#include <stdio.h>
#include <cstdint>
#include <vector>
#include <stdexcept>
#include <string>
// For reading FIFO
#include <fcntl.h>
#include <unistd.h>
// For sleep
#include <chrono>
#include <thread>
// MPD client
#include "mpd/client.h"

// TODO: Include this properly
#include "/usr/include/hunspell/hunspell.hxx"

// Local files
#include "utility/bitmap.hpp"
#include "utility/buffer.hpp"
#include "signal_processing/fft.hpp"
#include "ergodox.hpp"
#include "commands.h"
#include "config.h"

#include "spdlog/spdlog.h"

// TODO:
//
// MPD connection error handling
// Cleaner building
//
// FFT:
//   stereo support (and maybe different bitrates?)
//   Optimization: don't copy filename in buffer?
//   understand consumption rate
//   understand BIN2HZ
//   understand values and sizes (DFT_TOTAL, DFT_NONZERO, etc)
//     note that wave and spectrum have different sizes
//   clear fft when not in use
//
//
// Keyboard interface:
//   Fix segfault
//   Clean up reconnect code
//   Better log messages, compiled spdlog
//
//   Get parameters from keyboard (width, height, etc)
//
// Later:
//   beat detection
//   waveform animation
//   pcm from pulse


const size_t width = 10;
const size_t height = BOTTOM_SKIP + KB_RESOLUTION + TOP_SKIP;

enum hid_keyboard_keypad_usage {
	KC_NO = 0x00,
	KC_ROLL_OVER,
	KC_POST_FAIL,
	KC_UNDEFINED,
	KC_A,
	KC_B,
	KC_C,
	KC_D,
	KC_E,
	KC_F,
	KC_G,
	KC_H,
	KC_I,
	KC_J,
	KC_K,
	KC_L,
	KC_M, // 0x10
	KC_N,
	KC_O,
	KC_P,
	KC_Q,
	KC_R,
	KC_S,
	KC_T,
	KC_U,
	KC_V,
	KC_W,
	KC_X,
	KC_Y,
	KC_Z,
	KC_1,
	KC_2,
	KC_3, // 0x20
	KC_4,
	KC_5,
	KC_6,
	KC_7,
	KC_8,
	KC_9,
	KC_0,
	KC_ENTER,
	KC_ESCAPE,
	KC_BACKSPACE,
	KC_TAB,
	KC_SPACE,
	KC_MINUS,
	KC_EQUAL,
	KC_LEFT_BRACKET,
	KC_RIGHT_BRACKET, // 0x30
	KC_BACKSLASH,
	KC_NONUS_HASH,
	KC_SEMICOLON,
	KC_QUOTE,
	KC_GRAVE,
	KC_COMMA,
	KC_DOT,
	KC_SLASH,
	KC_CAPS_LOCK,
	KC_F1,
	KC_F2,
	KC_F3,
	KC_F4,
	KC_F5,
	KC_F6,
	KC_F7, // 0x40
	KC_F8,
	KC_F9,
	KC_F10,
	KC_F11,
	KC_F12,
	KC_PRINT_SCREEN,
	KC_SCROLL_LOCK,
	KC_PAUSE,
	KC_INSERT,
	KC_HOME,
	KC_PAGE_UP,
	KC_DELETE,
	KC_END,
	KC_PAGE_DOWN,
	KC_RIGHT,
	KC_LEFT, // 0x50
	KC_DOWN,
	KC_UP,
	KC_NUM_LOCK,
	KC_KP_SLASH,
	KC_KP_ASTERISK,
	KC_KP_MINUS,
	KC_KP_PLUS,
	KC_KP_ENTER,
	KC_KP_1,
	KC_KP_2,
	KC_KP_3,
	KC_KP_4,
	KC_KP_5,
	KC_KP_6,
	KC_KP_7,
	KC_KP_8, // 0x60
	KC_KP_9,
	KC_KP_0,
	KC_KP_DOT,
	KC_NONUS_BACKSLASH,
	KC_APPLICATION,
	KC_KB_POWER,
	KC_KP_EQUAL,
	KC_F13,
	KC_F14,
	KC_F15,
	KC_F16,
	KC_F17,
	KC_F18,
	KC_F19,
	KC_F20,
	KC_F21, // 0x70
	KC_F22,
	KC_F23,
	KC_F24,
	KC_EXECUTE,
	KC_HELP,
	KC_MENU,
	KC_SELECT,
	KC_STOP,
	KC_AGAIN,
	KC_UNDO,
	KC_CUT,
	KC_COPY,
	KC_PASTE,
	KC_FIND,
	KC_KB_MUTE,
	KC_KB_VOLUME_UP, // 0x80
	KC_KB_VOLUME_DOWN,
	KC_LOCKING_CAPS_LOCK,
	KC_LOCKING_NUM_LOCK,
	KC_LOCKING_SCROLL_LOCK,
	KC_KP_COMMA,
	KC_KP_EQUAL_AS400,
	KC_INTERNATIONAL_1,
	KC_INTERNATIONAL_2,
	KC_INTERNATIONAL_3,
	KC_INTERNATIONAL_4,
	KC_INTERNATIONAL_5,
	KC_INTERNATIONAL_6,
	KC_INTERNATIONAL_7,
	KC_INTERNATIONAL_8,
	KC_INTERNATIONAL_9,
	KC_LANGUAGE_1, // 0x90
	KC_LANGUAGE_2,
	KC_LANGUAGE_3,
	KC_LANGUAGE_4,
	KC_LANGUAGE_5,
	KC_LANGUAGE_6,
	KC_LANGUAGE_7,
	KC_LANGUAGE_8,
	KC_LANGUAGE_9,
	KC_ALTERNATE_ERASE,
	KC_SYSTEM_REQUEST,
	KC_CANCEL,
	KC_CLEAR,
	KC_PRIOR,
	KC_RETURN,
	KC_SEPARATOR,
	KC_OUT, // 0xA0
	KC_OPER,
	KC_CLEAR_AGAIN,
	KC_CRSEL,
	KC_EXSEL,
};

