/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Tests a very simple end to end T=1 using the echo backend.
 */

#include <string.h>

#include <vector>
#include <gtest/gtest.h>

#include <ese/ese.h>
#include <ese/teq1.h>
#define LOG_TAG "TEQ1_UNITTESTS"
#include <ese/log.h>

#include "teq1_private.h"

ESE_INCLUDE_HW(ESE_HW_FAKE);

using ::testing::Test;

// TODO:
// - Unittests of each function
// - teq1_rules matches Annex A of ISO 7816-3

// Tests teq1_frame_error_check to avoid testing every combo that
// ends in 255 in the rule engine.
class Teq1FrameErrorCheck : public virtual Test {
 public:
  Teq1FrameErrorCheck() { }
  virtual ~Teq1FrameErrorCheck() { }
  struct Teq1Frame tx_frame_, rx_frame_;
  struct Teq1State state_;
  struct Teq1CardState card_state_;
};

TEST_F(Teq1FrameErrorCheck, info_parity) {
  static const uint8_t kRxPCBs[] = {
    TEQ1_I(0, 0),
    TEQ1_I(1, 0),
    TEQ1_I(0, 1),
    TEQ1_I(1, 1),
    255,
  };
  const uint8_t *pcb = &kRxPCBs[0];
  /* The PCBs above are all valid for a sent unchained I block with advancing
   * sequence #s.
   */
  tx_frame_.header.PCB = TEQ1_I(0, 0);
  state_.card_state = &card_state_;
  state_.card_state->seq.card = 1;
  while (*pcb != 255) {
    rx_frame_.header.PCB = *pcb;
    rx_frame_.header.LEN = 2;
    rx_frame_.INF[0] = 'A';
    rx_frame_.INF[1] = 'B';
    rx_frame_.INF[2] = teq1_compute_LRC(&rx_frame_);
    EXPECT_EQ(0, teq1_frame_error_check(&state_, &tx_frame_, &rx_frame_)) << teq1_pcb_to_name(rx_frame_.header.PCB);
    rx_frame_.INF[2] = teq1_compute_LRC(&rx_frame_) - 1;
    // Reset so we check the LRC error instead of a wrong seq.
    state_.card_state->seq.card = !state_.card_state->seq.card;
    EXPECT_EQ(TEQ1_R(0, 0, 1), teq1_frame_error_check(&state_, &tx_frame_, &rx_frame_));
    state_.card_state->seq.card = !state_.card_state->seq.card;
    pcb++;
  }
};

TEST_F(Teq1FrameErrorCheck, length_mismatch) {
};

TEST_F(Teq1FrameErrorCheck, unchained_r_block) {
};

TEST_F(Teq1FrameErrorCheck, unexpected_seq) {
};

class Teq1RulesTest : public virtual Test {
 public:
  Teq1RulesTest() :
    tx_data_(INF_LEN, 'A'),
    rx_data_(INF_LEN, 'B'),
    card_state_({ .seq = { .card = 1, .interface = 1, }, }),
    state_(TEQ1_INIT_STATE(tx_data_.data(), static_cast<uint32_t>(tx_data_.size()),
                           rx_data_.data(), static_cast<uint32_t>(rx_data_.size()),
                           &card_state_)) {
    memset(&tx_frame_, 0, sizeof(struct Teq1Frame));
    memset(&tx_next_, 0, sizeof(struct Teq1Frame));
    memset(&rx_frame_, 0, sizeof(struct Teq1Frame));
  }
  virtual ~Teq1RulesTest() { }
  virtual void SetUp() {}
  virtual void TearDown() { }

  struct Teq1Frame tx_frame_;
  struct Teq1Frame tx_next_;
  struct Teq1Frame rx_frame_;
  std::vector<uint8_t> tx_data_;
  std::vector<uint8_t> rx_data_;
  struct Teq1CardState card_state_;
  struct Teq1State state_;
};

class Teq1ErrorFreeTest : public Teq1RulesTest {
};

class Teq1ErrorHandlingTest : public Teq1RulesTest {
};

class Teq1CompleteTest : public Teq1ErrorFreeTest {
 public:
  virtual void SetUp() {
    tx_frame_.header.PCB = TEQ1_I(0, 0);
    teq1_fill_info_block(&state_, &tx_frame_);
    // Check that the tx_data was fully consumed.
    EXPECT_EQ(0UL, state_.app_data.tx_len);

    rx_frame_.header.PCB = TEQ1_I(0, 0);
    rx_frame_.header.LEN = INF_LEN;
    ASSERT_EQ(static_cast<unsigned long>(INF_LEN), tx_data_.size());  // Catch fixture changes.
    // Supply TX data and make sure it overwrites RX data on consumption.
    memcpy(rx_frame_.INF, tx_data_.data(), INF_LEN);
    rx_frame_.INF[INF_LEN] = teq1_compute_LRC(&rx_frame_);
  }

  virtual void RunRules() {
    teq1_trace_header();
    teq1_trace_transmit(tx_frame_.header.PCB, tx_frame_.header.LEN);
    teq1_trace_receive(rx_frame_.header.PCB, rx_frame_.header.LEN);

    enum RuleResult result = teq1_rules(&state_,  &tx_frame_, &rx_frame_, &tx_next_);
    EXPECT_EQ(0, state_.errors);
    EXPECT_EQ(NULL,  state_.last_error_message)
      << "Last error: " << state_.last_error_message;
    EXPECT_EQ(0, tx_next_.header.PCB)
      << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
    EXPECT_EQ(kRuleResultComplete, result)
     << "Actual result name: " << teq1_rule_result_to_name(result);
  }
};

