"""
TestCases for python DB duplicate and Btree key comparison function.
"""

import sys, os, re
import test_all
from cStringIO import StringIO

import unittest

from test_all import db, dbshelve, test_support, \
        get_new_environment_path, get_new_database_path


# Needed for python 3. "cmp" vanished in 3.0.1
def cmp(a, b) :
    if a==b : return 0
    if a<b : return -1
    return 1

lexical_cmp = cmp

def lowercase_cmp(left, right) :
    return cmp(left.lower(), right.lower())

def make_reverse_comparator(cmp) :
    def reverse(left, right, delegate=cmp) :
        return - delegate(left, right)
    return reverse

_expected_lexical_test_data = ['', 'CCCP', 'a', 'aaa', 'b', 'c', 'cccce', 'ccccf']
_expected_lowercase_test_data = ['', 'a', 'aaa', 'b', 'c', 'CC', 'cccce', 'ccccf', 'CCCP']

class ComparatorTests(unittest.TestCase) :
    def comparator_test_helper(self, comparator, expected_data) :
        data = expected_data[:]

        import sys
        if sys.version_info < (2, 6) :
            data.sort(cmp=comparator)
        else :  # Insertion Sort. Please, improve
            data2 = []
            for i in data :
                for j, k in enumerate(data2) :
                    r = comparator(k, i)
                    if r == 1 :
                        data2.insert(j, i)
                        break
                else :
                    data2.append(i)
            data = data2

        self.assertEqual(data, expected_data,
                         "comparator `%s' is not right: %s vs. %s"
                         % (comparator, expected_data, data))
    def test_lexical_comparator(self) :
        self.comparator_test_helper(lexical_cmp, _expected_lexical_test_data)
    def test_reverse_lexical_comparator(self) :
        rev = _expected_lexical_test_data[:]
        rev.reverse()
        self.comparator_test_helper(make_reverse_comparator(lexical_cmp),
                                     rev)
    def test_lowercase_comparator(self) :
        self.comparator_test_helper(lowercase_cmp,
                                     _expected_lowercase_test_data)

class AbstractBtreeKeyCompareTestCase(unittest.TestCase) :
    env = None
    db = None

    if (sys.version_info < (2, 7)) or ((sys.version_info >= (3,0)) and
            (sys.version_info < (3, 2))) :
        def assertLess(self, a, b, msg=None) :
            return self.assertTrue(a<b, msg=msg)

    def setUp(self) :
        self.filename = self.__class__.__name__ + '.db'
        self.homeDir = get_new_environment_path()
        env = db.DBEnv()
        env.open(self.homeDir,
                  db.DB_CREATE | db.DB_INIT_MPOOL
                  | db.DB_INIT_LOCK | db.DB_THREAD)
        self.env = env

    def tearDown(self) :
        self.closeDB()
        if self.env is not None:
            self.env.close()
            self.env = None
        test_support.rmtree(self.homeDir)

    def addDataToDB(self, data) :
        i = 0
        for item in data:
            self.db.put(item, str(i))
            i = i + 1

    def createDB(self, key_comparator) :
        self.db = db.DB(self.env)
        self.setupDB(key_comparator)
        self.db.open(self.filename, "test", db.DB_BTREE, db.DB_CREATE)

    def setupDB(self, key_comparator) :
        self.db.set_bt_compare(key_comparator)

    def closeDB(self) :
        if self.db is not None:
            self.db.close()
            self.db = None

    def startTest(self) :
        pass

    def finishTest(self, expected = None) :
        if expected is not None:
            self.check_results(expected)
        self.closeDB()

    def check_results(self, expected) :
        curs = self.db.cursor()
        try:
            index = 0
            rec = curs.first()
            while rec:
                key, ignore = rec
                self.assertLess(index, len(expected),
                                 "to many values returned from cursor")
                self.assertEqual(expected[index], key,
                                 "expected value `%s' at %d but got `%s'"
                                 % (expected[index], index, key))
                index = index + 1
                rec = curs.next()
            self.assertEqual(index, len(expected),
                             "not enough values returned from cursor")
        finally:
            curs.close()

class BtreeKeyCompareTestCase(AbstractBtreeKeyCompareTestCase) :
    def runCompareTest(self, comparator, data) :
        self.startTest()
        self.createDB(comparator)
        self.addDataToDB(data)
        self.finishTest(data)

    def test_lexical_ordering(self) :
        self.runCompareTest(lexical_cmp, _expected_lexical_test_data)

    def test_reverse_lexical_ordering(self) :
        expected_rev_data = _expected_lexical_test_data[:]
        expected_rev_data.reverse()
        self.runCompareTest(make_reverse_comparator(lexical_cmp),
                             expected_rev_data)

