#include "keylayouts.h"
#include "usb_keyboard.h"



// which modifier keys are currently pressed
// 1=left ctrl,	   2=left shift,   4=left alt,	  8=left gui
// 16=right ctrl, 32=right shift, 64=right alt, 128=right gui
uint8_t keyboard_modifier_keys=0;

// which keys are currently pressed, up to 6 keys may be down at once
uint8_t keyboard_keys[6]={0,0,0,0,0,0};

// protocol setting from the host.  We use exactly the same report
// either way, so this variable only stores the setting since we
// are required to be able to report which setting is in use.
uint8_t keyboard_protocol=1;

// the idle configuration, how often we send the report to the
// host (ms * 4) even when it hasn't changed
uint8_t keyboard_idle_config=125;

// count until idle timeout
uint8_t keyboard_idle_count=0;

// 1=num lock, 2=caps lock, 4=scroll lock, 8=compose, 16=kana
volatile uint8_t keyboard_leds=0;



static KEYCODE_TYPE unicode_to_keycode(uint16_t cpoint);
static void write_key(KEYCODE_TYPE keycode);
static uint8_t keycode_to_modifier(KEYCODE_TYPE keycode);
static uint8_t keycode_to_key(KEYCODE_TYPE keycode);
static void usb_keyboard_press_key(uint8_t key, uint8_t modifier);
static void usb_keyboard_release_key(uint8_t key, uint8_t modifier);
#ifdef DEADKEYS_MASK
static KEYCODE_TYPE deadkey_to_keycode(KEYCODE_TYPE keycode);
#endif



// Step #1, decode UTF8 to Unicode code points
//
void usb_keyboard_write(uint8_t c)
{
	static int utf8_state=0;
	static uint16_t unicode_wchar=0;

	if (c < 0x80) {
		// single byte encoded, 0x00 to 0x7F
		utf8_state = 0;
		usb_keyboard_write_unicode(c);
	} else if (c < 0xC0) {
		// 2nd, 3rd or 4th byte, 0x80 to 0xBF
		c &= 0x3F;
		if (utf8_state == 1) {
			utf8_state = 0;
			usb_keyboard_write_unicode(unicode_wchar | c);
		} else if (utf8_state == 2) {
			unicode_wchar |= ((uint16_t)c << 6);
			utf8_state = 1;
		}
	} else if (c < 0xE0) {
		// begin 2 byte sequence, 0xC2 to 0xDF
		// or illegal 2 byte sequence, 0xC0 to 0xC1
		unicode_wchar = (uint16_t)(c & 0x1F) << 6;
		utf8_state = 1;
	} else if (c < 0xF0) {
		// begin 3 byte sequence, 0xE0 to 0xEF
		unicode_wchar = (uint16_t)(c & 0x0F) << 12;
		utf8_state = 2;
	} else {
		// begin 4 byte sequence (not supported), 0xF0 to 0xF4
		// or illegal, 0xF5 to 0xFF
		utf8_state = 255;
	}
}


// Step #2: translate Unicode code point to keystroke sequence
//
static KEYCODE_TYPE unicode_to_keycode(uint16_t cpoint)
{
	// Unicode code points beyond U+FFFF are not supported
	// technically this input should probably be called UCS-2
	if (cpoint < 32) {
		if (cpoint == 10) return KEY_ENTER & 0x3FFF;
		return 0;
	}
	if (cpoint < 128) {
		return keycodes_ascii[cpoint - 0x20];
	}
	#ifdef ISO_8859_1_A0
	if (cpoint >= 0xA0 && cpoint < 0x100) {
		return keycodes_iso_8859_1[cpoint - 0xA0];
	}
	#endif
	#ifdef UNICODE_20AC
	if (cpoint == 0x20AC) return UNICODE_20AC & 0x3FFF;
	#endif
	return 0;
}