TEST_F(Teq1CompleteTest, I00_I00_empty) {
  // No data.
  state_.app_data.tx_len = 0;
  state_.app_data.rx_len = 0;
  // Re-zero the prepared frames.
  teq1_fill_info_block(&state_, &tx_frame_);
  rx_frame_.header.LEN = 0;
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
  RunRules();
  EXPECT_EQ(0U, rx_frame_.header.LEN);
};

TEST_F(Teq1CompleteTest, I00_I00_data) {
  RunRules();
  // Ensure that the rx_frame data was copied out to rx_data.
  EXPECT_EQ(0UL, state_.app_data.rx_len);
  EXPECT_EQ(tx_data_, rx_data_);
};

TEST_F(Teq1CompleteTest, I10_I10_data) {
  tx_frame_.header.PCB = TEQ1_I(1, 0);
  rx_frame_.header.PCB = TEQ1_I(0, 0);
  rx_frame_.INF[INF_LEN] = teq1_compute_LRC(&rx_frame_);
  RunRules();
  // Ensure that the rx_frame data was copied out to rx_data.
  EXPECT_EQ(INF_LEN, rx_frame_.header.LEN);
  EXPECT_EQ(0UL, state_.app_data.rx_len);
  EXPECT_EQ(tx_data_, rx_data_);
};

// Note, IFS is not tested as it is not supported on current hardware.

TEST_F(Teq1ErrorFreeTest, I00_WTX0_WTX1_data) {
  tx_frame_.header.PCB = TEQ1_I(0, 0);
  teq1_fill_info_block(&state_, &tx_frame_);
  // Check that the tx_data was fully consumed.
  EXPECT_EQ(0UL, state_.app_data.tx_len);

  rx_frame_.header.PCB = TEQ1_S_WTX(0);
  rx_frame_.header.LEN = 1;
  rx_frame_.INF[0] = 2; /* Wait x 2 */
  rx_frame_.INF[1] = teq1_compute_LRC(&rx_frame_);

  teq1_trace_header();
  teq1_trace_transmit(tx_frame_.header.PCB, tx_frame_.header.LEN);
  teq1_trace_receive(rx_frame_.header.PCB, rx_frame_.header.LEN);

  enum RuleResult result = teq1_rules(&state_,  &tx_frame_, &rx_frame_, &tx_next_);
  teq1_trace_transmit(tx_next_.header.PCB, tx_next_.header.LEN);

  EXPECT_EQ(0, state_.errors);
  EXPECT_EQ(NULL,  state_.last_error_message)
    << "Last error: " << state_.last_error_message;
  EXPECT_EQ(TEQ1_S_WTX(1), tx_next_.header.PCB)
    << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
  EXPECT_EQ(state_.wait_mult, 2);
  EXPECT_EQ(state_.wait_mult, rx_frame_.INF[0]);
  // Ensure the next call will use the original TX frame.
  EXPECT_EQ(kRuleResultSingleShot, result)
   << "Actual result name: " << teq1_rule_result_to_name(result);
};

class Teq1ErrorFreeChainingTest : public Teq1ErrorFreeTest {
 public:
  virtual void RunRules() {
    state_.app_data.tx_len = oversized_data_len_;
    tx_data_.resize(oversized_data_len_, 'C');
    state_.app_data.tx_buf = tx_data_.data();
    teq1_fill_info_block(&state_, &tx_frame_);
    // Ensure More bit was set.
    EXPECT_EQ(1, bs_get(PCB.I.more_data, tx_frame_.header.PCB));
    // Check that the tx_data was fully consumed.
    EXPECT_EQ(static_cast<uint32_t>(oversized_data_len_ - INF_LEN),
              state_.app_data.tx_len);
    // No one is checking the TX LRC since there is no card present.

    rx_frame_.header.LEN = 0;
    rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);

    teq1_trace_header();
    teq1_trace_transmit(tx_frame_.header.PCB, tx_frame_.header.LEN);
    teq1_trace_receive(rx_frame_.header.PCB, rx_frame_.header.LEN);

    enum RuleResult result = teq1_rules(&state_,  &tx_frame_, &rx_frame_, &tx_next_);
    teq1_trace_transmit(tx_next_.header.PCB, tx_next_.header.LEN);
    EXPECT_EQ(0, state_.errors);
    EXPECT_EQ(NULL,  state_.last_error_message)
      << "Last error: " << state_.last_error_message;
    EXPECT_EQ(kRuleResultContinue, result)
      << "Actual result name: " << teq1_rule_result_to_name(result);
    // Check that the tx_buf was drained already for the next frame.
    // ...
    EXPECT_EQ(static_cast<uint32_t>(oversized_data_len_ - (2 * INF_LEN)),
              state_.app_data.tx_len);
    // Belt and suspenders: make sure no RX buf was used.
    EXPECT_EQ(rx_data_.size(), state_.app_data.rx_len);
  }
  int oversized_data_len_;
};

