refactor: устранить дублирование кода (Go-хендлеры, JS-автокомплит)

Найдено статическим анализом (dupl/jscpd) + проверено вручную:

Go:
- appstate/path.go: ResolveDBPath/ResolveConfigPath → общий resolvePath()
- handlers/respond.go: дженерик BindJSON[T] для bind+422-ошибки
- article/generator.go: buildNetSegment/buildPSUSegment → buildProfileSegment()
- cmd/qfs/main.go (+respond.go): 8 повторяющихся switch{case errors.Is(...)}
  → respondByErrCase(c, err, errCase{...}, ...)

Frontend (index.html):
- 5 идентичных обработчиков клавиатурной навигации автокомплита
  → handleAutocompleteKeyGeneric(event, onSelect)
- 4 функции сборки нового элемента корзины из автокомплита
  → buildNewCartItem()/commitCartChange()

Также: PricingMarkup — единая точка правды для аплифт-коэффициента
в JS (render + export), с cross-reference комментариями к Go-константам
в export.go (defaultSaleMarkup/stockCompetitorMarkupFactor).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/appstate/path.go

@@ -21,30 +21,23 @@ const (
 // ResolveDBPath returns the local SQLite path using priority:
 // explicit CLI path > QFS_DB_PATH > OS-specific user state directory.
 func ResolveDBPath(explicitPath string) (string, error) {
-	if explicitPath != "" {
-		return filepath.Clean(explicitPath), nil
-	}
-
-	if fromEnv := os.Getenv(envDBPath); fromEnv != "" {
-		return filepath.Clean(fromEnv), nil
-	}
-
-	dir, err := defaultStateDir()
-	if err != nil {
-		return "", err
-	}
-
-	return filepath.Join(dir, defaultDB), nil
+	return resolvePath(explicitPath, envDBPath, defaultDB)
 }
 
 // ResolveConfigPath returns the config path using priority:
 // explicit CLI path > QFS_CONFIG_PATH > OS-specific user state directory.
 func ResolveConfigPath(explicitPath string) (string, error) {
+	return resolvePath(explicitPath, envCfgPath, defaultCfg)
+}
+
+// resolvePath returns a path using priority: explicit CLI path > envVar > OS-specific
+// user state directory joined with defaultFilename.
+func resolvePath(explicitPath, envVar, defaultFilename string) (string, error) {
 	if explicitPath != "" {
 		return filepath.Clean(explicitPath), nil
 	}
 
-	if fromEnv := os.Getenv(envCfgPath); fromEnv != "" {
+	if fromEnv := os.Getenv(envVar); fromEnv != "" {
 		return filepath.Clean(fromEnv), nil
 	}
 
@@ -53,7 +46,7 @@ func ResolveConfigPath(explicitPath string) (string, error) {
 		return "", err
 	}
 
-	return filepath.Join(dir, defaultCfg), nil
+	return filepath.Join(dir, defaultFilename), nil
 }
 
 // ResolveConfigPathNearDB returns config path using priority:

internal/article/generator.go

@@ -260,17 +260,28 @@ func buildDiskSegment(items []models.ConfigItem, cats map[string]string) (string
 }
 
 func buildNetSegment(items []models.ConfigItem, cats map[string]string) (string, string) {
+	return buildProfileSegment(items, cats, GroupNET, parsePortSpeed, "UNKNET", "net_unknown")
+}
+
+func buildPSUSegment(items []models.ConfigItem, cats map[string]string) (string, string) {
+	return buildProfileSegment(items, cats, GroupPSU, parseWatts, "UNKPSU", "psu_unknown")
+}
+
+// buildProfileSegment groups items of the given category group by a profile token
+// parsed from their lot name (e.g. port speed, wattage rating), falling back to
+// unknownToken and warnCode when a lot's profile can't be determined.
+func buildProfileSegment(items []models.ConfigItem, cats map[string]string, group Group, parseProfile func(string) string, unknownToken, warnCode string) (string, string) {
 	groupQty := map[string]int{}
 	warn := ""
 	for _, it := range items {
-		group, ok := GroupForLotCategory(cats[it.LotName])
-		if !ok || group != GroupNET {
+		g, ok := GroupForLotCategory(cats[it.LotName])
+		if !ok || g != group {
 			continue
 		}
-		profile := parsePortSpeed(it.LotName)
+		profile := parseProfile(it.LotName)
 		if profile == "" {
-			profile = "UNKNET"
-			warn = "net_unknown"
+			profile = unknownToken
+			warn = warnCode
 		}
 		groupQty[profile] += it.Quantity
 	}
@@ -285,32 +296,6 @@ func buildNetSegment(items []models.ConfigItem, cats map[string]string) (string,
 	return strings.Join(parts, "+"), warn
 }
 
