/*
 * Copyright (C) 2018 Gunar Schorcht
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 *
 * FreeRTOS to RIOT-OS adaption module for source code compatibility
 */

#ifndef DOXYGEN

#define ENABLE_DEBUG 0
#include "debug.h"

#include <string.h>

#include "esp_common.h"
#include "esp_attr.h"
#include "log.h"
#include "syscalls.h"
#include "thread.h"
#include "xtimer.h"

#include "soc/soc.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define MHZ 1000000

/**
 * @brief   Architecture specific data of thread control blocks
 */
typedef struct {
    uint32_t saved_int_state;
    uint32_t critical_nesting;
} thread_arch_ext_t;

volatile thread_arch_ext_t threads_arch_exts[KERNEL_PID_LAST + 1] = {};

BaseType_t xTaskCreatePinnedToCore (TaskFunction_t pvTaskCode,
                                    const char * const pcName,
                                    const uint32_t usStackDepth,
                                    void * const pvParameters,
                                    UBaseType_t uxPriority,
                                    TaskHandle_t * const pvCreatedTask,
                                    const BaseType_t xCoreID)
{
    /* FreeRTOS priority values have to be inverted */
    uxPriority = SCHED_PRIO_LEVELS - uxPriority - 1;

    DEBUG("%s name=%s size=%d prio=%d pvCreatedTask=%p ",
          __func__, pcName, usStackDepth, uxPriority, pvCreatedTask);

    char* stack = malloc(usStackDepth + sizeof(thread_t));

    if (!stack) {
        return pdFALSE;
    }
    kernel_pid_t pid = thread_create(stack,
                                     usStackDepth + sizeof(thread_t),
                                     uxPriority,
                                     THREAD_CREATE_WOUT_YIELD |
                                     THREAD_CREATE_STACKTEST,
                                     (thread_task_func_t)pvTaskCode,
                                     pvParameters, pcName);
    DEBUG("pid=%d\n", pid);

    if (pvCreatedTask) {
        *pvCreatedTask = (TaskHandle_t)(0L + pid);
    }

    return (pid < 0) ? pdFALSE : pdTRUE;
}

BaseType_t xTaskCreate (TaskFunction_t pvTaskCode,
                        const char * const pcName,
                        const uint32_t usStackDepth,
                        void * const pvParameters,
                        UBaseType_t uxPriority,
                        TaskHandle_t * const pvCreatedTask)
{
    return xTaskCreatePinnedToCore (pvTaskCode,
                                    pcName,
                                    usStackDepth,
                                    pvParameters,
                                    uxPriority,
                                    pvCreatedTask,
                                    PRO_CPU_NUM);
}

void vTaskDelete (TaskHandle_t xTaskToDelete)
{
    DEBUG("%s pid=%d task=%p\n", __func__, thread_getpid(), xTaskToDelete);

    CHECK_PARAM(xTaskToDelete != NULL);

    uint32_t pid = (uint32_t)xTaskToDelete;

    /* remove old task from scheduling */
    thread_t* thread = (thread_t*)sched_threads[pid];
    sched_set_status(thread, STATUS_STOPPED);
    sched_threads[pid] = NULL;
    sched_num_threads--;
    sched_active_thread = NULL;

    /* determine the new running task */
    sched_run();
}

TaskHandle_t xTaskGetCurrentTaskHandle(void)
{
    DEBUG("%s pid=%d\n", __func__, thread_getpid());

    uint32_t pid = thread_getpid();
    return (TaskHandle_t)pid;
}

void vTaskDelay( const TickType_t xTicksToDelay )
{
    uint64_t us = xTicksToDelay * MHZ / xPortGetTickRateHz();
    xtimer_usleep(us);
}

TickType_t xTaskGetTickCount (void)
{
    return system_get_time() / USEC_PER_MSEC / portTICK_PERIOD_MS;
}

void vTaskEnterCritical( portMUX_TYPE *mux )
{
    /* determine calling thread pid (can't fail) */
    kernel_pid_t my_pid = thread_getpid();

    DEBUG("%s pid=%d prio=%d mux=%p\n", __func__,
          my_pid, sched_threads[my_pid]->priority, mux);

    /* disable interrupts */
    uint32_t state = irq_disable();

    /* aquire the mutex with interrupts disabled */
    mutex_lock(mux); /* TODO should be only a spin lock */

    /* increment nesting counter and save old interrupt level */
    threads_arch_exts[my_pid].critical_nesting++;
    if (threads_arch_exts[my_pid].critical_nesting == 1) {
        threads_arch_exts[my_pid].saved_int_state = state;
    }
}

void vTaskExitCritical( portMUX_TYPE *mux )
{
    /* determine calling thread pid (can't fail) */
    kernel_pid_t my_pid = thread_getpid();

    DEBUG("%s pid=%d prio=%d mux=%p\n", __func__,
          my_pid, sched_threads[my_pid]->priority, mux);

    /* release the mutex with interrupts disabled */
    mutex_unlock(mux); /* TODO should be only a spin lock */

    /* decrement nesting counter and restore old interrupt level */
    if (threads_arch_exts[my_pid].critical_nesting) {
        threads_arch_exts[my_pid].critical_nesting--;
        if (threads_arch_exts[my_pid].critical_nesting == 0) {
            irq_restore(threads_arch_exts[my_pid].saved_int_state);
        }
    }
}


#endif /* DOXYGEN */