/*
 * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Unlicense OR CC0-1.0
 */
#include <string.h>
#include <math.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "driver/rmt_tx.h"
#include "led_strip_encoder.h"

#define RMT_LED_STRIP_RESOLUTION_HZ 10000000 // 10MHz resolution
#define RMT_LED_STRIP_GPIO_NUM      10       // GPIO10

#define EXAMPLE_LED_NUMBERS         22       // 22个LED
#define REFRESH_MS                  20       // 刷新间隔，20ms = 50fps
#define BREATH_CYCLE_MS             3000     // 呼吸周期（淡入+淡出）
#define CHASE_SPEED_DEG             5        // 每次色环偏移角度

static const char *TAG = "rainbow_breath";

static uint8_t led_strip_pixels[EXAMPLE_LED_NUMBERS * 3];

/**
 * @brief HSV转RGB
 */
void led_strip_hsv2rgb(uint32_t h, uint32_t s, uint32_t v, uint32_t *r, uint32_t *g, uint32_t *b)
{
    h %= 360;
    uint32_t rgb_max = v * 255 / 100;
    uint32_t rgb_min = rgb_max * (100 - s) / 100;

    uint32_t i = h / 60;
    uint32_t diff = h % 60;

    uint32_t rgb_adj = (rgb_max - rgb_min) * diff / 60;

    switch (i) {
    case 0: *r = rgb_max; *g = rgb_min + rgb_adj; *b = rgb_min; break;
    case 1: *r = rgb_max - rgb_adj; *g = rgb_max; *b = rgb_min; break;
    case 2: *r = rgb_min; *g = rgb_max; *b = rgb_min + rgb_adj; break;
    case 3: *r = rgb_min; *g = rgb_max - rgb_adj; *b = rgb_max; break;
    case 4: *r = rgb_min + rgb_adj; *g = rgb_min; *b = rgb_max; break;
    default: *r = rgb_max; *g = rgb_min; *b = rgb_max - rgb_adj; break;
    }
}

void app_main(void)
{
    ESP_LOGI(TAG, "Create RMT TX channel on GPIO%d", RMT_LED_STRIP_GPIO_NUM);
    rmt_channel_handle_t led_chan = NULL;
    rmt_tx_channel_config_t tx_chan_config = {
        .clk_src = RMT_CLK_SRC_DEFAULT,
        .gpio_num = RMT_LED_STRIP_GPIO_NUM,
        .mem_block_symbols = 64,
        .resolution_hz = RMT_LED_STRIP_RESOLUTION_HZ,
        .trans_queue_depth = 4,
    };
    ESP_ERROR_CHECK(rmt_new_tx_channel(&tx_chan_config, &led_chan));

    ESP_LOGI(TAG, "Install led strip encoder");
    rmt_encoder_handle_t led_encoder = NULL;
    led_strip_encoder_config_t encoder_config = {
        .resolution = RMT_LED_STRIP_RESOLUTION_HZ,
    };
    ESP_ERROR_CHECK(rmt_new_led_strip_encoder(&encoder_config, &led_encoder));

    ESP_LOGI(TAG, "Enable RMT TX channel");
    ESP_ERROR_CHECK(rmt_enable(led_chan));

    ESP_LOGI(TAG, "Start Rainbow Breath Chase, LED count: %d", EXAMPLE_LED_NUMBERS);
    rmt_transmit_config_t tx_config = {
        .loop_count = 0,
    };

    uint16_t hue_offset = 0;   // 彩虹色环偏移（跑马灯）
    int breath_tick = 0;       // 呼吸时间计数器

    while (1) {
        // 计算当前呼吸亮度系数：0.0 ~ 1.0
        float breath_phase = (2.0f * 3.1415926f * breath_tick * REFRESH_MS) / BREATH_CYCLE_MS;
        float breath_brightness = (sinf(breath_phase) + 1.0f) / 2.0f;  // 0.0 ~ 1.0

        // 为每个LED计算颜色：彩虹分布 + 呼吸亮度
        for (int i = 0; i < EXAMPLE_LED_NUMBERS; i++) {
            // 每个LED在色环上均匀分布，加上偏移实现流动
            uint16_t hue = ((i * 360 / EXAMPLE_LED_NUMBERS) + hue_offset) % 360;

            uint32_t r, g, b;
            // 先计算全亮彩虹色
            led_strip_hsv2rgb(hue, 100, 100, &r, &g, &b);

            // 叠加呼吸亮度
            r = (uint32_t)(r * breath_brightness);
            g = (uint32_t)(g * breath_brightness);
            b = (uint32_t)(b * breath_brightness);

            // GRB顺序写入
            led_strip_pixels[i * 3 + 0] = (uint8_t)g;
            led_strip_pixels[i * 3 + 1] = (uint8_t)b;
            led_strip_pixels[i * 3 + 2] = (uint8_t)r;
        }

        // 发送数据到灯带
        ESP_ERROR_CHECK(rmt_transmit(led_chan, led_encoder, led_strip_pixels, sizeof(led_strip_pixels), &tx_config));
        ESP_ERROR_CHECK(rmt_tx_wait_all_done(led_chan, portMAX_DELAY));

        // 更新跑马灯偏移
        hue_offset = (hue_offset + CHASE_SPEED_DEG) % 360;

        // 更新呼吸计数器
        breath_tick++;

        vTaskDelay(pdMS_TO_TICKS(REFRESH_MS));
    }
}