#include <stdio.h>
#include <stdlib.h>

#include "data_manager.h"
#include "display.h"
#include "util.h"
#include "ui.h"

static void adjust_setting(struct ui_ctx *ui, struct data_ctx *dctx, int adj)
{
	/* FIXME enforce bounds on setting - is this responsibility of data man? */
	dctx->setting += adj;
}

static void adjust_selected_category(struct ui_ctx *ui, int adj)
{
	/* FIXME */
}

static void adjust_selected_unit(struct ui_ctx *ui, int adj)
{
	/* FIXME */
}


void ui_init(struct ui_ctx *ui, struct display *display)
{
	ui->display = display;
	ui->state = UI_STATE_MAIN;
	ui->display->init();
	ui->display->clear();
}

void ui_update(struct ui_ctx *ui, struct data_ctx *dctx)
{
	char line[LCD_WIDTH+1];

	/* FIXME these are missing from the data context, dummy values to test */
	float rate_m_s = 1.2;
	char rate_sym = '\0';
	if (rate_m_s < 0) {
		rate_sym = C_DESC;
	} else if (rate_m_s == 0) {
		rate_sym = C_IDLE;
	} else {
		rate_sym = C_ASC;
	}

	/* FIXME this is only valid display for UI_STATE_MAIN. Implement the other pages */
	/* line 1 */
	snprintf(line, sizeof(line), "%.1f m %c%d m/s", dctx->altitude, rate_sym, abs(rate_m_s));
	blank_to_eol(line, sizeof(line));
	ui->display->set_cursor(0, 0);
	ui->display->write(line);


	/* line 2 */
	snprintf(line, sizeof(line), "%.2f hPa", dctx->pressure);
	blank_to_eol(line, sizeof(line));
	ui->display->set_cursor(0, 1);
	ui->display->write(line);

	/* line 3 */
	/* FIXME make nicer */
	char extra_left, extra_right;
	if (ui->state == UI_STATE_MAIN_WITH_SETTING) {
		extra_left = '>';
		extra_right = '<';
	} else {
		extra_left = ' ';
		extra_right = ' ';
	}
	snprintf(line, sizeof(line), "Set%c%.2f%chPa", extra_left, dctx->setting, extra_right);
	blank_to_eol(line, sizeof(line));
	ui->display->set_cursor(0, 2);
	ui->display->write(line);

	/* line 4 */
	snprintf(line, sizeof(line), "%.1f ""\xdf""C", 12.3f);
	blank_to_eol(line, sizeof(line));
	ui->display->set_cursor(0, 3);
	ui->display->write(line);
}

void ui_input_event(struct ui_ctx *ui, struct data_ctx *dctx, enum ui_input_event event)
{
	/* FIXME state machine */
	/* XXX menus
	    1 main display screen (alt+rate, pres, set, temp)
		  - press moves to 2
		  - hold moves to 3
		2 main display screen with setting change (alt+rate, pres, set w/icon, temp
		  - up increases setting
		  - down decreases setting
		  - timeout ?
		  - press moves to 1
		  - hold? might be useful to switch unit while changing setting?
	    3 unit adjustment screen. something like:
		  alt: m (ft)
		  rate: m/s (ft/min)
		  pressure: hPa (kPa, inHg)
		  temperature: °C (°F, K)
		  - hold moves to 1
		  - if not in change mode:
			  - press enters change mode for the selected category
			  - up selects unit category above
			  - down selects unit category below
			else:
			  - press exits change mode for the selected unit, saving selection
			  - up selects previous/left unit for category
			  - down selects next/right unit for category
		  - timeouts?
		*/
	/* state:
	 *  - selected_unit_category
	 *  - selected_unit
	 */

	switch (ui->state) {
		case UI_STATE_MAIN:
			switch (event) {
				case UI_INPUT_EVENT_PRESS:
					ui->state = UI_STATE_MAIN_WITH_SETTING;
					break;
				case UI_INPUT_EVENT_HOLD:
					ui->state = UI_STATE_CHOOSE_UNIT_CATEGORY;
					break;

				/* nops for this state: */
				case UI_INPUT_EVENT_UP:
				case UI_INPUT_EVENT_DOWN:
					/* nop */
					break;
			}
			break;
		case UI_STATE_MAIN_WITH_SETTING:
			switch (event) {
				case UI_INPUT_EVENT_PRESS:
					ui->state = UI_STATE_MAIN;
					break;
				case UI_INPUT_EVENT_UP:
					adjust_setting(ui, dctx, +1);
					break;
				case UI_INPUT_EVENT_DOWN:
					adjust_setting(ui, dctx, -1);
					break;
				/* nops for this state: */
				case UI_INPUT_EVENT_HOLD:
					/* nop */
					break;
				/* XXX timeout? */
			}
			break;
		case UI_STATE_CHOOSE_UNIT_CATEGORY:
			switch (event) {
				case UI_INPUT_EVENT_HOLD:
					ui->state = UI_STATE_MAIN;
					break;
				case UI_INPUT_EVENT_PRESS:
					ui->state = UI_STATE_CHANGE_UNIT_MODE;
					break;
				case UI_INPUT_EVENT_UP:
					adjust_selected_category(ui, -1);
					break;
				case UI_INPUT_EVENT_DOWN:
					adjust_selected_category(ui, +1);
					break;
			}
			break;
		case UI_STATE_CHANGE_UNIT_MODE:
			switch (event) {
				case UI_INPUT_EVENT_PRESS:
					ui->state = UI_STATE_CHOOSE_UNIT_CATEGORY;
					break;
				case UI_INPUT_EVENT_UP:
					adjust_selected_unit(ui, -1);
					break;
				case UI_INPUT_EVENT_DOWN:
					adjust_selected_unit(ui, +1);
					break;
				/* nops for this state: */
				case UI_INPUT_EVENT_HOLD:
					/* nop */
					break;
				/* XXX timeout? */
			}
			break;
	}
}