// Replacement chars for now, since wide strings are hard.
char ru_kc_to_char(uint8_t keycode) {
	switch (keycode) {
		case KC_GRAVE:
			return '~';//L"ё";
		case KC_1:
			return '1';//L"1";
		case KC_2:
			return '2';//L"2";
		case KC_3:
			return '3';//L"3";
		case KC_4:
			return '4';//L"4";
		case KC_5:
			return '5';//L"5";
		case KC_6:
			return '6';//L"6";
		case KC_7:
			return '7';//L"7";
		case KC_8:
			return '8';//L"8";
		case KC_9:
			return '9';//L"9";
		case KC_0:
			return '0';//L"0";
		case KC_Q:
			return '^';//L"й";
		case KC_W:
			return '*';//L"ц";
		case KC_E:
			return 'y';//L"у";
		case KC_R:
			return 'k';//L"к";
		case KC_T:
			return 'e';//L"е";
		case KC_Y:
			return 'H';//L"н";
		case KC_U:
			return 'g';//L"г";
		case KC_I:
			return 'w';//L"ш";
		case KC_O:
			return 'W';//L"щ";
		case KC_P:
			return 'z';//L"з";
		case KC_LEFT_BRACKET:
			return 'x';//L"х";
		case KC_RIGHT_BRACKET:
			return '!';//L"ъ";
		case KC_A:
			return 'f';//L"ф";
		case KC_S:
			return 'i';//L"ы";
		case KC_D:
			return 'B';//L"в";
		case KC_F:
			return 'a';//L"а";
		case KC_G:
			return 'n';//L"п";
		case KC_H:
			return 'p';//L"р";
		case KC_J:
			return 'o';//L"о";
		case KC_K:
			return 'l';//L"л";
		case KC_L:
			return 'd';//L"д";
		case KC_SEMICOLON:
			return 'j';//L"ж";
		case KC_QUOTE:
			return 'E';//L"э";
		case KC_Z:
			return 'R';//L"я";
		case KC_X:
			return 'q';//L"ч";
		case KC_C:
			return 'c';//L"с";
		case KC_V:
			return 'm';//L"м";
		case KC_B:
			return 'n';//L"и";
		case KC_N:
			return 't';//L"т";
		case KC_M:
			return '=';//L"ь";
		case KC_COMMA:
			return 'b';//L"б";
		case KC_DOT:
			return 'u';//L"ю";
		default:
			spdlog::warn("Unknown keycode passed to ru_kc_to_char");
			return '?';//L"?";
	}
}


int main(int argc, char *argv[]) {

	Hunspell* hun = new Hunspell(HUNSPELL_AFF_EN, HUNSPELL_DIC_EN);

	spdlog::set_level(spdlog::level::info);

