#include "led_driver.h"
#include "driver/rmt_tx.h"
#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include <string.h>

#define LED_PIN 18  // <-- CERTIFICA-TE disto
#define RMT_RESOLUTION_HZ 10000000  // 10 MHz (1 tick = 0.1us)

typedef struct {
    uint8_t r,g,b;
} led_color_t;

static led_color_t leds[LED_COUNT];

static rmt_channel_handle_t rmt_chan = NULL;
static rmt_encoder_handle_t encoder = NULL;

static rmt_transmit_config_t tx_config = {
    .loop_count = 0
};

static uint8_t global_brightness = 255;

void led_set_global_brightness(uint8_t level)
{
    global_brightness = level;
}



void led_driver_init(void)
{
    gpio_set_direction(LED_PIN, GPIO_MODE_OUTPUT);

    rmt_tx_channel_config_t chan_cfg = {
        .gpio_num = LED_PIN,
        .clk_src = RMT_CLK_SRC_DEFAULT,
        .resolution_hz = RMT_RESOLUTION_HZ,
        .mem_block_symbols = 64,
        .trans_queue_depth = 1,
    };

    ESP_ERROR_CHECK(rmt_new_tx_channel(&chan_cfg, &rmt_chan));
    ESP_ERROR_CHECK(rmt_enable(rmt_chan));

    // WS2812B timings (EXATOS)
    rmt_bytes_encoder_config_t enc_cfg = {
        .bit0 = {
            .duration0 = 4, .level0 = 1,   // 0.4us HIGH
            .duration1 = 9, .level1 = 0    // 0.9us LOW
        },
        .bit1 = {
            .duration0 = 9, .level0 = 1,   // 0.9us HIGH
            .duration1 = 4, .level1 = 0    // 0.4us LOW
        },
        .flags.msb_first = 1
    };

    ESP_ERROR_CHECK(rmt_new_bytes_encoder(&enc_cfg, &encoder));

    memset(leds, 0, sizeof(leds));
    led_show();
}

void led_set_pixel(int index, uint8_t r, uint8_t g, uint8_t b)
{
    if (index < 0 || index >= LED_COUNT) return;
    leds[index].r = r;
    leds[index].g = g;
    leds[index].b = b;
}

void led_clear(void)
{
    memset(leds, 0, sizeof(leds));
}

static void hw_update(void)
{
    uint8_t buf[LED_COUNT * 3];

    // Previne divisão por zero
    uint8_t br = (global_brightness == 0) ? 1 : global_brightness;

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

        // Escala (r,g,b) com brilho global (0..255)
        uint8_t r = (leds[i].r * br) >> 8;
        uint8_t g = (leds[i].g * br) >> 8;
        uint8_t b = (leds[i].b * br) >> 8;

        // GRB
        buf[i*3 + 0] = g;
        buf[i*3 + 1] = r;
        buf[i*3 + 2] = b;
    }

    ESP_ERROR_CHECK(rmt_transmit(rmt_chan, encoder, buf, sizeof(buf), &tx_config));
    rmt_tx_wait_all_done(rmt_chan, -1);

    esp_rom_delay_us(60); // reset 60us
}


void led_show(void)
{
    hw_update();
}

int led_get_count(void)
{
    return LED_COUNT;
}
void led_spin_to(uint16_t target, int min_spins, int max_spins, int base_delay_ms)
{
    int n = LED_COUNT;
    if (min_spins < 1) min_spins = 1;
    if (max_spins < min_spins) max_spins = min_spins;

    int extra = 0;
    if (max_spins > min_spins)
        extra = rand() % (max_spins - min_spins + 1);

    int total_steps = (min_spins + extra) * n + (target % n);
    int delay = base_delay_ms;

    for (int step = 0; step <= total_steps; step++) {
        int pos = step % n;

        for (int i = 0; i < n; i++) {
            if (i == pos)
                led_set_pixel(i, 0, 40, 0);   // verde fraco no cursor
            else
                led_set_pixel(i, 0, 0, 0);
        }

        led_show();

        if (step < total_steps / 3 && delay > 3)
            delay--;
        else if (step > (2 * total_steps) / 3)
            delay++;

        vTaskDelay(pdMS_TO_TICKS(delay));
    }
}