// Include FreeRTOS headers.
#include "FreeRTOSConfig.h"
#include "FreeRTOS.h"
#include "task.h"
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include "lib_ee152.h"

//*****************************************************
// Our big-hammer debugging facility. It works with macros in FreeRTOSConfig.h.
// - At each 1ms SysTick interrupt, the macro traceTASK_INCREMENT_TICK() appends
//   the number 4 to g_debug_notes[].
// - Whenever we context switch to task_writer1() -- whether it's triggered by a
//   SysTick interrupt, by a task calling vTaskDelay(), or whatever -- we append
//   the number 1 to g_debug_notes[]
// - Similarly, switch to task_writer2() appends 2, switching to
//   task_UART_daemon() appends 3, and switching to the idle task appends 0.
// - Then, at the end of the run, task_UART_daemon() dump g_debug_notes[]:
//   printing out "*" for each SysTick interrupt, "1" for task_writer1, "2" for
//   task_writer2, "D" for the UART daemon and "I" for the idle task.
//*****************************************************
unsigned char g_debug_notes [MAX_DEBUG_NOTES];
unsigned g_n_debug_notes;

//*****************************************************
// The blinky task.
//*****************************************************

#define BLINK_GRN_ON  10
#define BLINK_GRN_OFF 40
void task_blink_grn( void * pvParameters )
{
    vTaskSetApplicationTaskTag (NULL, (void *)1);

    // The green LED is at Nano D13, or PB3.
    pinMode(D13, "OUTPUT");

    for ( ;; ) {
	digitalWrite (D13, 1);
	vTaskDelay (BLINK_GRN_ON);
	digitalWrite (D13, 0);
	vTaskDelay (BLINK_GRN_OFF);
    }
}

// 4 * (1 - 1/3 + 1/5 - 1/7 + 1/9 ...)
void task_pi (void *pvParameters) {
    vTaskSetApplicationTaskTag (NULL, (void *)2);

    float pi = 1;
    for (float denom=1.0; denom < 10000000; denom += 4) {
	pi -= 1.0 / denom;
	pi += 1.0 / (denom+2);
    }
    pi *= 4;

    // Done computing pi. Print the accumulated debug info and then spin.
    serial_write (USART2, "Printing debug info\r\n");

    char buf[2]; buf[1]='\0';
    for (int i=0; i<g_n_debug_notes; ++i) {
	buf[0] = "IBP*4567890"[g_debug_notes[i]];
	serial_write (USART2, buf);
    }
    serial_write (USART2, "\r\n");
    while (1);
}

int main()
{
    // The default clock is 4MHz, which is more than fast enough for LEDs.
    //clock_setup_16MHz();		// 16 MHz
    clock_setup_80MHz();		// 80 MHz

    serial_begin (USART2);
    serial_write (USART2, "In main()\r\n");

    // Create tasks.

    TaskHandle_t task_handle_grn = NULL;
    BaseType_t OK = xTaskCreate (
	    task_blink_grn,
	    "Blink Green LED",
	    100, // stack size in words
	    NULL, // parameter passed into task, e.g. "(void *) 1"
	    tskIDLE_PRIORITY+2, // priority
	    &task_handle_grn);
    if (OK != pdPASS) for ( ;; );

    TaskHandle_t task_handle_pi = NULL;
    OK = xTaskCreate (
	    task_pi,
	    "Decide which LEDs to blink",
	    100, // stack size in words
	    NULL, // parameter passed into task, e.g. "(void *) 1"
	    tskIDLE_PRIORITY+1, // priority
	    &task_handle_pi);
    if (OK != pdPASS) for ( ;; );

    vTaskStartScheduler();
}

/*
The final output:
In main()
Printing debug info
II**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP****************************************BP**********BP*******************

*/