	// buffer size for waveform:
	// (44100 / fps * 10), make 10 bigger for slower scrolling
	//
	// Double both buffer sizes if stereo

	// FFT generator
	FFT_Visualizer fft = FFT_Visualizer(
		width, height, MIN_HZ, MAX_HZ
	);

	// Audio buffer
	Buffer buf = Buffer(
		"/tmp/mpd.fifo",
		44100 / 2, // Keep 500ms of data in buffer
		fft.compute_buffer_output_size()
	);

	// HID interface wrapper
	Ergodox Dox = Ergodox::init(
		HID_VENDOR_ID,
		HID_PRODUCT_ID,
		HID_USAGE,
		HID_USAGE_PAGE
	);

	// Write buffer
	uint8_t hid_buf[Dox.packet_size];

	Dox.connect_loop();


	// Frame rate limiter
	std::chrono::time_point<
		std::chrono::steady_clock,
		std::chrono::nanoseconds
	> t = std::chrono::steady_clock::now();

	std::chrono::time_point<
		std::chrono::steady_clock,
		std::chrono::nanoseconds
	> last_fifo_sync = std::chrono::steady_clock::now();

	struct mpd_connection *conn = mpd_connection_new(NULL, 0, 0);

	while (1) {

		memset(hid_buf, 0, sizeof(uint8_t) * Dox.packet_size);

		if (Dox.is_connected()) {
			if (std::chrono::steady_clock::now() > t + std::chrono::milliseconds(30)) {
				if (Dox.get_animation_mode() == 0x02) {

					// Animation data type
					hid_buf[1] = CMD_ANIM_DATA_fft;

					if (std::chrono::steady_clock::now() > last_fifo_sync + std::chrono::seconds(10)) {
						mpd_run_disable_output(conn, 1);
						mpd_run_enable_output(conn, 1);
						last_fifo_sync = std::chrono::steady_clock::now();
						spdlog::info("Synchronized fifo");
					}

					buf.update();
					fft.update(buf);

					for (size_t i = 0; i < 10; i++) {
						// Get height from fft, apply bottom_skip
						ssize_t h = fft.get_output()[i] - BOTTOM_SKIP;

						// Enforce max and min
						// max implicitly enforces top_skip
						h = h>KB_RESOLUTION ? KB_RESOLUTION : h;
						h = h<0 ? 0 : h;

						hid_buf[i + 1] = h;
					}
					Dox.write(CMD_ANIM_DATA, hid_buf, Dox.packet_size);
				}


				t = std::chrono::steady_clock::now();
			}

			// Dox.write might detect that we've been disconnected,
			// and Dox.read will fail if we are.
			// This check prevents it from doing that, and instead jumps to reconnect.
			if (!Dox.is_connected()) { continue; }

			// Read a packet if there is a packet to read
			if (Dox.read()) {
				uint8_t cmd = Dox.read_buf[0];

				switch(cmd) {
					case CMD_SPELLCHECK_WORD:
						char word_chars[Dox.read_buf[1] + 1];

						if (Dox.get_layer_layout() == LAYOUT_EN) {
							for (int i=0; i < Dox.read_buf[1]; i++) {
								// A in ascii:
								// a in ascii: 0x61
								// KC_A: 0x04
								word_chars[i] = Dox.read_buf[i + 2] + 0x5D;
							}
						} else if (Dox.get_layer_layout() == LAYOUT_RU) {
							for (int i=0; i < Dox.read_buf[1]; i++) {
								word_chars[i] = ru_kc_to_char(Dox.read_buf[i + 2]);
							}
						}
						word_chars[Dox.read_buf[1]] = 0x00; // Terminate with null char
						std::string word = std::string(word_chars);

						int dp = hun->spell(word);
						if (!dp) {
							hid_buf[0] = 0x01;
							Dox.write(CMD_SPELLCHECK_WORD, hid_buf, Dox.packet_size);
							spdlog::info("Got typo: \"{0:s}\" not in dict", word);
						}

						break;
				}
			}

		} else {
			Dox.connect_loop();
		}

		// Sleep for a bit so we don't consume
		// 100% of a cpu.
		std::this_thread::sleep_for(
			std::chrono::milliseconds(LOOP_SLEEP_MS)
		);
	}

	mpd_connection_free(conn);
	return 0;
}