init

internal/validator/constants.go

@@ -0,0 +1,158 @@
+// Package validator provides validation utilities for API parameters
+package validator
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"time"
+)
+
+// Pagination constants
+const (
+	DefaultPageSize = 20
+	MaxPageSize     = 100
+	MinPageSize     = 1
+)
+
+// Amount constants
+const (
+	MinAmount = 0.01
+	MaxAmount = 999999999999.99
+)
+
+// Date constants
+const (
+	MaxDateRangeDays = 366
+	MaxFutureDays    = 365
+)
+
+// String length constants
+const (
+	MaxNameLength = 100
+	MaxNoteLength = 500
+)
+
+// Validation errors
+var (
+	ErrPaginationLimitExceeded = errors.New("pagination limit exceeded maximum allowed value")
+	ErrInvalidOffset           = errors.New("pagination offset cannot be negative")
+	ErrAmountTooSmall          = errors.New("amount is below minimum allowed value")
+	ErrAmountTooLarge          = errors.New("amount exceeds maximum allowed value")
+	ErrDateRangeExceeded       = errors.New("date range exceeds maximum allowed days")
+	ErrFutureDateExceeded      = errors.New("date exceeds maximum allowed future date")
+	ErrEndDateBeforeStartDate  = errors.New("end date must be after start date")
+	ErrNameTooLong             = errors.New("name exceeds maximum allowed length")
+	ErrNoteTooLong             = errors.New("note exceeds maximum allowed length")
+)
+
+// ValidatePagination validates and normalizes pagination parameters
+// Returns normalized offset and limit values
+// Feature: api-interface-optimization
+// Validates: Requirements 7.1, 7.2
+func ValidatePagination(offset, limit int) (int, int) {
+	// Normalize offset
+	if offset < 0 {
+		offset = 0
+	}
+
+	// Normalize limit
+	if limit <= 0 {
+		limit = DefaultPageSize
+	}
+	if limit > MaxPageSize {
+		limit = MaxPageSize
+	}
+
+	return offset, limit
+}
+
+// ValidatePaginationStrict validates pagination parameters and returns error if invalid
+// Feature: api-interface-optimization
+// Validates: Requirements 7.1, 7.2, 7.3
+func ValidatePaginationStrict(offset, limit int) error {
+	if offset < 0 {
+		return fmt.Errorf("%w: offset=%d", ErrInvalidOffset, offset)
+	}
+	if limit > MaxPageSize {
+		return fmt.Errorf("%w: limit=%d, max=%d", ErrPaginationLimitExceeded, limit, MaxPageSize)
+	}
+	return nil
+}
+
+// ValidateAmount validates that an amount is within acceptable bounds
+// Feature: api-interface-optimization
+// Validates: Requirements 8.1, 8.2, 8.3
+func ValidateAmount(amount float64) error {
+	if amount < MinAmount {
+		return fmt.Errorf("%w: amount=%.2f, min=%.2f", ErrAmountTooSmall, amount, MinAmount)
+	}
+	if amount > MaxAmount {
+		return fmt.Errorf("%w: amount=%.2f, max=%.2f", ErrAmountTooLarge, amount, MaxAmount)
+	}
+	return nil
+}
+
+// RoundAmount rounds an amount to 2 decimal places
+// Feature: api-interface-optimization
+// Validates: Requirements 8.2
+func RoundAmount(amount float64) float64 {
+	return math.Round(amount*100) / 100
+}
+
+// ValidateDateRange validates that a date range is within acceptable bounds
+// Feature: api-interface-optimization
+// Validates: Requirements 9.1
+func ValidateDateRange(startDate, endDate time.Time) error {
+	if endDate.Before(startDate) {
+		return ErrEndDateBeforeStartDate
+	}
+
+	days := int(endDate.Sub(startDate).Hours() / 24)
+	if days > MaxDateRangeDays {
+		return fmt.Errorf("%w: days=%d, max=%d", ErrDateRangeExceeded, days, MaxDateRangeDays)
+	}
+
+	return nil
+}
+
+// ValidateFutureDate validates that a date is not too far in the future
+// Feature: api-interface-optimization
+// Validates: Requirements 9.2
+func ValidateFutureDate(date time.Time) error {
+	maxFutureDate := time.Now().AddDate(0, 0, MaxFutureDays)
+	if date.After(maxFutureDate) {
+		return fmt.Errorf("%w: date=%s, max=%s", ErrFutureDateExceeded, date.Format("2006-01-02"), maxFutureDate.Format("2006-01-02"))
+	}
+	return nil
+}
+
+// ValidateStringLength validates that a string does not exceed the maximum length
+// Feature: api-interface-optimization
+// Validates: Requirements 10.1, 10.2
+func ValidateStringLength(s string, maxLen int, fieldName string) error {
+	if len(s) > maxLen {
+		if fieldName == "name" {
+			return fmt.Errorf("%w: length=%d, max=%d", ErrNameTooLong, len(s), maxLen)
+		}
+		if fieldName == "note" {
+			return fmt.Errorf("%w: length=%d, max=%d", ErrNoteTooLong, len(s), maxLen)
+		}
+		return fmt.Errorf("%s exceeds maximum length: length=%d, max=%d", fieldName, len(s), maxLen)
+	}
+	return nil
+}
+
+// ValidateName validates a name field
+// Feature: api-interface-optimization
+// Validates: Requirements 10.1
+func ValidateName(name string) error {
+	return ValidateStringLength(name, MaxNameLength, "name")
+}
+
+// ValidateNote validates a note field
+// Feature: api-interface-optimization
+// Validates: Requirements 10.2
+func ValidateNote(note string) error {
+	return ValidateStringLength(note, MaxNoteLength, "note")
+}