    def test_compare_function_useless(self) :
        self.startTest()
        def socialist_comparator(l, r) :
            return 0
        self.createDB(socialist_comparator)
        self.addDataToDB(['b', 'a', 'd'])
        # all things being equal the first key will be the only key
        # in the database...  (with the last key's value fwiw)
        self.finishTest(['b'])


class BtreeExceptionsTestCase(AbstractBtreeKeyCompareTestCase) :
    def test_raises_non_callable(self) :
        self.startTest()
        self.assertRaises(TypeError, self.createDB, 'abc')
        self.assertRaises(TypeError, self.createDB, None)
        self.finishTest()

    def test_set_bt_compare_with_function(self) :
        self.startTest()
        self.createDB(lexical_cmp)
        self.finishTest()

    def check_results(self, results) :
        pass

    def test_compare_function_incorrect(self) :
        self.startTest()
        def bad_comparator(l, r) :
            return 1
        # verify that set_bt_compare checks that comparator('', '') == 0
        self.assertRaises(TypeError, self.createDB, bad_comparator)
        self.finishTest()

    def verifyStderr(self, method, successRe) :
        """
        Call method() while capturing sys.stderr output internally and
        call self.fail() if successRe.search() does not match the stderr
        output.  This is used to test for uncatchable exceptions.
        """
        stdErr = sys.stderr
        sys.stderr = StringIO()
        try:
            method()
        finally:
            temp = sys.stderr
            sys.stderr = stdErr
            errorOut = temp.getvalue()
            if not successRe.search(errorOut) :
                self.fail("unexpected stderr output:\n"+errorOut)
        if sys.version_info < (3, 0) :  # XXX: How to do this in Py3k ???
            sys.exc_traceback = sys.last_traceback = None

    def _test_compare_function_exception(self) :
        self.startTest()
        def bad_comparator(l, r) :
            if l == r:
                # pass the set_bt_compare test
                return 0
            raise RuntimeError, "i'm a naughty comparison function"
        self.createDB(bad_comparator)
        #print "\n*** test should print 2 uncatchable tracebacks ***"
        self.addDataToDB(['a', 'b', 'c'])  # this should raise, but...
        self.finishTest()

    def test_compare_function_exception(self) :
        self.verifyStderr(
                self._test_compare_function_exception,
                re.compile('(^RuntimeError:.* naughty.*){2}', re.M|re.S)
        )

    def _test_compare_function_bad_return(self) :
        self.startTest()
        def bad_comparator(l, r) :
            if l == r:
                # pass the set_bt_compare test
                return 0
            return l
        self.createDB(bad_comparator)
        #print "\n*** test should print 2 errors about returning an int ***"
        self.addDataToDB(['a', 'b', 'c'])  # this should raise, but...
        self.finishTest()

    def test_compare_function_bad_return(self) :
        self.verifyStderr(
                self._test_compare_function_bad_return,
                re.compile('(^TypeError:.* return an int.*){2}', re.M|re.S)
        )


    def test_cannot_assign_twice(self) :

        def my_compare(a, b) :
            return 0

        self.startTest()
        self.createDB(my_compare)
        self.assertRaises(RuntimeError, self.db.set_bt_compare, my_compare)

class AbstractDuplicateCompareTestCase(unittest.TestCase) :
    env = None
    db = None

    if (sys.version_info < (2, 7)) or ((sys.version_info >= (3,0)) and
            (sys.version_info < (3, 2))) :
        def assertLess(self, a, b, msg=None) :
            return self.assertTrue(a<b, msg=msg)

    def setUp(self) :
        self.filename = self.__class__.__name__ + '.db'
        self.homeDir = get_new_environment_path()
        env = db.DBEnv()
        env.open(self.homeDir,
                  db.DB_CREATE | db.DB_INIT_MPOOL
                  | db.DB_INIT_LOCK | db.DB_THREAD)
        self.env = env

    def tearDown(self) :
        self.closeDB()
        if self.env is not None:
            self.env.close()
            self.env = None
        test_support.rmtree(self.homeDir)

    def addDataToDB(self, data) :
        for item in data:
            self.db.put("key", item)

    def createDB(self, dup_comparator) :
        self.db = db.DB(self.env)
        self.setupDB(dup_comparator)
        self.db.open(self.filename, "test", db.DB_BTREE, db.DB_CREATE)

    def setupDB(self, dup_comparator) :
        self.db.set_flags(db.DB_DUPSORT)
        self.db.set_dup_compare(dup_comparator)

    def closeDB(self) :
        if self.db is not None:
            self.db.close()
            self.db = None

    def startTest(self) :
        pass

    def finishTest(self, expected = None) :
        if expected is not None:
            self.check_results(expected)
        self.closeDB()

