/** @file task.c
 * Module handling the task creation and management
 *
 * The module provides an API to create, run and manage lightweight, stack-less
 * threads (tasks). This system is based on protothreads,
 * see https://dunkels.com/adam/pt/index.html
 */

//--includes--------------------------------------------------------------------

#include "task.h"
#include "error.h"


//--local definitions-----------------------------------------------------------

#define MAX_TASK_NB 10


//--local variables-------------------------------------------------------------

static struct Task task_list[MAX_TASK_NB];
static uint8_t task_nb;


//--public functions------------------------------------------------------------

void task_schedule(uint32_t elapsed_ms)
{
	for (uint8_t i = 0; i < task_nb; ++i) {
		if (task_list[i].function != nullptr) {

			if (task_list[i].state.is_active
					|| task_list[i].state.delay <= 0) {
				task_list[i].function(&task_list[i].state);
				if (task_list[i].state.count == _TASK_COUNT_EXIT) {
					task_list[i].function = nullptr;
				}
			} else {
				task_list[i].state.delay -= elapsed_ms;
			}

		}
	}
}

void task_start(TaskFunction function)
{
	for (uint8_t i = 0; i < MAX_TASK_NB; ++i) {
		if (task_list[i].function == nullptr) {

			task_list[i].function = function;
			task_list[i].state.delay = 0;
			task_list[i].state.count = 0;
			task_list[i].state.is_active = false;

			++task_nb;
			return;
		}
	}

	error_trigger("task list is full");
}

void task_stop(TaskFunction function)
{
	for (uint8_t i = 0; i < task_nb; ++i) {
		if (task_list[i].function == function) {
			task_list[i].state.count = _TASK_COUNT_CLEANUP & 0x7F;
			task_list[i].function(&task_list[i].state);
			task_list[i].function = nullptr;

			return;
		}
	}

	error_trigger("task does not exist");
}

bool task_is_running(TaskFunction function)
{
	for (uint8_t i = 0; i < task_nb; ++i) {
		if (task_list[i].function == function) {
			return true;
		}
	}

	return false;
}