#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "driver/uart.h"
#include "driver/rmt_tx.h"
#include "led_strip_encoder.h"

#define RMT_LED_STRIP_RESOLUTION_HZ 10000000
#define LED_GPIO_NUM 6
#define LED_NUMBERS 30

static const char *TAG = "led-laser";

static uint8_t led_pixels[LED_NUMBERS * 3];
static rmt_channel_handle_t led_chan = NULL;
static rmt_encoder_handle_t led_encoder = NULL;

typedef struct {
    const char *name;
    int freq_hz;
    int duration_min;
    uint32_t hue;
} preset_t;

static const preset_t presets[] = {
    {"Regeneration", 40, 60,   0},
    {"Durchblutung", 60, 60,  15},
    {"Tiefenwirkung",80,45,   5},
    {"Gepulst Rot",  50, 60,   0},
    {"Oberflächenlicht",30,45,20},
    {"Muskeln/Gelenke",65,60,10},
    {"Ganzkörper",   45, 90,   0}
};
#define PRESET_COUNT (sizeof(presets)/sizeof(presets[0]))

static int current_preset = -1;
static bool led_on = false;
static uint64_t last_toggle_ms = 0;

static void 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 adj = (rgb_max - rgb_min) * diff / 60;
    switch(i){
        case 0: *r=rgb_max; *g=rgb_min+adj; *b=rgb_min; break;
        case 1: *r=rgb_max-adj; *g=rgb_max; *b=rgb_min; break;
        case 2: *r=rgb_min; *g=rgb_max; *b=rgb_min+adj; break;
        case 3: *r=rgb_min; *g=rgb_max-adj; *b=rgb_max; break;
        case 4: *r=rgb_min+adj; *g=rgb_min; *b=rgb_max; break;
        default:*r=rgb_max; *g=rgb_min; *b=rgb_max-adj; break;
    }
}

static void set_all_pixels(uint32_t r, uint32_t g, uint32_t b) {
    for(int i=0;i<LED_NUMBERS;i++){
        led_pixels[i*3+0]= (uint8_t)g;
        led_pixels[i*3+1]= (uint8_t)b;
        led_pixels[i*3+2]= (uint8_t)r;
    }
}

static void flush_leds(void){
    rmt_transmit_config_t tx_cfg = { .loop_count = 0 };
    ESP_ERROR_CHECK(rmt_transmit(led_chan, led_encoder, led_pixels, sizeof(led_pixels), &tx_cfg));
    ESP_ERROR_CHECK(rmt_tx_wait_all_done(led_chan, portMAX_DELAY));
}

static void apply_preset(int idx){
    if(idx<0 || idx>=PRESET_COUNT) return;
    current_preset = idx;
    const preset_t *p = &presets[idx];
    uint32_t r,g,b;
    hsv2rgb(p->hue, 100, 100, &r,&g,&b);
    set_all_pixels(r,g,b);
    led_on = true;
    last_toggle_ms = esp_timer_get_time()/1000;
    ESP_LOGI(TAG, "Preset %d %s %dHz", idx, p->name, p->freq_hz);
}

static void stop_leds(void){
    current_preset = -1;
    memset(led_pixels,0,sizeof(led_pixels));
    flush_leds();
    ESP_LOGI(TAG,"LEDs stopped");
}

static void list_presets(void){
    printf("\n--- Presets ---\n");
    for(int i=0;i<PRESET_COUNT;i++){
        const preset_t *p=&presets[i];
        printf("%d - %s %dHz %dmin\n", i, p->name, p->freq_hz, p->duration_min);
    }
    printf("Commands: 0-6 select, next, stop, list\n");
}

static void process_line(char *line){
    if(strcmp(line,"stop")==0){ stop_leds(); return; }
    if(strcmp(line,"next")==0){
        int nxt = (current_preset+1)%PRESET_COUNT;
        apply_preset(nxt);
        return;
    }
    if(strcmp(line,"list")==0){ list_presets(); return; }
    if(strlen(line)==1 && line[0]>='0' && line[0]<='6'){
        int idx = line[0]-'0';
        if(idx<PRESET_COUNT){ apply_preset(idx); return; }
    }
    printf("Unknown: %s\n", line);
}

void app_main(void){
    ESP_LOGI(TAG,"LED Laser Frequenz start");

    uart_config_t uart_cfg = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };
    ESP_ERROR_CHECK(uart_driver_install(UART_NUM_0, 1024,0,0,NULL,0));
    ESP_ERROR_CHECK(uart_param_config(UART_NUM_0,&uart_cfg));

    rmt_tx_channel_config_t tx_cfg = {
        .clk_src = RMT_CLK_SRC_DEFAULT,
        .gpio_num = LED_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_cfg,&led_chan));
    led_strip_encoder_config_t enc_cfg = { .resolution = RMT_LED_STRIP_RESOLUTION_HZ };
    ESP_ERROR_CHECK(rmt_new_led_strip_encoder(&enc_cfg,&led_encoder));
    ESP_ERROR_CHECK(rmt_enable(led_chan));

    memset(led_pixels,0,sizeof(led_pixels));
    flush_leds();

    char line_buf[64];
    int line_pos=0;

    while(1){
        int ch;
        while(uart_get_buffered_data_len(UART_NUM_0) > 0){
            uint8_t c;
            int len = uart_read_bytes(UART_NUM_0,&c,1,0);
            if(len>0){
                if(c=='\r' || c=='\n'){
                    line_buf[line_pos]='\0';
                    if(line_pos>0){ process_line(line_buf); }
                    line_pos=0;
                }else{
                    if(line_pos < (int)sizeof(line_buf)-1){ line_buf[line_pos++]=c; }
                }
            }
        }

        if(current_preset>=0){
            const preset_t *p=&presets[current_preset];
            uint64_t now = esp_timer_get_time()/1000;
            uint64_t period_ms = 1000 / p->freq_hz;
            uint64_t half = period_ms/2;
            if(half<1) half=1;
            if(now - last_toggle_ms >= half){
                led_on = !led_on;
                last_toggle_ms = now;
                if(led_on){
                    uint32_t r,g,b;
                    hsv2rgb(p->hue,100,100,&r,&g,&b);
                    set_all_pixels(r,g,b);
                }else{
                    memset(led_pixels,0,sizeof(led_pixels));
                }
                flush_leds();
            }
        }
        vTaskDelay(pdMS_TO_TICKS(5));
    }
}