chore: migrate mail themes to shared framework and locked upstream inputs

tools/upstream/sync.go

@@ -0,0 +1,164 @@
+package upstream
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var tagPattern = regexp.MustCompile(`^v([0-9]+)\.[0-9]+\.[0-9]+$`)
+
+func validTag(tag string) bool {
+	m := tagPattern.FindStringSubmatch(tag)
+	if m == nil {
+		return false
+	}
+	major, err := strconv.Atoi(m[1])
+	return err == nil && major >= 28
+}
+
+// Sync downloads by resolved commit, validates in memory, then swaps the whole
+// snapshot. Network/adapter failures leave the existing snapshot untouched.
+func Sync(ctx context.Context, tag, dir string) error {
+	return syncFrom(ctx, tag, dir, "https://api.github.com/repos/go-gitea/gitea/", "https://raw.githubusercontent.com/go-gitea/gitea/")
+}
+
+func syncFrom(ctx context.Context, tag, dir, api, raw string) error {
+	if !validTag(tag) {
+		return fmt.Errorf("expected a stable Gitea 28+ tag, e.g. v28.0.0")
+	}
+	client := &http.Client{Timeout: 45 * time.Second}
+	get := func(url string) ([]byte, error) {
+		req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+		if err != nil {
+			return nil, err
+		}
+		req.Header.Set("User-Agent", "GiteaMailTemplates-snapshot")
+		resp, err := client.Do(req)
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode != 200 {
+			return nil, fmt.Errorf("%s: HTTP %d", url, resp.StatusCode)
+		}
+		b, err := io.ReadAll(io.LimitReader(resp.Body, 16<<20))
+		return b, err
+	}
+	b, err := get(api + "commits/" + tag)
+	if err != nil {
+		return err
+	}
+	var commit struct {
+		SHA    string `json:"sha"`
+		Commit struct {
+			Tree struct {
+				SHA string `json:"sha"`
+			} `json:"tree"`
+		} `json:"commit"`
+	}
+	if err := json.Unmarshal(b, &commit); err != nil {
+		return err
+	}
+	b, err = get(api + "git/trees/" + commit.Commit.Tree.SHA + "?recursive=1")
+	if err != nil {
+		return err
+	}
+	var tree struct {
+		Truncated bool `json:"truncated"`
+		Tree      []struct {
+			Path string `json:"path"`
+			Type string `json:"type"`
+		} `json:"tree"`
+	}
+	if err := json.Unmarshal(b, &tree); err != nil {
+		return err
+	}
+	if tree.Truncated {
+		return fmt.Errorf("upstream tree is truncated")
+	}
+	s := &Snapshot{Lock: Lock{Schema: 1, Repository: "https://github.com/go-gitea/gitea", Tag: tag, Commit: commit.SHA, Files: map[string]string{}}, Files: map[string][]byte{}}
+	for _, item := range tree.Tree {
+		p := item.Path
+		_, adapter := AdapterSources[p]
+		selected := adapter || p == "LICENSE" || p == "public/assets/img/favicon.png" || (strings.HasPrefix(p, "templates/mail/") && strings.HasSuffix(p, ".tmpl")) || (strings.HasPrefix(p, "options/locale/locale_") && strings.HasSuffix(p, ".json"))
+		if !selected || item.Type != "blob" {
+			continue
+		}
+		b, err := get(raw + commit.SHA + "/" + p)
+		if err != nil {
+			return err
+		}
+		s.Files[p] = b
+		s.Lock.Files[p] = Digest(b)
+	}
+	if err := s.validate(); err != nil {
+		return err
+	}
+	abs, err := filepath.Abs(dir)
+	if err != nil {
+		return err
+	}
+	// Never replace a checkout or arbitrary non-snapshot directory.
+	if filepath.Base(abs) != "upstream" {
+		return fmt.Errorf("snapshot destination must be named upstream")
+	}
+	if entries, err := os.ReadDir(abs); err == nil && len(entries) > 0 {
+		if _, err := loadFiles(abs); err != nil {
+			return fmt.Errorf("refusing to replace invalid existing snapshot: %w", err)
+		}
+	}
+	stage, err := os.MkdirTemp(filepath.Dir(abs), ".upstream-stage-")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(stage)
+	for p, data := range s.Files {
+		filename := filepath.Join(stage, filepath.FromSlash(p))
+		if err := os.MkdirAll(filepath.Dir(filename), 0755); err != nil {
+			return err
+		}
+		if err := os.WriteFile(filename, data, 0644); err != nil {
+			return err
+		}
+	}
+	b, err = json.MarshalIndent(s.Lock, "", "  ")
+	if err != nil {
+		return err
+	}
+	b = append(b, '\n')
+	if err := os.WriteFile(filepath.Join(stage, "lock.json"), b, 0644); err != nil {
+		return err
+	}
+	if _, err := os.Stat(abs); err == nil {
+		backup, err := os.MkdirTemp(filepath.Dir(abs), ".upstream-backup-")
+		if err != nil {
+			return err
+		}
+		if err := os.Remove(backup); err != nil {
+			return err
+		}
+		if err := os.Rename(abs, backup); err != nil {
+			return err
+		}
+		if err := os.Rename(stage, abs); err != nil {
+			_ = os.Rename(backup, abs)
+			return err
+		}
+		if err := os.RemoveAll(backup); err != nil {
+			return err
+		}
+	} else if err := os.Rename(stage, abs); err != nil {
+		return err
+	}
+	fmt.Printf("[PASS] Locked %s (%s): %d templates, %d languages\n", tag, commit.SHA, len(s.Templates), len(s.Locales))
+	return nil
+}