TEST_F(Teq1ErrorFreeChainingTest, I01_R1_I11_chaining) {
  oversized_data_len_ = INF_LEN * 3;
  tx_frame_.header.PCB = TEQ1_I(0, 0);
  rx_frame_.header.PCB = TEQ1_R(1, 0, 0);
  RunRules();
  EXPECT_EQ(TEQ1_I(1, 1), tx_next_.header.PCB)
    << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
};

TEST_F(Teq1ErrorFreeChainingTest, I11_R0_I01_chaining) {
  oversized_data_len_ = INF_LEN * 3;
  tx_frame_.header.PCB = TEQ1_I(1, 0);
  rx_frame_.header.PCB = TEQ1_R(0, 0, 0);
  RunRules();
  EXPECT_EQ(TEQ1_I(0, 1), tx_next_.header.PCB)
    << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
};

TEST_F(Teq1ErrorFreeChainingTest, I11_R0_I00_chaining) {
  oversized_data_len_ = INF_LEN * 2;  // Exactly 2 frames worth.
  tx_frame_.header.PCB = TEQ1_I(1, 0);
  rx_frame_.header.PCB = TEQ1_R(0, 0, 0);
  RunRules();
  EXPECT_EQ(TEQ1_I(0, 0), tx_next_.header.PCB)
    << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
};

//
// Error handling tests
//
//

class Teq1Retransmit : public Teq1ErrorHandlingTest {
 public:
  virtual void SetUp() {
    // No data.
    state_.app_data.rx_len = 0;
    state_.app_data.tx_len = 0;

    tx_frame_.header.PCB = TEQ1_I(0, 0);
    teq1_fill_info_block(&state_, &tx_frame_);
    // No one is checking the TX LRC since there is no card present.

    // Assume the card may not even set the error bit.
    rx_frame_.header.LEN = 0;
    rx_frame_.header.PCB = TEQ1_R(0, 0, 0);
    rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
  }
  virtual void TearDown() {
    teq1_trace_header();
    teq1_trace_transmit(tx_frame_.header.PCB, tx_frame_.header.LEN);
    teq1_trace_receive(rx_frame_.header.PCB, rx_frame_.header.LEN);

    enum RuleResult result = teq1_rules(&state_,  &tx_frame_, &rx_frame_, &tx_next_);
    // Not counted as an error as it was on the card-side.
    EXPECT_EQ(0, state_.errors);
    const char *kNull = NULL;
    EXPECT_EQ(kNull, state_.last_error_message) << state_.last_error_message;
    EXPECT_EQ(kRuleResultRetransmit, result)
     << "Actual result name: " << teq1_rule_result_to_name(result);
  }
};

TEST_F(Teq1Retransmit, I00_R000_I00) {
  rx_frame_.header.PCB = TEQ1_R(0, 0, 0);
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
};

TEST_F(Teq1Retransmit, I00_R001_I00) {
  rx_frame_.header.PCB = TEQ1_R(0, 0, 1);
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
};

TEST_F(Teq1Retransmit, I00_R010_I00) {
  rx_frame_.header.PCB = TEQ1_R(0, 1, 0);
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
};

TEST_F(Teq1Retransmit, I00_R011_I00) {
  rx_frame_.header.PCB = TEQ1_R(0, 1, 1);
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_);
}

TEST_F(Teq1ErrorHandlingTest, I00_I00_bad_lrc) {
  // No data.
  state_.app_data.rx_len = 0;
  state_.app_data.tx_len = 0;

  tx_frame_.header.PCB = TEQ1_I(0, 0);
  teq1_fill_info_block(&state_, &tx_frame_);
  // No one is checking the TX LRC since there is no card present.

  rx_frame_.header.PCB = TEQ1_I(0, 0);
  rx_frame_.header.LEN = 0;
  rx_frame_.INF[0] = teq1_compute_LRC(&rx_frame_) - 1;

  teq1_trace_header();
  teq1_trace_transmit(tx_frame_.header.PCB, tx_frame_.header.LEN);
  teq1_trace_receive(rx_frame_.header.PCB, rx_frame_.header.LEN);

  enum RuleResult result = teq1_rules(&state_,  &tx_frame_, &rx_frame_, &tx_next_);
  EXPECT_EQ(1, state_.errors);
  const char *kNull = NULL;
  EXPECT_NE(kNull, state_.last_error_message);
  EXPECT_STREQ("Invalid frame received", state_.last_error_message);
  EXPECT_EQ(TEQ1_R(0, 0, 1), tx_next_.header.PCB)
    << "Actual next TX: " << teq1_pcb_to_name(tx_next_.header.PCB);
  EXPECT_EQ(kRuleResultSingleShot, result)
   << "Actual result name: " << teq1_rule_result_to_name(result);
};