/*
 * simple.c: Yet another UI for the Emisar D3AA
 * Copyright (C) 2026 git@apexo.de
 * SPDX-License-Identifier: GPL-3.0-or-later
 */

/*
 * States:
 * - Off : all lights off, standby
 * - Aux : aux RGB shows color-coded battery voltage
 * - On  : main LED on (one of 4 different brightness levels),
 *         aux RGB shows color-coded battery voltage
 *
 * Transitions:
 * - Off + Click -> Aux
 * - Aux + Click -> On
 * - Aux + 5s -> Off
 * - On + Click -> Aux
 * - On + Hold -> cycle brightness levels, store on release
 */

#include "arch/mcu.h"

#include incfile(CFG_H)

#ifdef HWDEF_H
#include incfile(HWDEF_H)
#endif

#include "fsm/spaghetti-monster.h"

#ifdef HWDEF_C
#include incfile(HWDEF_C)
#endif

#define NUM_LEVELS 4
#define CEIL SIMPLE_UI_CEIL

static const uint8_t brightness_levels[NUM_LEVELS] = {
    1,
    1 * CEIL / 10,
    3 * CEIL / 10,
    CEIL,
};

#define HOLD_TICKS_PER_LEVEL 47  // cycle time ca 0.75s (47/62 Hz) 
#define AUX_TIMEOUT_TICKS 310  // ca. 5s

uint8_t off_state(Event event, uint16_t arg);
uint8_t aux_state(Event event, uint16_t arg);
uint8_t on_state(Event event, uint16_t arg);

uint8_t current_level_idx = 0;
uint8_t current_level = 0;
uint8_t thermal_limit = SIMPLE_UI_CEIL;

static const uint8_t voltage_levels[] = {
        0, 0,    // black
    #ifdef DUAL_VOLTAGE_FLOOR
    // NiMH
     9*dV, 0x01, // R
    10*dV, 0x05, // R+G
    11*dV, 0x04, //   G
    12*dV, 0x14, //   G+B
    13*dV, 0x10, //     B
    14*dV, 0x11, // R + B
    16*dV, 0x15, // R+G+B
    20*dV, 0,    // black
    #endif
    // li-ion
    29*dV, 0x01, // R
    33*dV, 0x05, // R+G
    35*dV, 0x04, //   G
    37*dV, 0x14, //   G+B
    39*dV, 0x10, //     B
    41*dV, 0x11, // R + B
    44*dV, 0x15, // R+G+B
      255, 0x15, // R+G+B
};

static uint8_t voltage_color(void) {
    uint8_t v = voltage;
    if (v == 0) return 0;
    v -= 1;
    uint8_t i;
    for (i = 0; v > voltage_levels[i]; i += 2) {}
    return voltage_levels[i - 1];
}

void set_level_therm(uint8_t value, uint16_t thermal_headroom, uint16_t thermal_overshoot) {
    if (current_level == thermal_limit && thermal_headroom > 0) {
        if (thermal_headroom >= CEIL - thermal_limit) {
            thermal_limit = CEIL;
        } else {
            thermal_limit += thermal_headroom;
        }
    }

    if (thermal_overshoot > 0) {
        if (thermal_overshoot >= current_level) {
            thermal_limit = 1;
        } else {
            thermal_limit = current_level - thermal_overshoot;
        }
    }

    current_level = value <= thermal_limit ? value : thermal_limit;
    set_level(current_level);
}

uint8_t off_state(Event event, uint16_t arg) {
    if (event == EV_enter_state) {
        set_level(0);
        rgb_led_set(0);
        button_led_set(0);
        go_to_standby = 1;
        return EVENT_HANDLED;
    }

    if (event == EV_1click) {
        set_state(aux_state, 0);
        return EVENT_HANDLED;
    }

    return EVENT_NOT_HANDLED;
}

uint8_t aux_state(Event event, uint16_t arg) {
    if (event == EV_enter_state) {
        set_level(0);
        rgb_led_set(voltage_color() << 1);
        button_led_set(1);
        return EVENT_HANDLED;
    }

    if (event == EV_1click) {
        set_state(on_state, 0);
        return EVENT_HANDLED;
    }

    if (event == EV_tick) {
        if (arg >= AUX_TIMEOUT_TICKS) {
            set_state(off_state, 0);
        }
        return EVENT_HANDLED;
    }

    return EVENT_NOT_HANDLED;
}

uint8_t on_state(Event event, uint16_t arg) {
    if (event == EV_enter_state) {
        set_level_therm(brightness_levels[current_level_idx], 0, 0);
        rgb_led_set(voltage_color() << 1);
        button_led_set(2);
        return EVENT_HANDLED;
    }

    if (event == EV_tick) {
        if ((arg & 63) == 0) {
            rgb_led_set(voltage_color() << 1);
        }
        return EVENT_HANDLED;
    }

    if (event == EV_temperature_high) {
        set_level_therm(brightness_levels[current_level_idx], 0, arg);
        return EVENT_HANDLED;
    }

    if (event == EV_temperature_low) {
        set_level_therm(brightness_levels[current_level_idx], arg, 0);
        return EVENT_HANDLED;
    }

    if (event == EV_1click) {
        set_state(aux_state, 0);
        return EVENT_HANDLED;
    }

    if (event == EV_click1_hold) {
        if (arg % HOLD_TICKS_PER_LEVEL == 0) {
            current_level_idx = (current_level_idx + 1) % NUM_LEVELS;
            set_level_therm(brightness_levels[current_level_idx], 0, 0);
        }
        return EVENT_HANDLED;
    }

    if (event == EV_click1_hold_release) {
        eeprom[0] = current_level_idx;
        save_eeprom();
        return EVENT_HANDLED;
    }

    return EVENT_NOT_HANDLED;
}

void low_voltage(void) {
    set_state(off_state, 0);
}

void setup(void) {
    if (load_eeprom()) {
        if (eeprom[0] < NUM_LEVELS)
            current_level_idx = eeprom[0];
    }
    push_state(off_state, 0);
}

void loop(void) { }