Unify connection handling

1 files changed, 88 insertions, 0 deletions

diff --git a/internal/http/client.go b/internal/http/client.go
new file mode 100644
index 0000000..c9af26e
--- /dev/null
+++ b/internal/http/client.go
@@ -0,0 +1,88 @@
+package http
+
+import (
+	ctxt "context"
+	"crypto/tls"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// share HTTP clients
+var (
+	stdClient    *http.Client
+	unsafeClient *http.Client
+)
+
+// Error represents an HTTP error returned by a server.
+type Error struct {
+	StatusCode int
+	Status     string
+}
+
+func (err Error) Error() string {
+	return fmt.Sprintf("http error: %s", err.Status)
+}
+
+func init() {
+	// std
+	stdClient = &http.Client{Transport: http.DefaultTransport}
+
+	// unsafe
+	tlsConfig := &tls.Config{InsecureSkipVerify: true}
+	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport.TLSClientConfig = tlsConfig
+	unsafeClient = &http.Client{Transport: transport}
+}
+
+func context(timeout int) (ctxt.Context, ctxt.CancelFunc) {
+	return ctxt.WithTimeout(ctxt.Background(), time.Duration(timeout)*time.Second)
+}
+
+func client(disableTLS bool) *http.Client {
+	if disableTLS {
+		return unsafeClient
+	}
+	return stdClient
+}
+
+var noop ctxt.CancelFunc = func() {}
+
+func Get(url string, timeout int, disableTLS bool) (resp *http.Response, cancel ctxt.CancelFunc, err error) {
+	prematureExit := true
+	ctx, ctxCancel := context(timeout)
+
+	cancel = func() {
+		if resp != nil {
+			_ = resp.Body.Close()
+		}
+		ctxCancel()
+	}
+
+	defer func() {
+		if prematureExit {
+			cancel()
+		}
+	}()
+
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, noop, err
+	}
+	req.Header.Set("User-Agent", "Feed2Imap-Go/1.0")
+
+	resp, err = client(disableTLS).Do(req)
+	if err != nil {
+		return nil, noop, err
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, noop, Error{
+			StatusCode: resp.StatusCode,
+			Status:     resp.Status,
+		}
+	}
+
+	prematureExit = false
+	return resp, cancel, nil
+}