feat: implement proto-gen platform

- Config loader with env var expansion and validation
- SQLite database with tasks and toolchain_versions tables
- Gitea REST API client for repository and branch operations
- K8s client for Job lifecycle management (with noop fallback for local dev)
- REST API: tasks CRUD, retry, plugins, version management
- Worker/scheduler with polling, concurrency control, and job tracking
- Static frontend: generate, tasks, settings pages
- Toolchain images: Go and Node.js Dockerfiles with entrypoint scripts
- Helm chart with deployment, service, configmap, ingress, PVC
- Multi-stage Dockerfile for service
- Unit tests for config, database, gitclient, k8s, api, worker
- E2E tests for idempotency, version switch, failure recovery

internal/api/handlers.go

@@ -0,0 +1,203 @@
+package api
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/google/uuid"
+
+	"proto-gen/internal/config"
+	"proto-gen/internal/models"
+)
+
+func writeJSON(w http.ResponseWriter, status int, v interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	json.NewEncoder(w).Encode(v)
+}
+
+func writeError(w http.ResponseWriter, status int, msg string) {
+	writeJSON(w, status, map[string]string{"error": msg})
+}
+
+type CreateTaskRequest struct {
+	Language    string `json:"language"`
+	ProtoRepo   string `json:"proto_repo"`
+	ProtoBranch string `json:"proto_branch"`
+	TargetRepo  string `json:"target_repo"`
+}
+
+func (s *Server) handleCreateTask(w http.ResponseWriter, r *http.Request) {
+	var req CreateTaskRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if req.Language == "" || req.ProtoRepo == "" || req.ProtoBranch == "" {
+		writeError(w, http.StatusBadRequest, "language, proto_repo, and proto_branch are required")
+		return
+	}
+
+	plugin := s.cfg.GetPluginByLanguage(req.Language)
+	if plugin == nil {
+		writeError(w, http.StatusBadRequest, fmt.Sprintf("unsupported language: %s", req.Language))
+		return
+	}
+
+	if req.TargetRepo == "" {
+		req.TargetRepo = strings.ReplaceAll(
+			strings.ReplaceAll(s.cfg.TargetRepoTemplate, "{proto_repo}", req.ProtoRepo),
+			"{lang}", req.Language,
+		)
+	}
+
+	branch, err := s.git.GetBranch(req.ProtoRepo, req.ProtoRepo, req.ProtoBranch)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, fmt.Sprintf("branch not found: %v", err))
+		return
+	}
+
+	hasRunning, err := s.db.HasRunningTask(req.TargetRepo)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "internal error")
+		return
+	}
+	if hasRunning {
+		writeError(w, http.StatusConflict, "target repo already has a running task")
+		return
+	}
+
+	task := &models.Task{
+		ID:             uuid.New().String(),
+		Status:         models.StatusPending,
+		Language:       req.Language,
+		ProtoRepo:      req.ProtoRepo,
+		ProtoBranch:    req.ProtoBranch,
+		ProtoCommit:    branch.Commit,
+		TargetRepo:     req.TargetRepo,
+		ToolchainImage: s.cfg.ToolchainRegistry + "/" + plugin.Image,
+	}
+
+	if err := s.db.CreateTask(task); err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to create task")
+		return
+	}
+
+	writeJSON(w, http.StatusCreated, task)
+}
+
+func (s *Server) handleListTasks(w http.ResponseWriter, r *http.Request) {
+	status := r.URL.Query().Get("status")
+	limit := 50
+	if l := r.URL.Query().Get("limit"); l != "" {
+		if parsed, err := strconv.Atoi(l); err == nil && parsed > 0 {
+			limit = parsed
+		}
+	}
+	offset := 0
+	if o := r.URL.Query().Get("offset"); o != "" {
+		if parsed, err := strconv.Atoi(o); err == nil && parsed >= 0 {
+			offset = parsed
+		}
+	}
+
+	tasks, err := s.db.ListTasks(status, limit, offset)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to list tasks")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, tasks)
+}
+
+func (s *Server) handleGetTask(w http.ResponseWriter, r *http.Request) {
+	id := chi.URLParam(r, "id")
+	task, err := s.db.GetTask(id)
+	if err != nil {
+		writeError(w, http.StatusNotFound, "task not found")
+		return
+	}
+	writeJSON(w, http.StatusOK, task)
+}
+
+func (s *Server) handleRetryTask(w http.ResponseWriter, r *http.Request) {
+	id := chi.URLParam(r, "id")
+	task, err := s.db.GetTask(id)
+	if err != nil {
+		writeError(w, http.StatusNotFound, "task not found")
+		return
+	}
+
+	if task.Status != models.StatusFailed {
+		writeError(w, http.StatusBadRequest, "can only retry failed tasks")
+		return
+	}
+
+	hasRunning, err := s.db.HasRunningTask(task.TargetRepo)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "internal error")
+		return
+	}
+	if hasRunning {
+		writeError(w, http.StatusConflict, "target repo already has a running task")
+		return
+	}
+
+	task.Status = models.StatusPending
+	task.Error = ""
+	task.Log = ""
+	task.Retries++
+	if err := s.db.UpdateTask(task); err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to retry task")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, task)
+}
+
+func (s *Server) handleListPlugins(w http.ResponseWriter, r *http.Request) {
+	var plugins []config.PluginConfig
+	for _, p := range s.cfg.Plugins {
+		plugins = append(plugins, p)
+	}
+	writeJSON(w, http.StatusOK, plugins)
+}
+
+func (s *Server) handleGetPluginVersion(w http.ResponseWriter, r *http.Request) {
+	lang := chi.URLParam(r, "lang")
+	plugin := s.cfg.GetPluginByLanguage(lang)
+	if plugin == nil {
+		writeError(w, http.StatusNotFound, "plugin not found")
+		return
+	}
+	writeJSON(w, http.StatusOK, plugin)
+}
+
+func (s *Server) handleUpdatePluginVersion(w http.ResponseWriter, r *http.Request) {
+	lang := chi.URLParam(r, "lang")
+	plugin := s.cfg.GetPluginByLanguage(lang)
+	if plugin == nil {
+		writeError(w, http.StatusNotFound, "plugin not found")
+		return
+	}
+
+	var req struct {
+		Image string `json:"image"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if req.Image == "" {
+		writeError(w, http.StatusBadRequest, "image is required")
+		return
+	}
+
+	plugin.Image = req.Image
+	writeJSON(w, http.StatusOK, plugin)
+}