// Copyright 2008 Google Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Author: vladl@google.com (Vlad Losev)

// Type and function utilities for implementing parameterized tests.

#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_

#include <iterator>
#include <utility>
#include <vector>

// scripts/fuse_gtest.py depends on gtest's own header being #included
// *unconditionally*.  Therefore these #includes cannot be moved
// inside #if GTEST_HAS_PARAM_TEST.
#include "gtest/internal/gtest-internal.h"
#include "gtest/internal/gtest-linked_ptr.h"
#include "gtest/internal/gtest-port.h"
#include "gtest/gtest-printers.h"

#if GTEST_HAS_PARAM_TEST

namespace testing
{
namespace internal
{

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Outputs a message explaining invalid registration of different
// fixture class for the same test case. This may happen when
// TEST_P macro is used to define two tests with the same name
// but in different namespaces.
GTEST_API_ void ReportInvalidTestCaseType(const char* test_case_name,
        const char* file, int line);

template <typename> class ParamGeneratorInterface;
template <typename> class ParamGenerator;

// Interface for iterating over elements provided by an implementation
// of ParamGeneratorInterface<T>.
template <typename T>
class ParamIteratorInterface
{
    public:
        virtual ~ParamIteratorInterface() {}
        // A pointer to the base generator instance.
        // Used only for the purposes of iterator comparison
        // to make sure that two iterators belong to the same generator.
        virtual const ParamGeneratorInterface<T>* BaseGenerator() const = 0;
        // Advances iterator to point to the next element
        // provided by the generator. The caller is responsible
        // for not calling Advance() on an iterator equal to
        // BaseGenerator()->End().
        virtual void Advance() = 0;
        // Clones the iterator object. Used for implementing copy semantics
        // of ParamIterator<T>.
        virtual ParamIteratorInterface* Clone() const = 0;
        // Dereferences the current iterator and provides (read-only) access
        // to the pointed value. It is the caller's responsibility not to call
        // Current() on an iterator equal to BaseGenerator()->End().
        // Used for implementing ParamGenerator<T>::operator*().
        virtual const T* Current() const = 0;
        // Determines whether the given iterator and other point to the same
        // element in the sequence generated by the generator.
        // Used for implementing ParamGenerator<T>::operator==().
        virtual bool Equals(const ParamIteratorInterface& other) const = 0;
};

// Class iterating over elements provided by an implementation of
// ParamGeneratorInterface<T>. It wraps ParamIteratorInterface<T>
// and implements the const forward iterator concept.
template <typename T>
class ParamIterator
{
    public:
        typedef T value_type;
        typedef const T& reference;
        typedef ptrdiff_t difference_type;

        // ParamIterator assumes ownership of the impl_ pointer.
        ParamIterator(const ParamIterator& other) : impl_(other.impl_->Clone()) {}
        ParamIterator& operator=(const ParamIterator& other) {
            if (this != &other)
                impl_.reset(other.impl_->Clone());
            return *this;
        }

        const T& operator*() const { return *impl_->Current(); }
        const T* operator->() const { return impl_->Current(); }
        // Prefix version of operator++.
        ParamIterator& operator++() {
            impl_->Advance();
            return *this;
        }
        // Postfix version of operator++.
        ParamIterator operator++(int /*unused*/) {
            ParamIteratorInterface<T>* clone = impl_->Clone();
            impl_->Advance();
            return ParamIterator(clone);
        }
        bool operator==(const ParamIterator& other) const {
            return impl_.get() == other.impl_.get() || impl_->Equals(*other.impl_);
        }
        bool operator!=(const ParamIterator& other) const {
            return !(*this == other);
        }

    private:
        friend class ParamGenerator<T>;
        explicit ParamIterator(ParamIteratorInterface<T>* impl) : impl_(impl) {}
        scoped_ptr<ParamIteratorInterface<T> > impl_;
};

// ParamGeneratorInterface<T> is the binary interface to access generators
// defined in other translation units.
template <typename T>
class ParamGeneratorInterface
{
    public:
        typedef T ParamType;

        virtual ~ParamGeneratorInterface() {}

        // Generator interface definition
        virtual ParamIteratorInterface<T>* Begin() const = 0;
        virtual ParamIteratorInterface<T>* End() const = 0;
};

