import Foundation

// MARK: - 条形码验证器
class BarcodeValidator {
    
    // MARK: - 验证结果
    struct ValidationResult {
        let isValid: Bool
        let formattedContent: String
        let errorMessage: String?
        let expectedLength: Int?
        let allowedCharacters: String?
    }
    
    // MARK: - 条形码格式验证规则
    static func validateBarcode(_ content: String, type: BarcodeType) -> ValidationResult {
        let cleanedContent = content.replacingOccurrences(of: " ", with: "")
        
        switch type {
        case .ean13:
            return validateEAN13(cleanedContent)
        case .ean8:
            return validateEAN8(cleanedContent)
        case .upce:
            return validateUPCE(cleanedContent)
        case .code39:
            return validateCode39(cleanedContent)
        case .code128:
            return validateCode128(cleanedContent)
        case .itf14:
            return validateITF14(cleanedContent)
        case .pdf417:
            return validatePDF417(cleanedContent)
        }
    }
    
    // MARK: - EAN-13 验证
    private static func validateEAN13(_ content: String) -> ValidationResult {
        // EAN-13: 13位数字
        let pattern = "^[0-9]{13}$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatEAN13(content),
                errorMessage: nil,
                expectedLength: 13,
                allowedCharacters: "numbers_0_9".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "ean_13_must_be_13_digits".localized,
                expectedLength: 13,
                allowedCharacters: "numbers_0_9".localized
            )
        }
    }
    
    // MARK: - EAN-8 验证
    private static func validateEAN8(_ content: String) -> ValidationResult {
        // EAN-8: 8位数字
        let pattern = "^[0-9]{8}$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatEAN8(content),
                errorMessage: nil,
                expectedLength: 8,
                allowedCharacters: "numbers_0_9".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "ean_8_must_be_8_digits".localized,
                expectedLength: 8,
                allowedCharacters: "numbers_0_9".localized
            )
        }
    }
    
    // MARK: - UPC-E 验证
    private static func validateUPCE(_ content: String) -> ValidationResult {
        // UPC-E: 8位数字
        let pattern = "^[0-9]{8}$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatUPCE(content),
                errorMessage: nil,
                expectedLength: 8,
                allowedCharacters: "numbers_0_9".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "upc_e_must_be_8_digits".localized,
                expectedLength: 8,
                allowedCharacters: "numbers_0_9".localized
            )
        }
    }
    
    // MARK: - Code 39 验证
    private static func validateCode39(_ content: String) -> ValidationResult {
        // Code 39: 字母、数字、空格和特殊字符
        let pattern = "^[A-Z0-9\\s\\-\\+\\.\\/\\$\\(\\)\\%\\s]+$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatCode39(content),
                errorMessage: nil,
                expectedLength: nil,
                allowedCharacters: "code_39_characters".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "code_39_only_contains".localized,
                expectedLength: nil,
                allowedCharacters: "code_39_characters".localized
            )
        }
    }
    

    
    // MARK: - Code 128 验证
    private static func validateCode128(_ content: String) -> ValidationResult {
        // Code 128: 支持所有ASCII字符
        let pattern = "^[\\x00-\\x7F]+$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatCode128(content),
                errorMessage: nil,
                expectedLength: nil,
                allowedCharacters: "code_128_characters".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "code_128_only_contains".localized,
                expectedLength: nil,
                allowedCharacters: "code_128_characters".localized
            )
        }
    }
    
    // MARK: - ITF-14 验证
    private static func validateITF14(_ content: String) -> ValidationResult {
        // ITF-14: 14位数字
        let pattern = "^[0-9]{14}$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatITF14(content),
                errorMessage: nil,
                expectedLength: 14,
                allowedCharacters: "numbers_0_9".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "itf_14_must_be_14_digits".localized,
                expectedLength: 14,
                allowedCharacters: "numbers_0_9".localized
            )
        }
    }
    
    // MARK: - PDF417 验证
    private static func validatePDF417(_ content: String) -> ValidationResult {
        // PDF417: 支持所有ASCII字符
        let pattern = "^[\\x00-\\x7F]+$"
        let isValid = content.range(of: pattern, options: .regularExpression) != nil
        
        if isValid {
            return ValidationResult(
                isValid: true,
                formattedContent: formatPDF417(content),
                errorMessage: nil,
                expectedLength: nil,
                allowedCharacters: "pdf417_characters".localized
            )
        } else {
            return ValidationResult(
                isValid: false,
                formattedContent: content,
                errorMessage: "pdf417_only_contains".localized,
                expectedLength: nil,
                allowedCharacters: "pdf417_characters".localized
            )
        }
    }
    
    // MARK: - 格式化方法
    private static func formatEAN13(_ content: String) -> String {
        // EAN-13: 添加空格分隔符
        let formatted = content.enumerated().map { index, char in
            if index == 0 || index == 6 || index == 12 {
                return " \(char)"
            }
            return String(char)
        }.joined()
        return formatted.trimmingCharacters(in: .whitespaces)
    }
    
    private static func formatEAN8(_ content: String) -> String {
        // EAN-8: 添加空格分隔符
        let formatted = content.enumerated().map { index, char in
            if index == 0 || index == 4 {
                return " \(char)"
            }
            return String(char)
        }.joined()
        return formatted.trimmingCharacters(in: .whitespaces)
    }
    
    private static func formatUPCE(_ content: String) -> String {
        // UPC-E: 添加空格分隔符
        let formatted = content.enumerated().map { index, char in
            if index == 0 || index == 4 {
                return " \(char)"
            }
            return String(char)
        }.joined()
        return formatted.trimmingCharacters(in: .whitespaces)
    }
    
    private static func formatCode39(_ content: String) -> String {
        // Code 39: 保持原样，但去除多余空格
        return content.trimmingCharacters(in: .whitespaces)
    }
    

    
    private static func formatCode128(_ content: String) -> String {
        // Code 128: 保持原样
        return content.trimmingCharacters(in: .whitespaces)
    }
    
    private static func formatITF14(_ content: String) -> String {
        // ITF-14: 添加空格分隔符
        let formatted = content.enumerated().map { index, char in
            if index == 0 || index == 5 || index == 10 {
                return " \(char)"
            }
            return String(char)
        }.joined()
        return formatted.trimmingCharacters(in: .whitespaces)
    }
    
    private static func formatPDF417(_ content: String) -> String {
        // PDF417: 保持原样
        return content.trimmingCharacters(in: .whitespaces)
    }
}