//
//  Status.swift
//  Cryptor
//
// 	Licensed under the Apache License, Version 2.0 (the "License");
// 	you may not use this file except in compliance with the License.
// 	You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// 	Unless required by applicable law or agreed to in writing, software
// 	distributed under the License is distributed on an "AS IS" BASIS,
// 	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// 	See the License for the specific language governing permissions and
// 	limitations under the License.
//

import Foundation

#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
	import CommonCrypto
#elseif os(Linux)
	import OpenSSL
#endif

#if os(macOS) || os(iOS) || os(tvOS) || os(watchOS)
///
/// Links the native CommonCryptoStatus enumeration to Swift versions.
///
public enum Status: CCCryptorStatus, Swift.Error, CustomStringConvertible {

    /// Successful
    case success
	
    /// Parameter Error
    case paramError
	
    /// Buffer too Small
    case bufferTooSmall
	
    /// Memory Failure
    case memoryFailure
	
    /// Alignment Error
    case alignmentError
	
    /// Decode Error
    case decodeError
	
    /// Unimplemented
    case unimplemented
	
    /// Overflow
    case overflow
	
    /// Random Number Generator Err
    case rngFailure
    
    ///
    /// Converts this value to a native `CCCryptorStatus` value.
    ///
	public func toRaw() -> CCCryptorStatus {
		
        switch self {
			
        case .success:
			return CCCryptorStatus(kCCSuccess)
        case .paramError:
			return CCCryptorStatus(kCCParamError)
        case .bufferTooSmall:
   			return CCCryptorStatus(kCCBufferTooSmall)
        case .memoryFailure:
			return CCCryptorStatus(kCCMemoryFailure)
        case .alignmentError:
   			return CCCryptorStatus(kCCAlignmentError)
        case .decodeError:
			return CCCryptorStatus(kCCDecodeError)
        case .unimplemented:
			return CCCryptorStatus(kCCUnimplemented)
        case .overflow:
			return CCCryptorStatus(kCCOverflow)
        case .rngFailure:
			return CCCryptorStatus(kCCRNGFailure)
        }
    }
    
    ///
    /// Human readable descriptions of the values. (Not needed in Swift 2.0?)
    ///
    static let descriptions = [
        success: "Success",
        paramError: "ParamError",
        bufferTooSmall: "BufferTooSmall",
        memoryFailure: "MemoryFailure",
        alignmentError: "AlignmentError",
        decodeError: "DecodeError",
        unimplemented: "Unimplemented",
        overflow: "Overflow",
        rngFailure: "RNGFailure"
    ]

    ///
    /// Obtain human-readable string from enum value.
    ///
	public var description: String {
		
        return (Status.descriptions[self] != nil) ? Status.descriptions[self]! : ""
    }

	///
    /// Create enum value from raw `CCCryptorStatus` value.
    ///
	public static func fromRaw(status: CCCryptorStatus) -> Status? {
		
        let from = [
            kCCSuccess: success,
            kCCParamError: paramError,
            kCCBufferTooSmall: bufferTooSmall,
            kCCMemoryFailure: memoryFailure,
            kCCAlignmentError: alignmentError,
            kCCDecodeError: decodeError,
            kCCUnimplemented: unimplemented,
            kCCOverflow: overflow,
            kCCRNGFailure: rngFailure
        ]
        
        return from[Int(status)]
    
    }
}
	
#elseif os(Linux)
	
///
/// Error status
///
public enum Status: Swift.Error, CustomStringConvertible {
	
	/// Success
	case success
	
	/// Unimplemented with reason
	case unimplemented(String)
	
	/// Not supported with reason
	case notSupported(String)
	
	/// Parameter Error
	case paramError
	
	/// Failure with error code
 	case fail(UInt)
	
	/// Random Byte Generator Failure with error code
	case rngFailure(UInt)
	
	/// The error code itself
	public var code: Int {
		
		switch self {
			
		case .success:
			return 0
			
		case .notSupported:
			return -1
			
		case .unimplemented:
			return -2
			
		case .paramError:
			return -3
			
		case .fail(let code):
			return Int(code)
			
		case .rngFailure(let code):
			return Int(code)
		}
	}
	
	///
	/// Create enum value from raw `SSL error code` value.
	///
	public static func fromRaw(status: UInt) -> Status? {
		
		return Status.fail(status)
	}
	
	///
	/// Obtain human-readable string for the error code.
	///
	public var description: String {
		
		switch self {
			
		case .success:
			return "No error"
			
		case .notSupported(let reason):
			return "Not supported: \(reason)"
			
		case .unimplemented(let reason):
			return "Not implemented: \(reason)"
			
		case .paramError:
			return "Invalid parameters passed"
			
		case .fail(let errorCode):
			return "ERROR: code: \(errorCode), reason: \(errToString(ERR_error_string(UInt(errorCode), nil)))"

		case .rngFailure(let errorCode):
			return "Random Byte Generator ERROR: code: \(errorCode), reason: \(errToString(ERR_error_string(UInt(errorCode), nil)))"
		}
	}
}

//	MARK: Operators

func == (lhs: Status, rhs: Status) -> Bool {
	
	return lhs.code == rhs.code
}

func != (lhs: Status, rhs: Status) -> Bool {
	
	return lhs.code != rhs.code
}

#endif

///
/// CryptorError
///		Thrown in caaes where a _fatalError()_ is **NOT** appropriate.
///
public enum CryptorError: Swift.Error, CustomStringConvertible {

	/// Success
	case success
	
	/// Invalid key size
	case invalidKeySize
	
	/// Invalid IV size
	case invalidIVSizeOrLength
	
	/// Fail with code and string
	case fail(Int32, String)
	
	/// The error code itself
	public var errCode: Int32 {
		
		switch self {
			
		case .success:
			return 0
			
		case .invalidKeySize:
			return -1
			
		case .invalidIVSizeOrLength:
			return -2
			
		case .fail(let errCode, _):
			return Int32(errCode)
		}
	}
	
	/// Error Description
	public var description: String {
		
		switch self {
			
		case .success:
			return "Success"
			
		case .invalidKeySize:
			return "Invalid key size."
			
		case .invalidIVSizeOrLength:
			return "Invalid IV size or length."
			
		case .fail(_, let reason):
			return reason
		}
	}
}