// Wraps ParamGeneratorInterface<T> and provides general generator syntax
// compatible with the STL Container concept.
// This class implements copy initialization semantics and the contained
// ParamGeneratorInterface<T> instance is shared among all copies
// of the original object. This is possible because that instance is immutable.
template<typename T>
class ParamGenerator
{
    public:
        typedef ParamIterator<T> iterator;

        explicit ParamGenerator(ParamGeneratorInterface<T>* impl) : impl_(impl) {}
        ParamGenerator(const ParamGenerator& other) : impl_(other.impl_) {}

        ParamGenerator& operator=(const ParamGenerator& other) {
            impl_ = other.impl_;
            return *this;
        }

        iterator begin() const { return iterator(impl_->Begin()); }
        iterator end() const { return iterator(impl_->End()); }

    private:
        linked_ptr<const ParamGeneratorInterface<T> > impl_;
};

// Generates values from a range of two comparable values. Can be used to
// generate sequences of user-defined types that implement operator+() and
// operator<().
// This class is used in the Range() function.
template <typename T, typename IncrementT>
class RangeGenerator : public ParamGeneratorInterface<T>
{
    public:
        RangeGenerator(T begin, T end, IncrementT step)
            : begin_(begin), end_(end),
              step_(step), end_index_(CalculateEndIndex(begin, end, step)) {}
        virtual ~RangeGenerator() {}

        virtual ParamIteratorInterface<T>* Begin() const {
            return new Iterator(this, begin_, 0, step_);
        }
        virtual ParamIteratorInterface<T>* End() const {
            return new Iterator(this, end_, end_index_, step_);
        }

    private:
        class Iterator : public ParamIteratorInterface<T>
        {
            public:
                Iterator(const ParamGeneratorInterface<T>* base, T value, int index,
                         IncrementT step)
                    : base_(base), value_(value), index_(index), step_(step) {}
                virtual ~Iterator() {}

                virtual const ParamGeneratorInterface<T>* BaseGenerator() const {
                    return base_;
                }
                virtual void Advance() {
                    value_ = value_ + step_;
                    index_++;
                }
                virtual ParamIteratorInterface<T>* Clone() const {
                    return new Iterator(*this);
                }
                virtual const T* Current() const { return &value_; }
                virtual bool Equals(const ParamIteratorInterface<T>& other) const {
                    // Having the same base generator guarantees that the other
                    // iterator is of the same type and we can downcast.
                    GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
                            << "The program attempted to compare iterators "
                            << "from different generators." << std::endl;
                    const int other_index =
                        CheckedDowncastToActualType<const Iterator>(&other)->index_;
                    return index_ == other_index;
                }

            private:
                Iterator(const Iterator& other)
                    : ParamIteratorInterface<T>(),
                      base_(other.base_), value_(other.value_), index_(other.index_),
                      step_(other.step_) {}

                // No implementation - assignment is unsupported.
                void operator=(const Iterator& other);

                const ParamGeneratorInterface<T>* const base_;
                T value_;
                int index_;
                const IncrementT step_;
        };  // class RangeGenerator::Iterator

        static int CalculateEndIndex(const T& begin,
                                     const T& end,
                                     const IncrementT& step) {
            int end_index = 0;
            for (T i = begin; i < end; i = i + step)
                end_index++;
            return end_index;
        }

        // No implementation - assignment is unsupported.
        void operator=(const RangeGenerator& other);

        const T begin_;
        const T end_;
        const IncrementT step_;
        // The index for the end() iterator. All the elements in the generated
        // sequence are indexed (0-based) to aid iterator comparison.
        const int end_index_;
};  // class RangeGenerator