// Step #3: execute keystroke sequence
//
#ifdef DEADKEYS_MASK
static KEYCODE_TYPE deadkey_to_keycode(KEYCODE_TYPE keycode)
{
	keycode &= DEADKEYS_MASK;
	if (keycode == 0) return 0;
	#ifdef ACUTE_ACCENT_BITS
	if (keycode == ACUTE_ACCENT_BITS) return DEADKEY_ACUTE_ACCENT;
	#endif
	#ifdef CEDILLA_BITS
	if (keycode == CEDILLA_BITS) return DEADKEY_CEDILLA;
	#endif
	#ifdef CIRCUMFLEX_BITS
	if (keycode == CIRCUMFLEX_BITS) return DEADKEY_CIRCUMFLEX;
	#endif
	#ifdef DIAERESIS_BITS
	if (keycode == DIAERESIS_BITS) return DEADKEY_DIAERESIS;
	#endif
	#ifdef GRAVE_ACCENT_BITS
	if (keycode == GRAVE_ACCENT_BITS) return DEADKEY_GRAVE_ACCENT;
	#endif
	#ifdef TILDE_BITS
	if (keycode == TILDE_BITS) return DEADKEY_TILDE;
	#endif
	#ifdef RING_ABOVE_BITS
	if (keycode == RING_ABOVE_BITS) return DEADKEY_RING_ABOVE;
	#endif
	return 0;
}
#endif

void usb_keyboard_write_unicode(uint16_t cpoint)
{
	KEYCODE_TYPE keycode;
	#ifdef DEADKEYS_MASK
	KEYCODE_TYPE deadkeycode;
	#endif

	keycode = unicode_to_keycode(cpoint);
	if (keycode) {
		#ifdef DEADKEYS_MASK
		KEYCODE_TYPE deadkeycode = deadkey_to_keycode(keycode);
		if (deadkeycode) write_key(deadkeycode);
		#endif
		write_key(keycode);
	}
}


// Step #4: do each keystroke
//
static void write_key(KEYCODE_TYPE keycode)
{
/*
	uint8_t key, modifier=0;

	#ifdef SHIFT_MASK
	if (keycode & SHIFT_MASK) modifier |= MODIFIERKEY_SHIFT;
	#endif
	#ifdef ALTGR_MASK
	if (keycode & ALTGR_MASK) modifier |= MODIFIERKEY_RIGHT_ALT;
	#endif
	#ifdef RCTRL_MASK
	if (keycode & RCTRL_MASK) modifier |= MODIFIERKEY_RIGHT_CTRL;
	#endif
	key = keycode & 0x3F;
	#ifdef KEY_NON_US_100
	if (key == KEY_NON_US_100) key = 100;
	#endif
	usb_keyboard_press(key, modifier);
*/
	usb_keyboard_press(keycode_to_key(keycode), keycode_to_modifier(keycode));
}

static uint8_t keycode_to_modifier(KEYCODE_TYPE keycode)
{
	uint8_t modifier=0;

	#ifdef SHIFT_MASK
	if (keycode & SHIFT_MASK) modifier |= MODIFIERKEY_SHIFT;
	#endif
	#ifdef ALTGR_MASK
	if (keycode & ALTGR_MASK) modifier |= MODIFIERKEY_RIGHT_ALT;
	#endif
	#ifdef RCTRL_MASK
	if (keycode & RCTRL_MASK) modifier |= MODIFIERKEY_RIGHT_CTRL;
	#endif
	return modifier;
}

static uint8_t keycode_to_key(KEYCODE_TYPE keycode)
{
	uint8_t key = keycode & 0x3F;
	#ifdef KEY_NON_US_100
	if (key == KEY_NON_US_100) key = 100;
	#endif
	return key;
}



void usb_keyboard_press_keycode(uint16_t n)
{
	uint8_t key, mod, msb, modrestore=0;
	KEYCODE_TYPE keycode;
	#ifdef DEADKEYS_MASK
	KEYCODE_TYPE deadkeycode;
	#endif

