From cbdd1a933c92336c5458de5580b1fe627d92431f Mon Sep 17 00:00:00 2001
From: Jeremy Lin <jjlin@users.noreply.github.com>
Date: Sun, 6 Oct 2024 06:30:33 -0700
Subject: [PATCH] feat(publicip): `cloudflare` API support (#2502)

---
 internal/publicip/api/api.go        |  7 ++-
 internal/publicip/api/cloudflare.go | 91 +++++++++++++++++++++++++++++
 internal/publicip/api/errors.go     |  1 +
 3 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 internal/publicip/api/cloudflare.go

diff --git a/internal/publicip/api/api.go b/internal/publicip/api/api.go
index e5e19252..6f12439c 100644
--- a/internal/publicip/api/api.go
+++ b/internal/publicip/api/api.go
@@ -19,6 +19,7 @@ type API interface {
 type Provider string
 
 const (
+	Cloudflare  Provider = "cloudflare"
 	IPInfo      Provider = "ipinfo"
 	IP2Location Provider = "ip2location"
 )
@@ -26,6 +27,8 @@ const (
 func New(provider Provider, client *http.Client, token string) ( //nolint:ireturn
 	a API, err error) {
 	switch provider {
+	case Cloudflare:
+		return newCloudflare(client), nil
 	case IPInfo:
 		return newIPInfo(client, token), nil
 	case IP2Location:
@@ -41,12 +44,14 @@ var (
 
 func ParseProvider(s string) (provider Provider, err error) {
 	switch strings.ToLower(s) {
+	case "cloudflare":
+		return Cloudflare, nil
 	case "ipinfo":
 		return IPInfo, nil
 	case "ip2location":
 		return IP2Location, nil
 	default:
-		return "", fmt.Errorf(`%w: %q can only be "ipinfo" or "ip2location"`,
+		return "", fmt.Errorf(`%w: %q can only be "cloudflare", "ipinfo", or "ip2location"`,
 			ErrProviderNotValid, s)
 	}
 }
diff --git a/internal/publicip/api/cloudflare.go b/internal/publicip/api/cloudflare.go
new file mode 100644
index 00000000..867e7595
--- /dev/null
+++ b/internal/publicip/api/cloudflare.go
@@ -0,0 +1,91 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/netip"
+	"strings"
+
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+type cloudflare struct {
+	client *http.Client
+}
+
+func newCloudflare(client *http.Client) *cloudflare {
+	return &cloudflare{
+		client: client,
+	}
+}
+
+// FetchInfo obtains information on the public IP address of the machine,
+// and returns an error if the `ip` argument is set since the Cloudflare API
+// can only be used to provide details about the current machine public IP.
+func (c *cloudflare) FetchInfo(ctx context.Context, ip netip.Addr) (
+	result models.PublicIP, err error) {
+	url := "https://speed.cloudflare.com/meta"
+	if ip.IsValid() {
+		return result, fmt.Errorf("%w: cloudflare cannot provide information on the arbitrary IP address %s",
+			ErrServiceLimited, ip)
+	}
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return result, err
+	}
+
+	response, err := c.client.Do(request)
+	if err != nil {
+		return result, err
+	}
+	defer response.Body.Close()
+
+	switch response.StatusCode {
+	case http.StatusOK:
+	case http.StatusTooManyRequests:
+		return result, fmt.Errorf("%w from %s: %d %s",
+			ErrTooManyRequests, url, response.StatusCode, response.Status)
+	default:
+		return result, fmt.Errorf("%w from %s: %d %s",
+			ErrBadHTTPStatus, url, response.StatusCode, response.Status)
+	}
+
+	decoder := json.NewDecoder(response.Body)
+	var data struct {
+		Hostname       string     `json:"hostname,omitempty"`
+		ClientIP       netip.Addr `json:"clientIp,omitempty"`
+		ASOrganization string     `json:"asOrganization,omitempty"`
+		Country        string     `json:"country,omitempty"`
+		City           string     `json:"city,omitempty"`
+		Region         string     `json:"region,omitempty"`
+		PostalCode     string     `json:"postalCode,omitempty"`
+		Latitude       string     `json:"latitude,omitempty"`
+		Longitude      string     `json:"longitude,omitempty"`
+	}
+	if err := decoder.Decode(&data); err != nil {
+		return result, fmt.Errorf("decoding response: %w", err)
+	}
+
+	countryCode := strings.ToLower(data.Country)
+	country, ok := constants.CountryCodes()[countryCode]
+	if ok {
+		data.Country = country
+	}
+
+	result = models.PublicIP{
+		IP:           data.ClientIP,
+		Region:       data.Region,
+		Country:      data.Country,
+		City:         data.City,
+		Hostname:     data.Hostname,
+		Location:     data.Latitude + "," + data.Longitude,
+		Organization: data.ASOrganization,
+		PostalCode:   data.PostalCode,
+		Timezone:     "", // no timezone
+	}
+	return result, nil
+}
diff --git a/internal/publicip/api/errors.go b/internal/publicip/api/errors.go
index 7ef8f1fb..0b479551 100644
--- a/internal/publicip/api/errors.go
+++ b/internal/publicip/api/errors.go
@@ -6,4 +6,5 @@ var (
 	ErrTokenNotValid   = errors.New("token is not valid")
 	ErrTooManyRequests = errors.New("too many requests sent for this month")
 	ErrBadHTTPStatus   = errors.New("bad HTTP status received")
+	ErrServiceLimited  = errors.New("service is limited")
 )