// Generates values from a pair of STL-style iterators. Used in the
// ValuesIn() function. The elements are copied from the source range
// since the source can be located on the stack, and the generator
// is likely to persist beyond that stack frame.
template <typename T>
class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T>
{
    public:
        template <typename ForwardIterator>
        ValuesInIteratorRangeGenerator(ForwardIterator begin, ForwardIterator end)
            : container_(begin, end) {}
        virtual ~ValuesInIteratorRangeGenerator() {}

        virtual ParamIteratorInterface<T>* Begin() const {
            return new Iterator(this, container_.begin());
        }
        virtual ParamIteratorInterface<T>* End() const {
            return new Iterator(this, container_.end());
        }

    private:
        typedef typename ::std::vector<T> ContainerType;

        class Iterator : public ParamIteratorInterface<T>
        {
            public:
                Iterator(const ParamGeneratorInterface<T>* base,
                         typename ContainerType::const_iterator iterator)
                    : base_(base), iterator_(iterator) {}
                virtual ~Iterator() {}

                virtual const ParamGeneratorInterface<T>* BaseGenerator() const {
                    return base_;
                }
                virtual void Advance() {
                    ++iterator_;
                    value_.reset();
                }
                virtual ParamIteratorInterface<T>* Clone() const {
                    return new Iterator(*this);
                }
                // We need to use cached value referenced by iterator_ because *iterator_
                // can return a temporary object (and of type other then T), so just
                // having "return &*iterator_;" doesn't work.
                // value_ is updated here and not in Advance() because Advance()
                // can advance iterator_ beyond the end of the range, and we cannot
                // detect that fact. The client code, on the other hand, is
                // responsible for not calling Current() on an out-of-range iterator.
                virtual const T* Current() const {
                    if (value_.get() == NULL)
                        value_.reset(new T(*iterator_));
                    return value_.get();
                }
                virtual bool Equals(const ParamIteratorInterface<T>& other) const {
                    // Having the same base generator guarantees that the other
                    // iterator is of the same type and we can downcast.
                    GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
                            << "The program attempted to compare iterators "
                            << "from different generators." << std::endl;
                    return iterator_ ==
                           CheckedDowncastToActualType<const Iterator>(&other)->iterator_;
                }

            private:
                Iterator(const Iterator& other)
                // The explicit constructor call suppresses a false warning
                // emitted by gcc when supplied with the -Wextra option.
                    : ParamIteratorInterface<T>(),
                      base_(other.base_),
                      iterator_(other.iterator_) {}

                const ParamGeneratorInterface<T>* const base_;
                typename ContainerType::const_iterator iterator_;
                // A cached value of *iterator_. We keep it here to allow access by
                // pointer in the wrapping iterator's operator->().
                // value_ needs to be mutable to be accessed in Current().
                // Use of scoped_ptr helps manage cached value's lifetime,
                // which is bound by the lifespan of the iterator itself.
                mutable scoped_ptr<const T> value_;
        };  // class ValuesInIteratorRangeGenerator::Iterator

        // No implementation - assignment is unsupported.
        void operator=(const ValuesInIteratorRangeGenerator& other);

        const ContainerType container_;
};  // class ValuesInIteratorRangeGenerator

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Stores a parameter value and later creates tests parameterized with that
// value.
template <class TestClass>
class ParameterizedTestFactory : public TestFactoryBase
{
    public:
        typedef typename TestClass::ParamType ParamType;
        explicit ParameterizedTestFactory(ParamType parameter) :
            parameter_(parameter) {}
        virtual Test* CreateTest() {
            TestClass::SetParam(&parameter_);
            return new TestClass();
        }

    private:
        const ParamType parameter_;

        GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestFactory);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// TestMetaFactoryBase is a base class for meta-factories that create
// test factories for passing into MakeAndRegisterTestInfo function.
template <class ParamType>
class TestMetaFactoryBase
{
    public:
        virtual ~TestMetaFactoryBase() {}

        virtual TestFactoryBase* CreateTestFactory(ParamType parameter) = 0;
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// TestMetaFactory creates test factories for passing into
// MakeAndRegisterTestInfo function. Since MakeAndRegisterTestInfo receives
// ownership of test factory pointer, same factory object cannot be passed
// into that method twice. But ParameterizedTestCaseInfo is going to call
// it for each Test/Parameter value combination. Thus it needs meta factory
// creator class.
template <class TestCase>
class TestMetaFactory
    : public TestMetaFactoryBase<typename TestCase::ParamType>
{
    public:
        typedef typename TestCase::ParamType ParamType;

