package security

import (
	"fmt"
	"math"
)

// SafeUint64ToUint32 converts uint64 to uint32 with overflow check
func SafeUint64ToUint32(value uint64) (uint32, error) {
	if value > math.MaxUint32 {
		return 0, fmt.Errorf("value %d exceeds maximum uint32 value %d", value, math.MaxUint32)
	}
	return uint32(value), nil
}

// SafeUint64ToInt64 converts uint64 to int64 with bounds check
func SafeUint64ToInt64(value uint64) (int64, error) {
	if value > math.MaxInt64 {
		return 0, fmt.Errorf("value %d exceeds maximum int64 value %d", value, math.MaxInt64)
	}
	return int64(value), nil
}

// SafeUint64ToUint32WithDefault converts uint64 to uint32 with overflow check and default value
func SafeUint64ToUint32WithDefault(value uint64, defaultValue uint32) uint32 {
	if value > math.MaxUint32 {
		return defaultValue
	}
	return uint32(value)
}

// SafeAddUint64 adds two uint64 values with overflow check
func SafeAddUint64(a, b uint64) (uint64, error) {
	if a > math.MaxUint64-b {
		return 0, fmt.Errorf("addition overflow: %d + %d exceeds maximum uint64 value", a, b)
	}
	return a + b, nil
}

// SafeSubtractUint64 subtracts b from a with underflow check
func SafeSubtractUint64(a, b uint64) (uint64, error) {
	if a < b {
		return 0, fmt.Errorf("subtraction underflow: %d - %d results in negative value", a, b)
	}
	return a - b, nil
}

// SafeMultiplyUint64 multiplies two uint64 values with overflow check
func SafeMultiplyUint64(a, b uint64) (uint64, error) {
	if b != 0 && a > math.MaxUint64/b {
		return 0, fmt.Errorf("multiplication overflow: %d * %d exceeds maximum uint64 value", a, b)
	}
	return a * b, nil
}