Initial Commit

2 files changed, 284 insertions, 0 deletions

diff --git a/web/server.go b/web/server.go
new file mode 100644
index 0000000..121b197
--- /dev/null
+++ b/web/server.go
@@ -0,0 +1,181 @@
+package web
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"html/template"
+	"log"
+	"net/http"
+	"strings"
+
+	"git.wilk.cx/cr-browser/registry"
+)
+
+type RepositoryLister interface {
+	Repositories(ctx context.Context) ([]registry.Repository, error)
+	Repository(ctx context.Context, name string) (registry.Repository, error)
+	Manifest(ctx context.Context, repository, digest string) (registry.Manifest, error)
+}
+
+type Server struct {
+	provider     RepositoryLister
+	registryHost string
+	tmpl         *template.Template
+}
+
+type PageData struct {
+	Title        string
+	RegistryHost string
+	Repositories []registry.Repository
+	Repository   registry.Repository
+	Manifest     registry.Manifest
+	SelectedTag  string
+}
+
+func NewServer(provider RepositoryLister, registryHost string) (*Server, error) {
+	tmpl, err := template.New("").
+		Funcs(templateFuncs()).
+		ParseGlob("templates/*.gohtml")
+	if err != nil {
+		return nil, err
+	}
+
+	return &Server{
+		provider:     provider,
+		registryHost: registryHost,
+		tmpl:         tmpl,
+	}, nil
+}
+
+func (s *Server) Handler() http.Handler {
+	mux := http.NewServeMux()
+
+	// Static assets
+	mux.Handle(
+		"/assets/",
+		http.StripPrefix(
+			"/assets/",
+			http.FileServer(http.Dir("./assets")),
+		),
+	)
+
+	// Repository listing page
+	mux.HandleFunc("/", s.repositories)
+	mux.HandleFunc("/r/{name...}", s.repository)
+
+	return mux
+}
+
+func (s *Server) repositories(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path != "/" {
+		http.NotFound(w, r)
+		return
+	}
+
+	if r.Method != http.MethodGet {
+		w.Header().Set("Allow", "GET")
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	repos, err := s.provider.Repositories(r.Context())
+	if err != nil {
+		log.Printf("fetch repositories: %v", err)
+		http.Error(w, "failed to fetch repositories", http.StatusBadGateway)
+		return
+	}
+
+	data := PageData{
+		Title:        "Container Registry",
+		RegistryHost: s.registryHost,
+		Repositories: repos,
+	}
+
+	var buf bytes.Buffer
+	if err := s.tmpl.ExecuteTemplate(&buf, "repositories", data); err != nil {
+		log.Printf("render repositories: %v", err)
+		http.Error(w, "failed to render page", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write(buf.Bytes())
+}
+
+func (s *Server) repository(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		w.Header().Set("Allow", "GET")
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	name := strings.TrimSuffix(r.PathValue("name"), "/")
+	// Dispatch manifest links while allowing slashes in repository names.
