refactor backend API structure

internal/httpapi/admin/version/deps.go

@@ -0,0 +1,16 @@
+package version
+
+import (
+	"ds2api/internal/chathistory"
+	adminshared "ds2api/internal/httpapi/admin/shared"
+)
+
+type Handler struct {
+	Store       adminshared.ConfigStore
+	Pool        adminshared.PoolController
+	DS          adminshared.DeepSeekCaller
+	OpenAI      adminshared.OpenAIChatCaller
+	ChatHistory *chathistory.Store
+}
+
+var writeJSON = adminshared.WriteJSON

internal/httpapi/admin/version/handler_version.go

@@ -0,0 +1,75 @@
+package version
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+	"time"
+
+	"ds2api/internal/version"
+)
+
+const latestReleaseAPI = "https://api.github.com/repos/CJackHwang/ds2api/releases/latest"
+
+type latestReleasePayload struct {
+	TagName     string `json:"tag_name"`
+	HTMLURL     string `json:"html_url"`
+	PublishedAt string `json:"published_at"`
+}
+
+func (h *Handler) getVersion(w http.ResponseWriter, _ *http.Request) {
+	current, source := version.Current()
+	resp := map[string]any{
+		"success":         true,
+		"current_version": current,
+		"current_tag":     version.Tag(current),
+		"source":          source,
+		"checked_at":      time.Now().UTC().Format(time.RFC3339),
+	}
+
+	req, err := http.NewRequest(http.MethodGet, latestReleaseAPI, nil)
+	if err != nil {
+		resp["check_error"] = err.Error()
+		writeJSON(w, http.StatusOK, resp)
+		return
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+	req.Header.Set("User-Agent", "ds2api-version-check")
+
+	client := &http.Client{Timeout: 4 * time.Second}
+	r, err := client.Do(req)
+	if err != nil {
+		resp["check_error"] = err.Error()
+		writeJSON(w, http.StatusOK, resp)
+		return
+	}
+	defer func() { _ = r.Body.Close() }()
+	if r.StatusCode < 200 || r.StatusCode >= 300 {
+		resp["check_error"] = "github api status: " + r.Status
+		writeJSON(w, http.StatusOK, resp)
+		return
+	}
+
+	var data latestReleasePayload
+	if err := json.NewDecoder(r.Body).Decode(&data); err != nil {
+		resp["check_error"] = err.Error()
+		writeJSON(w, http.StatusOK, resp)
+		return
+	}
+
+	latest := strings.TrimSpace(data.TagName)
+	if latest == "" {
+		resp["check_error"] = "missing latest tag"
+		writeJSON(w, http.StatusOK, resp)
+		return
+	}
+	latestVersion := strings.TrimPrefix(latest, "v")
+
+	resp["latest_tag"] = latest
+	resp["latest_version"] = latestVersion
+	resp["release_url"] = data.HTMLURL
+	resp["published_at"] = data.PublishedAt
+	resp["has_update"] = version.Compare(current, latestVersion) < 0
+
+	writeJSON(w, http.StatusOK, resp)
+}

internal/httpapi/admin/version/routes.go

@@ -0,0 +1,7 @@
+package version
+
+import "github.com/go-chi/chi/v5"
+
+func RegisterRoutes(r chi.Router, h *Handler) {
+	r.Get("/version", h.getVersion)
+}