chore(all): move sub-packages to internal/provider

internal/provider/mullvad/updater/servers.go

@@ -0,0 +1,40 @@
+// Package mullvad contains code to obtain the server information
+// for the Mullvad provider.
+package mullvad
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+var ErrNotEnoughServers = errors.New("not enough servers found")
+
+func GetServers(ctx context.Context, client *http.Client, minServers int) (
+	servers []models.Server, err error) {
+	data, err := fetchAPI(ctx, client)
+	if err != nil {
+		return nil, err
+	}
+
+	hts := make(hostToServer)
+	for _, serverData := range data {
+		if err := hts.add(serverData); err != nil {
+			return nil, err
+		}
+	}
+
+	if len(hts) < minServers {
+		return nil, fmt.Errorf("%w: %d and expected at least %d",
+			ErrNotEnoughServers, len(hts), minServers)
+	}
+
+	servers = hts.toServersSlice()
+
+	sortServers(servers)
+
+	return servers, nil
+}