        TestMetaFactory() {}

        virtual TestFactoryBase* CreateTestFactory(ParamType parameter) {
            return new ParameterizedTestFactory<TestCase>(parameter);
        }

    private:
        GTEST_DISALLOW_COPY_AND_ASSIGN_(TestMetaFactory);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseInfoBase is a generic interface
// to ParameterizedTestCaseInfo classes. ParameterizedTestCaseInfoBase
// accumulates test information provided by TEST_P macro invocations
// and generators provided by INSTANTIATE_TEST_CASE_P macro invocations
// and uses that information to register all resulting test instances
// in RegisterTests method. The ParameterizeTestCaseRegistry class holds
// a collection of pointers to the ParameterizedTestCaseInfo objects
// and calls RegisterTests() on each of them when asked.
class ParameterizedTestCaseInfoBase
{
    public:
        virtual ~ParameterizedTestCaseInfoBase() {}

        // Base part of test case name for display purposes.
        virtual const string& GetTestCaseName() const = 0;
        // Test case id to verify identity.
        virtual TypeId GetTestCaseTypeId() const = 0;
        // UnitTest class invokes this method to register tests in this
        // test case right before running them in RUN_ALL_TESTS macro.
        // This method should not be called more then once on any single
        // instance of a ParameterizedTestCaseInfoBase derived class.
        virtual void RegisterTests() = 0;

    protected:
        ParameterizedTestCaseInfoBase() {}

    private:
        GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseInfoBase);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseInfo accumulates tests obtained from TEST_P
// macro invocations for a particular test case and generators
// obtained from INSTANTIATE_TEST_CASE_P macro invocations for that
// test case. It registers tests with all values generated by all
// generators when asked.
template <class TestCase>
class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase
{
    public:
        // ParamType and GeneratorCreationFunc are private types but are required
        // for declarations of public methods AddTestPattern() and
        // AddTestCaseInstantiation().
        typedef typename TestCase::ParamType ParamType;
        // A function that returns an instance of appropriate generator type.
        typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();

        explicit ParameterizedTestCaseInfo(const char* name)
            : test_case_name_(name) {}

        // Test case base name for display purposes.
        virtual const string& GetTestCaseName() const { return test_case_name_; }
        // Test case id to verify identity.
        virtual TypeId GetTestCaseTypeId() const { return GetTypeId<TestCase>(); }
        // TEST_P macro uses AddTestPattern() to record information
        // about a single test in a LocalTestInfo structure.
        // test_case_name is the base name of the test case (without invocation
        // prefix). test_base_name is the name of an individual test without
        // parameter index. For the test SequenceA/FooTest.DoBar/1 FooTest is
        // test case base name and DoBar is test base name.
        void AddTestPattern(const char* test_case_name,
                            const char* test_base_name,
                            TestMetaFactoryBase<ParamType>* meta_factory) {
            tests_.push_back(linked_ptr<TestInfo>(new TestInfo(test_case_name,
                                                  test_base_name,
                                                  meta_factory)));
        }
        // INSTANTIATE_TEST_CASE_P macro uses AddGenerator() to record information
        // about a generator.
        int AddTestCaseInstantiation(const string& instantiation_name,
                                     GeneratorCreationFunc* func,
                                     const char* /* file */,
                                     int /* line */) {
            instantiations_.push_back(::std::make_pair(instantiation_name, func));
            return 0;  // Return value used only to run this method in namespace scope.
        }
        // UnitTest class invokes this method to register tests in this test case
        // test cases right before running tests in RUN_ALL_TESTS macro.
        // This method should not be called more then once on any single
        // instance of a ParameterizedTestCaseInfoBase derived class.
        // UnitTest has a guard to prevent from calling this method more then once.
        virtual void RegisterTests() {
            for (typename TestInfoContainer::iterator test_it = tests_.begin();
                 test_it != tests_.end(); ++test_it) {
                linked_ptr<TestInfo> test_info = *test_it;
                for (typename InstantiationContainer::iterator gen_it =
                         instantiations_.begin(); gen_it != instantiations_.end();
                     ++gen_it) {
                    const string& instantiation_name = gen_it->first;
                    ParamGenerator<ParamType> generator((*gen_it->second)());

                    string test_case_name;
                    if (!instantiation_name.empty())
                        test_case_name = instantiation_name + "/";
                    test_case_name += test_info->test_case_base_name;

