#include "multi_converter_mode_display.h"

#define MULTI_CONVERTER_DISPLAY_KEYS                 18   // [0] to [F] + [BACK] + [SELECT]
	
#define MULTI_CONVERTER_DISPLAY_KEY_NEGATIVE         0    // long press
#define MULTI_CONVERTER_DISPLAY_KEY_COMMA            1    // long press
#define MULTI_CONVERTER_DISPLAY_KEY_DEL              16
#define MULTI_CONVERTER_DISPLAY_KEY_SELECT           17

#define MULTI_CONVERTER_DISPLAY_CHAR_COMMA           '.'
#define MULTI_CONVERTER_DISPLAY_CHAR_NEGATIVE        '-'
#define MULTI_CONVERTER_DISPLAY_CHAR_DEL             '<'
#define MULTI_CONVERTER_DISPLAY_CHAR_SELECT          '#'
#define MULTI_CONVERTER_DISPLAY_CHAR_BLANK           ' '

#define MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN     3
#define MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT      8


void multi_converter_mode_display_convert(MultiConverterState* const multi_converter_state) {

	// 1.- if origin == destination (in theory user won't be allowed to choose the same options, but it's kinda "valid"...)
	// just copy buffer_orig to buffer_dest and that's it
	
	if (multi_converter_state->unit_type_orig == multi_converter_state->unit_type_dest) {
		memcpy(multi_converter_state->buffer_dest, multi_converter_state->buffer_orig, MULTI_CONVERTER_NUMBER_DIGITS);
		return;
	}

	// 2.- origin_buffer has not null functions
	if (multi_converter_get_unit(multi_converter_state->unit_type_orig).convert_function == NULL || multi_converter_get_unit(multi_converter_state->unit_type_orig).allowed_function == NULL) return;

	// 3.- valid destination type (using allowed_destinations function)
	if (!multi_converter_get_unit(multi_converter_state->unit_type_orig).allowed_function(multi_converter_state->unit_type_dest)) return;

	multi_converter_get_unit(multi_converter_state->unit_type_orig).convert_function(multi_converter_state);

}

void multi_converter_mode_display_draw(Canvas* const canvas, const MultiConverterState* multi_converter_state) {
	
	canvas_set_color(canvas, ColorBlack);

	// ORIGIN
	canvas_set_font(canvas, FontPrimary);
	canvas_draw_str(canvas, 2, 10, multi_converter_get_unit(multi_converter_state->unit_type_orig).mini_name);

	canvas_set_font(canvas, FontPrimary);
	canvas_draw_str(canvas, 2 + 30, 10, multi_converter_state->buffer_orig);

	// DESTINATION
	canvas_set_font(canvas, FontPrimary);
	canvas_draw_str(canvas, 2, 10 + 12, multi_converter_get_unit(multi_converter_state->unit_type_dest).mini_name);

	canvas_set_font(canvas, FontPrimary);
	canvas_draw_str(canvas, 2 + 30, 10 + 12, multi_converter_state->buffer_dest);

	// SEPARATOR_LINE
	canvas_draw_line(canvas, 2, 25, 128 - 3, 25);

	// KEYBOARD
	uint8_t _x = 5;
	uint8_t _y = 25 + 15; // line + 10

	for (int i = 0; i < MULTI_CONVERTER_DISPLAY_KEYS; i++) {

		char g;
		if (i < 10) g = (i + '0');
		else if (i < 16) g = ((i - 10) + 'A');
		else if (i == MULTI_CONVERTER_DISPLAY_KEY_DEL) g = MULTI_CONVERTER_DISPLAY_CHAR_DEL;
		else g = MULTI_CONVERTER_DISPLAY_CHAR_SELECT;
		
		uint8_t g_w = canvas_glyph_width(canvas, g);

		if (i < 16 && i > multi_converter_get_unit(multi_converter_state->unit_type_orig).max_number_keys-1) {
			// some units won't use the full [0] - [F] keyboard, in those situations just hide the char
			// (won't be selectable anyway, so no worries here; this is just about drawing stuff)
			g = MULTI_CONVERTER_DISPLAY_CHAR_BLANK;
		}

