feat: add cost-safe AI growth configuration

internal/config/config.go

@@ -8,6 +8,7 @@ import (
 )
 
 type Config struct {
+	AppEnv                 string
 	HTTPAddr               string
 	DatabaseURL            string
 	RedisAddr              string
@@ -19,10 +20,20 @@ type Config struct {
 	CursorSecret           string
 	FrontendOrigin         string
 	CookieSecure           bool
+	AIGrowthEnabled        bool
+	AvalAIAPIKey           string
+	AvalAIBaseURL          string
+	AvalAIModel            string
+	AIDailyRequestBudget   int64
+	AIDailyTokenBudget     int64
+	AIMaxConcurrent        int
+	AICreatePerMinute      int64
+	AIUncachedScopesPerDay int64
 }
 
 func Load() (Config, error) {
 	cfg := Config{
+		AppEnv:         value("APP_ENV", "development"),
 		HTTPAddr:       value("HTTP_ADDR", "127.0.0.1:8080"),
 		DatabaseURL:    os.Getenv("DATABASE_URL"),
 		RedisAddr:      value("REDIS_ADDR", "localhost:6379"),
@@ -33,6 +44,9 @@ func Load() (Config, error) {
 		SessionSecret:  os.Getenv("SESSION_SECRET"),
 		CursorSecret:   os.Getenv("CURSOR_SECRET"),
 		FrontendOrigin: value("FRONTEND_ORIGIN", "http://localhost:5173"),
+		AvalAIAPIKey:   os.Getenv("AVALAI_API_KEY"),
+		AvalAIBaseURL:  value("AVALAI_BASE_URL", "https://api.avalai.ir"),
+		AvalAIModel:    value("AVALAI_MODEL", "gpt-5-mini-2025-08-07"),
 	}
 
 	var err error
@@ -40,6 +54,31 @@ func Load() (Config, error) {
 	if err != nil {
 		return Config{}, fmt.Errorf("parsing cookie secure: %w", err)
 	}
+	cfg.AIGrowthEnabled, err = strconv.ParseBool(value("AI_GROWTH_ENABLED", "false"))
+	if err != nil {
+		return Config{}, fmt.Errorf("parsing AI growth enabled: %w", err)
+	}
+	cfg.AIDailyRequestBudget, err = parseInt64("AI_DAILY_REQUEST_BUDGET", 0)
+	if err != nil {
+		return Config{}, err
+	}
+	cfg.AIDailyTokenBudget, err = parseInt64("AI_DAILY_TOKEN_BUDGET", 0)
+	if err != nil {
+		return Config{}, err
+	}
+	maxConcurrent, err := parseInt64("AI_MAX_CONCURRENT", 4)
+	if err != nil {
+		return Config{}, err
+	}
+	cfg.AIMaxConcurrent = int(maxConcurrent)
+	cfg.AICreatePerMinute, err = parseInt64("AI_CREATE_PER_MINUTE", 10)
+	if err != nil {
+		return Config{}, err
+	}
+	cfg.AIUncachedScopesPerDay, err = parseInt64("AI_UNCACHED_SCOPES_PER_DAY", 5)
+	if err != nil {
+		return Config{}, err
+	}
 	if cfg.DatabaseURL == "" {
 		return Config{}, errors.New("config: DATABASE_URL is required")
 	}
@@ -56,6 +95,17 @@ func (c Config) ValidateAPI() error {
 	if c.CursorSecret == c.SessionSecret {
 		return errors.New("config: CURSOR_SECRET must differ from SESSION_SECRET")
 	}
+	if c.AIMaxConcurrent < 1 || c.AICreatePerMinute < 1 || c.AIUncachedScopesPerDay < 1 {
+		return errors.New("config: AI limits must be positive")
+	}
+	if c.AppEnv == "production" && c.AIGrowthEnabled {
+		if c.AvalAIAPIKey == "" || c.AvalAIModel == "" {
+			return errors.New("config: enabled production AI requires AVALAI_API_KEY and AVALAI_MODEL")
+		}
+		if c.AIDailyRequestBudget < 1 || c.AIDailyTokenBudget < 1 {
+			return errors.New("config: enabled production AI requires positive daily budgets")
+		}
+	}
 	return nil
 }
 
@@ -72,3 +122,12 @@ func value(name, fallback string) string {
 	}
 	return fallback
 }
+
+func parseInt64(name string, fallback int64) (int64, error) {
+	raw := value(name, strconv.FormatInt(fallback, 10))
+	parsed, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil || parsed < 0 {
+		return 0, fmt.Errorf("config: %s must be a non-negative integer", name)
+	}
+	return parsed, nil
+}

internal/config/config_test.go

@@ -33,3 +33,26 @@ func TestValidateAPIRequiresIndependentCursorSecret(t *testing.T) {
 		t.Fatal("ValidateAPI() error = nil, want independent secrets error")
 	}
 }
+
+func TestValidateAPIRequiresGrowthBudgetsInProduction(t *testing.T) {
+	t.Parallel()
+	cfg := Config{SessionSecret: "session-secret-that-is-at-least-32-bytes", CursorSecret: "cursor-secret-that-is-at-least-32-bytes", AppEnv: "production", AIGrowthEnabled: true, AvalAIAPIKey: "key", AvalAIModel: "model", AIMaxConcurrent: 4, AICreatePerMinute: 10, AIUncachedScopesPerDay: 5}
+	if err := cfg.ValidateAPI(); err == nil {
+		t.Fatal("ValidateAPI() error = nil, want AI budget error")
+	}
+	cfg.AIDailyRequestBudget, cfg.AIDailyTokenBudget = 10, 10_000
+	if err := cfg.ValidateAPI(); err != nil {
+		t.Fatalf("ValidateAPI() error = %v", err)
+	}
+}
+
+func TestLoadGrowthDefaultsAreCostSafe(t *testing.T) {
+	t.Setenv("DATABASE_URL", "postgresql://example")
+	cfg, err := Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.AIGrowthEnabled || cfg.AIDailyRequestBudget != 0 || cfg.AIDailyTokenBudget != 0 || cfg.AIMaxConcurrent != 4 {
+		t.Fatalf("unsafe AI defaults: %+v", cfg)
+	}
+}