59 ++++++++++++++++++++++++++++++++++++++++++++
 proposal/api.go      | 22 +++++++++++++++--
 4 files changed, 101 insertions(+), 9 deletions(-)
 create mode 100644 location/location.go

diff --git a/cmd/main.go b/cmd/main.go
index 8aa1627..42dd001 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -13,11 +13,17 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/go-redis/redis/v8"
+	"github.com/rs/zerolog/log"
+	swaggerFiles "github.com/swaggo/files"
+	ginSwagger "github.com/swaggo/gin-swagger"
+	_ "go.uber.org/automaxprocs"
+
 	"github.com/mysteriumnetwork/discovery/config"
 	"github.com/mysteriumnetwork/discovery/db"
 	_ "github.com/mysteriumnetwork/discovery/docs"
 	"github.com/mysteriumnetwork/discovery/health"
 	"github.com/mysteriumnetwork/discovery/listener"
+	"github.com/mysteriumnetwork/discovery/location"
 	"github.com/mysteriumnetwork/discovery/price"
 	"github.com/mysteriumnetwork/discovery/price/pricing"
 	"github.com/mysteriumnetwork/discovery/proposal"
@@ -25,12 +31,6 @@ import (
 	"github.com/mysteriumnetwork/discovery/quality/oracleapi"
 	"github.com/mysteriumnetwork/discovery/tags"
 	mlog "github.com/mysteriumnetwork/logger"
-	"github.com/rs/zerolog/log"
-	swaggerFiles "github.com/swaggo/files"
-	ginSwagger "github.com/swaggo/gin-swagger"
-
-	// unconfuse the number of cores go can use in k8s
-	_ "go.uber.org/automaxprocs"
 )
 
 var Version = "<dev>"
@@ -83,8 +83,10 @@ func main() {
 	go proposalService.StartExpirationJob()
 	defer proposalService.Shutdown()
 
+	locationProvider := location.NewLocationProvider(cfg.LocationAddress.String(), cfg.LocationUser, cfg.LocationPass)
+
 	v3 := r.Group("/api/v3")
-	proposal.NewAPI(proposalService, proposalRepo).RegisterRoutes(v3)
+	proposal.NewAPI(proposalService, proposalRepo, locationProvider).RegisterRoutes(v3)
 	health.NewAPI(rdb, database).RegisterRoutes(v3)
 
 	cfger := pricing.NewConfigProviderDB(rdb)
diff --git a/config/options.go b/config/options.go
index 24080a6..8c09ed0 100644
--- a/config/options.go
+++ b/config/options.go
@@ -20,6 +20,9 @@ type Options struct {
 	RedisPass         string
 	RedisDB           int
 	BadgerAddress     url.URL
+	LocationAddress   url.URL
+	LocationUser      string
+	LocationPass      string
 }
 
 func Read() (*Options, error) {
@@ -48,6 +51,13 @@ func Read() (*Options, error) {
 		return nil, err
 	}
 
+	locationUser := OptionalEnv("LOCATION_USER", "")
+	locationPass := OptionalEnv("LOCATION_PASS", "")
+	locationAddress, err := RequiredEnvURL("LOCATION_ADDRESS")
+	if err != nil {
+		return nil, err
+	}
+
 	redisPass := OptionalEnv("REDIS_PASS", "")
 
 	redisDBint := 0
@@ -68,6 +78,9 @@ func Read() (*Options, error) {
 		RedisPass:         redisPass,
 		RedisDB:           redisDBint,
 		BadgerAddress:     *badgerAddress,
+		LocationAddress:   *locationAddress,
+		LocationUser:      locationUser,
+		LocationPass:      locationPass,
 	}, nil
 }
 
diff --git a/location/location.go b/location/location.go
new file mode 100644
index 0000000..e82a289
--- /dev/null
+++ b/location/location.go
@@ -0,0 +1,59 @@
+// Copyright (c) 2021 BlockDev AG
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package location
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type locationProvider struct {
+	address string
+	user    string
+	pass    string
+}
+
+// NewLocationProvider create a new location provider instance.
+func NewLocationProvider(address, user, pass string) *locationProvider {
+	return &locationProvider{
+		address: address,
+		user:    user,
+		pass:    pass,
+	}
+}
+
+// Country returns a country code for the provided IP-address.
+func (lp *locationProvider) Country(ip string) (countryCode string, err error) {
+	url := fmt.Sprintf("%s/%s", lp.address, ip)
+
+	req, err := http.NewRequest("GET", url, nil)
+	req.SetBasicAuth(lp.user, lp.pass)
+
+	ctx, cancel := context.WithTimeout(req.Context(), 5*time.Second)
+	defer cancel()
+
+	req = req.WithContext(ctx)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+
+	defer resp.Body.Close()
+
+	var country struct {
+		Country string `json:"country"`
+	}
+
+	err = json.NewDecoder(resp.Body).Decode(&country)
+	if err != nil {
+		return "", err
+	}
+
+	return country.Country, nil
+}
diff --git a/proposal/api.go b/proposal/api.go
index 32e8b77..790886e 100644
--- a/proposal/api.go
+++ b/proposal/api.go
@@ -17,10 +17,19 @@ import (
 type API struct {
 	service    *Service
 	repository *Repository
+	location   locationProvider
 }
 
-func NewAPI(service *Service, repository *Repository) *API {
-	return &API{service: service, repository: repository}
+type locationProvider interface {
+	Country(ip string) (countryCode string, err error)
+}
+
+func NewAPI(service *Service, repository *Repository, location locationProvider) *API {
+	return &API{
+		service:    service,
+		repository: repository,
+		location:   location,
+	}
 }
 
 // Proposals list proposals.
@@ -52,6 +61,15 @@ func (a *API) Proposals(c *gin.Context) {
 		tags:               c.Query("tags"),
 	}
 
+	if len(opts.from) != 2 {
+		country, err := a.location.Country(c.ClientIP())
+		if err != nil {
+			log.Warn().Err(err).Msg("Failed to autodetect client country")
+		} else {
+			opts.from = country
+		}
+	}
+
 	pids, _ := c.GetQueryArray("provider_id")
 	opts.providerIDS = pids