feat(codegen): rename "fields" to "codegen" for more meaningful naming

codegen/version.go

@@ -0,0 +1,111 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"go/format"
+	"net/http"
+	"net/url"
+	"os"
+	"path/filepath"
+
+	"github.com/hashicorp/go-version"
+)
+
+const (
+	LatestVersionMarker = "latest"
+	baseDownloadUrl     = "https://dl.ui.com/unifi/%s/unifi_sysvinit_all.deb"
+)
+
+type UnifiVersion struct {
+	Version     *version.Version
+	DownloadUrl *url.URL
+}
+
+func NewUnifiVersion(unifiVersion *version.Version, downloadUrl *url.URL) *UnifiVersion {
+	return &UnifiVersion{
+		Version:     unifiVersion,
+		DownloadUrl: downloadUrl,
+	}
+}
+
+func latestUnifiVersion() (*UnifiVersion, error) {
+	url, err := url.Parse(firmwareUpdateApi)
+	if err != nil {
+		return nil, err
+	}
+
+	query := url.Query()
+	query.Add("filter", firmwareUpdateApiFilter("channel", releaseChannel))
+	query.Add("filter", firmwareUpdateApiFilter("product", unifiControllerProduct))
+	url.RawQuery = query.Encode()
+
+	req, err := http.NewRequestWithContext(context.Background(), http.MethodGet, url.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var respData firmwareUpdateApiResponse
+	err = json.NewDecoder(resp.Body).Decode(&respData)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, firmware := range respData.Embedded.Firmware {
+		if firmware.Platform != debianPlatform {
+			continue
+		}
+		return NewUnifiVersion(firmware.Version.Core(), firmware.Links.Data.Href), nil
+	}
+
+	return nil, errors.New("no Unifi Controller firmware found")
+}
+
+func determineUnifiVersion(versionMarker string) (*UnifiVersion, error) {
+	if versionMarker == LatestVersionMarker {
+		return latestUnifiVersion()
+	} else {
+		unifiVersion, err := version.NewVersion(versionMarker)
+		if err != nil {
+			return nil, err
+		}
+		unifiVersion = unifiVersion.Core()
+		downloadUrl := fmt.Sprintf(baseDownloadUrl, unifiVersion)
+		unifiDownloadUrl, err := url.Parse(downloadUrl)
+		if err != nil {
+			return nil, err
+		}
+		return NewUnifiVersion(unifiVersion, unifiDownloadUrl), nil
+	}
+}
+
+func writeVersionFile(version *version.Version, outDir string) error {
+	versionGo := []byte(fmt.Sprintf(`
+// Generated code. DO NOT EDIT.
+
+package unifi
+
+const UnifiVersion = %q
+`, version.Core()))
+
+	versionGo, err := format.Source(versionGo)
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(filepath.Join(outDir, "version.generated.go"), versionGo, 0o644)
+}
+
+func writeVersionRepoMarkerFile(version *version.Version, outDir string) error {
+	versionRepoMarker := []byte(version.Core().String())
+	return os.WriteFile(filepath.Join(outDir, ".unifi-version"), versionRepoMarker, 0o644)
+}