                    int i = 0;
                    for (typename ParamGenerator<ParamType>::iterator param_it =
                             generator.begin();
                         param_it != generator.end(); ++param_it, ++i) {
                        Message test_name_stream;
                        test_name_stream << test_info->test_base_name << "/" << i;
                        MakeAndRegisterTestInfo(
                            test_case_name.c_str(),
                            test_name_stream.GetString().c_str(),
                            NULL,  // No type parameter.
                            PrintToString(*param_it).c_str(),
                            GetTestCaseTypeId(),
                            TestCase::SetUpTestCase,
                            TestCase::TearDownTestCase,
                            test_info->test_meta_factory->CreateTestFactory(*param_it));
                    }  // for param_it
                }  // for gen_it
            }  // for test_it
        }  // RegisterTests

    private:
        // LocalTestInfo structure keeps information about a single test registered
        // with TEST_P macro.
        struct TestInfo {
            TestInfo(const char* a_test_case_base_name,
                     const char* a_test_base_name,
                     TestMetaFactoryBase<ParamType>* a_test_meta_factory) :
                test_case_base_name(a_test_case_base_name),
                test_base_name(a_test_base_name),
                test_meta_factory(a_test_meta_factory) {}

            const string test_case_base_name;
            const string test_base_name;
            const scoped_ptr<TestMetaFactoryBase<ParamType> > test_meta_factory;
        };
        typedef ::std::vector<linked_ptr<TestInfo> > TestInfoContainer;
        // Keeps pairs of <Instantiation name, Sequence generator creation function>
        // received from INSTANTIATE_TEST_CASE_P macros.
        typedef ::std::vector<std::pair<string, GeneratorCreationFunc*> >
        InstantiationContainer;

        const string test_case_name_;
        TestInfoContainer tests_;
        InstantiationContainer instantiations_;

        GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseInfo);
};  // class ParameterizedTestCaseInfo

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseRegistry contains a map of ParameterizedTestCaseInfoBase
// classes accessed by test case names. TEST_P and INSTANTIATE_TEST_CASE_P
// macros use it to locate their corresponding ParameterizedTestCaseInfo
// descriptors.
class ParameterizedTestCaseRegistry
{
    public:
        ParameterizedTestCaseRegistry() {}
        ~ParameterizedTestCaseRegistry() {
            for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
                 it != test_case_infos_.end(); ++it) {
                delete *it;
            }
        }

        // Looks up or creates and returns a structure containing information about
        // tests and instantiations of a particular test case.
        template <class TestCase>
        ParameterizedTestCaseInfo<TestCase>* GetTestCasePatternHolder(
            const char* test_case_name,
            const char* file,
            int line) {
            ParameterizedTestCaseInfo<TestCase>* typed_test_info = NULL;
            for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
                 it != test_case_infos_.end(); ++it) {
                if ((*it)->GetTestCaseName() == test_case_name) {
                    if ((*it)->GetTestCaseTypeId() != GetTypeId<TestCase>()) {
                        // Complain about incorrect usage of Google Test facilities
                        // and terminate the program since we cannot guaranty correct
                        // test case setup and tear-down in this case.
                        ReportInvalidTestCaseType(test_case_name,  file, line);
                        posix::Abort();
                    } else {
                        // At this point we are sure that the object we found is of the same
                        // type we are looking for, so we downcast it to that type
                        // without further checks.
                        typed_test_info = CheckedDowncastToActualType<
                                          ParameterizedTestCaseInfo<TestCase> >(*it);
                    }
                    break;
                }
            }
            if (typed_test_info == NULL) {
                typed_test_info = new ParameterizedTestCaseInfo<TestCase>(test_case_name);
                test_case_infos_.push_back(typed_test_info);
            }
            return typed_test_info;
        }
        void RegisterTests() {
            for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
                 it != test_case_infos_.end(); ++it) {
                (*it)->RegisterTests();
            }
        }

    private:
        typedef ::std::vector<ParameterizedTestCaseInfoBase*> TestCaseInfoContainer;

        TestCaseInfoContainer test_case_infos_;

        GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseRegistry);
};

}  // namespace internal
}  // namespace testing

#endif  //  GTEST_HAS_PARAM_TEST

#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