+	if i := strings.LastIndex(name, "/m/"); i >= 0 {
+		digest := name[i+3:]
+		if strings.Contains(digest, ":") && !strings.Contains(digest, "/") {
+			s.manifest(w, r, name[:i], digest)
+			return
+		}
+	}
+
+	repo, err := s.provider.Repository(r.Context(), name)
+	if err != nil {
+		if errors.Is(err, registry.ErrNotFound) {
+			http.NotFound(w, r)
+			return
+		}
+
+		log.Printf("fetch repository: %v", err)
+		http.Error(w, "failed to fetch repository", http.StatusBadGateway)
+		return
+	}
+
+	data := PageData{
+		Title:        repo.Name,
+		RegistryHost: s.registryHost,
+		Repository:   repo,
+	}
+
+	var buf bytes.Buffer
+	if err := s.tmpl.ExecuteTemplate(&buf, "repository", data); err != nil {
+		log.Printf("render repository: %v", err)
+		http.Error(w, "failed to render page", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write(buf.Bytes())
+}
+
+func (s *Server) manifest(w http.ResponseWriter, r *http.Request, repository, digest string) {
+	manifest, err := s.provider.Manifest(r.Context(), repository, digest)
+	if err != nil {
+		if errors.Is(err, registry.ErrNotFound) {
+			http.NotFound(w, r)
+			return
+		}
+		log.Printf("fetch manifest: %v", err)
+		http.Error(w, "failed to fetch manifest", http.StatusBadGateway)
+		return
+	}
+
+	data := PageData{
+		Title:        "Manifest in " + repository,
+		RegistryHost: s.registryHost,
+		Repository:   registry.Repository{Name: repository},
+		Manifest:     manifest,
+		SelectedTag:  r.URL.Query().Get("tag"),
+	}
+
+	var buf bytes.Buffer
+	if err := s.tmpl.ExecuteTemplate(&buf, "manifest", data); err != nil {
+		log.Printf("render manifest: %v", err)
+		http.Error(w, "failed to render page", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	_, _ = w.Write(buf.Bytes())
+}
diff --git a/web/utils.go b/web/utils.go
new file mode 100644
index 0000000..18b5b52
--- /dev/null
+++ b/web/utils.go
@@ -0,0 +1,103 @@
+package web
+
+import (
+	"fmt"
+	"html/template"
+	"net/url"
+	"strings"
+	"time"
+)
+
+func templateFuncs() template.FuncMap {
+	return template.FuncMap{
+		"repoURL":     repoURL,
+		"manifestURL": manifestURL,
+		"pull":        pullAddress,
+		"size":        formatSize,
+		"timestamp":   timestamp,
+		"age":         displayAge,
+		"join":        strings.Join,
+	}
+}
+
+// sanitizeURLPath escapes each path segment separately, preserving slashes in
+// names such as group/repository. Appends a trailing slash.
+func sanitizeURLPath(path string) string {
+	parts := strings.Split(path, "/")
+	for i := range parts {
+		parts[i] = url.PathEscape(parts[i])
+	}
+	return strings.Join(parts, "/") + "/"
+}
+
+func repoURL(name string) string {
+	return "/r/" + sanitizeURLPath(name)
+}
+
+func manifestURL(repository, digest, tag string) string {
+	path := repoURL(repository) + "m/" + sanitizeURLPath(digest)
+	if tag != "" {
+		path += "?" + url.Values{"tag": {tag}}.Encode()
+	}
+	return path
+}
+
+func pullAddress(host, repository, tag, digest string) string {
+	address := strings.TrimSuffix(host, "/") + "/" + repository
+	if tag != "" {
+		address += ":" + tag
+	}
+	if digest != "" {
+		address += "@" + digest
+	}
+	return address
+}
+
+func formatSize(value int64) string {
+	if value >= 1024*1024 {
+		return fmt.Sprintf("%.1fMB", float64(value)/(1024*1024))
+	}
+	if value >= 1024 {
+		return fmt.Sprintf("%.1fKB", float64(value)/1024)
+	}
+	return fmt.Sprintf("%dB", value)
+}
+
+func timestamp(t time.Time) string {
+	if t.IsZero() {
+		return ""
+	}
+	return t.Format(time.DateTime + " MST")
+}
+
+func displayAge(updated time.Time, frozen string) string {
+	if frozen != "" {
+		return frozen
+	}
+	if updated.IsZero() {
+		return "unknown"
+	}
+	elapsed := time.Since(updated)
+	if elapsed < time.Minute {
+		return "just now"
+	}
+	for _, unit := range []struct {
+		duration time.Duration
+		label    string
+	}{
+		{365 * 24 * time.Hour, "year"},
+		{30 * 24 * time.Hour, "month"},
+		{24 * time.Hour, "day"},
+		{time.Hour, "hour"},
+		{time.Minute, "minute"},
+	} {
+		if count := int(elapsed / unit.duration); count > 0 {
+			suffix := "s"
+			if count == 1 {
+				suffix = ""
+			}
+			return fmt.Sprintf("%d %s%s ago", count, unit.label, suffix)
+		}
+	}
+	return "just now"
+}