#include <bit>

#include "maple/maple_bus_ft6_key_scan_codes.hpp"
#include "maple/maple_bus_commands.hpp"
#include "maple/maple_bus_bits.hpp"
#include "maple/maple_impl.hpp"

#include "sh7091/serial.hpp"

#include "keyboard.hpp"

void keyboard_do_get_condition(uint32_t * command_buf,
			       uint32_t * receive_buf,
			       ft6::data_transfer::data_format& data)
{
  using command_type = get_condition;
  using response_type = data_transfer<ft6::data_transfer::data_format>;

  get_condition::data_fields data_fields = {
    .function_type = std::byteswap(function_type::keyboard)
  };

  const uint32_t command_size = maple::init_host_command_all_ports<command_type, response_type>(command_buf, receive_buf, data_fields);
  using host_response_type = struct maple::host_response<response_type::data_fields>;
  auto host_response = reinterpret_cast<host_response_type *>(receive_buf);

  maple::dma_start(command_buf, command_size,
                   receive_buf, maple::sizeof_command(host_response));

  for (uint8_t port = 0; port < 4; port++) {
    auto& bus_data = host_response[port].bus_data;
    if (bus_data.command_code != response_type::command_code) {
      continue;
    }
    auto& data_fields = bus_data.data_fields;
    if ((data_fields.function_type & std::byteswap(function_type::keyboard)) == 0) {
      continue;
    }

    data.modifier_key = data_fields.data.modifier_key;
    data.led_state = data_fields.data.led_state;
    data.scan_code_array[0] = data_fields.data.scan_code_array[0];
    data.scan_code_array[1] = data_fields.data.scan_code_array[1];
    data.scan_code_array[2] = data_fields.data.scan_code_array[2];
    data.scan_code_array[3] = data_fields.data.scan_code_array[3];
    data.scan_code_array[4] = data_fields.data.scan_code_array[4];
    data.scan_code_array[5] = data_fields.data.scan_code_array[5];

    return;
  }
}

void keyboard_debug(ft6::data_transfer::data_format * keyboards, uint32_t frame_ix)
{
  uint32_t this_frame = (frame_ix + 0) & 1;
  bool difference = false;
  for (int i = 0; i < 6; i++) {
    if (keyboards[0].scan_code_array[i] != keyboards[1].scan_code_array[i]) {
      difference = true;
      break;
    }
  }
  if (difference) {
    for (int i = 0; i < 6; i++) {
      serial::integer<uint8_t>(keyboards[this_frame].scan_code_array[i], ' ');
    }
    serial::string("\n");
  }
}

static inline bool is_shifted(const uint8_t modifier_key)
{
  return
    (ft6::data_transfer::modifier_key::right_shift() & modifier_key) ||
    (ft6::data_transfer::modifier_key::left_shift() & modifier_key);
}

void keyboard_update(ft6::data_transfer::data_format * keyboards, uint32_t frame_ix, gap_buffer& gb)
{
  uint32_t this_frame = (frame_ix + 0) & 1;
  uint32_t next_frame = (frame_ix + 1) & 1;
  for (int i = 0; i < 6; i++) {
    if (keyboards[this_frame].scan_code_array[i] == ft6::scan_code::no_operation)
      break;
    if (i < 5 && keyboards[this_frame].scan_code_array[i + 1] != ft6::scan_code::no_operation)
      continue;
    bool make = true;
    for (int j = 0; j < 6; j++) {
      if (keyboards[next_frame].scan_code_array[j] == keyboards[this_frame].scan_code_array[i]) {
	make = false;
	break;
      }
    }
    if (make) {
      // make
      uint8_t scan_code = keyboards[this_frame].scan_code_array[i];
      if (scan_code <= ft6::scan_code::last_printable) {
	bool shifted = is_shifted(keyboards[this_frame].modifier_key);
	char_type code_point = ft6::scan_code::code_point[scan_code][shifted];
	if (code_point != 0) {
	  gap_append(gb, code_point);
	  continue;
	}
      }
      switch (scan_code) {
	case ft6::scan_code::_return:   gap_append(gb, '\n'); break;
	case ft6::scan_code::backspace: gap_pop(gb);          break;
	case ft6::scan_code::spacebar:  gap_append(gb, ' ');  break;

	case ft6::scan_code::left_arrow:  gap_cursor_pos(gb, -1);      break;
	case ft6::scan_code::right_arrow: gap_cursor_pos(gb, 1);       break;
	case ft6::scan_code::up_arrow:    gap_cursor_pos_line(gb, -1); break;
	case ft6::scan_code::down_arrow:  gap_cursor_pos_line(gb, 1);  break;
	default:
	  break;
      }
    }
  }
}