feat: runtime config, Matomo analytics, chat accounts, DM history/search, and Prometheus retention

backend/chat/src/handlers/handlers.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"golang.org/x/crypto/bcrypt"
 	"gorm.io/gorm"
 
 	"chat/src/auth"
@@ -197,6 +198,7 @@ type Dependencies struct {
 	Redis       db.RedisClient
 	Hub         *ws.Hub
 	SessionStore *auth.SessionStore
+	UserSessions *auth.UserSessionStore
 	DBDriver    string
 }
 
@@ -333,6 +335,251 @@ func HandleAdminSession(deps *Dependencies) http.HandlerFunc {
 	}
 }
 
+// userSessionCookieName is the cookie for registered chat users.
+const userSessionCookieName = "linearvoid_user_session"
+
+// UserCredentialsPayload is used by registration and login.
+type UserCredentialsPayload struct {
+	Username string `json:"username"`
+	Password string `json:"password"`
+}
+
+// validateUsername checks the username length constraints.
+func validateUsername(username string) error {
+	if len(username) < 3 || len(username) > 32 {
+		return fmt.Errorf("username must be 3-32 characters")
+	}
+	return nil
+}
+
+// validatePassword checks the password length constraints.
+func validatePassword(password string) error {
+	if len(password) < 6 {
+		return fmt.Errorf("password must be at least 6 characters")
+	}
+	return nil
+}
+
+// startUserSession issues a user session cookie for the given username.
+func startUserSession(deps *Dependencies, w http.ResponseWriter, r *http.Request, username string) {
+	token, err := auth.GenerateToken()
+	if err != nil {
+		return
+	}
+	expiresAt := time.Now().Add(config.UserSessionTTL())
+	deps.UserSessions.Add(token, username, expiresAt)
+	auth.SetCookie(w, r, userSessionCookieName, token, expiresAt)
+}
+
+// HandleUserRegister creates a new chat user and signs them in.
+func HandleUserRegister(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		var payload UserCredentialsPayload
+		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
+			http.Error(w, "invalid body", http.StatusBadRequest)
+			return
+		}
+		username := strings.TrimSpace(payload.Username)
+		if err := validateUsername(username); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		if err := validatePassword(payload.Password); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+
+		var count int64
+		deps.DB.Model(&db.User{}).Where("username = ?", username).Count(&count)
+		if count > 0 {
+			http.Error(w, "username already taken", http.StatusConflict)
+			return
+		}
+
+		hash, err := bcrypt.GenerateFromPassword([]byte(payload.Password), bcrypt.DefaultCost)
+		if err != nil {
+			http.Error(w, "failed to hash password", http.StatusInternalServerError)
+			return
+		}
+		user := db.User{Username: username, PasswordHash: string(hash)}
+		if err := deps.DB.Create(&user).Error; err != nil {
+			http.Error(w, "failed to create user", http.StatusInternalServerError)
+			return
+		}
+
+		startUserSession(deps, w, r, user.Username)
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{"username": user.Username})
+	}
+}
+
+// HandleUserLogin verifies credentials and signs the user in.
+func HandleUserLogin(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		var payload UserCredentialsPayload
+		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
+			http.Error(w, "invalid body", http.StatusBadRequest)
+			return
+		}
+		username := strings.TrimSpace(payload.Username)
+
+		var user db.User
+		if err := deps.DB.Where("username = ?", username).First(&user).Error; err != nil {
+			http.Error(w, "invalid credentials", http.StatusUnauthorized)
+			return
+		}
+		if err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(payload.Password)); err != nil {
+			http.Error(w, "invalid credentials", http.StatusUnauthorized)
+			return
+		}
+
+		startUserSession(deps, w, r, user.Username)
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{"username": user.Username})
+	}
+}
+
+// HandleUserSession returns the current user session state.
+func HandleUserSession(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		token, _ := auth.GetTokenFromCookie(r, userSessionCookieName)
+		username, ok := deps.UserSessions.Username(token)
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{
+			"authenticated": ok,
+			"username":      username,
+		})
+	}
+}
+
+// HandleUserLogout clears the user session.
+func HandleUserLogout(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		if token, ok := auth.GetTokenFromCookie(r, userSessionCookieName); ok {
+			deps.UserSessions.Remove(token)
+		}
+		auth.ClearCookie(w, r, userSessionCookieName)
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]bool{"ok": true})
+	}
+}
+
+// currentUsername returns the authenticated username from the user session cookie.
+func currentUsername(deps *Dependencies, r *http.Request) (string, bool) {
+	token, ok := auth.GetTokenFromCookie(r, userSessionCookieName)
+	if !ok {
+		return "", false
+	}
+	return deps.UserSessions.Username(token)
+}
+
+// dmRoomFor returns the canonical DM room for two users (sorted, prefixed).
+func dmRoomFor(a, b string) string {
+	if a > b {
+		a, b = b, a
+	}
+	return "dm:" + a + "-" + b
+}
+
+// HandleUserDMHistory returns paginated private message history with a target user.
+func HandleUserDMHistory(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		username, ok := currentUsername(deps, r)
+		if !ok {
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+		target := strings.TrimSpace(r.URL.Query().Get("with"))
+		if target == "" {
+			http.Error(w, "missing target user", http.StatusBadRequest)
+			return
+		}
+		limit := 50
+		if raw := r.URL.Query().Get("limit"); raw != "" {
+			if n, err := strconv.Atoi(raw); err == nil && n > 0 && n <= 200 {
+				limit = n
+			}
+		}
+		room := dmRoomFor(username, target)
+
+		query := deps.DB.Where("room = ?", room)
+		if beforeRaw := r.URL.Query().Get("before"); beforeRaw != "" {
+			if t, err := time.Parse(time.RFC3339, beforeRaw); err == nil {
+				query = query.Where("timestamp < ?", t)
+			}
+		}
+		var messages []db.Message
+		if err := query.Order("timestamp desc").Limit(limit).Find(&messages).Error; err != nil {
+			http.Error(w, "failed to load history", http.StatusInternalServerError)
+			return
+		}
+		for i, j := 0, len(messages)-1; i < j; i, j = i+1, j-1 {
+			messages[i], messages[j] = messages[j], messages[i]
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(messages)
+	}
+}
+
+// HandleUserDMSearch searches private messages with a target user.
+func HandleUserDMSearch(deps *Dependencies) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		username, ok := currentUsername(deps, r)
+		if !ok {
+			http.Error(w, "unauthorized", http.StatusUnauthorized)
+			return
+		}
+		target := strings.TrimSpace(r.URL.Query().Get("with"))
+		q := strings.TrimSpace(r.URL.Query().Get("q"))
+		if target == "" || q == "" {
+			http.Error(w, "missing target or query", http.StatusBadRequest)
+			return
+		}
+		limit := 50
+		if raw := r.URL.Query().Get("limit"); raw != "" {
+			if n, err := strconv.Atoi(raw); err == nil && n > 0 && n <= 200 {
+				limit = n
+			}
+		}
+		room := dmRoomFor(username, target)
+		var messages []db.Message
+		if err := deps.DB.Where("room = ? AND LOWER(text) LIKE ?", room, "%"+strings.ToLower(q)+"%").
+			Order("timestamp desc").Limit(limit).Find(&messages).Error; err != nil {
+			http.Error(w, "failed to search", http.StatusInternalServerError)
+			return
+		}
+		for i, j := 0, len(messages)-1; i < j; i, j = i+1, j-1 {
+			messages[i], messages[j] = messages[j], messages[i]
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(messages)
+	}
+}
+
 // HandleAdminOverview returns the admin dashboard overview.
 func HandleAdminOverview(deps *Dependencies) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -757,29 +1004,83 @@ func HandleAdminSystemSummary(deps *Dependencies) http.HandlerFunc {
 	}
 }
 