		// currently hover key is highlighted
		if ((multi_converter_state->display).key == i) {
			canvas_draw_box(canvas,
				_x - MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN,
				_y - (MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN),
				MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN + g_w + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN,
				MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN * 2
			);
			canvas_set_color(canvas, ColorWhite);
		} else {
			canvas_draw_frame(canvas,
				_x - MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN,
				_y - (MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN),
				MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN + g_w + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN,
				MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN * 2
			);
		}

		// draw key
		canvas_draw_glyph(canvas, _x, _y, g);

		// certain keys have long_press features, draw whatever they're using there too
		if (i == MULTI_CONVERTER_DISPLAY_KEY_NEGATIVE) {
			canvas_draw_box(canvas,
				_x + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN + g_w - 4,
				_y + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN - 2,
				4,
				2
			);
		} else if (i == MULTI_CONVERTER_DISPLAY_KEY_COMMA) {
			canvas_draw_box(canvas,
				_x + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN + g_w - 2,
				_y + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN - 2,
				2,
				2
			);
		}

		// back to black
		canvas_set_color(canvas, ColorBlack);

		if (i < 8) {
			_x += g_w + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN * 2 + 2;
		} else if (i == 8) {
			_y += (MULTI_CONVERTER_DISPLAY_KEY_CHAR_HEIGHT + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN * 2) + 3;
			_x = 8; // some padding at the beginning on second line
		} else {
			_x += g_w + MULTI_CONVERTER_DISPLAY_KEY_FRAME_MARGIN * 2 + 1;
		}
	}

}

void multi_converter_mode_display_navigation(InputKey key, MultiConverterState* const multi_converter_state) {

	// first move to keyboard position, then check if the ORIGIN allows that specific key, if not jump to the "closest one"
	switch (key) {

		default:
			break;

		case InputKeyUp:
		case InputKeyDown:
			if ((multi_converter_state->display).key >= 9) (multi_converter_state->display).key -= 9;
			else (multi_converter_state->display).key += 9;
			break;

		case InputKeyLeft:
		case InputKeyRight:

			(multi_converter_state->display).key += (key == InputKeyLeft ? -1 : 1);

			if ((multi_converter_state->display).key > MULTI_CONVERTER_DISPLAY_KEYS-1) (multi_converter_state->display).key = 0;
			else if ((multi_converter_state->display).key < 0) (multi_converter_state->display).key = MULTI_CONVERTER_DISPLAY_KEYS-1;
			break;
	}

	// if destination key is disabled by max_number_keys, move to the closest one
	// (this could be improved with more accurate keys movements, probably...)
	if (multi_converter_get_unit(multi_converter_state->unit_type_orig).max_number_keys >= 16) return; // weird, since this means "do not show any number on the keyboard, but just in case..."

	int8_t i = -1;
	if (key == InputKeyRight || key == InputKeyDown) i = 1;

	while ((multi_converter_state->display).key < 16 && (multi_converter_state->display).key > multi_converter_get_unit(multi_converter_state->unit_type_orig).max_number_keys-1) {
		(multi_converter_state->display).key += i;
		if ((multi_converter_state->display).key > MULTI_CONVERTER_DISPLAY_KEYS-1) (multi_converter_state->display).key = 0;
		else if ((multi_converter_state->display).key < 0) (multi_converter_state->display).key = MULTI_CONVERTER_DISPLAY_KEYS-1;
	}

}

void multi_converter_mode_display_reset(MultiConverterState* const multi_converter_state) {

	// clean the buffers
	for (int i = 0; i < MULTI_CONVERTER_NUMBER_DIGITS; i++) {
		multi_converter_state->buffer_orig[i] = MULTI_CONVERTER_DISPLAY_CHAR_BLANK;
		multi_converter_state->buffer_dest[i] = MULTI_CONVERTER_DISPLAY_CHAR_BLANK;
	}

	// reset the display flags and index
	multi_converter_state->display.cursor = 0;
	multi_converter_state->display.key = 0;
	multi_converter_state->display.comma = 0;
	multi_converter_state->display.negative = 0;
}

void multi_converter_mode_display_toggle_negative(MultiConverterState* const multi_converter_state) {
	if (multi_converter_get_unit(multi_converter_state->unit_type_orig).allow_negative) {
		
		if (!(multi_converter_state->display).negative) {
			// shift origin buffer one to right + add the "-" sign (last digit will be lost)
			for (int i = MULTI_CONVERTER_NUMBER_DIGITS-1; i > 0; i--) {
				// we could avoid the blanks, but nevermind
				multi_converter_state->buffer_orig[i] = multi_converter_state->buffer_orig[i-1];
			}
			multi_converter_state->buffer_orig[0] = MULTI_CONVERTER_DISPLAY_CHAR_NEGATIVE;

