/* -*- mode: c++ -*-
 * Copyright (C) 2020  Eric Paniagua (epaniagua@google.com)
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <cstddef>

#include "testing/Cycles.h"
#include "testing/Millis.h"
#include "testing/ExpectedKeyboardReport.h"
#include "testing/SimHarness.h"
#include "testing/State.h"

// Out of order due to macro conflicts.
#include "testing/fix-macros.h"
#include "gtest/gtest.h"
#include <memory>

namespace kaleidoscope {
namespace testing {

// -----------------------------------------------------------------------------
// Utility classes for use in `PressKey()`/`ReleaseKey()` & `ExpectReport()`
// method invocations. These make those calls simpler by providing
// differentiated types for those polymorphic functions.
class AddKeycodes : public std::set<Key> {
 public:
  AddKeycodes(std::initializer_list<Key> list) : std::set<Key>(list) {}
};
class RemoveKeycodes : public std::set<Key> {
 public:
  RemoveKeycodes(std::initializer_list<Key> list) : std::set<Key>(list) {}
};

class Keycodes : public std::set<Key> {
 public:
  Keycodes(std::initializer_list<Key> list) : std::set<Key>(list) {}
};


// -----------------------------------------------------------------------------
// The base class for testcases
class VirtualDeviceTest : public ::testing::Test {
 protected:
  void SetUp();

  std::unique_ptr<State> RunCycle();

  SimHarness sim_;

  // ---------------------------------------------------------------------------
  // Utility functions to advance time in the simulator.

  // Run the simulator `n` cycles
  void Run(Cycles n);

  // Run the simulator `t` (virtual) milliseconds
  void Run(Millis t);

  // Run the simulator until the (virtual) clock reaches `end` milliseconds
  void RunUntil(Millis end);

  // Run the simulator until the (virtual) clock advances `t` milliseconds past
  // `start`. This is most useful when testing timeouts based on an input event
  // that is not the most recent one (e.g. a timeout following a keypress, but
  // with a key release in between).
  void RunFrom(Millis start, Millis t);

  // ---------------------------------------------------------------------------
  // A representation of the set of observed HID reports accumulated by the
  // simulator as a testcase executes. It starts out empty, and a call to
  // `LoadState()` is required in order to load those reports into this
  // `output_state_` variable so that they can be used.
  std::unique_ptr<State> output_state_ = nullptr;

  // Load any accumulated observed HID reports from the simulator (since the
  // previous call to this function).
  void LoadState();

  // Clear previous state. This should be used at the beginning of each
  // `TEST_F()` call to clear out any accumulated state in the input and output
  // queues.
  void ClearState();

  // Get a pointer to the current list of observed HID reports
  const HIDState* HIDReports() const;

  // Get the timestamp of a logged Keyboard HID report
  Millis ReportTimestamp(size_t index) const;

  // ---------------------------------------------------------------------------
  // A vector of timestamps for input events. Calls to `PressKey()` &
  // `ReleaseKey()` append timestamps to it when called.
  std::vector<Millis> input_timestamps_ = {};

  // Get the timestamp of a logged input event from `output_state_`
  Millis EventTimestamp(size_t index) const;

  // ---------------------------------------------------------------------------
  // Press/release a keyswitch & log the input event timestamp
  void PressKey(KeyAddr addr);
  void ReleaseKey(KeyAddr addr);

  // Run for `n` cycles, then press/release a keyswitch
  void PressKey(Cycles n, KeyAddr addr);
  void ReleaseKey(Cycles n, KeyAddr addr);

  // Run for `t` milliseconds, then press/release a keyswitch
  void PressKey(Millis t, KeyAddr addr);
  void ReleaseKey(Millis t, KeyAddr addr);

  // ---------------------------------------------------------------------------
  // The following functions all add an expected value of HID report to the
  // queue. They specify modifications to the current (expected) report, and a
  // message to display if verification fails. Some versions allow multiple
  // keycode changes in a single report; others only a single keycode. Some run
  // the simulator for a specified number of milliseconds or cycles first. These
  // expected-value reports are all stored in a vector:
  std::vector<ExpectedKeyboardReport> expected_reports_ = {};

  void ExpectReport(AddKeycodes added_keys,
                    RemoveKeycodes removed_keys,
                    std::string description);

  void ExpectReport(Keycodes added_keys, std::string description);
  void ExpectReport(AddKeycodes added_keys, std::string description);
  void ExpectReport(RemoveKeycodes removed_keys, std::string description);

  void ExpectReport(Cycles n, AddKeycodes added_keys, std::string description);
  void ExpectReport(Cycles n, RemoveKeycodes removed_keys, std::string description);

  void ExpectReport(Millis t, AddKeycodes added_keys, std::string description);
  void ExpectReport(Millis t, RemoveKeycodes removed_keys, std::string description);

  // ---------------------------------------------------------------------------
  std::set<uint8_t> current_keyboard_keycodes_ = {};
  // Manage the set of keycodes expected in the next report
  void ClearReport();
  void AddToReport(Key key);
  void RemoveFromReport(Key key);

};

}  // namespace testing
}  // namespace kaleidoscope


// XXX  This is a horrible hack and this should be a function, but I (Jesse)
// can't quite figure out the right way to get ASSERT_EQ and ElementsAreArray
// into a method in VirtualDeviceTest
#define CHECK_EXPECTED_REPORTS()  							\
  LoadState(); 										\
  ASSERT_EQ(HIDReports()->Keyboard().size(), expected_reports_.size());                 \
                                                                                        \
  for (auto i = 0; i < expected_reports_.size(); ++i) {                                 \
    EXPECT_THAT(HIDReports()->Keyboard(i).ActiveKeycodes(),                             \
                ::testing::ElementsAreArray(expected_reports_[i].Keycodes()))           \
        << expected_reports_[i].Message();                                              \
  }                                                                                     \