"""
This module uses ctypes to bind a whole bunch of functions and constants from
SecureTransport. The goal here is to provide the low-level API to
SecureTransport. These are essentially the C-level functions and constants, and
they're pretty gross to work with.

This code is a bastardised version of the code found in Will Bond's oscrypto
library. An enormous debt is owed to him for blazing this trail for us. For
that reason, this code should be considered to be covered both by urllib3's
license and by oscrypto's:

    Copyright (c) 2015-2016 Will Bond <will@wbond.net>

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.
"""
from __future__ import absolute_import

import platform
from ctypes.util import find_library
from ctypes import (
    c_void_p, c_int32, c_char_p, c_size_t, c_byte, c_uint32, c_ulong, c_long,
    c_bool
)
from ctypes import CDLL, POINTER, CFUNCTYPE


security_path = find_library('Security')
if not security_path:
    raise ImportError('The library Security could not be found')


core_foundation_path = find_library('CoreFoundation')
if not core_foundation_path:
    raise ImportError('The library CoreFoundation could not be found')


version = platform.mac_ver()[0]
version_info = tuple(map(int, version.split('.')))
if version_info < (10, 8):
    raise OSError(
        'Only OS X 10.8 and newer are supported, not %s.%s' % (
            version_info[0], version_info[1]
        )
    )

Security = CDLL(security_path, use_errno=True)
CoreFoundation = CDLL(core_foundation_path, use_errno=True)

Boolean = c_bool
CFIndex = c_long
CFStringEncoding = c_uint32
CFData = c_void_p
CFString = c_void_p
CFArray = c_void_p
CFMutableArray = c_void_p
CFDictionary = c_void_p
CFError = c_void_p
CFType = c_void_p
CFTypeID = c_ulong

CFTypeRef = POINTER(CFType)
CFAllocatorRef = c_void_p

OSStatus = c_int32

CFDataRef = POINTER(CFData)
CFStringRef = POINTER(CFString)
CFArrayRef = POINTER(CFArray)
CFMutableArrayRef = POINTER(CFMutableArray)
CFDictionaryRef = POINTER(CFDictionary)
CFArrayCallBacks = c_void_p
CFDictionaryKeyCallBacks = c_void_p
CFDictionaryValueCallBacks = c_void_p

SecCertificateRef = POINTER(c_void_p)
SecExternalFormat = c_uint32
SecExternalItemType = c_uint32
SecIdentityRef = POINTER(c_void_p)
SecItemImportExportFlags = c_uint32
SecItemImportExportKeyParameters = c_void_p
SecKeychainRef = POINTER(c_void_p)
SSLProtocol = c_uint32
SSLCipherSuite = c_uint32
SSLContextRef = POINTER(c_void_p)
SecTrustRef = POINTER(c_void_p)
SSLConnectionRef = c_uint32
SecTrustResultType = c_uint32
SecTrustOptionFlags = c_uint32
SSLProtocolSide = c_uint32
SSLConnectionType = c_uint32
SSLSessionOption = c_uint32


try:
    Security.SecItemImport.argtypes = [
        CFDataRef,
        CFStringRef,
        POINTER(SecExternalFormat),
        POINTER(SecExternalItemType),
        SecItemImportExportFlags,
        POINTER(SecItemImportExportKeyParameters),
        SecKeychainRef,
        POINTER(CFArrayRef),
    ]
    Security.SecItemImport.restype = OSStatus

    Security.SecCertificateGetTypeID.argtypes = []
    Security.SecCertificateGetTypeID.restype = CFTypeID

    Security.SecIdentityGetTypeID.argtypes = []
    Security.SecIdentityGetTypeID.restype = CFTypeID

    Security.SecKeyGetTypeID.argtypes = []
    Security.SecKeyGetTypeID.restype = CFTypeID

    Security.SecCertificateCreateWithData.argtypes = [
        CFAllocatorRef,
        CFDataRef
    ]
    Security.SecCertificateCreateWithData.restype = SecCertificateRef

    Security.SecCertificateCopyData.argtypes = [
        SecCertificateRef
    ]
    Security.SecCertificateCopyData.restype = CFDataRef

    Security.SecCopyErrorMessageString.argtypes = [
        OSStatus,
        c_void_p
    ]
    Security.SecCopyErrorMessageString.restype = CFStringRef

    Security.SecIdentityCreateWithCertificate.argtypes = [
        CFTypeRef,
        SecCertificateRef,
        POINTER(SecIdentityRef)
    ]
    Security.SecIdentityCreateWithCertificate.restype = OSStatus

    Security.SecKeychainCreate.argtypes = [
        c_char_p,
        c_uint32,
        c_void_p,
        Boolean,
        c_void_p,
        POINTER(SecKeychainRef)
    ]
    Security.SecKeychainCreate.restype = OSStatus

    Security.SecKeychainDelete.argtypes = [
        SecKeychainRef
    ]
    Security.SecKeychainDelete.restype = OSStatus

    Security.SecPKCS12Import.argtypes = [
        CFDataRef,
        CFDictionaryRef,
        POINTER(CFArrayRef)
    ]
    Security.SecPKCS12Import.restype = OSStatus