			// only increment cursor if we're not out of bound
			if ((multi_converter_state->display).cursor < MULTI_CONVERTER_NUMBER_DIGITS) (multi_converter_state->display).cursor++;
		} else {
			// shift origin buffer one to left, append ' ' on the end
			for (int i = 0; i < MULTI_CONVERTER_NUMBER_DIGITS-1; i++) {
				if (multi_converter_state->buffer_orig[i] == MULTI_CONVERTER_DISPLAY_CHAR_BLANK) break;

				multi_converter_state->buffer_orig[i] = multi_converter_state->buffer_orig[i+1];
			}
			multi_converter_state->buffer_orig[MULTI_CONVERTER_NUMBER_DIGITS-1] = MULTI_CONVERTER_DISPLAY_CHAR_BLANK;

			(multi_converter_state->display).cursor--;
		}

		// toggle flag
		(multi_converter_state->display).negative ^= 1;
	}
}

void multi_converter_mode_display_add_comma(MultiConverterState* const multi_converter_state) {
	if (
		!multi_converter_get_unit(multi_converter_state->unit_type_orig).allow_comma ||
		(multi_converter_state->display).comma ||
		!(multi_converter_state->display).cursor ||
		((multi_converter_state->display).cursor == (MULTI_CONVERTER_NUMBER_DIGITS - 1))
	) return; // maybe not allowerd; or one comma already in place; also cannot add commas as first or last chars

	// set flag to one
	(multi_converter_state->display).comma = 1;

	multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] = MULTI_CONVERTER_DISPLAY_CHAR_COMMA;
	(multi_converter_state->display).cursor++;
}

void multi_converter_mode_display_add_number(MultiConverterState* const multi_converter_state) {
	if ((multi_converter_state->display).key > multi_converter_get_unit(multi_converter_state->unit_type_orig).max_number_keys-1) return;

	if ((multi_converter_state->display).key < 10) {
		multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] = (multi_converter_state->display).key + '0';
	} else {
		multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] = ((multi_converter_state->display).key - 10) + 'A';
	}

	(multi_converter_state->display).cursor++;
}

MultiConverterModeTrigger multi_converter_mode_display_ok(uint8_t long_press, MultiConverterState* const multi_converter_state) {

	if ((multi_converter_state->display).key < MULTI_CONVERTER_DISPLAY_KEY_DEL) {
		if ((multi_converter_state->display).cursor >= MULTI_CONVERTER_NUMBER_DIGITS) return None; // limit reached, ignore

		// long press on 0 toggle NEGATIVE if allowed, on 1 adds COMMA if allowed
		if (long_press) {

			if ((multi_converter_state->display).key == MULTI_CONVERTER_DISPLAY_KEY_NEGATIVE) {
				// toggle negative
				multi_converter_mode_display_toggle_negative(multi_converter_state);
			} else if ((multi_converter_state->display).key == MULTI_CONVERTER_DISPLAY_KEY_COMMA) {
				// add comma
				multi_converter_mode_display_add_comma(multi_converter_state);
			}

		} else {
			// regular keys
			multi_converter_mode_display_add_number(multi_converter_state);	
		}

		multi_converter_mode_display_convert(multi_converter_state);

	} else if ((multi_converter_state->display).key == MULTI_CONVERTER_DISPLAY_KEY_DEL) {
		if ((multi_converter_state->display).cursor > 0) (multi_converter_state->display).cursor--;

		if (multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] == MULTI_CONVERTER_DISPLAY_CHAR_COMMA) (multi_converter_state->display).comma = 0;
		if (multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] == MULTI_CONVERTER_DISPLAY_CHAR_NEGATIVE) (multi_converter_state->display).negative = 0;

		multi_converter_state->buffer_orig[(multi_converter_state->display).cursor] = MULTI_CONVERTER_DISPLAY_CHAR_BLANK;

		multi_converter_mode_display_convert(multi_converter_state);

	} else { // MULTI_CONVERTER_DISPLAY_KEY_SELECT
		return Reset;
	}

	return None;

}