59 lines
1.6 KiB
Go
59 lines
1.6 KiB
Go
package util
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import (
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"fmt"
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"strconv"
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)
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// ParseHex parses a hexadecimal value from the hash string
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// This implementation is shared between engine and jdenticon packages for consistency
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func ParseHex(hash string, startPosition, octets int) (int, error) {
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// Handle negative indices (count from end like JavaScript)
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if startPosition < 0 {
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startPosition = len(hash) + startPosition
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}
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// Ensure we don't go out of bounds
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if startPosition < 0 || startPosition >= len(hash) {
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return 0, fmt.Errorf("parseHex: position %d out of bounds for hash length %d", startPosition, len(hash))
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}
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// If octets is 0 or negative, read from startPosition to end (like JavaScript default)
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end := len(hash)
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if octets > 0 {
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end = startPosition + octets
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if end > len(hash) {
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end = len(hash)
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}
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}
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// Extract substring and parse as hexadecimal
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substr := hash[startPosition:end]
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if len(substr) == 0 {
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return 0, fmt.Errorf("parseHex: empty substring at position %d", startPosition)
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}
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result, err := strconv.ParseInt(substr, 16, 64)
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if err != nil {
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return 0, fmt.Errorf("parseHex: failed to parse hex '%s' at position %d: %w", substr, startPosition, err)
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}
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return int(result), nil
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}
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// IsValidHash checks if a hash string is valid for jdenticon generation
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// This implementation is shared between engine and jdenticon packages for consistency
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func IsValidHash(hash string) bool {
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if len(hash) < 11 {
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return false
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}
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// Check if all characters are valid hexadecimal
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for _, r := range hash {
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if !((r >= '0' && r <= '9') || (r >= 'a' && r <= 'f') || (r >= 'A' && r <= 'F')) {
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return false
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}
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}
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return true
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} |