import os
import sys
import unittest
import re
import glob
import inspect
import platform

import ibm_db
import config
if sys.version_info >= (3, ):
    from io import StringIO
else:
    from cStringIO import StringIO


class IbmDbTestFunctions(unittest.TestCase):
    if hasattr(config, 'hostname') and config.hostname:
        _dsn = (f"DATABASE={config.database};HOSTNAME={config.hostname};"
                f"PORT={config.port};PROTOCOL=TCPIP;"
                f"UID={config.user};PWD={config.password}")
        prepconn = ibm_db.connect(_dsn, '', '')
    else:
        prepconn = ibm_db.connect(config.database, config.user, config.password)
    server = ibm_db.server_info(prepconn)
    ibm_db.close(prepconn)

    # See the tests.py comments for this function.
    def setUp(self):
        pass

    # This function captures the output of the current test file.
    def capture(self, func):
        buffer = StringIO()
        sys.stdout = buffer
        func()
        sys.stdout = sys.__stdout__
        # str() ensures not Unicode object on Python 2
        var = str(buffer.getvalue())
        var = var.replace('\n', '').replace('\r', '')
        return var

    def testCasesIn(self, fileName):
        basename = os.path.basename(fileName)
        if (basename.startswith('test_017') or \
                basename.startswith('test_005') or \
                basename.startswith('test_018') or \
                basename.startswith('test_019') or \
                basename.startswith('test_024') or \
                basename.startswith('test_053') or \
                basename.startswith('test_054') or \
                basename.startswith('test_080') or \
                basename.startswith('test_081') or \
                basename.startswith('test_082') or \
                basename.startswith('test_090') or \
                basename.startswith('test_091') or \
                basename.startswith('test_092') or \
                basename.startswith('test_103') or \
                basename.startswith('test_116') or \
                basename.startswith('test_133') or \
                basename.startswith('test_147') or \
                basename.startswith('test_157a') or \
                basename.startswith('test_240') or \
                basename.startswith('test_241') or \
                basename.startswith('test_cursortype') or \
                basename.startswith('test_decfloat') or \
                basename.startswith('test_setgetOption') or \
                basename.startswith('test_warn') \
                ):
            return True
        else:
            return False

    # This function grabs the expected output of the current test function for LUW,
    #   located at the bottom of the current test file.
    def expected_LUW(self, fileName):
        fileHandle = open(fileName, 'r')
        fileInput = fileHandle.read().split('#__LUW_EXPECTED__')[-1].split('#__ZOS_EXPECTED__')[0].replace('\n', '').replace('#', '')
        fileHandle.close()
        return fileInput

    # This function grabs the expected output of the current test function for IDS,
    #   located at the bottom of the current test file.
    def expected_IDS(self, fileName):
        fileHandle = open(fileName, 'r')
        fileInput = fileHandle.read().split('#__IDS_EXPECTED__')[-1].split('#__ZOS_ODBC_EXPECTED__')[0].replace('\n', '').replace('#', '')
        fileHandle.close()
        return fileInput

    # This function grabs the expected output of the current test function for zOS,
    #   located at the bottom of the current test file.
    def expected_ZOS(self, fileName):
        fileHandle = open(fileName, 'r')
        fileInput = fileHandle.read().split('#__ZOS_EXPECTED__')[-1].split('#__SYSTEMI_EXPECTED__')[0].replace('\n', '').replace('#', '')
        fileHandle.close()
        return fileInput

    # This function grabs the expected output of the current test function for zOS,
    #   located at the bottom of the current test file.
    def expected_AS(self, fileName):
        fileHandle = open(fileName, 'r')
        fileInput = fileHandle.read().split('#__SYSTEMI_EXPECTED__')[-1].split('#__IDS_EXPECTED__')[0].replace('\n', '').replace('#', '')
        fileHandle.close()
        return fileInput

    # This function grabs the expected output of the current test function for z/OS ODBC driver,
    # located at the bottom of the current test file.
    # Falls back to expected_ZOS if no #__ZOS_ODBC_EXPECTED__ section exists.
    def expected_ZOS_ODBC(self, fileName):
        fileHandle = open(fileName, 'r')
        fileContent = fileHandle.read()
        fileHandle.close()
        if '#__ZOS_ODBC_EXPECTED__' in fileContent:
            fileInput = fileContent.split('#__ZOS_ODBC_EXPECTED__')[-1].replace('\n', '').replace('#', '')
        else:
            fileInput = fileContent.split('#__ZOS_EXPECTED__')[-1].split('#__SYSTEMI_EXPECTED__')[0].replace('\n', '').replace('#', '')
        return fileInput

    # This function compares the captured outout with the expected out of
    #   the current test file.
    def assert_expect(self, testFuncName):
        callstack = inspect.stack(0)
        try:
            if (self.server.DBMS_NAME[0:2] == "AS"):
                self.assertEqual(self.capture(testFuncName), self.expected_AS(callstack[1][1]))
            elif ((platform.system() == 'z/OS' or platform.system() == 'OS/390') and self.testCasesIn(callstack[1][1])):
                self.assertEqual(self.capture(testFuncName), self.expected_ZOS_ODBC(callstack[1][1]))
            elif (self.server.DBMS_NAME == "DB2" or "DSN" in self.server.DBMS_NAME):
                self.assertEqual(self.capture(testFuncName), self.expected_ZOS(callstack[1][1]))
            elif (self.server.DBMS_NAME[0:3] == "IDS"):
                self.assertEqual(self.capture(testFuncName), self.expected_IDS(callstack[1][1]))
            else:
                self.assertEqual(self.capture(testFuncName), self.expected_LUW(callstack[1][1]))

        finally:
            del callstack

    # This function will compare using Regular Expressions
    # based on the server
    def assert_expectf(self, testFuncName):
        callstack = inspect.stack(0)
        try:
            if (self.server.DBMS_NAME[0:2] == "AS"):
                pattern = self.expected_AS(callstack[1][1])
            elif ((platform.system() == 'z/OS' or platform.system() == 'OS/390') and self.testCasesIn(callstack[1][1])):
                pattern = self.expected_ZOS_ODBC(callstack[1][1])
            elif (self.server.DBMS_NAME == "DB2" or "DSN" in self.server.DBMS_NAME):
                pattern = self.expected_ZOS(callstack[1][1])
            elif (self.server.DBMS_NAME[0:3] == "IDS"):
                pattern = self.expected_IDS(callstack[1][1])
            else:
                pattern = self.expected_LUW(callstack[1][1])

            pattern = pattern.replace('%s', '\x00WILDCARD_S\x00')
            pattern = pattern.replace('%d', '\x00WILDCARD_D\x00')
            pattern = re.escape(pattern)
            pattern = pattern.replace('\x00WILDCARD_S\x00', '.*?')
            pattern = pattern.replace('\x00WILDCARD_D\x00', r'\d+')

            result = re.match(pattern, self.capture(testFuncName))
            self.assertNotEqual(result, None)
        finally:
            del callstack

    #def assert_throw_blocks(self, testFuncName):
    #  callstack = inspect.stack(0)
    #  try:

    # This function needs to be declared here, regardless of if there
    #   is any body to this function
    def runTest(self):
        pass