// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include <config.h>
#include <eval/token.h>
#include <dhcp/pkt4.h>
#include <dhcp/pkt6.h>
#include <dhcp/dhcp4.h>
#include <dhcp/dhcp6.h>
#include <dhcp/option_string.h>

#include <boost/shared_ptr.hpp>
#include <boost/scoped_ptr.hpp>
#include <gtest/gtest.h>

using namespace std;
using namespace isc::dhcp;

namespace {

/// @brief Test fixture for testing Tokens.
///
/// This class provides several convenience objects to be used during testing
/// of the Token family of classes.
class TokenTest : public ::testing::Test {
public:

    /// @brief Initializes Pkt4,Pkt6 and options that can be useful for
    ///        evaluation tests.
    TokenTest() {
        pkt4_.reset(new Pkt4(DHCPDISCOVER, 12345));
        pkt6_.reset(new Pkt6(DHCPV6_SOLICIT, 12345));

        // Add options with easily identifiable strings in them
        option_str4_.reset(new OptionString(Option::V4, 100, "hundred4"));
        option_str6_.reset(new OptionString(Option::V6, 100, "hundred6"));

        pkt4_->addOption(option_str4_);
        pkt6_->addOption(option_str6_);
    }

    TokenPtr t_; ///< Just a convenience pointer

    ValueStack values_; ///< evaluated values will be stored here

    Pkt4Ptr pkt4_; ///< A stub DHCPv4 packet
    Pkt6Ptr pkt6_; ///< A stub DHCPv6 packet

    OptionPtr option_str4_; ///< A string option for DHCPv4
    OptionPtr option_str6_; ///< A string option for DHCPv6

    /// @todo: Add more option types here
};

// This simple test checks that a TokenString, representing a constant string,
// can be used in Pkt4 evaluation. (The actual packet is not used)
TEST_F(TokenTest, string4) {

    // Store constant string "foo" in the TokenString object.
    ASSERT_NO_THROW(t_.reset(new TokenString("foo")));

    // Make sure that the token can be evaluated without exceptions.
    ASSERT_NO_THROW(t_->evaluate(*pkt4_, values_));

    // Check that the evaluation put its value on the values stack.
    ASSERT_EQ(1, values_.size());
    EXPECT_EQ("foo", values_.top());
}

// This simple test checks that a TokenString, representing a constant string,
// can be used in Pkt6 evaluation. (The actual packet is not used)
TEST_F(TokenTest, string6) {

    // Store constant string "foo" in the TokenString object.
    ASSERT_NO_THROW(t_.reset(new TokenString("foo")));

    // Make sure that the token can be evaluated without exceptions.
    ASSERT_NO_THROW(t_->evaluate(*pkt6_, values_));

    // Check that the evaluation put its value on the values stack.
    ASSERT_EQ(1, values_.size());
    EXPECT_EQ("foo", values_.top());
}

// This test checks if a token representing an option value is able to extract
// the option from a packet and properly store the option's value.
TEST_F(TokenTest, optionString) {
    TokenPtr found;
    TokenPtr not_found;

    // The packets we use have option 100 with a string in them.
    ASSERT_NO_THROW(found.reset(new TokenOption(100)));
    ASSERT_NO_THROW(not_found.reset(new TokenOption(101)));

    // This should evaluate to the content of the option 100 (i.e. "hundred4")
    ASSERT_NO_THROW(found->evaluate(*pkt4_, values_));

    // This should evaluate to "" as there is no option 101.
    ASSERT_NO_THROW(not_found->evaluate(*pkt4_, values_));

    // There should be 2 values evaluated.
    ASSERT_EQ(2, values_.size());

    // This is a stack, so the pop order is inversed. We should get the empty
    // string first.
    EXPECT_EQ("", values_.top());
    values_.pop();

    // Then the content of the option 100.
    EXPECT_EQ("hundred4", values_.top());
}

// This test checks if a token representing an == operator is able to
// compare two values (with incorrectly built stack).
TEST_F(TokenTest, optionEqualInvalid) {

    ASSERT_NO_THROW(t_.reset(new TokenEqual()));

    // CASE 1: There's not enough values on the stack. == is an operator that
    // takes two parameters. There are 0 on the stack.
    EXPECT_THROW(t_->evaluate(*pkt4_, values_), EvalBadStack);

    // CASE 2: One value is still not enough.
    values_.push("foo");
    EXPECT_THROW(t_->evaluate(*pkt4_, values_), EvalBadStack);
}

// This test checks if a token representing an == operator is able to
// compare two different values.
TEST_F(TokenTest, optionEqualFalse) {

    ASSERT_NO_THROW(t_.reset(new TokenEqual()));

    values_.push("foo");
    values_.push("bar");
    EXPECT_NO_THROW(t_->evaluate(*pkt4_, values_));

    // After evaluation there should be a single value that represents
    // result of "foo" == "bar" comparision.
    ASSERT_EQ(1, values_.size());
    EXPECT_EQ("false", values_.top());
}

// This test checks if a token representing an == operator is able to
// compare two identical values.
TEST_F(TokenTest, optionEqualTrue) {

    ASSERT_NO_THROW(t_.reset(new TokenEqual()));

    values_.push("foo");
    values_.push("foo");
    EXPECT_NO_THROW(t_->evaluate(*pkt4_, values_));

    // After evaluation there should be a single value that represents
    // result of "foo" == "foo" comparision.
    ASSERT_EQ(1, values_.size());
    EXPECT_EQ("true", values_.top());
}

};