    SSLReadFunc = CFUNCTYPE(OSStatus, SSLConnectionRef, c_void_p, POINTER(c_size_t))
    SSLWriteFunc = CFUNCTYPE(OSStatus, SSLConnectionRef, POINTER(c_byte), POINTER(c_size_t))

    Security.SSLSetIOFuncs.argtypes = [
        SSLContextRef,
        SSLReadFunc,
        SSLWriteFunc
    ]
    Security.SSLSetIOFuncs.restype = OSStatus

    Security.SSLSetPeerID.argtypes = [
        SSLContextRef,
        c_char_p,
        c_size_t
    ]
    Security.SSLSetPeerID.restype = OSStatus

    Security.SSLSetCertificate.argtypes = [
        SSLContextRef,
        CFArrayRef
    ]
    Security.SSLSetCertificate.restype = OSStatus

    Security.SSLSetCertificateAuthorities.argtypes = [
        SSLContextRef,
        CFTypeRef,
        Boolean
    ]
    Security.SSLSetCertificateAuthorities.restype = OSStatus

    Security.SSLSetConnection.argtypes = [
        SSLContextRef,
        SSLConnectionRef
    ]
    Security.SSLSetConnection.restype = OSStatus

    Security.SSLSetPeerDomainName.argtypes = [
        SSLContextRef,
        c_char_p,
        c_size_t
    ]
    Security.SSLSetPeerDomainName.restype = OSStatus

    Security.SSLHandshake.argtypes = [
        SSLContextRef
    ]
    Security.SSLHandshake.restype = OSStatus

    Security.SSLRead.argtypes = [
        SSLContextRef,
        c_char_p,
        c_size_t,
        POINTER(c_size_t)
    ]
    Security.SSLRead.restype = OSStatus

    Security.SSLWrite.argtypes = [
        SSLContextRef,
        c_char_p,
        c_size_t,
        POINTER(c_size_t)
    ]
    Security.SSLWrite.restype = OSStatus

    Security.SSLClose.argtypes = [
        SSLContextRef
    ]
    Security.SSLClose.restype = OSStatus

    Security.SSLGetNumberSupportedCiphers.argtypes = [
        SSLContextRef,
        POINTER(c_size_t)
    ]
    Security.SSLGetNumberSupportedCiphers.restype = OSStatus

    Security.SSLGetSupportedCiphers.argtypes = [
        SSLContextRef,
        POINTER(SSLCipherSuite),
        POINTER(c_size_t)
    ]
    Security.SSLGetSupportedCiphers.restype = OSStatus

    Security.SSLSetEnabledCiphers.argtypes = [
        SSLContextRef,
        POINTER(SSLCipherSuite),
        c_size_t
    ]
    Security.SSLSetEnabledCiphers.restype = OSStatus

    Security.SSLGetNumberEnabledCiphers.argtype = [
        SSLContextRef,
        POINTER(c_size_t)
    ]
    Security.SSLGetNumberEnabledCiphers.restype = OSStatus

    Security.SSLGetEnabledCiphers.argtypes = [
        SSLContextRef,
        POINTER(SSLCipherSuite),
        POINTER(c_size_t)
    ]
    Security.SSLGetEnabledCiphers.restype = OSStatus

    Security.SSLGetNegotiatedCipher.argtypes = [
        SSLContextRef,
        POINTER(SSLCipherSuite)
    ]
    Security.SSLGetNegotiatedCipher.restype = OSStatus

    Security.SSLGetNegotiatedProtocolVersion.argtypes = [
        SSLContextRef,
        POINTER(SSLProtocol)
    ]
    Security.SSLGetNegotiatedProtocolVersion.restype = OSStatus

    Security.SSLCopyPeerTrust.argtypes = [
        SSLContextRef,
        POINTER(SecTrustRef)
    ]
    Security.SSLCopyPeerTrust.restype = OSStatus

    Security.SecTrustSetAnchorCertificates.argtypes = [
        SecTrustRef,
        CFArrayRef
    ]
    Security.SecTrustSetAnchorCertificates.restype = OSStatus

    Security.SecTrustSetAnchorCertificatesOnly.argstypes = [
        SecTrustRef,
        Boolean
    ]
    Security.SecTrustSetAnchorCertificatesOnly.restype = OSStatus

    Security.SecTrustEvaluate.argtypes = [
        SecTrustRef,
        POINTER(SecTrustResultType)
    ]
    Security.SecTrustEvaluate.restype = OSStatus

    Security.SecTrustGetCertificateCount.argtypes = [
        SecTrustRef
    ]
    Security.SecTrustGetCertificateCount.restype = CFIndex

    Security.SecTrustGetCertificateAtIndex.argtypes = [
        SecTrustRef,
        CFIndex
    ]
    Security.SecTrustGetCertificateAtIndex.restype = SecCertificateRef

    Security.SSLCreateContext.argtypes = [
        CFAllocatorRef,
        SSLProtocolSide,
        SSLConnectionType
    ]
    Security.SSLCreateContext.restype = SSLContextRef

    Security.SSLSetSessionOption.argtypes = [
        SSLContextRef,
        SSLSessionOption,
        Boolean
    ]
    Security.SSLSetSessionOption.restype = OSStatus

    Security.SSLSetProtocolVersionMin.argtypes = [
        SSLContextRef,
        SSLProtocol
    ]
    Security.SSLSetProtocolVersionMin.restype = OSStatus