#include <gtest/gtest.h>

#include "esphome/components/hoermann_hcp/cover/hoermann_hcp_cover.h"

namespace esphome::hoermann_hcp {

using modbus::RegisterValues;

namespace {

constexpr uint16_t COMMAND_REG = 0x9C41;
constexpr uint16_t STATE_REG = 0x9CB9;
constexpr uint16_t BROADCAST_REG = 0x9D31;

RegisterValues make_registers(std::initializer_list<uint16_t> values) {
  RegisterValues registers;
  for (uint16_t value : values)
    registers.push_back(value);
  return registers;
}

// The door only accepts commands once the bus controller has actually talked to it.
void connect(HoermannHcp &door) { door.on_write_registers(COMMAND_REG, make_registers({0x0000, 0x0000})); }

// Runs one command poll (write 2 / read 8) and returns the register carrying the key-press value.
uint16_t poll_command(HoermannHcp &door) {
  door.on_write_registers(COMMAND_REG, make_registers({0x0000, 0x0000}));
  RegisterValues response;
  door.on_read_holding_registers(STATE_REG, 8, response);
  EXPECT_EQ(response.size(), 8u);
  return response.size() == 8u ? response[2] : 0xFFFF;
}

}  // namespace

// Cover::position starts at COVER_OPEN, so a door that is already closed still has a state to publish.
TEST(HoermannHcpCoverTest, ClosedDoorPublishesItsInitialPosition) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  int publishes = 0;
  cover.add_on_state_callback([&publishes]() { publishes++; });
  ASSERT_FLOAT_EQ(cover.position, cover::COVER_OPEN);

  // Any request marks the device connected, which is itself a state change.
  door.on_write_registers(COMMAND_REG, make_registers({0x0000, 0x0000}));
  door.update();

  EXPECT_EQ(publishes, 1);
  EXPECT_FLOAT_EQ(cover.position, cover::COVER_CLOSED);
}

// Venting and half-open moves report no direction, so one is only derived once the position has moved.
TEST(HoermannHcpCoverTest, DirectionlessMoveHoldsTheOperationUntilThePositionMoves) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();

  // Position 100/200 = 0.5, state 0x80 -> resting half open.
  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0064, 0x8000}));
  door.update();
  ASSERT_EQ(cover.current_operation, cover::COVER_OPERATION_IDLE);

  // State 0x05 -> moving to half-open, but the position has not moved yet.
  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0064, 0x0500}));
  door.update();
  EXPECT_EQ(cover.current_operation, cover::COVER_OPERATION_IDLE);

  // Position 120/200 = 0.6 is higher than before, so the door is opening.
  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0078, 0x0500}));
  door.update();
  EXPECT_EQ(cover.current_operation, cover::COVER_OPERATION_OPENING);
  EXPECT_FLOAT_EQ(cover.position, 0.6f);
}

// Booting while the door is already mid-move gives no baseline to compare against, so no direction
// may be inferred from the first update.
TEST(HoermannHcpCoverTest, FirstDirectionlessMoveDoesNotGuessADirection) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();

  // The very first thing seen is a half-open move already at 100/200 = 0.5.
  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0064, 0x0500}));
  door.update();
  EXPECT_EQ(cover.current_operation, cover::COVER_OPERATION_IDLE);
}

// A cover.open arrives as a position of 1.0, so it has to reach the door as a plain open command rather
// than as a target the door would be stopped at.
TEST(HoermannHcpCoverTest, OpenCommandOpensTheDoor) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  connect(door);

  cover.make_call().set_command_open().perform();
  EXPECT_EQ(poll_command(door), 0x0210);  // COMMAND_OPEN pressed
}

// The same for cover.close, which arrives as a position of 0.0.
TEST(HoermannHcpCoverTest, CloseCommandClosesTheDoor) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  connect(door);

  cover.make_call().set_command_close().perform();
  EXPECT_EQ(poll_command(door), 0x0220);  // COMMAND_CLOSE pressed
}

TEST(HoermannHcpCoverTest, ToggleCommandSendsAnImpulse) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  connect(door);

  cover.make_call().set_command_toggle().perform();
  EXPECT_EQ(poll_command(door), 0x0240);  // COMMAND_IMPULSE pressed
}

TEST(HoermannHcpCoverTest, StopCommandStopsAMovingDoor) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  connect(door);
  // The door is opening, so it takes an impulse to stop it.
  door.on_write_registers(BROADCAST_REG, make_registers({0x0000, 0x0064, 0x0100}));

  cover.make_call().set_command_stop().perform();
  EXPECT_EQ(poll_command(door), 0x0240);  // COMMAND_IMPULSE pressed
}

// A position between the end stops starts the door in the right direction; it is stopped there later.
TEST(HoermannHcpCoverTest, PositionCommandStartsTheDoorTowardsTheTarget) {
  HoermannHcp door;  // starts out fully closed
  HoermannHcpCover cover(&door);
  cover.setup();
  connect(door);

  cover.make_call().set_position(0.5f).perform();
  EXPECT_EQ(poll_command(door), 0x0210);  // COMMAND_OPEN pressed
}

// A command the door cannot take is assumed to have worked by whoever sent it, so the unchanged state has
// to be published back over that assumption.
TEST(HoermannHcpCoverTest, RefusedCommandPublishesTheUnchangedState) {
  HoermannHcp door;  // never contacted by a bus controller
  HoermannHcpCover cover(&door);
  cover.setup();
  int publishes = 0;
  cover.add_on_state_callback([&publishes]() { publishes++; });

  cover.make_call().set_command_close().perform();

  EXPECT_EQ(poll_command(door), 0x0000);
  EXPECT_EQ(publishes, 1);
  EXPECT_FLOAT_EQ(cover.position, cover::COVER_OPEN);
}

// Nothing is published before the bus controller is heard from, so a door that never reaches the bus would
// otherwise sit at its fully open default and look healthy.
TEST(HoermannHcpCoverTest, MissingBusControllerIsFlaggedUntilFirstContact) {
  HoermannHcp door;
  HoermannHcpCover cover(&door);
  cover.setup();
  EXPECT_TRUE(cover.status_has_warning());

  connect(door);
  door.update();
  EXPECT_FALSE(cover.status_has_warning());
}

}  // namespace esphome::hoermann_hcp