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

#include "pico/stdlib.h"
#include "hardware/pio.h"
#include "hardware/clocks.h"
//#include "ws2812.pio.h"


// -------------------------------------------------- //
// This file is autogenerated by pioasm; do not edit! //
// -------------------------------------------------- //

#pragma once

#if !PICO_NO_HARDWARE
#include "hardware/pio.h"
#endif

// ------ //
// ws2812 //
// ------ //

#define ws2812_wrap_target 0
#define ws2812_wrap 3

#define ws2812_T1 2
#define ws2812_T2 5
#define ws2812_T3 3

static const uint16_t ws2812_program_instructions[] = {
            //     .wrap_target
    0x6221, //  0: out    x, 1            side 0 [2] 
    0x1123, //  1: jmp    !x, 3           side 1 [1] 
    0x1400, //  2: jmp    0               side 1 [4] 
    0xa442, //  3: nop                    side 0 [4] 
            //     .wrap
};

#if !PICO_NO_HARDWARE
static const struct pio_program ws2812_program = {
    .instructions = ws2812_program_instructions,
    .length = 4,
    .origin = -1,
};

static inline pio_sm_config ws2812_program_get_default_config(uint offset) {
    pio_sm_config c = pio_get_default_sm_config();
    sm_config_set_wrap(&c, offset + ws2812_wrap_target, offset + ws2812_wrap);
    sm_config_set_sideset(&c, 1, false, false);
    return c;
}

#include "hardware/clocks.h"
static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw) {
    pio_gpio_init(pio, pin);
    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
    pio_sm_config c = ws2812_program_get_default_config(offset);
    sm_config_set_sideset_pins(&c, pin);
    sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
    int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3;
    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
    sm_config_set_clkdiv(&c, div);
    pio_sm_init(pio, sm, offset, &c);
    pio_sm_set_enabled(pio, sm, true);
}

#endif



#define IS_RGBW true        // Will use RGBW format
#define NUM_PIXELS 1        // There is 1 WS2812 device in the chain
#define WS2812_PIN 7       // The GPIO pin that the WS2812 connected to


/**
 * @brief Wrapper function used to call the underlying PIO
 *        function that pushes the 32-bit RGB colour value
 *        out to the LED serially using the PIO0 block. The
 *        function does not return until all of the data has
 *        been written out.
 * 
 * @param pixel_grb The 32-bit colour value generated by urgb_u32()
 */
static inline void put_pixel(uint32_t pixel_grb) {
    pio_sm_put_blocking(pio0, 0, pixel_grb << 8u);
}


/**
 * @brief Function to generate an unsigned 32-bit composit GRB
 *        value by combining the individual 8-bit paramaters for
 *        red, green and blue together in the right order.
 * 
 * @param r     The 8-bit intensity value for the red component
 * @param g     The 8-bit intensity value for the green component
 * @param b     The 8-bit intensity value for the blue component
 * @return uint32_t Returns the resulting composit 32-bit RGB value
 */
static inline uint32_t urgb_u32(uint8_t r, uint8_t g, uint8_t b) {
    return  ((uint32_t) (r) << 8)  |
            ((uint32_t) (g) << 16) |
            (uint32_t) (b);
}


/**
 * @brief EXAMPLE - WS2812_RGB
 *        Simple example to initialise the NeoPixel RGB LED on
 *        the MAKER-PI-PICO and then flash it in alternating
 *        colours between red, green and blue forever using
 *        one of the RP2040 built-in PIO controllers.
 * 
 * @return int  Application return code (zero for success).
 */
int main() {
 
    // Initialise all STDIO as we will be using the GPIOs
    stdio_init_all();
 
    // Initialise the PIO interface with the WS2812 code
    PIO pio = pio0;
    uint offset = pio_add_program(pio, &ws2812_program);
    ws2812_program_init(pio, 0, offset, WS2812_PIN, 800000, IS_RGBW);

    // Do forever...
    while(true) {

        // Set the color to red at half intensity
        put_pixel(urgb_u32(0x7F, 0x00, 0x00));
        sleep_ms(500);

        // Set the color to green at half intensity
        put_pixel(urgb_u32(0x00, 0x7F, 0x00));
        sleep_ms(500);

        // Set the color to blue at half intensity
        put_pixel(urgb_u32(0x00, 0x00, 0x7F));
        sleep_ms(500);

    }

    // Should never get here due to infinite while-loop.
    return 0;

}