	msb = n >> 8;
	if (msb >= 0xC2 && msb <= 0xDF) {
		n = (n & 0x3F) | ((uint16_t)(msb & 0x1F) << 6);
	} else
	if (msb == 0x80) {
		usb_keyboard_press_key(0, n);
		return;
	} else
	if (msb == 0x40) {
		usb_keyboard_press_key(n, 0);
		return;
	}
	keycode = unicode_to_keycode(n);
	if (!keycode) return;
	#ifdef DEADKEYS_MASK
	deadkeycode = deadkey_to_keycode(keycode);
	if (deadkeycode) {
		modrestore = keyboard_report_data[0];
		if (modrestore) {
			keyboard_report_data[0] = 0;
			send_now();
		}
		// TODO: test if operating systems recognize
		// deadkey sequences when other keys are held
		mod = keycode_to_modifier(deadkeycode);
		key = keycode_to_key(deadkeycode);
		usb_keyboard_press_key(key, mod);
		usb_keyboard_release_key(key, mod);
	}
	#endif
	mod = keycode_to_modifier(keycode);
	key = keycode_to_key(keycode);
	usb_keyboard_press_key(key, mod | modrestore);
}


void usb_keyboard_release_keycode(uint16_t n)
{
	uint8_t key, mod, msb;

	msb = n >> 8;
	if (msb >= 0xC2 && msb <= 0xDF) {
		n = (n & 0x3F) | ((uint16_t)(msb & 0x1F) << 6);
	} else
	if (msb == 0x80) {
		usb_keyboard_release_key(0, n);
		return;
	} else
	if (msb == 0x40) {
		usb_keyboard_release_key(n, 0);
		return;
	}
	KEYCODE_TYPE keycode = unicode_to_keycode(n);
	if (!keycode) return;
	mod = keycode_to_modifier(keycode);
	key = keycode_to_key(keycode);
	usb_keyboard_release_key(key, mod);
}


static void usb_keyboard_press_key(uint8_t key, uint8_t modifier)
{
	int i, send_required = 0;

	if (modifier) {
		if ((keyboard_modifier_keys & modifier) != modifier) {
			keyboard_modifier_keys |= modifier;
			send_required = 1;
		}
	}
	if (key) {
		for (i=0; i < 6; i++) {
			if (keyboard_keys[i] == key) goto end;
		}
		for (i=0; i < 6; i++) {
			if (keyboard_keys[i] == 0) {
				keyboard_keys[i] = key;
				send_required = 1;
				goto end;
			}
		}
	}
	end:
	if (send_required) usb_keyboard_send();
}


static void usb_keyboard_release_key(uint8_t key, uint8_t modifier)
{
	int i, send_required = 0;

	if (modifier) {
		if ((keyboard_modifier_keys & modifier) != 0) {
			keyboard_modifier_keys &= ~modifier;
			send_required = 1;
		}
	}
	if (key) {
		for (i=0; i < 6; i++) {
			if (keyboard_keys[i] == key) {
				keyboard_keys[i] = 0;
				send_required = 1;
			}
		}
	}
	if (send_required) usb_keyboard_send();
}

void usb_keyboard_release_all(void)
{
	uint8_t i, anybits;

	anybits = keyboard_modifier_keys;
	keyboard_modifier_keys = 0;
	for (i=0; i < 6; i++) {
		anybits |= keyboard_keys[i];
		keyboard_keys[i] = 0;
	}
	if (anybits) usb_keyboard_send();
}


int usb_keyboard_press(uint8_t key, uint8_t modifier)
{
	int r;
	keyboard_modifier_keys = modifier;
	keyboard_keys[0] = key;
	keyboard_keys[1] = 0;
	keyboard_keys[2] = 0;
	keyboard_keys[3] = 0;
	keyboard_keys[4] = 0;
	keyboard_keys[5] = 0;
	r = usb_keyboard_send();
	if (r) return r;
	keyboard_modifier_keys = 0;
	keyboard_keys[0] = 0;
	return usb_keyboard_send();
}


// send the contents of keyboard_keys and keyboard_modifier_keys
int usb_keyboard_send(void)
{



}