    def check_results(self, expected) :
        curs = self.db.cursor()
        try:
            index = 0
            rec = curs.first()
            while rec:
                ignore, data = rec
                self.assertLess(index, len(expected),
                                 "to many values returned from cursor")
                self.assertEqual(expected[index], data,
                                 "expected value `%s' at %d but got `%s'"
                                 % (expected[index], index, data))
                index = index + 1
                rec = curs.next()
            self.assertEqual(index, len(expected),
                             "not enough values returned from cursor")
        finally:
            curs.close()

class DuplicateCompareTestCase(AbstractDuplicateCompareTestCase) :
    def runCompareTest(self, comparator, data) :
        self.startTest()
        self.createDB(comparator)
        self.addDataToDB(data)
        self.finishTest(data)

    def test_lexical_ordering(self) :
        self.runCompareTest(lexical_cmp, _expected_lexical_test_data)

    def test_reverse_lexical_ordering(self) :
        expected_rev_data = _expected_lexical_test_data[:]
        expected_rev_data.reverse()
        self.runCompareTest(make_reverse_comparator(lexical_cmp),
                             expected_rev_data)

class DuplicateExceptionsTestCase(AbstractDuplicateCompareTestCase) :
    def test_raises_non_callable(self) :
        self.startTest()
        self.assertRaises(TypeError, self.createDB, 'abc')
        self.assertRaises(TypeError, self.createDB, None)
        self.finishTest()

    def test_set_dup_compare_with_function(self) :
        self.startTest()
        self.createDB(lexical_cmp)
        self.finishTest()

    def check_results(self, results) :
        pass

    def test_compare_function_incorrect(self) :
        self.startTest()
        def bad_comparator(l, r) :
            return 1
        # verify that set_dup_compare checks that comparator('', '') == 0
        self.assertRaises(TypeError, self.createDB, bad_comparator)
        self.finishTest()

    def test_compare_function_useless(self) :
        self.startTest()
        def socialist_comparator(l, r) :
            return 0
        self.createDB(socialist_comparator)
        # DUPSORT does not allow "duplicate duplicates"
        self.assertRaises(db.DBKeyExistError, self.addDataToDB, ['b', 'a', 'd'])
        self.finishTest()

    def verifyStderr(self, method, successRe) :
        """
        Call method() while capturing sys.stderr output internally and
        call self.fail() if successRe.search() does not match the stderr
        output.  This is used to test for uncatchable exceptions.
        """
        stdErr = sys.stderr
        sys.stderr = StringIO()
        try:
            method()
        finally:
            temp = sys.stderr
            sys.stderr = stdErr
            errorOut = temp.getvalue()
            if not successRe.search(errorOut) :
                self.fail("unexpected stderr output:\n"+errorOut)
        if sys.version_info < (3, 0) :  # XXX: How to do this in Py3k ???
            sys.exc_traceback = sys.last_traceback = None

    def _test_compare_function_exception(self) :
        self.startTest()
        def bad_comparator(l, r) :
            if l == r:
                # pass the set_dup_compare test
                return 0
            raise RuntimeError, "i'm a naughty comparison function"
        self.createDB(bad_comparator)
        #print "\n*** test should print 2 uncatchable tracebacks ***"
        self.addDataToDB(['a', 'b', 'c'])  # this should raise, but...
        self.finishTest()

    def test_compare_function_exception(self) :
        self.verifyStderr(
                self._test_compare_function_exception,
                re.compile('(^RuntimeError:.* naughty.*){2}', re.M|re.S)
        )

    def _test_compare_function_bad_return(self) :
        self.startTest()
        def bad_comparator(l, r) :
            if l == r:
                # pass the set_dup_compare test
                return 0
            return l
        self.createDB(bad_comparator)
        #print "\n*** test should print 2 errors about returning an int ***"
        self.addDataToDB(['a', 'b', 'c'])  # this should raise, but...
        self.finishTest()

    def test_compare_function_bad_return(self) :
        self.verifyStderr(
                self._test_compare_function_bad_return,
                re.compile('(^TypeError:.* return an int.*){2}', re.M|re.S)
        )


    def test_cannot_assign_twice(self) :

        def my_compare(a, b) :
            return 0

        self.startTest()
        self.createDB(my_compare)
        self.assertRaises(RuntimeError, self.db.set_dup_compare, my_compare)

def test_suite() :
    res = unittest.TestSuite()

    res.addTest(unittest.makeSuite(ComparatorTests))
    res.addTest(unittest.makeSuite(BtreeExceptionsTestCase))
    res.addTest(unittest.makeSuite(BtreeKeyCompareTestCase))
    res.addTest(unittest.makeSuite(DuplicateExceptionsTestCase))
    res.addTest(unittest.makeSuite(DuplicateCompareTestCase))
    return res

if __name__ == '__main__':
    unittest.main(defaultTest = 'suite')