-func buildPSUSegment(items []models.ConfigItem, cats map[string]string) (string, string) {
-	groupQty := map[string]int{}
-	warn := ""
-	for _, it := range items {
-		group, ok := GroupForLotCategory(cats[it.LotName])
-		if !ok || group != GroupPSU {
-			continue
-		}
-		rating := parseWatts(it.LotName)
-		if rating == "" {
-			rating = "UNKPSU"
-			warn = "psu_unknown"
-		}
-		groupQty[rating] += it.Quantity
-	}
-	if len(groupQty) == 0 {
-		return "", ""
-	}
-	parts := make([]string, 0, len(groupQty))
-	for rating, qty := range groupQty {
-		parts = append(parts, fmt.Sprintf("%dx%s", qty, rating))
-	}
-	sort.Strings(parts)
-	return strings.Join(parts, "+"), warn
-}
-
 func normalizeModelToken(lotName string) string {
 	if idx := strings.Index(lotName, "_"); idx >= 0 && idx+1 < len(lotName) {
 		lotName = lotName[idx+1:]

internal/handlers/quote.go

@@ -16,13 +16,12 @@ func NewQuoteHandler(quoteService *services.QuoteService) *QuoteHandler {
 }
 
 func (h *QuoteHandler) Validate(c *gin.Context) {
-	var req services.QuoteRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
+	req, ok := BindJSON[services.QuoteRequest](c)
+	if !ok {
 		return
 	}
 
-	result, err := h.quoteService.ValidateAndCalculate(&req)
+	result, err := h.quoteService.ValidateAndCalculate(req)
 	if err != nil {
 		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
 		return
@@ -32,13 +31,12 @@ func (h *QuoteHandler) Validate(c *gin.Context) {
 }
 
 func (h *QuoteHandler) Calculate(c *gin.Context) {
-	var req services.QuoteRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
+	req, ok := BindJSON[services.QuoteRequest](c)
+	if !ok {
 		return
 	}
 
-	result, err := h.quoteService.ValidateAndCalculate(&req)
+	result, err := h.quoteService.ValidateAndCalculate(req)
 	if err != nil {
 		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
 		return
@@ -51,13 +49,12 @@ func (h *QuoteHandler) Calculate(c *gin.Context) {
 }
 
 func (h *QuoteHandler) PriceLevels(c *gin.Context) {
-	var req services.PriceLevelsRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
+	req, ok := BindJSON[services.PriceLevelsRequest](c)
+	if !ok {
 		return
 	}
 
-	result, err := h.quoteService.CalculatePriceLevels(&req)
+	result, err := h.quoteService.CalculatePriceLevels(req)
 	if err != nil {
 		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
 		return

internal/handlers/respond.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"errors"
 	"io"
+	"net/http"
 	"strings"
 
 	"github.com/gin-gonic/gin"
@@ -16,6 +17,17 @@ func RespondError(c *gin.Context, status int, fallback string, err error) {
 	c.JSON(status, gin.H{"error": clientFacingErrorMessage(status, fallback, err)})
 }
 
+// BindJSON decodes the request body into T, responding with a 422 and writing
+// the error via RespondError on failure. The second return value reports success.
+func BindJSON[T any](c *gin.Context) (*T, bool) {
+	var req T
+	if err := c.ShouldBindJSON(&req); err != nil {
+		RespondError(c, http.StatusUnprocessableEntity, "invalid request", err)
+		return nil, false
+	}
+	return &req, true
+}
+
 func clientFacingErrorMessage(status int, fallback string, err error) string {
 	if err == nil {
 		return fallback

internal/services/export.go

@@ -63,11 +63,16 @@ type ProjectPricingExportOptions struct {
 	ManualPrice       *float64 `json:"manual_price"`  // user-defined total price; distributed proportionally across rows
 }
 
+// defaultSaleMarkup mirrors PricingMarkup.DEFAULT_SALE_UPLIFT in web/templates/index.html.
+// Keep both in sync; the frontend always sends an explicit value, this is a fallback for
+// other API callers that omit sale_markup.
+const defaultSaleMarkup = 1.3
+
 func (o ProjectPricingExportOptions) saleMarkupFactor() float64 {
 	if o.SaleMarkup > 0 {
 		return o.SaleMarkup
 	}
-	return 1.3
+	return defaultSaleMarkup
 }
 
 func (o ProjectPricingExportOptions) isDDP() bool {
@@ -516,6 +521,7 @@ func sortConfigItemsByCategoryMap(items models.ConfigItems, catOrder map[string]
 
 // stockCompetitorMarkupFactor is the fixed DDP multiplier applied to Stock and
 // Competitor columns, independent of the user-configurable estimate uplift.
+// Mirrors PricingMarkup.STOCK_COMPETITOR_FIXED in web/templates/index.html.
 const stockCompetitorMarkupFactor = 1.3
 
 func applyDDPMarkup(rows []ProjectPricingExportRow, estimateFactor float64) {