+// HandlePublicMatomo exposes the Matomo analytics settings for the viewer frontend.
+func HandlePublicMatomo() http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]any{
+			"matomoUrl":    config.MatomoURL(),
+			"matomoSiteId": config.MatomoSiteID(),
+		})
+	}
+}
+
+// adminConfigResponse builds the admin configuration payload from runtime config
+// and read-only runtime facts.
+func adminConfigResponse(deps *Dependencies) map[string]any {
+	resp := config.RuntimeConfigSnapshot()
+	resp["rateLimitMax"] = config.RateLimitMax()
+	resp["rateLimitWindowSec"] = int(config.RateLimitWindow().Seconds())
+	resp["databaseDriver"] = deps.DBDriver
+	resp["redisEnabled"] = deps.Redis != nil
+	resp["sessionTTLHours"] = int(config.AdminSessionTTL().Hours())
+	return resp
+}
+
 // HandleAdminConfig returns/updates runtime configuration.
 func HandleAdminConfig(deps *Dependencies) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case http.MethodGet:
 			w.Header().Set("Content-Type", "application/json")
-			json.NewEncoder(w).Encode(map[string]any{
-				"rateLimitMax":       config.RateLimitMax(),
-				"rateLimitWindowSec": int(config.RateLimitWindow().Seconds()),
-				"databaseDriver":     deps.DBDriver,
-				"redisEnabled":       deps.Redis != nil,
-				"sessionTTLHours":    int(config.AdminSessionTTL().Hours()),
-			})
+			json.NewEncoder(w).Encode(adminConfigResponse(deps))
 		case http.MethodPut:
-			var payload map[string]any
+			// Editable runtime fields (Matomo + HLS). Rate limit fields remain
+			// env-driven and are intentionally read-only here.
+			var payload struct {
+				MatomoURL          *string `json:"matomoUrl"`
+				MatomoSiteID       *string `json:"matomoSiteId"`
+				HLSSegmentDuration *int    `json:"hlsSegmentDuration"`
+				HLSWindowSize      *int    `json:"hlsWindowSize"`
+			}
 			if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
 				http.Error(w, "invalid body", http.StatusBadRequest)
 				return
 			}
-			// Note: rate limit config is read-only at runtime in this refactored version.
-			// To change, restart with env vars.
+			if payload.MatomoURL != nil {
+				if err := config.SetMatomoURL(*payload.MatomoURL); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+					return
+				}
+			}
+			if payload.MatomoSiteID != nil {
+				if err := config.SetMatomoSiteID(*payload.MatomoSiteID); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+					return
+				}
+			}
+			if payload.HLSSegmentDuration != nil {
+				if err := config.SetHLSSegmentDuration(*payload.HLSSegmentDuration); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+					return
+				}
+			}
+			if payload.HLSWindowSize != nil {
+				if err := config.SetHLSWindowSize(*payload.HLSWindowSize); err != nil {
+					http.Error(w, err.Error(), http.StatusBadRequest)
+					return
+				}
+			}
+			if err := config.SaveRuntimeConfig(); err != nil {
+				http.Error(w, fmt.Sprintf("failed to save config: %v", err), http.StatusInternalServerError)
+				return
+			}
 			w.Header().Set("Content-Type", "application/json")
-			json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
+			json.NewEncoder(w).Encode(adminConfigResponse(deps))
 		default:
 			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 		}